135 results on '"Rebekah M Ahmed"'
Search Results
2. A study protocol for a phase II randomised, double-blind, placebo-controlled trial of sodium selenate as a disease-modifying treatment for behavioural variant frontotemporal dementia
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Rebekah M Ahmed, Lucy Vivash, Dennis Velakoulis, Leonid Churilov, Olivier Piguet, David Darby, Terence J O'Brien, Charles B Malpas, Mark Walterfang, Amy Brodtmann, Ashley I Bush, Christopher M Hovens, and T Kalincik
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Medicine - Abstract
Introduction Behavioural variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder often neuropathologically associated with the accumulation of abnormally hyperphosphorylated tau, for which there is currently no disease-modifying treatment. Previous work by our group has shown sodium selenate upregulates the activity of protein phosphatase 2 in the brain, increasing the rate of tau dephosphorylation. The objective of this study is to evaluate the efficacy and safety of sodium selenate as a disease-modifying treatment for bvFTD.Methods and analysis This will be a multisite, phase IIb, double-blind placebo-controlled trial of sodium selenate. One hundred and twenty participants will be enrolled across 4 Australian academic hospitals. Following screening eligible participants will be randomised (1:1) to sodium selenate (15 mg three times a day) or placebo for 52 weeks. Participants will have regular safety and efficacy visits throughout the study period. The primary study outcome will be percentage brain volume change (PBVC) as measured on MRI over 52 weeks of treatment. This will be analysed with a general linear model (analysis of covariance (ANCOVA)) with the PBVC as an output, the treatment as an input and the baseline brain volume as covariate for adjustment purposes. Secondary outcomes include safety and tolerability measures, and efficacy measures; change in cerebrospinal fluid total-tau, Addenbrooke’s Cognitive Examination-III and Cambridge Behavioural Inventory-Revised scores over the 52 weeks of treatment. These will also be analysed with ANCOVA where the corresponding baseline measure will be incorporated in the model. Additional exploratory outcomes will include other imaging, cognitive and biospecimen analyses.Ethics and dissemination The study was approved by the Human Research and Ethics Committee of the lead site as part of the Australian Multisite Ethics approval system. The results of the study will be presented at national and international conferences and published in peer-reviewed journals.Trial registration number ACTRN12620000236998 .
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- 2020
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3. Distinct hypothalamic involvement in the amyotrophic lateral sclerosis-frontotemporal dementia spectrum
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Nga Yan Tse, Martina Bocchetta, Emily G. Todd, Emma M. Devenney, Sicong Tu, Jashelle Caga, John R. Hodges, Glenda M. Halliday, Muireann Irish, Matthew C. Kiernan, Olivier Piguet, Jonathan D. Rohrer, and Rebekah M. Ahmed
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Frontotemporal dementia ,Amyotrophic lateral sclerosis ,Hypothalamus ,Neuroimaging ,Neuropathophysiology ,Cognitive and behavioural impairment ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background: Hypothalamic dysregulation plays an established role in eating abnormalities in behavioural variant frontotemporal dementia (bvFTD) and amyotrophic lateral sclerosis (ALS). Its contribution to cognitive and behavioural impairments, however, remains unexplored. Methods: Correlation between hypothalamic subregion atrophy and cognitive and behavioural impairments was examined in a large sample of 211 participants (52 pure ALS, 42 mixed ALS-FTD, 59 bvFTD, and 58 age- and education- matched healthy controls). Results: Graded variation in hypothalamic involvement but relative sparing of the inferior tuberal region was evident across all patient groups. Bilateral anterior inferior, anterior superior, and posterior hypothalamic subregions were selectively implicated in memory, fluency and processing speed impairments in addition to apathy and abnormal eating habits, taking into account disease duration, age, sex, total intracranial volume, and acquisition parameters (all p ≤ .001). Conclusions: These findings revealed that subdivisions of the hypothalamus are differentially affected in the ALS-FTD spectrum and contribute to canonical cognitive and behavioural disturbances beyond eating abnormalities. The anterior superior and superior tuberal subregions containing the paraventricular nucleus (housing oxytocin-producing neurons) displayed the greatest volume loss in bvFTD and ALS-FTD, and ALS, respectively. Importantly, the inferior tuberal subregion housing the arcuate nucleus (containing different groups of neuroendocrine neurons) was selectively preserved across the ALS-FTD spectrum, supporting pathophysiological findings of discrete neuropeptide expression abnormalities that may underlie the pathogenesis of autonomic and metabolic abnormalities and potentially certain cognitive and behavioural symptom manifestations, representing avenues for more refined symptomatic treatment targets.
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- 2023
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4. Error profiles of facial emotion recognition in frontotemporal dementia and Alzheimer’s disease
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Kimberly Gressie, Fiona Kumfor, Her Teng, David Foxe, Emma Devenney, Rebekah M. Ahmed, and Olivier Piguet
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Psychiatry and Mental health ,Clinical Psychology ,Geriatrics and Gerontology ,Gerontology - Abstract
Objectives: To identify the patterns of errors in facial emotion recognition in frontotemporal dementia (FTD) subtypes compared with Alzheimer’s disease (AD) and healthy controls. Design: Retrospective analysis. Setting: Participants were recruited from FRONTIER, the frontotemporal dementia research group at the University of Sydney, Australia. Participants: A total of 356 participants (behavioral-variant FTD (bvFTD): 62, semantic dementia (SD)-left: 29, SD-right: 14, progressive non-fluent aphasia (PNFA): 21, AD: 76, controls: 90) were included. Measurements: Facial emotion recognition was assessed using the Facial Affect Selection Task, a word-face matching task measuring recognition of the six basic emotions (anger, disgust, fear, happiness, sadness, and surprise), as well as neutral emotion, portrayed by black and white faces. Results: Overall, all clinical groups performed significantly worse than controls with the exception of the PNFA subgroup (p = .051). The SD-right group scored worse than all other clinical groups (all p values < .027) and the bvFTD subgroup performed worse than the PNFA group (p < .001). The most frequent errors were in response to the facial emotions disgust (26.1%) and fear (22.9%). The primary error response to each target emotion was identified; patterns of errors were similar across all clinical groups. Conclusions: Facial emotion recognition is impaired in FTD and AD compared to healthy controls. Within FTD, bvFTD and SD-right are particularly impaired. Dementia groups cannot be distinguished based on error responses alone. Implications for future clinical diagnosis and research are discussed.
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- 2023
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5. Olfactory Bulb Integrity in Frontotemporal Dementia and Alzheimer’s Disease
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Sarah E. Carnemolla, Fiona Kumfor, Cheng Tao Liang, David Foxe, Rebekah M. Ahmed, and Olivier Piguet
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Olfaction Disorders ,Psychiatry and Mental health ,Clinical Psychology ,Alzheimer Disease ,Frontotemporal Dementia ,General Neuroscience ,Aphasia ,Humans ,General Medicine ,Atrophy ,Geriatrics and Gerontology ,Magnetic Resonance Imaging ,Olfactory Bulb - Abstract
Background: Olfactory dysfunction is highly prevalent in dementia syndromes, including Alzheimer’s disease (AD) and frontotemporal dementia (FTD). The structural integrity of the olfactory bulb (OB) is thought to play a critical role in odor detection and identification, but no MRI study has measured OB volume in FTD, or measured OB volume longitudinally in AD. Objective: To measure OB volume in FTD and AD patients longitudinally using MRI. Methods: This study measured OB volumes using MRI in patients diagnosed with behavioral-variant FTD (n = 55), semantic dementia (n = 34), progressive non-fluent aphasia (n = 30), AD (n = 50), and healthy age-matched controls (n = 55) at their first visit to a dementia research clinic (‘baseline’). Imaging data in patients 12-months later were analyzed where available (n = 84) for longitudinal assessment. Volumes of subcortical and cortical olfactory regions (‘olfactory network’) were obtained via surface-based morphometry. Results: Results revealed that in AD and FTD at baseline, OB volumes were similar to controls, whereas volumes of olfactory network regions were significantly reduced in all patient groups except in progressive non-fluent aphasia. Longitudinal data revealed that OB volume became significantly reduced (10–25% volume reduction) in all dementia groups with disease progression. Conclusion: Olfactory dysfunction is common in patients diagnosed with AD or FTD, but our results indicate that there is no detectable volume loss to the OBs upon first presentation to the clinic. Our findings indicate that the OBs become detectably atrophied later in the disease process. OB atrophy indicates the potential usefulness for OBs to be targeted in interventions to improve olfactory function.
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- 2022
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6. Schizotypal traits across the amyotrophic lateral sclerosis–frontotemporal dementia spectrum: pathomechanistic insights
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Nga Yan Tse, Sicong Tu, Yu Chen, Jashelle Caga, Carol Dobson-Stone, John B. Kwok, Glenda M. Halliday, Rebekah M. Ahmed, John R. Hodges, Olivier Piguet, Matthew C. Kiernan, and Emma M. Devenney
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Neurology ,mental disorders ,Neurology (clinical) - Abstract
Background Psychiatric presentations similar to that observed in primary psychiatric disorders are well described across the amyotrophic lateral sclerosis–frontotemporal dementia (ALS–FTD) spectrum. Despite this, schizotypal personality traits associated with increased risks of clinical psychosis development and poor psychosocial outcomes have never been examined. The current study aimed to provide the first exploration of schizotypal traits and its neural underpinnings in the ALS–FTD spectrum to gain insights into a broader spectrum of psychiatric overlap with psychiatric disorders. Methods Schizotypal traits were assessed using the targeted Schizotypal Personality Questionnaire in 99 participants (35 behavioural variant FTD, 10 ALS–FTD and 37 ALS patients, and 17 age-, sex- and education-matched healthy controls). Voxel-based morphometry analysis of whole-brain grey matter volume was conducted. Results Relative to controls, pervasive schizotypal personality traits across positive and negative schizotypy and disorganised thought disorders were identified in behavioural variant FTD, ALS (with the exception of negative schizotypy) and ALS–FTDALS–FTD patients (all p Conclusions The frontal–striatal–limbic regions underpinning manifestation of schizotypy in the ALS–FTDALS–FTD spectrum are similar to that established in previous schizophrenia research. This finding expands the concept of a psychiatric overlap in ALS–FTD and schizophrenia, and suggests potentially common underlying mechanisms involving disruptions to frontal-striatal-limbic networks, warranting a transdiagnostic approach for future investigations.
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- 2022
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7. Pearls and Oy-sters: Huntington Disease Presenting as Primary Progressive Aphasia: A Case of Semantics
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Antonia J Clarke, David Manser, Ronald Fleischer GradDipGC, Michael Fulham, and Rebekah M Ahmed
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Neurology (clinical) - Abstract
We present a case of semantic variant primary progressive aphasia (PPA) as the presenting feature in a patient with Huntington disease (HD). The patient initially developed progressive language impairment including impaired naming, object knowledge and single word comprehension and then developed chorea and behavioural changes. Magnetic resonance imaging (MRI) of the brain showed left anterior temporal lobe and hippocampal atrophy. A neurological FDG PET/CT showed reduced metabolism in the head of the left caudate nucleus. Huntingtin gene testing revealed an expansion of 39 CAG repeats in one allele. This case outlines the substantial overlap between the clinical presentation of HD and frontotemporal lobar degeneration (FTLD) syndromes and provides commentary on the investigation of these neurodegenerative diseases.
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- 2023
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8. Altered High Density Lipoprotein Composition in Behavioral Variant Frontotemporal Dementia
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Woojin Scott Kim, Ying He, Katherine Phan, Rebekah M. Ahmed, Kerry-Anne Rye, Olivier Piguet, John R. Hodges, and Glenda M. Halliday
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frontotemporal dementia ,Alzheimer’s disease ,HDL ,LDL ,apolipoprotein ,lipid ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Frontotemporal dementia (FTD) is a common cause of early onset dementia with behavioral variant FTD (bvFTD) being the most common form. bvFTD is characterized clinically by behavioral and personality changes, eating abnormalities, and pathologically, by systemic lipid dysregulation that impacts on survival. As lipoprotein metabolism is at the core of lipid dysregulation, here, we analyzed the composition, both proteins and lipids, of the two major lipoprotein classes in blood – high density lipoproteins (HDLs) and low density lipoproteins (LDLs). Fasted plasmas from bvFTD and Alzheimer’s disease (AD) patients and controls were fractionated using fast protein liquid chromatography (FPLC) and samples analyzed by lipid assays, ELISA and western blotting. We found that apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II) levels in HDLs were decreased in bvFTD compared to controls, whereas apolipoprotein B (apoB) levels in LDLs were unaltered. We also found that cholesterol and triglyceride levels in FPLC fractions were altered in bvFTD compared to controls. The apoB:apoA-I ratio and the standard lipid ratios were significantly increased in bvFTD compared to AD and controls. Furthermore, we found that plasma apolipoprotein C-I and paraoxonase 1 levels were significantly altered in bvFTD and AD, respectively, compared controls. This study represents the first apolipoprotein analysis of bvFTD, and our results suggest altered HDL function and elevated cardiovascular disease risk in bvFTD.
