94 results on '"MacKay CE"'
Search Results
2. Subcortical volumetric abnormalities in bipolar disorder.
- Author
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Hibar, DP, Westlye, LT, van Erp, TGM, Rasmussen, J, Leonardo, CD, Faskowitz, J, Haukvik, UK, Hartberg, CB, Doan, NT, Agartz, I, Dale, AM, Gruber, O, Krämer, B, Trost, S, Liberg, B, Abé, C, Ekman, CJ, Ingvar, M, Landén, M, Fears, SC, Freimer, NB, Bearden, CE, Costa Rica/Colombia Consortium for Genetic Investigation of Bipolar Endophenotypes, Sprooten, E, Glahn, DC, Pearlson, GD, Emsell, L, Kenney, J, Scanlon, C, McDonald, C, Cannon, DM, Almeida, J, Versace, A, Caseras, X, Lawrence, NS, Phillips, ML, Dima, D, Delvecchio, G, Frangou, S, Satterthwaite, TD, Wolf, D, Houenou, J, Henry, C, Malt, UF, Bøen, E, Elvsåshagen, T, Young, AH, Lloyd, AJ, Goodwin, GM, Mackay, CE, Bourne, C, Bilderbeck, A, Abramovic, L, Boks, MP, van Haren, NEM, Ophoff, RA, Kahn, RS, Bauer, M, Pfennig, A, Alda, M, Hajek, T, Mwangi, B, Soares, JC, Nickson, T, Dimitrova, R, Sussmann, JE, Hagenaars, S, Whalley, HC, McIntosh, AM, Thompson, PM, and Andreassen, OA
- Subjects
Costa Rica/Colombia Consortium for Genetic Investigation of Bipolar Endophenotypes ,Brain ,Humans ,Magnetic Resonance Imaging ,Organ Size ,Case-Control Studies ,Retrospective Studies ,Bipolar Disorder ,Adult ,Middle Aged ,Female ,Male ,Clinical Research ,Mental Health ,Brain Disorders ,Serious Mental Illness ,Neurosciences ,Aetiology ,2.1 Biological and endogenous factors ,Mental health ,Biological Sciences ,Medical and Health Sciences ,Psychology and Cognitive Sciences ,Psychiatry - Abstract
Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10-7) and thalamus (d=-0.148; P=4.27 × 10-3) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10-5) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons.
- Published
- 2016
3. Multimodal MRI of grey matter, white matter, and functional connectivity in cognitively healthy mutation carriers at risk for frontotemporal dementia and Alzheimer's disease
- Author
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Feis, RA, Bouts, M, Dopper, Elise, Filippini, N, Heise, V, Trachtenberg, AJ, van Swieten, J.C., van Buchem, MA, van der Grond, J, Mackay, CE, Rombouts, S, Feis, RA, Bouts, M, Dopper, Elise, Filippini, N, Heise, V, Trachtenberg, AJ, van Swieten, J.C., van Buchem, MA, van der Grond, J, Mackay, CE, and Rombouts, S
- Published
- 2019
4. Allostatic load as a predictor of grey matter volume and white matter integrity in old age: The Whitehall II MRI study.
- Author
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Zsoldos, E, Filippini, N, Mahmood, A, Mackay, CE, Singh-Manoux, A, Kivimäki, M, Jenkinson, M, Ebmeier, KP, Zsoldos, E, Filippini, N, Mahmood, A, Mackay, CE, Singh-Manoux, A, Kivimäki, M, Jenkinson, M, and Ebmeier, KP
- Abstract
The allostatic load index quantifies the cumulative multisystem physiological response to chronic everyday stress, and includes cardiovascular, metabolic and inflammatory measures. Despite its central role in the stress response, research of the effect of allostatic load on the ageing brain has been limited. We investigated the relation of mid-life allostatic load index and multifactorial predictors of stroke (Framingham stroke risk) and diabetes (metabolic syndrome) with voxelwise structural grey and white matter brain integrity measures in the ageing Whitehall II cohort (N = 349, mean age = 69.6 (SD 5.2) years, N (male) = 281 (80.5%), mean follow-up before scan = 21.4 (SD 0.82) years). Higher levels of all three markers were significantly associated with lower grey matter density. Only higher Framingham stroke risk was significantly associated with lower white matter integrity (low fractional anisotropy and high mean diffusivity). Our findings provide some empirical support for the concept of allostatic load, linking the effect of everyday stress on the body with features of the ageing human brain.
- Published
- 2018
5. Brain torque relates to laterality of motor function but not hand preference
- Author
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Mackay, CE, Robson, MD, Cugno, S, Connell, J, van Aarde, JB, Crow, TJ, and Roberts, N
- Published
- 2016
6. Evidence for altered cerebral laterality in early onset schizophrenia
- Author
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Collinson, SL, Mackay, CE, Clark, GM, Davidson, ME, James, AC, Phillips, TJ, and Roberts, N
- Published
- 2016
7. Assessment of arterial arrival times derived from multiple inversion time pulsed arterial spin labeling MRI
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MacIntosh, BJ, Filippini, N, Chappell, MA, Woolrich, MW, Mackay, CE, and Jezzard, P
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities - Abstract
The purpose of this study was to establish a normal range for the arterial arrival time (AAT) in whole-brain pulsed arterial spin labeling (PASL) cerebral perfusion MRI. Healthy volunteers (N = 36, range: 20 to 35 years) provided informed consent to participate in this study. AAT was assessed in multiple brain regions, using three-dimensional gradient and spin echo (GRASE) pulsed arterial spin labeling at 3.0 T, and found to be 641 +/- 95, 804 +/- 91, 802 +/- 126, and 935 +/- 108 ms in the temporal, parietal, frontal, and occipital lobes, respectively. Mean gray matter AAT was found to be 694 +/- 89 ms for females (N = 15), which was significantly shorter than for men, 814 +/- 192 ms (N = 21; P < 0.0003), and significant after correcting for brain volume (P < 0.001). Significant AAT sex differences were also found using voxelwise permutation testing. An atlas of AAT values across the healthy brain is presented here and may be useful for future experiments that aim to quantify cerebral blood flow from ASL data, as well as for clinical comparisons where disease pathology may lead to altered AAT. Pulsed arterial spin labeling signals were simulated using an identical sampling scheme as the empiric study and revealed AAT can be estimated robustly when simulated arrival times are well beyond the normal range.
- Published
- 2016
- Full Text
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8. Temporal horn lengthening as an early index of progression in psychosis
- Author
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Clark, GM, Mackay, CE, Collinson, SL, James, AC, Roberts, N, and Crow, TJ
- Published
- 2016
9. Abnormal functional correlate precedes loss of structural asymmetry in the paracingulate sulcus in adolescent psychosis
- Author
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Clark, GM, Mackay, CE, Davidson, ME, Collinson, SL, James, AC, Roberts, N, and Crow, TJ
- Published
- 2016
10. Lobar and hemispheric lengths in adolescent onset schizophrenia
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Clark, GM, Mackay, CE, James, AC, Phillips, TJ, Roberts, N, and Crow, TJ
- Published
- 2016
11. Development of torque: Automatic assessment of cerebral asymmetry in children and adolescents aged 4-18
- Author
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Mackay, Ce, Thomas Barrick, Schmitt, W., Kempton, M., Roberts, N., and Crow, Tj
- Published
- 2016
12. Comprehensive morphometry of subcortical grey matter structures in early-stage Parkinson's disease
- Author
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Menke, RA, Szewczyk-Krolikowski, K, Jbabdi, S, Jenkinson, M, Talbot, K, Mackay, CE, and Hu, M
- Abstract
Previous imaging studies that investigated morphometric group differences of subcortical regions outside the substantia nigra between non-demented Parkinson's patients and controls either did not find any significant differences, or reported contradictory results. Here, we performed a comprehensive morphometric analysis of 20 cognitively normal, early-stage PD patients and 19 matched control subjects. In addition to relatively standard analyses of whole-brain grey matter volume and overall regional volumes, we examined subtle localized surface shape differences in striatal and limbic grey matter structures and tested their utility as a diagnostic marker. Voxel-based morphometry and volumetric comparisons did not reveal significant group differences. Shape analysis, on the other hand, demonstrated significant between-group shape differences for the right pallidum. Careful diffusion tractography analysis showed that the affected parts of the pallidum are connected subcortically with the subthalamic nucleus, the pedunculopontine nucleus, and the thalamus and cortically with the frontal lobe. Additionally, microstructural measurements along these pathways, but not along other pallidal connections, were significantly different between the two groups. Vertex-wise linear discriminant analysis, however, revealed limited accuracy of pallidal shape for the discrimination between patients and controls. We conclude that localized disease-related changes in the right pallidum in early Parkinson's disease, undetectable using standard voxel-based morphometry or volumetry, are evident using sensitive shape analysis. However, the subtle nature of these changes makes it unlikely that shape analysis alone will be useful for early diagnosis.