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- 2018
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9. Plasma Oxytocin Is Not Associated with Social Cognition or Behavior in Frontotemporal Dementia and Alzheimer’s Disease Syndromes
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Emma G. Johnson, Wytse Kuiper, Rebekah M. Ahmed, Glenda M. Halliday, James R. Burrell, John R. Hodges, Adam J. Guastella, Olivier Piguet, and Fiona Kumfor
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Social Cognition ,Psychiatry and Mental health ,Alzheimer Disease ,Frontotemporal Dementia ,Cognitive Neuroscience ,Humans ,Neuropsychological Tests ,Geriatrics and Gerontology ,Oxytocin ,Social Behavior - Abstract
Introduction: Changes in social behavior and emotion processing are common in frontotemporal dementia (FTD) and semantic dementia (SD), and less so in Alzheimer’s disease (AD). Recent research has investigated oxytocin as a potential treatment for these symptoms; however, whether plasma oxytocin is associated with social-emotional symptoms of dementia remains underexplored. Methods: Thirty behavioral-variant FTD (bvFTD), 28 SD, 39 AD, and 24 controls underwent blood sampling to measure oxytocin. Participants completed an emotion processing battery. Carers completed the Cambridge Behavioral Inventory and the Neuropsychiatric Inventory. Results: Patients with bvFTD were severely impaired in emotion processing and behavioral ratings, with milder impairment in SD and AD. No difference in plasma oxytocin was observed between groups (p = 0.632). No significant associations were found between oxytocin and social behavior or emotion processing (r values between −0.241 and 0.227, all p values >0.099). Conclusion: Our results indicate that plasma oxytocin is not reduced in dementia and is unrelated to social, emotional, and behavioral features. We noted high interindividual variability in our data; hence, future investigations should consider methodological influences such as serum versus saliva and diurnal variation on oxytocin function. These results demonstrate that current measurement measures of plasma oxytocin have limited utility in determining the role of oxytocin in FTD. Alternative oxytocin measures may prove more sensitive and should be considered when conducting clinical trials.
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- 2022
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10. Mapping behavioural, cognitive and affective transdiagnostic dimensions in frontotemporal dementia
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Siddharth Ramanan, Hashim El-Omar, Daniel Roquet, Rebekah M Ahmed, John R Hodges, Olivier Piguet, Matthew A Lambon Ralph, Muireann Irish, Ahmed, Rebekah M [0000-0001-6996-8317], Piguet, Olivier [0000-0002-6696-1440], Lambon Ralph, Matthew A [0000-0001-5907-2488], Irish, Muireann [0000-0002-4950-8169], and Apollo - University of Cambridge Repository
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Cellular and Molecular Neuroscience ,Psychiatry and Mental health ,Neurology ,principal component analysis ,transdiagnostic ,semantic variant primary progressive aphasia ,heterogeneity ,Biological Psychiatry ,dementia - Abstract
Two common clinical variants of frontotemporal dementia are the behavioural variant frontotemporal dementia, presenting with behavioural and personality changes attributable to prefrontal atrophy, and semantic dementia, displaying early semantic dysfunction primarily due to anterior temporal degeneration. Despite representing independent diagnostic entities, mounting evidence indicates overlapping cognitive–behavioural profiles in these syndromes, particularly with disease progression. Why such overlap occurs remains unclear. Understanding the nature of this overlap, however, is essential to improve early diagnosis, characterization and management of those affected. Here, we explored common cognitive–behavioural and neural mechanisms contributing to heterogeneous frontotemporal dementia presentations, irrespective of clinical diagnosis. This transdiagnostic approach allowed us to ascertain whether symptoms not currently considered core to these two syndromes are present in a significant proportion of cases and to explore the neural basis of clinical heterogeneity. Sixty-two frontotemporal dementia patients (31 behavioural variant frontotemporal dementia and 31 semantic dementia) underwent comprehensive neuropsychological, behavioural and structural neuroimaging assessments. Orthogonally rotated principal component analysis of neuropsychological and behavioural data uncovered eight statistically independent factors explaining the majority of cognitive–behavioural performance variation in behavioural variant frontotemporal dementia and semantic dementia. These factors included Behavioural changes, Semantic dysfunction, General Cognition, Executive function, Initiation, Disinhibition, Visuospatial function and Affective changes. Marked individual-level overlap between behavioural variant frontotemporal dementia and semantic dementia was evident on the Behavioural changes, General Cognition, Initiation, Disinhibition and Affective changes factors. Compared to behavioural variant frontotemporal dementia, semantic dementia patients displayed disproportionate impairment on the Semantic dysfunction factor, whereas greater impairment on Executive and Visuospatial function factors was noted in behavioural variant frontotemporal dementia. Both patient groups showed comparable magnitude of atrophy to frontal regions, whereas severe temporal lobe atrophy was characteristic of semantic dementia. Whole-brain voxel-based morphometry correlations with emergent factors revealed associations between fronto-insular and striatal grey matter changes with Behavioural, Executive and Initiation factor performance, bilateral temporal atrophy with Semantic dysfunction factor scores, parietal-subcortical regions with General Cognitive performance and ventral temporal atrophy associated with Visuospatial factor scores. Together, these findings indicate that cognitive–behavioural overlap (i) occurs systematically in frontotemporal dementia; (ii) varies in a graded manner between individuals and (iii) is associated with degeneration of different neural systems. Our findings suggest that phenotypic heterogeneity in frontotemporal dementia syndromes can be captured along continuous, multidimensional spectra of cognitive–behavioural changes. This has implications for the diagnosis of both syndromes amidst overlapping features as well as the design of symptomatic treatments applicable to multiple syndromes.
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- 2023
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11. Distinct hypothalamic involvement in the amyotrophic lateral sclerosis-frontotemporal dementia spectrum
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Nga Yan Tse, Martina Bocchetta, Emily G. Todd, Emma M. Devenney, Sicong Tu, Jashelle Caga, John R. Hodges, Glenda M. Halliday, Muireann Irish, Matthew C. Kiernan, Olivier Piguet, Jonathan D. Rohrer, and Rebekah M. Ahmed
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Neuropathophysiology ,Cognitive and behavioural impairment ,Neurology ,Cognitive Neuroscience ,Hypothalamus ,Radiology, Nuclear Medicine and imaging ,Neuroimaging ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,Frontotemporal dementia - Abstract
Background Hypothalamic dysregulation plays an established role in eating abnormalities in behavioural variant frontotemporal dementia (bvFTD) and amyotrophic lateral sclerosis (ALS). Its contribution to cognitive and behavioural impairments, however, remains unexplored. Methods Correlation between hypothalamic subregion atrophy and cognitive and behavioural impairments was examined in a large sample of 211 participants (52 pure ALS, 42 mixed ALS-FTD, 59 bvFTD, and 58 age- and education- matched healthy controls). Results Graded variation in hypothalamic involvement but relative sparing of the inferior tuberal region was evident across all patient groups. Bilateral anterior inferior, anterior superior, and posterior hypothalamic subregions were selectively implicated in memory, fluency and processing speed impairments in addition to apathy and abnormal eating habits, taking into account disease duration, age, sex, total intracranial volume, and acquisition parameters (all p ≤ .001). Conclusions These findings revealed that subdivisions of the hypothalamus are differentially affected in the ALS-FTD spectrum and contribute to canonical cognitive and behavioural disturbances beyond eating abnormalities. The anterior superior and superior tuberal subregions containing the paraventricular nucleus (housing oxytocin-producing neurons) displayed the greatest volume loss in bvFTD and ALS-FTD, and ALS, respectively. Importantly, the inferior tuberal subregion housing the arcuate nucleus (containing different groups of neuroendocrine neurons) was selectively preserved across the ALS-FTD spectrum, supporting pathophysiological findings of discrete neuropeptide expression abnormalities that may underlie the pathogenesis of autonomic and metabolic abnormalities and potentially certain cognitive and behavioural symptom manifestations, representing avenues for more refined symptomatic treatment targets. National Health and Medical Research Council of Australia program (#1037746 and #1132524) and dementia team (#1095127) grants and the Australian Research Council Centre of Excellence in Cognition and its Disorders Memory Program (#CE110001021). Dr E.M. Devenney is supported by a MNDRIA post-doctoral fellowship. Dr S. Tu is supported by a NHMRC post-doctoral fellowship (APP1121859). Dr R.M. Ahmed is supported by a NHMRC post-doctoral fellowship. Prof G.M. Halliday is a NHMRC Leadership Fellow (#1176607). Prof M.C. Kiernan received funding support from NHMRC Partnership Grant (#1153439) and Practitioner Fellowship (#115609). Prof O. Piguet is supported by a NHMRC Leadership Fellowship (GNT2008020). Dr M. Bocchetta is supported by a Fellowship award from the Alzheimer’s Society, UK (AS-JF-19a-004-517). Dr M. Bocchetta’s work was also supported by the UK Dementia Research Institute which receives its funding from DRI ltd, funded by the UK Medical Research Council, Alzheimer’s Society and Alzheimer’s Research UK. Dr M. Bocchetta acknowledges the support of NVIDIA Corporation with the donation of the Titan V GPU used for part of the analyses in this research. Prof J. D Rohrer is supported by the Miriam Marks Brain Research UK Senior Fellowship and has received funding from an MRC Clinician Scientist Fellowship (MR/M008525/1) and the NIHR Rare Disease Translational Research Collaboration (BRC149/NS/MH).
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- 2022
12. Neural mechanisms of psychosis vulnerability and perceptual abnormalities in the ALS‐FTD spectrum
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Glenda M. Halliday, Eleanor Ramsey, Matthew C. Kiernan, Sicong Tu, Rebekah M. Ahmed, Emma Devenney, John R. Hodges, Margie C. Zoing, Olivier Piguet, John B.J. Kwok, and Jashelle Caga
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Male ,0301 basic medicine ,Psychosis ,media_common.quotation_subject ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Perceptual Disorders ,03 medical and health sciences ,0302 clinical medicine ,Stimulus modality ,Atrophy ,Perception ,Humans ,Medicine ,Dementia ,Prospective Studies ,RC346-429 ,Research Articles ,Aged ,media_common ,C9orf72 Protein ,business.industry ,General Neuroscience ,Amyotrophic Lateral Sclerosis ,Social anxiety ,Cognition ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,Psychotic Disorders ,Case-Control Studies ,Frontotemporal Dementia ,Female ,Neurology. Diseases of the nervous system ,Neurology (clinical) ,business ,Psychosocial ,030217 neurology & neurosurgery ,Research Article ,RC321-571 ,Clinical psychology - Abstract
Objective The aims of this study were to (i) explore psychotic experiences across the entire amyotrophic lateral sclerosis‐frontotemporal dementia (ALS‐FTD) spectrum from a clinical and genetic perspective, (ii) determine the rate of abnormal perceptual experiences across the five sensory modalities and (iii) explore the neurobiological factors that lead to psychosis vulnerability in ALS‐FTD. Methods In a prospective case‐controlled study design, 100 participants were enrolled including ALS (n = 37, 24% satisfied criteria for ALS‐Plus), ALS‐FTD (n = 11), bvFTD (n = 27) and healthy controls (n = 25). Psychotic experiences, perceptual abnormalities and psychosocial factors were determined by means of the clinical interview and carer and patient reports. Voxel‐based morphometry analyses determined atrophy patterns in patients experiencing psychosis‐like experiences and other perceptual abnormalities. Results The rates of psychotic experiences and abnormalities of perception in each sensory modality were high across the entire ALS‐FTD continuum. The rate was highest in those with C9orf72 expansions. Rates were also high in patients with pure ALS including psychosis measured by carer‐based reports (18%) and self‐report measures of psychotic‐like experiences (21%). In an ENTER regression model, social anxiety and ACE‐III scores were the best predictors of psychosis proneness, accounting for 44% of the score variance. Psychosis‐like experiences and perceptual abnormalities were associated with a predominantly frontal and temporal pattern of atrophy that extended to the cerebellum and centred on the anterior thalamus. Interpretation The model for psychosis proneness in ALS‐FTD likely includes complex interactions between cognitive, social and neurobiological factors that determine vulnerability to psychosis and that may have relevance for individualised patient management.