- Published
- 2016
13. An MRI biomarker for motor neuron disease?
- Author
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Filippini, N, Mackay, CE, Douaud, G, Knight, S, Talbot, K, and Turner, MR
- Published
- 2016
- Full Text
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14. Prefrontal cortical activation during word-associative, face-associative, and word-face-associative encoding
- Author
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Downes, JJ, Mackay, CE, Tsivilis, D, Mayes, AR, Montaldi, D, Hunkin, NM, Singh, KD, and Roberts, N
- Published
- 2016
15. Associations between Mobility, Cognition, and Brain Structure in Healthy Older Adults
- Author
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Demnitz, N, Zsoldos, E, Mahmood, A, Mackay, CE, Kivimaki, M, Singh-Manoux, A, Dawes, H, Johansen-Berg, H, Ebmeier, KP, Sexton, CE, Demnitz, N, Zsoldos, E, Mahmood, A, Mackay, CE, Kivimaki, M, Singh-Manoux, A, Dawes, H, Johansen-Berg, H, Ebmeier, KP, and Sexton, CE
- Abstract
Mobility limitations lead to a cascade of adverse events in old age, yet the neural and cognitive correlates of mobility performance in older adults remain poorly understood. In a sample of 387 adults (mean age 69.0 ± 5.1 years), we tested the relationship between mobility measures, cognitive assessments, and MRI markers of brain structure. Mobility was assessed in 2007–2009, using gait, balance and chair-stands tests. In 2012–2015, cognitive testing assessed executive function, memory and processing-speed; gray matter volumes (GMV) were examined using voxel-based morphometry, and white matter microstructure was assessed using tract-based spatial statistics of fractional anisotropy, axial diffusivity (AD), and radial diffusivity (RD). All mobility measures were positively associated with processing-speed. Faster walking speed was also correlated with higher executive function, while memory was not associated with any mobility measure. Increased GMV within the cerebellum, basal ganglia, post-central gyrus, and superior parietal lobe was associated with better mobility. In addition, better performance on the chair-stands test was correlated with decreased RD and AD. Overall, our results indicate that, even in non-clinical populations, mobility measures can be sensitive to sub-clinical variance in cognition and brain structures.
- Published
- 2017
16. Donepezil Enhances Frontal Functional Connectivity in Alzheimer's Disease: A Pilot Study.
- Author
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Griffanti, L, Wilcock, GK, Voets, N, Bonifacio, G, Mackay, CE, Jenkinson, M, Zamboni, G, Griffanti, L, Wilcock, GK, Voets, N, Bonifacio, G, Mackay, CE, Jenkinson, M, and Zamboni, G
- Abstract
BACKGROUND: We have previously shown that increased resting-state functional magnetic resonance imaging (fMRI)-based functional connectivity (FC) within the frontal resting-state networks in Alzheimer's disease (AD) patients reflects residual, possibly compensatory, function. This suggests that symptomatic treatments should aim to enhance FC specifically in these networks. METHODS: 18 patients with probable AD underwent brain MRI and neuropsychological assessment at baseline and after 12 weeks of treatment with donepezil. We tested if changes in cognitive performance after treatment correlated with changes in FC in resting-state networks known to be altered in AD. RESULTS: We found increases in FC in the orbitofrontal network that correlated with cognitive improvement after treatment. The increased FC was greatest in patients who responded most to treatment. CONCLUSION: This 'proof of concept' study suggests that changes in network-specific FC might be a biomarker of pharmacological intervention efficacy in AD.