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- 2021
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13. Pathophysiology and Treatment of Non-motor Dysfunction in Amyotrophic Lateral Sclerosis
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Matthew C. Kiernan, Orla Hardiman, Jonathan D. Rohrer, Rebekah M. Ahmed, William Huynh, Richard Bedlack, Sicong Tu, and Colin J. Mahoney
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Weakness ,medicine.medical_specialty ,Neurology ,Disease ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Risk Factors ,Outcome Assessment, Health Care ,Epidemiology ,Humans ,Medicine ,Cognitive Dysfunction ,Pharmacology (medical) ,Amyotrophic lateral sclerosis ,business.industry ,Clinical study design ,Amyotrophic Lateral Sclerosis ,Cognition ,medicine.disease ,030227 psychiatry ,Psychiatry and Mental health ,Research Design ,Disease Progression ,Neurology (clinical) ,Psychopharmacology ,medicine.symptom ,business ,030217 neurology & neurosurgery - Abstract
Amyotrophic lateral sclerosis is a progressive and fatal neurodegenerative disease typically presenting with bulbar or limb weakness. There is increasing evidence that amyotrophic lateral sclerosis is a multisystem disease with early and frequent impacts on cognition, behaviour, sleep, pain and fatigue. Dysfunction of normal physiological and metabolic processes also appears common. Evidence from pre-symptomatic studies and large epidemiological cohorts examining risk factors for the future development of amyotrophic lateral sclerosis have reported a high prevalence of changes in behaviour and mental health before the emergence of motor weakness. This suggests that changes beyond the motor system are underway at an early stage with dysfunction across brain networks regulating a variety of cognitive, behavioural and other homeostatic processes. The full impact of non-motor dysfunction continues to be established but there is now sufficient evidence that the presence of non-motor symptoms impacts overall survival in amyotrophic lateral sclerosis, and with up to 80% reporting non-motor symptoms, there is an urgent need to develop more robust therapeutic approaches. This review provides a contemporary overview of the pathobiology of non-motor dysfunction, offering readers a practical approach with regard to assessment and management. We review the current evidence for pharmacological and non-pharmacological treatment of non-motor dysfunction in amyotrophic lateral sclerosis and highlight the need to further integrate non-motor dysfunction as an important outcome measure for future clinical trial design.
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- 2021
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14. Loss of the metabolism and sleep regulating neuronal populations expressing orexin and oxytocin in the hypothalamus in amyotrophic lateral sclerosis
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Jashelle Caga, Glenda M. Halliday, Åsa Petersén, Matthew C. Kiernan, Rebekah M. Ahmed, and Sanaz Gabery
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Male ,0301 basic medicine ,endocrine system ,Vasopressin ,medicine.medical_specialty ,Histology ,Neurology ,Hypothalamus ,Oxytocin ,Pathology and Forensic Medicine ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Physiology (medical) ,Internal medicine ,medicine ,Humans ,Amyotrophic lateral sclerosis ,Aged ,Aged, 80 and over ,Neurons ,Orexins ,business.industry ,Amyotrophic Lateral Sclerosis ,digestive, oral, and skin physiology ,Fornix ,Middle Aged ,medicine.disease ,Orexin ,030104 developmental biology ,Endocrinology ,nervous system ,Female ,Neurology (clinical) ,Sleep ,business ,hormones, hormone substitutes, and hormone antagonists ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Aims: To determine the underlying cellular changes and clinical correlates associated with pathology of the hypothalamus in amyotrophic lateral sclerosis (ALS), as hypothalamic atrophy occurs in the preclinical phase of the disease. Methods: The hypothalamus was pathologically examined in nine patients with amyotrophic lateral sclerosis in comparison to eight healthy control subjects. The severity of regional atrophy (paraventricular nucleus: PVN, fornix and total hypothalamus) and peptidergic neuronal loss (oxytocin, vasopressin, cocaine- and amphetamine-regulating transcript: CART, and orexin) was correlated with changes in eating behaviour, sleep function, cognition, behaviour and disease progression. Results: Tar DNA-binding protein 43 (TDP-43) inclusions were present in the hypothalamus of all patients with amyotrophic lateral sclerosis. When compared to controls, there was atrophy of the hypothalamus (average 21% atrophy, p = 0.004), PVN (average 30% atrophy p = 0.014) and a loss of paraventricular oxytocin-producing neurons (average 49% loss p = 0.02) and lateral hypothalamic orexin-producing neurons (average 37% loss, significance p = 0.02). Factor analysis identified strong relationships between abnormal eating behaviour, hypothalamic atrophy and loss of orexin-producing neurons. With increasing disease progression, abnormal sleep behaviour and cognition associated with atrophy of the fornix. Conclusions: Substantial loss of hypothalamic oxytocin-producing neurons occurs in ALS, with regional atrophy and the loss of orexin neurons relating to abnormal eating behaviour in ALS. Oxytocin- and orexin neurons display TDP43 inclusions. Our study points to significant pathology in the hypothalamus that may play a key role in metabolic and pathogenic changes in ALS. (Less)
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- 2021
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15. Longitudinal cognitive and functional changes in primary progressive aphasia
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Olivier Piguet, Rebekah M. Ahmed, Muireann Irish, James Carrick, Anne Hu, James R. Burrell, John R. Hodges, and David Foxe
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medicine.medical_specialty ,Neurology ,Audiology ,Primary progressive aphasia ,03 medical and health sciences ,Cognition ,0302 clinical medicine ,medicine ,Humans ,Memory impairment ,Cognitive Dysfunction ,030212 general & internal medicine ,Functional decline ,Cognitive decline ,Language ,Memory Disorders ,Multilevel model ,respiratory system ,Addenbrooke's cognitive examination ,medicine.disease ,Aphasia, Primary Progressive ,Neurology (clinical) ,Psychology ,030217 neurology & neurosurgery - Abstract
The variants of primary progressive aphasia (PPA) are predominantly diagnosed on the basis of specific profiles of language impairments. Deficits in other cognitive domains and their evolution over time are less well documented. This study examined the cognitive profiles of the PPA variants over time and determined the contribution of cognition on functional capacity. Longitudinal performance on the Addenbrooke’s Cognitive Examination-III (ACE-III) total and cognitive subdomains were investigated in 147 PPA individuals (41 logopenic [lv-PPA], 44 non-fluent [nfv-PPA], and 62 semantic variants [sv-PPA]). The relative contribution of ACE-III subdomain scores to overall functional capacity over time was identified using mixed and hierarchical regression modelling. The annual rate of global ACE-III decline was twice that in lv-PPA than in nfv-PPA and sv-PPA, despite lv-PPA performing intermediate to the other variants at baseline assessment. Notably, attention and visuospatial subdomains declined faster in lv-PPA than in nfv-PPA and sv-PPA; and memory impairment was more severe in lv-PPA than in nfv-PPA at all time points. Functional decline was comparable across PPA variants; however, the contribution of cognition on functional capacity varied across variants and over time. The cognitive profiles of the PPA variants are distinct at baseline and over time. Crucially, cognitive decline in lv-PPA was more widespread and pervasive than in nfv-PPA and sv-PPA. Our findings also demonstrate the complex interplay between cognition and functional capacity. This study underscores the importance of routinely assessing cognition and functional capacity in PPA to improve diagnostic accuracy and provide targeted support services.
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- 2021
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16. Using a second-person approach to identify disease-specific profiles of social behavior in frontotemporal dementia and Alzheimer's disease
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Tim Van Langenhove, Mandy Visser, John R. Hodges, James R. Burrell, Jessica L. Hazelton, Emma Devenney, Stephanie Wong, Rebekah M. Ahmed, Simone Simonetti, Fiona Kumfor, and Deborah Parker
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Cognitive Neuroscience ,Eye contact ,Semantic dementia ,Experimental and Cognitive Psychology ,Disease ,Neuropsychological Tests ,050105 experimental psychology ,03 medical and health sciences ,0302 clinical medicine ,Pick Disease of the Brain ,Social neuroscience ,Alzheimer Disease ,medicine ,Humans ,Dementia ,0501 psychology and cognitive sciences ,Social Behavior ,05 social sciences ,medicine.disease ,Neuropsychology and Physiological Psychology ,Mentalization ,First person ,Frontotemporal Dementia ,Psychology ,030217 neurology & neurosurgery ,Frontotemporal dementia ,Clinical psychology - Abstract
Changes in social behavior are recognized as potential symptoms of behavioral-variant frontotemporal dementia (bvFTD) and semantic dementia (SD), yet objective ways to assess these behaviors in natural social situations are lacking. This study takes a truly social (or second-person) approach and examines changes in real-world social behavior in different dementia syndromes, by analyzing non-scripted social interactions in bvFTD patients (n = 20) and SD patients (n = 20), compared to patients with Alzheimer's disease (AD) (n = 20). Video recordings of 10-min conversations between patients and behavioral neurologists were analyzed for the presence of socially engaging (e.g., nodding, smiling, gesturing) and disengaging behavior (e.g., avoiding eye contact, self-grooming, interrupting). Results demonstrated disease-specific profiles, with bvFTD patients showing less nodding and more looking away than AD, and SD patients showing more gesturing than AD. A principal components analysis revealed the presence of four unobserved components, showing atypical disengaging patterns of behavior. Whole-brain voxel-based morphometry analyses revealed distinct neurobiological bases for each of these components, with the brain regions identified previously associated with behavior selection, abstract mentalization and processing of multi-sensory and socially-relevant information, in mediating socially engaging and disengaging behavior. This study demonstrates the utility of systematic behavioral observation of social interactions in the differential diagnosis of dementia.
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- 2020
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17. Phenotypic variability in ALS-FTD and effect on survival
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John R. Hodges, Matthew C. Kiernan, Emma Devenney, Olivier Piguet, Rebekah M. Ahmed, and Cherie Strikwerda-Brown
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0301 basic medicine ,education.field_of_study ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Population ,Magnetic resonance imaging ,Cognition ,Audiology ,medicine.disease ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Atrophy ,Neuroimaging ,medicine ,Dementia ,Neurology (clinical) ,Presentation (obstetrics) ,education ,business ,030217 neurology & neurosurgery ,Survival analysis - Abstract
ObjectiveTo determine if survival and cognitive profile is affected by initial presentation in amyotrophic lateral sclerosis–frontotemporal dementia (ALS-FTD) (motor vs cognitive), we compared survival patterns in ALS-FTD based on initial phenotypic presentation and their cognitive profile compared to behavioral variant FTD (bvFTD).MethodsCognitive/behavioral profiles were examined in 98 patients (59 ALS-FTD and 39 bvFTD). The initial presentation of ALS-FTD was categorized into either motor or cognitive. Survival was calculated from initial symptom onset. MRI brain atrophy patterns were examined using a validated visual rating scale.ResultsIn the ALS-FTD group, 41 (69%) patients were categorized as having an initial cognitive presentation and 18 (31%) a motor presentation. Patients with motor presentation experienced a significantly shorter median survival of 2.7 years compared to 4.4 years (p < 0.001) in those with a cognitive presentation. No differences between motor vs cognitive onset ALS-FTD were found on cognitive testing. When compared to bvFTD, ALS-FTD–cognitive presentation was characterized by reduced language function (p < 0.001), verbal fluency (p = 0.001), and naming (p = 0.007). Both motor and cognitive onset ALS-FTD showed reduced emotion processing (p = 0.01) and exhibited greater motor cortex and dorsal lateral prefrontal cortex atrophy than bvFTD. Increased motor cortex atrophy was associated with 1.5-fold reduction in survival.ConclusionsInitial motor presentation in ALS-FTD leads to faster progression than in those with a cognitive presentation, despite similar overall cognitive deficits. These findings suggest that disease progression in ALS-FTD may be critically linked to physiologic and motor changes.
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- 2020
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18. Thalamic and Cerebellar Regional Involvement across the ALS-FTD Spectrum and the Effect of
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Martina, Bocchetta, Emily G, Todd, Nga Yan, Tse, Emma M, Devenney, Sicong, Tu, Jashelle, Caga, John R, Hodges, Glenda M, Halliday, Muireann, Irish, Olivier, Piguet, Matthew C, Kiernan, Jonathan D, Rohrer, and Rebekah M, Ahmed
- Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are part of the same disease spectrum. While thalamic-cerebellar degeneration has been observed in
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- 2022
19. Putting the Pieces Together: Mental Construction of Semantically Congruent and Incongruent Scenes in Dementia
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Nikki-Anne Wilson, Rebekah M. Ahmed, Olivier Piguet, and Muireann Irish
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semantic memory ,General Neuroscience ,05 social sciences ,Neurosciences. Biological psychiatry. Neuropsychiatry ,episodic memory ,social cognition ,frontotemporal dementia ,050105 experimental psychology ,Article ,03 medical and health sciences ,0302 clinical medicine ,schema ,0501 psychology and cognitive sciences ,scene construction ,imagination ,030217 neurology & neurosurgery ,RC321-571 - Abstract
Scene construction refers to the process by which humans generate richly detailed and spatially cohesive scenes in the mind’s eye. The cognitive processes that underwrite this capacity remain unclear, particularly when the envisaged scene calls for the integration of various types of contextual information. Here, we explored social and non-social forms of scene construction in Alzheimer’s disease (AD; n = 11) and the behavioural variant of frontotemporal dementia (bvFTD; n = 15) relative to healthy older control participants (n = 16) using a novel adaptation of the scene construction task. Participants mentally constructed detailed scenes in response to scene–object cues that varied in terms of their sociality (social; non-social) and congruence (congruent; incongruent). A significant group × sociality × congruence interaction was found whereby performance on the incongruent social scene condition was significantly disrupted in both patient groups relative to controls. Moreover, bvFTD patients produced significantly less contextual detail in social relative to non-social incongruent scenes. Construction of social and non-social incongruent scenes in the patient groups combined was significantly associated with independent measures of semantic processing and visuospatial memory. Our findings demonstrate the influence of schema-incongruency on scene construction performance and reinforce the importance of episodic–semantic interactions during novel event construction.
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- 2021
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20. Cognitive and Neural Mechanisms of Social Communication Dysfunction in Primary Progressive Aphasia
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David Foxe, Olivier Piguet, Zoë-Lee Goldberg, Hashim El-Omar, Rebekah M. Ahmed, Cristian E. Leyton, and Muireann Irish
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Semantic dementia ,Neurosciences. Biological psychiatry. Neuropsychiatry ,social cognition ,frontotemporal dementia ,050105 experimental psychology ,Article ,Primary progressive aphasia ,03 medical and health sciences ,0302 clinical medicine ,Social cognition ,Aphasia ,thalamus ,medicine ,Dementia ,0501 psychology and cognitive sciences ,language ,General Neuroscience ,Logopenic progressive aphasia ,05 social sciences ,Cognition ,medicine.disease ,frontal lobe ,Alzheimer’s disease ,medicine.symptom ,Psychology ,030217 neurology & neurosurgery ,Frontotemporal dementia ,Clinical psychology ,RC321-571 - Abstract
Mounting evidence suggests that, in parallel with well-defined changes in language, primary progressive aphasia (PPA) syndromes display co-occurring social cognitive impairments. Here, we explored multidimensional profiles of carer-rated social communication using the La Trobe Communication Questionnaire (LCQ) in 11 semantic dementia (SD), 12 logopenic progressive aphasia (LPA) and 9 progressive non-fluent aphasia (PNFA) cases and contrasted their performance with 19 Alzheimer’s disease (AD) cases, 26 behavioural variant frontotemporal dementia (bvFTD) cases and 31 healthy older controls. Relative to the controls, the majority of patient groups displayed significant overall social communication difficulties, with common and unique profiles of impairment evident on the LCQ subscales. Correlation analyses revealed a differential impact of social communication disturbances on functional outcomes in patient and carer well-being, most pronounced for SD and bvFTD. Finally, voxel-based morphometry analyses based on a structural brain MRI pointed to the degradation of a distributed brain network in mediating social communication dysfunction in dementia. Our findings suggest that social communication difficulties are an important feature of PPA, with significant implications for patient function and carer well-being. The origins of these changes are likely to be multifactorial, reflecting the breakdown of fronto-thalamic brain circuits specialised in the integration of complex information.
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- 2021
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21. Metabolism in frontotemporal dementia
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Rebekah M Ahmed
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Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Epidemiology ,Health Policy ,Neurology (clinical) ,Geriatrics and Gerontology - Published
- 2021
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22. Mapping behavioural, cognitive and affective transdiagnostic dimensions in frontotemporal dementia
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John R. Hodges, Muireann Irish, Rebekah M. Ahmed, Matthew A. Lambon Ralph, Olivier Piguet, Daniel Roquet, Siddharth Ramanan, and Hashim El-Omar
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business.industry ,Neuropsychology ,Semantic dementia ,Cognition ,medicine.disease ,Personality changes ,Atrophy ,Disinhibition ,medicine ,Effects of sleep deprivation on cognitive performance ,medicine.symptom ,business ,Frontotemporal dementia ,Clinical psychology - Abstract
Two common clinical variants of frontotemporal dementia (FTD) are the behavioural variant (bvFTD) presenting with behavioural and personality changes attributable to prefrontal atrophy, and semantic dementia (SD) displaying early semantic dysfunction primarily due to anterior temporal degeneration. Despite representing independent diagnostic entities, mounting evidence indicates overlapping cognitive-behavioural profiles in these syndromes, particularly with disease progression. Why such overlap occurs remains unclear. Understanding the nature of this overlap, however, is essential to improve early diagnosis, characterisation, and management of those affected. Here, we explored common cognitive-behavioural and neural mechanisms contributing to heterogeneous FTD presentations, irrespective of clinical diagnosis. This transdiagnostic approach allowed us to ascertain whether symptoms not currently considered core to these two syndromes are present in a significant proportion of cases and explore the neural basis of clinical heterogeneity. Sixty-two FTD patients (31 bvFTD, 31 SD) underwent comprehensive neuropsychological, behavioural, and structural neuroimaging assessments. Orthogonally-rotated principal component analysis of neuropsychological and behavioural data uncovered eight statistically independent factors explaining the majority of cognitive-behavioural performance variation in bvFTD and SD. These factors included Behavioural changes, Semantic dysfunction, General Cognition, Executive function, Initiation, Disinhibition, Visuospatial function, and Affective changes. Marked individual-level overlap between bvFTD and SD was evident on the Behavioural changes, General Cognition, Initiation, Disinhibition, and Affective changes factors. Compared to bvFTD, SD patients displayed disproportionate impairment on the Semantic dysfunction factor, whereas greater impairment on Executive and Visuospatial function factors was noted in bvFTD. Both patient groups showed comparable magnitude of atrophy to frontal regions, whereas severe temporal lobe atrophy was characteristic of SD. Whole-brain voxel-based morphometry correlations with emergent factors revealed associations between fronto-insular and striatal grey matter changes with Behavioural, Executive, and Initiation factor performance, bilateral temporal atrophy with Semantic dysfunction factor scores, parietal-subcortical regions with General Cognitive performance, and ventral temporal atrophy associated with Visuospatial factor scores. Together, these findings indicate that cognitive-behavioural overlap (i) occurs systematically in FTD, (ii) varies in a graded manner between individuals, and (iii) is associated with degeneration of different neural systems. Our findings suggest that phenotypic heterogeneity in FTD syndromes can be captured along continuous, multidimensional spectra of cognitive-behavioural changes. This has implications for the diagnosis of both syndromes amidst overlapping features as well as the design of symptomatic treatments applicable to multiple syndromes.
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- 2021
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23. Tackling clinical heterogeneity across the amyotrophic lateral sclerosis–frontotemporal dementia spectrum using a transdiagnostic approach
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Martina Bocchetta, Glenda M. Halliday, Matthew C. Kiernan, John R. Hodges, Emma Devenney, Nga Yan Tse, Jonathan D. Rohrer, Olivier Piguet, Rebekah M. Ahmed, Muireann Irish, Emily Todd, Sicong Tu, and Jashelle Caga
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cognition ,Frontotemporal dementia-amyotrophic lateral sclerosis ,AcademicSubjects/SCI01870 ,business.industry ,behavioural ,Putamen ,Thalamus ,General Engineering ,imaging ,Hippocampus ,frontotemporal dementia-amyotrophic lateral sclerosis ,medicine.disease ,medicine.anatomical_structure ,Atrophy ,mental disorders ,Medicine ,Original Article ,AcademicSubjects/MED00310 ,Amyotrophic lateral sclerosis ,business ,Insula ,Neuroscience ,Motor cortex ,Frontotemporal dementia - Abstract
The disease syndromes of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) display considerable clinical, genetic and pathological overlap, yet mounting evidence indicates substantial differences in progression and survival. To date, there has been limited examination of how profiles of brain atrophy might differ between clinical phenotypes. Here, we address this longstanding gap in the literature by assessing cortical and subcortical grey and white matter volumes on structural MRI in a large cohort of 209 participants. Cognitive and behavioural changes were assessed using the Addenbrooke’s Cognitive Examination and the Cambridge Behavioural Inventory. Relative to 58 controls, behavioural variant FTD (n = 58) and ALS–FTD (n = 41) patients displayed extensive atrophy of frontoinsular, cingulate, temporal and motor cortices, with marked subcortical atrophy targeting the hippocampus, amygdala, thalamus and striatum, with atrophy further extended to the brainstem, pons and cerebellum in the latter group. At the other end of the spectrum, pure-ALS patients (n = 52) displayed considerable frontoparietal atrophy, including right insular and motor cortices and pons and brainstem regions. Subcortical regions included the bilateral pallidum and putamen, but to a lesser degree than in the ALS–FTD and behavioural variant FTD groups. Across the spectrum the most affected region in all three groups was the insula, and specifically the anterior part (76–90% lower than controls). Direct comparison of the patient groups revealed disproportionate temporal atrophy and widespread subcortical involvement in ALS–FTD relative to pure-ALS. In contrast, pure-ALS displayed significantly greater parietal atrophy. Both behavioural variant FTD and ALS–FTD were characterized by volume decrease in the frontal lobes relative to pure-ALS. The motor cortex and insula emerged as differentiating structures between clinical syndromes, with bilateral motor cortex atrophy more pronounced in ALS–FTD compared with pure-ALS, and greater left motor cortex and insula atrophy relative to behavioural variant FTD. Taking a transdiagnostic approach, we found significant associations between abnormal behaviour and volume loss in a predominantly frontoinsular network involving the amygdala, striatum and thalamus. Our findings demonstrate the presence of distinct atrophy profiles across the ALS–FTD spectrum, with key structures including the motor cortex and insula. Notably, our results point to subcortical involvement in the origin of behavioural disturbances, potentially accounting for the marked phenotypic variability typically observed across the spectrum., Ahmed et al.’s findings demonstrate the presence of distinct atrophy profiles across the ALS–FTD spectrum, with key structures including the motor cortex and insula. Subcortical involvement is likely the origin of behavioural disturbances, potentially accounting for the marked phenotypic variability typically observed across the ALS-FTD spectrum., Graphical Abstract Graphical Abstract
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- 2021
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24. Illness Cognitions in ALS: New Insights Into Clinical Management of Behavioural Symptoms
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Jashelle Caga, Emma Devenney, William Huynh, Margaret C. Zoing, Rebekah M. Ahmed, and Matthew C. Kiernan
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health care delivery ,amyotrophic lateral sclerosis (ALS) ,adherence - compliance - persistance ,media_common.quotation_subject ,Psychological intervention ,Illness perceptions ,behavioural intervention ,Emotional distress ,Perception ,Illness cognitions ,Intervention (counseling) ,medicine ,Amyotrophic lateral sclerosis ,RC346-429 ,Original Research ,media_common ,illness perceptions ,patient decision-making ,business.industry ,Cognition ,medicine.disease ,Neurology ,Neurology. Diseases of the nervous system ,Neurology (clinical) ,behavioural symptoms ,business ,Clinical psychology - Abstract
Timely management of frontotemporal dysfunction associated with amyotrophic lateral sclerosis (ALS) has important prognostic and therapeutic implications. However, there remains a paucity of research on best practise recommendations to guide the development of interventions for cognitive and behavioural symptoms as part of ALS care. Accordingly, a focus on illness perceptions may provide a preliminary framework for managing cognitive and behavioural symptoms. The aim of the present study was to explore the nature of illness perceptions among ALS patients with cognitive and behavioural symptoms. A total of 39 patients were recruited from a specialised ALS clinic. Factor analysis showed three independent and clinically interpretable factors corresponding to “cognitive and emotion related ALS perceptions,” “cognitive- specific ALS perceptions” and “ALS coherence”. Of these factors, greater perceived cognitive and emotional impacts of ALS were associated with an approximate 4-fold increased risk of behavioural changes (p < 0.05). Greater perceived cognitive and emotional impacts of ALS was also associated with more rapid disease progression (p < 0.001). As such, timely provision of intervention addressing perceptions about the impact of ALS on functioning as well as associated emotional distress may optimise clinical management of cognitive and behavioural symptoms of ALS.