- Published
- 2016
17. ICA-based artifact removal diminishes scan site differences in multi-center resting-state fMRI
- Author
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Feis, RA, Smith, SM, Filippini, N, Douaud, G, Dopper, EGP, Heise, V, Trachtenberg, AJ, van Swieten, J.C., van Buchem, MA, Rombouts, SARB, Mackay, CE, Feis, RA, Smith, SM, Filippini, N, Douaud, G, Dopper, EGP, Heise, V, Trachtenberg, AJ, van Swieten, J.C., van Buchem, MA, Rombouts, SARB, and Mackay, CE
- Published
- 2015
18. Author Correction: Targeting HDAC6 to treat heart failure with preserved ejection fraction in mice.
- Author
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Ranjbarvaziri S, Zeng A, Wu I, Greer-Short A, Farshidfar F, Budan A, Xu E, Shenwai R, Kozubov M, Li C, Van Pell M, Grafton F, MacKay CE, Song X, Priest JR, Argast G, Mandegar MA, Hoey T, and Yang J
- Published
- 2024
- Full Text
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19. A comprehensive analysis of APOE genotype effects on human brain structure in the UK Biobank.
- Author
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Heise V, Offer A, Whiteley W, Mackay CE, Armitage JM, and Parish S
- Subjects
- Female, Humans, Male, Apolipoproteins E genetics, Biological Specimen Banks, Brain pathology, Diffusion Tensor Imaging methods, Genotype, UK Biobank, Alzheimer Disease genetics, Apolipoprotein E4 genetics
- Abstract
Alzheimer's disease (AD) risk is increased in carriers of the apolipoprotein E (APOE) ε4 allele and decreased in ε2 allele carriers compared with the ε3ε3 genotype. The aim of this study was to determine whether: the APOE genotype affects brain grey (GM) or white matter (WM) structure; and if differences exist, the age when they become apparent and whether there are differential effects by sex. We used cross-sectional magnetic resonance imaging data from ~43,000 (28,494 after pre-processing) white British cognitively healthy participants (7,446 APOE ε4 carriers) aged 45-80 years from the UK Biobank cohort and investigated image-derived phenotypes (IDPs). We observed no statistically significant effects of APOE genotype on GM structure volumes or median T2* in subcortical structures, a measure related to iron content. The volume of white matter hyperintensities differed significantly between APOE genotype groups with higher volumes in APOE ε4ε4 (effect size 0.14 standard deviations [SD]) and ε3ε4 carriers (effect size 0.04 SD) but no differences in ε2 carriers compared with ε3ε3 carriers. WM integrity measures in the dorsal (mean diffusivity [MD]) and ventral cingulum (MD and intracellular volume fraction), posterior thalamic radiation (MD and isotropic volume fraction) and sagittal stratum (MD) indicated lower integrity in APOE ε4ε4 carriers (effect sizes around 0.2-0.3 SD) and ε3ε4 (effect sizes around 0.05 SD) carriers but no differences in ε2 carriers compared with the APOE ε3ε3 genotype. Effects did not differ between men and women. APOE ε4 homozygotes had lower WM integrity specifically at older ages with a steeper decline of WM integrity from the age of 60 that corresponds to around 5 years greater "brain age". APOE genotype affects various white matters measures, which might be indicative of preclinical AD processes. This hypothesis can be assessed in future when clinical outcomes become available., (© 2024. The Author(s).)
- Published
- 2024
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20. Targeting HDAC6 to treat heart failure with preserved ejection fraction in mice.