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- 2021
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25. The Role of Oxytocin in Social Circuits and Social Behavior in Dementia
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Rebekah M. Ahmed, Fiona Kumfor, and Olivier Piguet
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media_common.quotation_subject ,Semantic dementia ,Empathy ,medicine.disease ,Progressive nonfluent aphasia ,Social cognition ,Autism spectrum disorder ,Schizophrenia ,mental disorders ,medicine ,Dementia ,Psychology ,Neuroscience ,Frontotemporal dementia ,media_common - Abstract
Administration of intranasal oxytocin has been found to improve social cognition in a number of brain conditions, including autism spectrum disorder and schizophrenia. Whether this approach is relevant in dementias is currently unknown, particularly in frontotemporal dementia, a younger-onset dementia characterized clinically by marked changes in social cognition and behavior and focal atrophy of the frontal and temporal lobes. This chapter provides an overview of the deficits in social cognition in frontotemporal dementia and reviews the emerging evidence of intranasal oxytocin administration as a potential treatment option for these deficits. Future research directions will also be discussed.
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- 2021
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26. The Role of Oxytocin in Social Circuits and Social Behavior in Dementia
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Olivier, Piguet, Rebekah M, Ahmed, and Fiona, Kumfor
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Autism Spectrum Disorder ,Frontotemporal Dementia ,Humans ,Neuropsychological Tests ,Oxytocin ,Social Behavior - Abstract
Administration of intranasal oxytocin has been found to improve social cognition in a number of brain conditions, including autism spectrum disorder and schizophrenia. Whether this approach is relevant in dementias is currently unknown, particularly in frontotemporal dementia, a younger-onset dementia characterized clinically by marked changes in social cognition and behavior and focal atrophy of the frontal and temporal lobes. This chapter provides an overview of the deficits in social cognition in frontotemporal dementia and reviews the emerging evidence of intranasal oxytocin administration as a potential treatment option for these deficits. Future research directions will also be discussed.
- Published
- 2021
27. Evidence for a pervasive autobiographical memory impairment in Logopenic Progressive Aphasia
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Siddharth Ramanan, Olivier Piguet, Rebekah M. Ahmed, Hashim El-Omar, Muireann Irish, David Foxe, John R. Hodges, Ramanan, Siddharth [0000-0002-8591-042X], and Apollo - University of Cambridge Repository
- Subjects
Adult ,Male ,Aging ,Adolescent ,Memory, Episodic ,Amnesia ,Primary progressive aphasia ,Young Adult ,Alzheimer Disease ,medicine ,Aphasia ,Humans ,Language disorder ,Gray Matter ,Episodic memory ,Aged ,Parietal ,Recall ,Autobiographical memory ,General Neuroscience ,Logopenic progressive aphasia ,Alzheimer's disease ,Middle Aged ,medicine.disease ,Healthy Volunteers ,Free recall ,Mental Recall ,lipids (amino acids, peptides, and proteins) ,Dementia ,Female ,Neurology (clinical) ,Geriatrics and Gerontology ,medicine.symptom ,Psychology ,Neuroscience ,Developmental Biology - Abstract
Although characterized primarily as a language disorder, mounting evidence indicates episodic amnesia in Logopenic Progressive Aphasia (LPA). Whether such memory disturbances extend to information encoded pre-disease onset remains unclear. To address this question, we examined autobiographical memory in 10 LPA patients, contrasted with 18 typical amnestic Alzheimer's disease and 16 healthy Control participants. A validated assessment, the Autobiographical Interview, was employed to explore autobiographical memory performance across the lifespan under free and probed recall conditions. Relative to Controls, LPA patients showed global impairments across all time periods for free recall, scoring at the same level as disease-matched cases of Alzheimer's disease. Importantly, these retrieval deficits persisted in LPA, even when structured probing was provided, and could not be explained by overall level of language disruption or amount of information generated during autobiographical narration. Autobiographical memory impairments in LPA related to gray matter intensity decrease in predominantly posterior parietal brain regions implicated in memory retrieval. Together, our results suggest that episodic memory disturbances may be an under-appreciated clinical feature of LPA.
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- 2021
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28. The impact of cognitive and behavioral impairment in amyotrophic lateral sclerosis
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Jashelle Caga, Colin J. Mahoney, William Huynh, Cindy S.-Y. Lin, Sicong Tu, Rebekah M. Ahmed, Matthew C. Kiernan, Patricia Loh, and Chilan Nguyen
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business.industry ,General Neuroscience ,Amyotrophic Lateral Sclerosis ,Cognition ,Behavioral Symptoms ,medicine.disease ,030227 psychiatry ,03 medical and health sciences ,0302 clinical medicine ,Frontotemporal Dementia ,Cognitive Changes ,medicine ,Humans ,Cognitive Dysfunction ,Pharmacology (medical) ,Spectrum disorder ,Neurology (clinical) ,Cognitive Assessment System ,Motor Manifestations ,Amyotrophic lateral sclerosis ,business ,Pathological ,030217 neurology & neurosurgery ,Clinical psychology ,Frontotemporal dementia - Abstract
Introduction: A spectrum of non-motor manifestations in amyotrophic lateral sclerosis (ALS) patients has been increasingly recognized, with cognitive and behavioral impairments the most prominent. Evidence suggests that ALS overlaps on a pathological, genetic, and clinical level with frontotemporal dementia (FTD), thereby suggesting a frontotemporal spectrum disorder (ALS-FTSD). Cognitive impairment has been reported in up to 75% of ALS patients, whilst the rate of behavioral dysfunction ranges up to 50%.Areas covered: The present review explores the current understanding of cognitive and behavioral changes in ALS with a particular emphasis on its implications on prognosis and survival.Expert commentary: Further longitudinal studies are needed to clarify the evolution of cognitive impairment in ALS and how this may ultimately influence survival. Improving understanding of cognitive changes has important implications toward the capacity of patients in making critical medical decisions. There is a need to develop a universally accepted and validated cognitive assessment tool to be administered in a multidisciplinary clinic that is efficient and sensitive, as well as being integrated into the design and analysis of future ALS drug trials. In addition, revision of the ALS diagnostic criteria is critically needed that should accommodate cognitive and behavioral symptoms in addition to motor manifestations.
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- 2020
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29. Theme 11 Cognitive and psychological assessment and support
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Matthew C. Kiernan, Emma Devenney, John R. Hodges, Rebekah M. Ahmed, Cherie Strikwerda-Brown, and Olivier Piguet
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medicine.medical_specialty ,business.industry ,nutritional and metabolic diseases ,Cognition ,Audiology ,medicine.disease ,nervous system diseases ,Cognitive test ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Cog ,Atrophy ,Neurology ,mental disorders ,medicine ,Verbal fluency test ,Dementia ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,business ,030217 neurology & neurosurgery ,Motor cortex - Abstract
Background: Within the Amyotrophic Lateral Sclerosis (ALS)-Frontotemporal dementia (FTD) spectrum there is considerable heterogeneity in clinical presentation and survival.Objectives: The current study aimed to examine how initial symptoms (motor compared to cognitive) may affect survival, with specific focus on structural cognitive and behavioural differences between ALS-FTD and bvFTD cohorts.Methods: Cognitive and behavioural profiles were examined in 98 patients (59 ALS-FTD and 39 bvFTD patients). The initial presentation of ALS-FTD was categorized into either motor or cognitive, based on symptoms combined with carer reports. Survival was calculated from initial symptom onset. Brain atrophy patterns on MRI were examined using a verified visual rating scale.Results: In the ALS-FTD group, 69% were categorized as having an initial cognitive presentation and 31% a motor presentation. Those patients with motor presentation of ALS-FTD experienced a significantly shorter survival of 33 months, compared to 63 months (p
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- 2019
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30. Neural networks associated with body composition in frontotemporal dementia
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Cheng T. Liang, Julia M. Keogh, Cherie Strikwerda-Brown, Matthew C. Kiernan, Emma Devenney, John R. Hodges, I. Sadaf Farooqi, Rebekah M. Ahmed, Ramon Landin-Romero, Elana Henning, and Olivier Piguet
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0301 basic medicine ,Male ,medicine.medical_specialty ,media_common.quotation_subject ,Thalamus ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Nucleus accumbens ,Amygdala ,03 medical and health sciences ,0302 clinical medicine ,Absorptiometry, Photon ,Internal medicine ,Medicine ,Humans ,Gray Matter ,skin and connective tissue diseases ,RC346-429 ,Research Articles ,media_common ,Aged ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Putamen ,Brain ,Magnetic resonance imaging ,Appetite ,Feeding Behavior ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Adipose Tissue ,Frontotemporal Dementia ,Body Composition ,Female ,Neurology (clinical) ,sense organs ,Neurology. Diseases of the nervous system ,Atrophy ,Nerve Net ,business ,Insula ,030217 neurology & neurosurgery ,Frontotemporal dementia ,Research Article ,RC321-571 - Abstract
Background Frontotemporal dementia (FTD) is associated with complex changes in eating behavior and metabolism, which potentially affect disease pathogenesis and survival. It is currently not known if body composition changes and changes in fat deposition also exist in FTD, the relationship of these changes in eating behavior and appetite, and whether these changes are centrally mediated. Methods Body composition was measured in 28 people with behavioral‐variant frontotemporal dementia (bvFTD), 16 with Alzheimer’s disease (AD), and 19 healthy controls, using dual energy x‐ray absorptiometry. Changes in body composition were correlated to brain grey matter atrophy using voxel‐based morphometry on high‐resolution magnetic resonance imaging. Results Behavioral‐variant FTD was characterized by changes in body composition, with increased total fat mass, visceral adipose tissue area (VAT area), and android: gynoid ratio compared to control and AD participants (all P values
- Published
- 2019
31. Verbal Short-Term Memory Disturbance in the Primary Progressive Aphasias: Challenges and Distinctions in a Clinical Setting
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Sau Chi Cheung, Olivier Piguet, Rebekah M. Ahmed, David Foxe, Muireann Irish, Cathleen Taylor-Rubin, James R. Burrell, and Nicholas J Cordato
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neuropsychology ,Short-term memory ,Neurosciences. Biological psychiatry. Neuropsychiatry ,frontotemporal dementia ,Article ,050105 experimental psychology ,working memory ,Primary progressive aphasia ,03 medical and health sciences ,0302 clinical medicine ,visuospatial ,span ,medicine ,Dementia ,0501 psychology and cognitive sciences ,Working memory ,General Neuroscience ,sentence repetition ,05 social sciences ,Neuropsychology ,phonological ,Cognition ,medicine.disease ,Comprehension ,primary progressive aphasia ,Verbal memory ,Psychology ,Alzheimer’s disease ,030217 neurology & neurosurgery ,RC321-571 ,Cognitive psychology - Abstract
Impaired verbal ‘phonological’ short-term memory is considered a cardinal feature of the logopenic variant of primary progressive aphasia (lv-PPA) and is assumed to underpin most of the language deficits in this syndrome. Clinically, examination of verbal short-term memory in individuals presenting with PPA is common practice and serves two objectives: (i) to help understand the possible mechanisms underlying the patient’s language profile and (ii) to help differentiate lv-PPA from other PPA variants or from other dementia syndromes. Distinction between lv-PPA and the non-fluent variant of PPA (nfv-PPA), however, can be especially challenging due to overlapping language profiles and comparable psychometric performances on verbal short-term memory tests. Here, we present case vignettes of the three PPA variants (lv-PPA, nfv-PPA, and the semantic variant (sv-PPA)) and typical Alzheimer’s disease (AD). These vignettes provide a detailed description of the short-term and working memory profiles typically found in these patients and highlight how speech output and language comprehension deficits across the PPA variants differentially interfere with verbal memory performance. We demonstrate that a combination of verbal short-term and working memory measures provides crucial information regarding the cognitive mechanisms underlying language disturbances in PPA. In addition, we propose that analogous visuospatial span tasks are essential for the assessment of PPA as they measure memory capacity without language contamination.
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- 2021
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32. 041 Cognitive impairment in late onset epilepsy
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Rebekah M. Ahmed, Xin Zhang, and Armin Nikpour
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Pediatrics ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Neuropsychology ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Late onset ,Cognition ,medicine.disease ,Epilepsy ,Mood ,Neuroimaging ,Medicine ,Dementia ,Neuropsychological assessment ,business ,RC321-571 - Abstract
Objective Late onset, unprovoked epilepsy patients with cognitive impairment can have complex pathophysiology.1 Our objective was to study the characteristics and contributors of cognitive impairment in this group; and how patients with dementia could be differentiated from late onset epilepsy patients. Methods Twenty-six patients with epilepsy, onset after 50 years of age, with new cognitive complaints and 26 patients with clinically diagnosed Alzheimer’s Disease (AD) were recruited. These participants had comprehensive neuropsychological and neuroimaging assessments. A subset of 17 participants from the Epilepsy group underwent longitudinal neuropsychological assessment. Results In the Epilepsy group, the neuropsychological profile of cognitive impairment was consistent with the foci and severity of seizure activity in 46% of participants; subcortical microvascular change in 15%; mood disturbance in 15%; medication in 15%; alcohol in 4% and AD in 4%. Compared with the Epilepsy group, the AD group had a lower Addenbrookes Cognitive Examination III (ACE-III) score (79.3±10.8 versus 87.5±6.5, p=0.01); specifically in the attention, memory and visuospatial subdomains (p=0.004, p=0.002 and p=0.02) but not fluency and language subdomains (p>0.05); and lower scores on additional assessments of naming, visuospatial and executive function (p≤ 0.001). The AD group had more abnormal metabolism in the temporal, parietal and occipital lobes than the Epilepsy group (p=0.02, p=0.006 and p=0.005). Conclusion Patients with late onset epilepsy and cognitive complaints rarely have dementia diagnosed at their first neuropsychological assessment and tend to have milder cognitive impairment than patients with AD. The two groups can be differentiated by their neuropsychological and FDG-PET profiles. Reference Sen A, Capelli V, Husain M. Cognition and dementia in older patients with epilepsy. Brain 2018;141(6):1592–1608.
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- 2021
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33. Factors That Influence Non-Motor Impairment Across the ALS-FTD Spectrum: Impact of Phenotype, Sex, Age, Onset and Disease Stage
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Emma M. Devenney, Kate McErlean, Nga Yan Tse, Jashelle Caga, Thanuja Dharmadasa, William Huynh, Colin J. Mahoney, Margaret Zoing, Srestha Mazumder, Carol Dobson-Stone, John B. Kwok, Glenda M. Halliday, John R. Hodges, Olivier Piguet, Rebekah M. Ahmed, and Matthew C. Kiernan
- Subjects
ALS (amyotrophic lateral sclerosis) ,medicine.medical_specialty ,business.industry ,Cognition ,Disease ,medicine.disease ,frontotemporal dementia ,Mood ,Mood disorders ,Neuroimaging ,Neurology ,non-motor deficits ,Internal medicine ,medicine ,Apathy ,neuropsychiatric symptoms ,Neurology. Diseases of the nervous system ,Neurology (clinical) ,medicine.symptom ,Amyotrophic lateral sclerosis ,RC346-429 ,business ,Frontotemporal dementia ,Original Research ,behavioral impairment - Abstract
Objective: This study aimed to establish (1) the pattern and severity of neuropsychiatric symptoms and other non-motor symptoms of sleep and mood, across ALS phenotypes in comparison to bvFTD and (2) the contribution of non-modifiable factors including age, sex and disease state to the severity of symptoms experienced by ALS patients.Methods: Consecutive participants were recruited to the study and underwent a detailed clinical, cognitive, behavioral and neuroimaging assessment. Neuropsychiatric and other non-motor symptoms were determined using the Cambridge Behavioral Inventory, the CBI-R. The scores were converted to define impairment in terms of mild, moderate and severe symptoms for each subscale. Rate, severity and contribution of King's staging and modifiable factors were also determined and a regression model identified predictors of symptom severity.Results: In total, 250 participants (115 ALS, 98 bvFTD, and 37 ALS-FTD patients) were recruited. A similar pattern of neuropsychiatric symptom severity was identified (apathy, disinhibition and stereotypic behavior) for all behavioral phenotypes of ALS compared to bvFTD (all p > 0.05). Neuropsychiatric symptoms were also present in cases defined as ALSpure and the cognitive phenotype of ALS (ALSci) although they occurred less frequently and were at the milder end of the spectrum. Disordered sleep and disrupted mood were common across all phenotypes (all p < 0.05). The severity of sleep dysfunction was influenced by both sex and age (all p < 0.05). Neuropsychiatric symptoms, sleep and mood disorders were common early in the disease process and deteriorated in line with progression on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R; all p < 0.05). Diagnostic phenotype, disease duration and global cognition scores were the strongest predictors of non-motor and neuropsychiatric impairments.Conclusion: The current findings reveal strikingly similar patterns of changes across the subgroups of ALS and bvFTD, supporting the concept of the ALS-FTD spectrum. The findings further highlight the impact of non-motor and neuropsychiatric symptoms in patients with ALS, that are often as severe as that seen in ALS-FTD and bvFTD. This study advances understanding across the ALS-FTD spectrum that may accelerate the early identification of patient needs, to ensure prompt recognition of symptoms and thereby to improve clinical awareness, patient care and management.
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- 2021
34. Hypothalamic symptoms of frontotemporal dementia disorders
- Author
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Rebekah M, Ahmed, Glenda, Halliday, and John R, Hodges
- Subjects
Cognition ,Frontotemporal Dementia ,Amyotrophic Lateral Sclerosis ,Disease Progression ,Hypothalamus ,Humans ,Feeding Behavior - Abstract
Frontotemporal dementia (FTD) has traditionally been regarded as a disease of cognition and behavior, but emerging evidence suggests that the disease also affects body functions including changes in eating behavior and metabolism, autonomic function, sleep behavior, and sexual function. Central to these changes are potentially complex neural networks involving the hypothalamus, with hypothalamic atrophy shown in behavioral variant FTD. The physiological changes found in FTD are reviewed and the key neural networks and neuroendocrine changes mediating these changes in function discussed, including the ability to use these changes as biomarkers to aid in disease diagnosis, monitoring disease progression, and as potential treatment targets.
- Published
- 2021
35. Hypothalamus and weight loss in amyotrophic lateral sclerosis
- Author
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Rebekah M, Ahmed, Frederik, Steyn, and Luc, Dupuis
- Subjects
Amyotrophic Lateral Sclerosis ,Weight Loss ,Hypothalamus ,Humans - Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disorder. While initially pathophysiology was thought to be restricted to motor deficits, it is increasingly recognized that patients develop prominent changes in weight and eating behavior that result from and mediate the underlying neurodegenerative process. These changes include alterations in metabolism, lipid levels, and insulin resistance. Emerging research suggests that these alterations may be mediated through changes in the hypothalamic function, with atrophy of the hypothalamus shown in both ALS patients and also presymptomatic genetic at-risk patients. This chapter reviews the evidence for hypothalamic involvement in ALS, including melanocortin pathways and potential treatment targets.
- Published
- 2021
36. Problem-focused coping underlying lower caregiver burden in ALS-FTD: Implications for caregiver intervention
- Author
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Mirelle D’Mello, Rebekah M. Ahmed, Jashelle Caga, David Foxe, Eleanor Ramsey, Eneida Mioshi, Olivier Piguet, Margaret C. Zoing, and Matthew C. Kiernan
- Subjects
Coping (psychology) ,business.industry ,Amyotrophic Lateral Sclerosis ,Caregiver Burden ,Problem focused ,Cognition ,Caregiver burden ,medicine.disease ,nervous system diseases ,03 medical and health sciences ,0302 clinical medicine ,Neurology ,Caregivers ,Intervention (counseling) ,Frontotemporal Dementia ,mental disorders ,Adaptation, Psychological ,Medicine ,Humans ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,business ,030217 neurology & neurosurgery ,Clinical psychology ,Frontotemporal dementia - Abstract
Objective: Amyotrophic lateral sclerosis (ALS) is a multisystem neurodegenerative disorder which includes cognitive and behavioral symptoms akin to frontotemporal dementia (FTD). Despite the necessity of caregiver intervention to assist with the management of cognitive and behavioral symptoms, there has been a lack of research on the topic. A focus on caregiver coping may offer a promising foundation to guide the development of interventions as part of ALS care. Accordingly, the aim of the present study was to examine the relationships between caregiver coping, psychological morbidity and burden of care in the context of ALS cognitive and behavioral symptoms. Methods: Fifty-five patient-caregiver dyads were recruited from specialized ALS and FTD clinics. Specific coping strategies were examined using the COPE Inventory/Brief COPE and psychological morbidity and burden were assessed using the Depression, Anxiety, and Stress Scale–21 and Zarit Burden Interview. The relationship between coping, psychological morbidity and burden of care were analyzed using univariate and multivariate methods. Results: High-burden caregivers were more likely to be caring for patients with a diagnosis of ALS-FTD (p =.0001). Caregivers used problem-focused strategies (particularly planning) more frequently (M = 71.4, SD = 15.3) compared to emotion-focused (M = 60.8, SD = 12.3) and dysfunctional coping strategies (M = 42.2, SD = 8.6). A diagnosis of ALS-FTD (p=.0001) and problem-focused strategies (p=.024) emerged as significant predictors of caregiver burden. Caregiver anxiety, depression and stress were not predictive of caregiver burden (p=.151). Conclusions: Timely provision of caregiver support optimizing problem-focused coping strategies as part of multidisciplinary ALS care, particularly for caregivers of ALS-FTD patients may mitigate caregiver burden.
- Published
- 2021
37. Anhedonia in Semantic Dementia-Exploring Right Hemispheric Contributions to the Loss of Pleasure
- Author
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Olivier Piguet, Muireann Irish, Rebekah M. Ahmed, Siddharth Ramanan, Hashim El-Omar, Siobhán R Shaw, Alexis E. Whitton, El-Omar, Hashim [0000-0003-2304-7277], Ramanan, Siddharth [0000-0002-8591-042X], Piguet, Olivier [0000-0002-6696-1440], Whitton, Alexis E. [0000-0002-7944-2172], Irish, Muireann [0000-0002-4950-8169], and Apollo - University of Cambridge Repository
- Subjects
medicine.medical_specialty ,striatum ,Semantic dementia ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Context (language use) ,Audiology ,frontotemporal dementia ,Article ,Temporal lobe ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,motivation ,medicine ,Dementia ,030304 developmental biology ,0303 health sciences ,neuroimaging ,General Neuroscience ,Anhedonia ,medicine.disease ,medicine.anatomical_structure ,depression ,medicine.symptom ,Psychology ,Alzheimer’s disease ,030217 neurology & neurosurgery ,Parahippocampal gyrus ,RC321-571 ,Frontotemporal dementia - Abstract
Semantic dementia (SD) is a younger-onset neurodegenerative disease characterised by progressive deterioration of the semantic knowledge base in the context of predominantly left-lateralised anterior temporal lobe (ATL) atrophy. Mounting evidence indicates the emergence of florid socioemotional changes in SD as atrophy encroaches into right temporal regions. How lateralisation of temporal lobe pathology impacts the hedonic experience in SD remains largely unknown yet has important implications for understanding socioemotional and functional impairments in this syndrome. Here, we explored how lateralisation of temporal lobe atrophy impacts anhedonia severity on the Snaith–Hamilton Pleasure Scale in 28 SD patients presenting with variable right- (SD-R) and left-predominant (SD-L) profiles of temporal lobe atrophy compared to that of 30 participants with Alzheimer’s disease and 30 healthy older Control participants. Relative to Controls, SD-R but not SD-L or Alzheimer’s patients showed clinically significant anhedonia, representing a clear departure from premorbid levels. Overall, anhedonia was more strongly associated with functional impairment on the Frontotemporal Dementia Functional Rating Scale and motivational changes on the Cambridge Behavioural Inventory in SD than in Alzheimer’s disease patients. Voxel-based morphometry analyses revealed that anhedonia severity correlated with reduced grey matter intensity in a restricted set of regions centred on right orbitofrontal and temporopolar cortices, bilateral posterior temporal cortices, as well as the anterior cingulate gyrus and parahippocampal gyrus, bilaterally. Finally, regression and mediation analysis indicated a unique role for right temporal lobe structures in modulating anhedonia in SD. Our findings suggest that degeneration of predominantly right-hemisphere structures deleteriously impacts the capacity to experience pleasure in SD. These findings offer important insights into hemispheric lateralisation of motivational disturbances in dementia and suggest that anhedonia may emerge at different timescales in the SD disease trajectory depending on the integrity of the right hemisphere.
- Published
- 2021
38. Author Response: Phenotypic Variability in ALS-FTD and Effect on Survival
- Author
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Rebekah M. Ahmed and Matthew C. Kiernan
- Subjects
Population ,Disease ,03 medical and health sciences ,0302 clinical medicine ,Text mining ,mental disorders ,medicine ,Dementia ,Humans ,030212 general & internal medicine ,education ,education.field_of_study ,C9orf72 Protein ,business.industry ,Amyotrophic Lateral Sclerosis ,Cognition ,medicine.disease ,Phenotype ,medicine.anatomical_structure ,Biological Variation, Population ,Frontotemporal Dementia ,Neurology (clinical) ,business ,Neuroscience ,030217 neurology & neurosurgery ,Motor cortex - Abstract
We thank Dr. Abe for his interest in our study1 that investigated survival in patients with amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD). Specific comparison of motor and cognitive presentations in ALS-FTD established that patients with a motor onset of their disease had reduced survival—which was associated with increased motor cortex atrophy—suggesting that survival may be mediated by motor function and other critical physiologic aspects.
- Published
- 2021
39. Neural correlates of fat preference in frontotemporal dementia: translating insights from the obesity literature
- Author
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Yu Chen, Elana Henning, Muireann Irish, John R. Hodges, Rebekah M. Ahmed, Matthew C. Kiernan, Olivier Piguet, I. Sadaf Farooqi, Nga Yan Tse, Ahmed, Rebekah M [0000-0001-6996-8317], Chen, Yu [0000-0001-5863-7002], Kiernan, Matthew C [0000-0001-9054-026X], and Apollo - University of Cambridge Repository
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Audiology ,Affect (psychology) ,03 medical and health sciences ,Food Preferences ,0302 clinical medicine ,Atrophy ,Rating scale ,Alzheimer Disease ,medicine ,Humans ,Obesity ,RC346-429 ,Research Articles ,Aged ,Cerebral Cortex ,Neural correlates of consciousness ,business.industry ,General Neuroscience ,Putamen ,Patient Acuity ,Middle Aged ,medicine.disease ,Amygdala ,Dietary Fats ,Magnetic Resonance Imaging ,Preference ,030104 developmental biology ,Frontotemporal Dementia ,Female ,Neurology (clinical) ,Neurology. Diseases of the nervous system ,Nerve Net ,business ,030217 neurology & neurosurgery ,Frontotemporal dementia ,RC321-571 ,Research Article - Abstract
Funder: Royal Australasian College of Physicians; Id: http://dx.doi.org/10.13039/501100001232, Funder: MND Research Institute of Australia; Id: http://dx.doi.org/10.13039/100008714, Funder: Australian Research Council Future Fellowship; Id: http://dx.doi.org/10.13039/501100000923, OBJECTIVE: Alterations in eating behaviour are one of the diagnostic features of behavioural variant frontotemporal dementia (bvFTD). It is hypothesised that underlying brain network disturbances and atrophy to key structures may affect macronutrient preference in bvFTD. We aimed to establish whether a preference for dietary fat exists in bvFTD, its association with cognitive symptoms and the underlying neural mechanisms driving these changes. METHODS: Using a test meal paradigm, adapted from the obesity literature, with variable fat content (low 20%, medium 40% and high 60%), preference for fat in 20 bvFTD was compared to 16 Alzheimer's disease (AD) and 13 control participants. MRI brain scans were analysed to determine the neural correlates of fat preference. RESULTS: Behavioural variant FTD patients preferred the high-fat meal compared to both AD (U = 61.5; p = 0.001) and controls (U = 41.5; p = 0.001), with 85% of bvFTD participants consistently rating the high-fat content meal as their preferred option. This increased preference for the high-fat meal was associated with total behavioural change (Cambridge Behavioural Inventory: rs = 0.462; p = 0.001), as well as overall functional decline (Frontotemporal Dementia Rating Scale: rs = -0.420; p = 0.03). A preference for high-fat content in bvFTD was associated with atrophy in an extended brain network including frontopolar, anterior cingulate, insular cortices, putamen and amygdala extending into lateral temporal, posteromedial parietal and occipital cortices. CONCLUSIONS: Increased preference for fat content is associated with many of the canonical features of bvFTD. These findings offer new insights into markers of disease progression and pathogenesis, providing potential treatment targets.
- Published
- 2021
40. Author response for 'Loss of the metabolism and sleep regulating neuronal populations expressing orexin and oxytocin in the hypothalamus in amyotrophic lateral sclerosis'
- Author
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null Sanaz Gabery, null Rebekah M Ahmed, null Jashelle Caga, null Matthew C Kiernan, null Glenda M Halliday, and null Åsa Petersén
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- 2021
- Full Text
- View/download PDF
41. Author response for 'Loss of the metabolism and sleep regulating neuronal populations expressing orexin and oxytocin in the hypothalamus in amyotrophic lateral sclerosis'
- Author
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Matthew C Kiernan, Åsa Petersén, Jashelle Caga, Glenda M. Halliday, Rebekah M. Ahmed, and Sanaz Gabery
- Subjects
medicine.medical_specialty ,business.industry ,Metabolism ,medicine.disease ,Sleep in non-human animals ,Orexin ,Endocrinology ,Oxytocin ,Hypothalamus ,Internal medicine ,Medicine ,Amyotrophic lateral sclerosis ,business ,medicine.drug - Published
- 2021
- Full Text
- View/download PDF
42. Motor cortical excitability predicts cognitive phenotypes in amyotrophic lateral sclerosis
- Author
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José Manuel Matamala, James Howells, John R. Hodges, Smriti Agarwal, Kazumoto Shibuya, Rebekah M. Ahmed, Yan Ma, Jashelle Caga, Matthew C. Kiernan, Thanuja Dharmadasa, Elizabeth Highton-Williamson, and Steve Vucic
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Neurology ,Science ,medicine.medical_treatment ,Article ,03 medical and health sciences ,Cognition ,0302 clinical medicine ,mental disorders ,Humans ,Medicine ,Motor neuron disease ,Amyotrophic lateral sclerosis ,Pathological ,Aged ,Behavior ,Multidisciplinary ,business.industry ,Amyotrophic Lateral Sclerosis ,Motor Cortex ,Middle Aged ,Motor neuron ,medicine.disease ,Transcranial Magnetic Stimulation ,Pathophysiology ,Transcranial magnetic stimulation ,Phenotype ,030104 developmental biology ,medicine.anatomical_structure ,ROC Curve ,Cortical Excitability ,Female ,business ,Neuroscience ,030217 neurology & neurosurgery ,Frontotemporal dementia - Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are well-recognised as an extended disease spectrum. This study hypothesised that cortical hyperexcitability, an early pathophysiological abnormality in ALS, would distinguish cognitive phenotypes, as a surrogate marker of pathological disease burden. 61 patients with ALS, matched for disease duration (pure motor ALS, n = 39; ALS with coexistent FTD, ALS-FTD, n = 12; ALS with cognitive/behavioural abnormalities not meeting FTD criteria, ALS-Cog, n = 10) and 30 age-matched healthy controls. Cognitive function on the Addenbrooke’s cognitive examination (ACE) scale, behavioural function on the motor neuron disease behavior scale (MiND-B) and cortical excitability using transcranial magnetic stimulation (TMS) were documented. Cortical resting motor threshold (RMT), lower threshold indicating hyperexcitability, was lower in ALS-FTD (50.2 ± 6.9) compared to controls (64.3 ± 12.6, p
- Published
- 2021
- Full Text
- View/download PDF
43. Behavioural Variant Frontotemporal Dementia: Recent Advances in the Diagnosis and Understanding of the Disorder
- Author
-
Rebekah M, Ahmed, John R, Hodges, and Olivier, Piguet
- Subjects
Diagnosis, Differential ,C9orf72 Protein ,Frontotemporal Dementia ,Disease Progression ,Humans ,Neuropsychological Tests ,Biomarkers - Abstract
Frontotemporal dementia (FTD), particularly the behavioural variant (bvFTD) form, has fascinated researchers. Recent years have seen an increasing interest in aspects of bvFTD that extend beyond the initial focus on cognitive changes and frontal executive dysfunction. Changes have been identified in aspects including fundamental changes in physiology and metabolism, and cognitive domains such as episodic memory. Work on social cognition has emphasised the importance of a breakdown in interpreting and expressing emotions, while the overlap between psychiatric disorders and bvFTD has been brought into focus by the finding of high rates of psychotic features in carriers of the c9orf72 gene expansion. We review these aspects in the chapter " Behavioural variant frontotemporal dementia: Recent advances in diagnosis and understanding of the disorder" and also potential markers of disease progression and early diagnosis that may aid in the development of treatment options, which have thus far eluded us.
- Published
- 2021
44. Behavioural Variant Frontotemporal Dementia: Recent Advances in the Diagnosis and Understanding of the Disorder
- Author
-
Olivier Piguet, Rebekah M. Ahmed, and John R. Hodges
- Subjects
High rate ,Disease progression ,Cognition ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,Social cognition ,Cognitive Changes ,medicine ,030212 general & internal medicine ,Psychology ,Episodic memory ,Frontotemporal dementia ,Cognitive psychology ,Executive dysfunction - Abstract
Frontotemporal dementia (FTD), particularly the behavioural variant (bvFTD) form, has fascinated researchers. Recent years have seen an increasing interest in aspects of bvFTD that extend beyond the initial focus on cognitive changes and frontal executive dysfunction. Changes have been identified in aspects including fundamental changes in physiology and metabolism, and cognitive domains such as episodic memory. Work on social cognition has emphasised the importance of a breakdown in interpreting and expressing emotions, while the overlap between psychiatric disorders and bvFTD has been brought into focus by the finding of high rates of psychotic features in carriers of the c9orf72 gene expansion. We review these aspects in the chapter " Behavioural variant frontotemporal dementia: Recent advances in diagnosis and understanding of the disorder" and also potential markers of disease progression and early diagnosis that may aid in the development of treatment options, which have thus far eluded us.
- Published
- 2021
- Full Text
- View/download PDF
45. Hypothalamic symptoms of frontotemporal dementia disorders
- Author
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Glenda M. Halliday, Rebekah M. Ahmed, and John R. Hodges
- Subjects
business.industry ,Cognition ,Disease ,medicine.disease ,Sleep in non-human animals ,Hypothalamus ,mental disorders ,medicine ,Eating behavior ,sense organs ,Amyotrophic lateral sclerosis ,skin and connective tissue diseases ,Sexual function ,business ,Neuroscience ,Frontotemporal dementia - Abstract
Frontotemporal dementia (FTD) has traditionally been regarded as a disease of cognition and behavior, but emerging evidence suggests that the disease also affects body functions including changes in eating behavior and metabolism, autonomic function, sleep behavior, and sexual function. Central to these changes are potentially complex neural networks involving the hypothalamus, with hypothalamic atrophy shown in behavioral variant FTD. The physiological changes found in FTD are reviewed and the key neural networks and neuroendocrine changes mediating these changes in function discussed, including the ability to use these changes as biomarkers to aid in disease diagnosis, monitoring disease progression, and as potential treatment targets.
- Published
- 2021
- Full Text
- View/download PDF
46. Hypothalamus and weight loss in amyotrophic lateral sclerosis
- Author
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Frederik J. Steyn, Rebekah M. Ahmed, and Luc Dupuis
- Subjects
0303 health sciences ,business.industry ,media_common.quotation_subject ,Appetite ,medicine.disease ,Pathophysiology ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Insulin resistance ,Hypothalamus ,Weight loss ,medicine ,sense organs ,Amyotrophic lateral sclerosis ,Melanocortin ,medicine.symptom ,business ,Neuroscience ,030217 neurology & neurosurgery ,030304 developmental biology ,media_common - Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disorder. While initially pathophysiology was thought to be restricted to motor deficits, it is increasingly recognized that patients develop prominent changes in weight and eating behavior that result from and mediate the underlying neurodegenerative process. These changes include alterations in metabolism, lipid levels, and insulin resistance. Emerging research suggests that these alterations may be mediated through changes in the hypothalamic function, with atrophy of the hypothalamus shown in both ALS patients and also presymptomatic genetic at-risk patients. This chapter reviews the evidence for hypothalamic involvement in ALS, including melanocortin pathways and potential treatment targets.
- Published
- 2021
- Full Text
- View/download PDF
47. Predictors of survival in frontotemporal lobar degeneration syndromes
- Author
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Matthew C. Kiernan, Shadi El-Wahsh, Rebekah M. Ahmed, Olivier Piguet, Elizabeth Finger, Vincent Mok, and Jonathan D. Rohrer
- Subjects
Oncology ,0303 health sciences ,medicine.medical_specialty ,business.industry ,Disease ,Frontotemporal lobar degeneration ,medicine.disease ,Precision medicine ,Progressive supranuclear palsy ,Clinical trial ,03 medical and health sciences ,Psychiatry and Mental health ,0302 clinical medicine ,Internal medicine ,medicine ,Dementia ,Surgery ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,business ,030217 neurology & neurosurgery ,030304 developmental biology ,Frontotemporal dementia - Abstract
After decades of research, large-scale clinical trials in patients diagnosed with frontotemporal lobar degeneration (FTLD) are now underway across multiple centres worldwide. As such, refining the determinants of survival in FTLD represents a timely and important challenge. Specifically, disease outcome measures need greater clarity of definition to enable accurate tracking of therapeutic interventions in both clinical and research settings. Multiple factors potentially determine survival, including the clinical phenotype at presentation; radiological patterns of atrophy including markers on both structural and functional imaging; metabolic factors including eating behaviour and lipid metabolism; biomarkers including both serum and cerebrospinal fluid markers of underlying pathology; as well as genetic factors, including both dominantly inherited genes, but also genetic modifiers. The present review synthesises the effect of these factors on disease survival across the syndromes of frontotemporal dementia, with comparison to amyotrophic lateral sclerosis, progressive supranuclear palsy and corticobasal syndrome. A pathway is presented that outlines the utility of these varied survival factors for future clinical trials and drug development. Given the complexity of the FTLD spectrum, it seems unlikely that any single factor may predict overall survival in individual patients, further suggesting that a precision medicine approach will need to be developed in predicting disease survival in FTLD, to enhance drug target development and future clinical trial methodologies.
- Published
- 2020
48. The interplay of emotional and social conceptual processes during moral reasoning in frontotemporal dementia – a role for the uncinate fasciculus
- Author
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John R. Hodges, Muireann Irish, Olivier Piguet, Cherie Strikwerda-Brown, Rebekah M. Ahmed, Zoë-Lee Goldberg, Siddharth Ramanan, and Annu Mothakunnel
- Subjects
medicine ,Uncinate fasciculus ,Moral reasoning ,medicine.disease ,Psychology ,humanities ,Frontotemporal dementia ,Cognitive psychology - Abstract
Co-operative social behaviour in humans hinges upon our unique ability to make appropriate moral decisions in accordance with our ethical values. The complexity of the neurocognitive mechanisms underlying moral reasoning is revealed when this capacity breaks down. Patients with the behavioural variant of frontotemporal dementia (bvFTD) display striking moral transgressions in the context of atrophy to frontotemporal regions supporting affective and social conceptual processing. Developmental studies have highlighted the importance of social knowledge to moral decision making in children, yet the role of social knowledge in relation to moral reasoning impairments in neurodegeneration has largely been overlooked. Here, we sought to examine the role of affective and social conceptual processes in personal moral reasoning in bvFTD, and their relationship to the integrity and structural connectivity of frontotemporal brain regions. Personal moral reasoning across varying degrees of conflict was assessed in 26 bvFTD patients and compared with demographically matched Alzheimer’s disease (AD) patients (n = 14), and healthy older adults (n = 22). Following each moral decision, we directly probed participants’ subjective emotional experience as an index of their affective response, while social norm knowledge was assessed via an independent task. While groups did not differ significantly in terms of their moral decisions, bvFTD patients reported feeling better about their decisions than healthy Controls. In other words, although bvFTD patients could adjudicate between different courses of action in the moral scenarios, their affective responses to these decisions were highly irregular. This blunted emotional reaction was exclusive to the personal high-conflict condition, with 61.5% of bvFTD patients reporting feeling ‘extremely good’ about their decisions, and was correlated with reduced knowledge of socially acceptable behaviour. Voxel-based morphometry analyses revealed a distributed network of frontal, subcortical, and lateral temporal grey matter regions involved in the attenuated affective response to moral conflict in bvFTD. Crucially, diffusion-tensor imaging implicated the uncinate fasciculus as the pathway by which social conceptual knowledge may influence emotional reactions to personal high-conflict moral dilemmas in bvFTD. Our findings suggest that altered moral behaviour in bvFTD reflects the dynamic interplay between degraded social conceptual knowledge and blunted affective responsiveness, attributable to atrophy of, and impaired information transfer between, frontal and temporal cortices. Delineating the mechanisms of impaired morality in bvFTD provides crucial clinical information for understanding and treating this challenging symptom, which may help pave the way for targeted behavioural interventions.
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- 2020
- Full Text
- View/download PDF
49. The interplay of emotional and social conceptual processes during moral reasoning in frontotemporal dementia
- Author
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Rebekah M. Ahmed, Annu Mothakunnel, Siddharth Ramanan, Muireann Irish, John R. Hodges, Zoë-Lee Goldberg, Olivier Piguet, and Cherie Strikwerda-Brown
- Subjects
Male ,media_common.quotation_subject ,Emotions ,Uncinate fasciculus ,Context (language use) ,Moral reasoning ,Morals ,Social cognition ,medicine ,Humans ,Social Behavior ,media_common ,Aged ,Brain ,Middle Aged ,Morality ,medicine.disease ,humanities ,Diffusion Tensor Imaging ,Feeling ,Frontotemporal Dementia ,Female ,Neurology (clinical) ,Psychology ,Neurocognitive ,Cognitive psychology ,Frontotemporal dementia - Abstract
Cooperative social behaviour in humans hinges upon our unique ability to make appropriate moral decisions in accordance with our ethical values. The complexity of the neurocognitive mechanisms underlying moral reasoning is revealed when this capacity breaks down. Patients with the behavioural variant of frontotemporal dementia (bvFTD) display striking moral transgressions in the context of atrophy to frontotemporal regions supporting affective and social conceptual processing. Developmental studies have highlighted the importance of social knowledge to moral decision making in children, yet the role of social knowledge in relation to moral reasoning impairments in neurodegeneration has largely been overlooked. Here, we sought to examine the role of affective and social conceptual processes in personal moral reasoning in bvFTD, and their relationship to the integrity and structural connectivity of frontotemporal brain regions. Personal moral reasoning across varying degrees of conflict was assessed in 26 bvFTD patients and compared with demographically matched Alzheimer’s disease patients (n = 14), and healthy older adults (n = 22). Following each moral decision, we directly probed participants’ subjective emotional experience as an index of their affective response, while social norm knowledge was assessed via an independent task. While groups did not differ significantly in terms of their moral decisions, bvFTD patients reported feeling ‘better’ about their decisions than healthy control subjects. In other words, although bvFTD patients could adjudicate between different courses of action in the moral scenarios, their affective responses to these decisions were highly irregular. This blunted emotional reaction was exclusive to the personal high-conflict condition, with 61.5% of bvFTD patients reporting feeling ‘extremely good’ about their decisions, and was correlated with reduced knowledge of socially acceptable behaviour. Voxel-based morphometry analyses revealed a distributed network of frontal, subcortical, and lateral temporal grey matter regions involved in the attenuated affective response to moral conflict in bvFTD. Crucially, diffusion-tensor imaging implicated the uncinate fasciculus as the pathway by which social conceptual knowledge may influence emotional reactions to personal high-conflict moral dilemmas in bvFTD. Our findings suggest that altered moral behaviour in bvFTD reflects the dynamic interplay between degraded social conceptual knowledge and blunted affective responsiveness, attributable to atrophy of, and impaired information transfer between, frontal and temporal cortices. Delineating the mechanisms of impaired morality in bvFTD provides crucial clinical information for understanding and treating this challenging symptom, which may help pave the way for targeted behavioural interventions.
- Published
- 2020
50. Evidence for a pervasive autobiographical memory impairment in Logopenic Progressive Aphasia: clinical and neural correlates
- Author
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Hodges, Muireann Irish, Hashim El-Omar, Siddharth Ramanan, David Foxe, Rebekah M. Ahmed, and Olivier Piguet
- Subjects
medicine.medical_specialty ,Recall ,Autobiographical memory ,Logopenic progressive aphasia ,Amnesia ,Cognition ,Audiology ,medicine.disease ,Free recall ,medicine ,Language disorder ,medicine.symptom ,Psychology ,Episodic memory - Abstract
Logopenic Progressive Aphasia is a rare language disorder characterised by repetition and naming difficulties, reflecting the progressive degeneration of left-lateralized peri-sylvian temporal and inferior parietal regions. Mounting evidence suggests that cognitive impairments in this syndrome extend beyond the language domain to include episodic encoding and retrieval disturbances. To date, it remains unknown whether autobiographical memories from across the lifespan are also subject to decline, yet this information is critical to arrive at a comprehensive understanding of the Logopenic syndrome. The objective of this study was to provide the first in depth examination of autobiographical memory function in Logopenic Progressive Aphasia using the Autobiographical Interview, a validated semi-structured interview which assesses recollection of the past under free and probed recall conditions. Autobiographical memory performance in 10 well-characterised Logopenic Progressive Aphasia patients was contrasted with that of 18 typical amnestic Alzheimer’s disease and 16 healthy Control participants. Relative to Controls, Logopenic Progressive Aphasia cases showed marked impairment in the free recall of episodic details, scoring comparably to disease-matched cases of Alzheimer’s disease. This impairment was evident across all time periods and persisted even when formal structured probing was provided. Importantly, controlling for overall level of language disruption failed to ameliorate the autobiographical memory impairment in the Logopenic Progressive Aphasia group, suggesting a genuine amnesia spanning recent and remote memories. Whole-brain voxel-based morphometry analyses revealed that total episodic information retrieved in Logopenic Progressive Aphasia was associated with decreased grey matter intensity predominantly in a bilateral posterior parietal network. Taken together, our findings reveal for the first time the presence of marked remote and recent autobiographical memory impairments in Logopenic Progressive Aphasia, that cannot be explained solely due to their language difficulties or disease staging. Our findings hold important clinical implications for the accurate characterization of Logopenic Progressive Aphasia, and suggest that episodic memory difficulties should be considered as one of the core clinical features of this syndrome.
- Published
- 2020
- Full Text
- View/download PDF
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