- Author
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Ranjbarvaziri S, Zeng A, Wu I, Greer-Short A, Farshidfar F, Budan A, Xu E, Shenwai R, Kozubov M, Li C, Van Pell M, Grafton F, MacKay CE, Song X, Priest JR, Argast G, Mandegar MA, Hoey T, and Yang J
- Subjects
- Animals, Humans, Male, Mice, Histone Deacetylase 6 genetics, Myocytes, Cardiac metabolism, Stroke Volume physiology, Cardiomyopathies, Heart Failure drug therapy, Heart Failure genetics, Heart Failure diagnosis
- Abstract
Heart failure with preserved ejection fraction (HFpEF) poses therapeutic challenges due to the limited treatment options. Building upon our previous research that demonstrates the efficacy of histone deacetylase 6 (HDAC6) inhibition in a genetic cardiomyopathy model, we investigate HDAC6's role in HFpEF due to their shared mechanisms of inflammation and metabolism. Here, we show that inhibiting HDAC6 with TYA-018 effectively reverses established heart failure and its associated symptoms in male HFpEF mouse models. Additionally, in male mice lacking Hdac6 gene, HFpEF progression is delayed and they are resistant to TYA-018's effects. The efficacy of TYA-018 is comparable to a sodium-glucose cotransporter 2 (SGLT2) inhibitor, and the combination shows enhanced effects. Mechanistically, TYA-018 restores gene expression related to hypertrophy, fibrosis, and mitochondrial energy production in HFpEF heart tissues. Furthermore, TYA-018 also inhibits activation of human cardiac fibroblasts and enhances mitochondrial respiratory capacity in cardiomyocytes. In this work, our findings show that HDAC6 impacts on heart pathophysiology and is a promising target for HFpEF treatment., (© 2024. The Author(s).)
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- 2024
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21. High intake of ultra-processed food is associated with dementia in adults: a systematic review and meta-analysis of observational studies.
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Henney AE, Gillespie CS, Alam U, Hydes TJ, Mackay CE, and Cuthbertson DJ
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- Adult, Humans, Diet, Public Health, Observational Studies as Topic, Food, Processed, Dementia etiology, Dementia pathology
- Abstract
Background and Aims: Poor cardiometabolic health is associated with dementia. Considering previous meta-analyses have confirmed associations between ultra-processed foods (UPFs) and cardiometabolic disease, we were interested in the contribution of UPF consumption to the risk of developing dementia., Methods: We performed a systematic review and meta-analysis of all records registered on Ovid Medline and Web of Science from inception until December 2022 [PROSPERO (CRD42023388363)]. Studies that assessed UPF consumption in adults, determined according to NOVA, and that reported dementia (Alzheimer's disease, vascular dementia and mild cognitive impairment) determined by clearly stated diagnostic criteria (including formal assessment of dementia or use of diagnostic codes) were included. The association between UPF consumption and dementia was assessed using random-effects meta-analysis, controlling for confounding variables. Study quality was assessed using the Newcastle Ottawa Scale and evidence credibility evaluated using the NutriGrade system., Results: Seven thousand ten records were screened, and 122 records underwent full text review. From these, 10 observational (8 longitudinal) studies, analysing 867,316 individuals, were included. Included studies adjusted for age, socioeconomic status and co-morbidity, alongside other confounders. High (vs. low) intake of UPF was associated with increased risk of dementia (pooled relative risk 1.44 (95% confidence interval 1.09-1.90) (p = 0.02)) (I
2 = 97.0%), although moderate (vs. low) intake of UPF was not (1.12 (0.96-1.31) (0.13)) (85.0%). Funnel plots demonstrate low risk of publication bias., Conclusion: High UPF consumption is associated with dementia. Public health measures to reduce overconsumption of UPFs are imperative to reduce the burden of dementia., (© 2023. The Author(s).)- Published
- 2024
- Full Text
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22. An Event-Related Potential (ERP) Examination of the Neural Responses to Emotional and Movement-Related Images.
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MacKay CE, Desroches AS, and Smith SD
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- Humans, Emotions physiology, Brain physiology, Visual Perception physiology, Electroencephalography, Evoked Potentials physiology
- Abstract
Previous research has suggested that the perception of emotional images may also activate brain regions related to the preparation of motoric plans. However, little research has investigated whether these emotion-movement interactions occur at early or later stages of visual perception. In the current research, event-related potentials (ERPs) were used to examine the time course of the independent - and combined - effects of perceiving emotions and implied movement. Twenty-five participants viewed images from four categories: 1) emotional with implied movement, 2) emotional with no implied movement, 3) neutral with implied movement, and 4) neutral with no implied movement. Both emotional stimuli and movement-related stimuli led to larger N200 (200-300 ms) waveforms. Furthermore, at frontal sites, there was a marginal interaction between emotion and implied movement, such that negative stimuli showed greater N200 amplitudes vs. neutral stimuli, but only for images with implied movement. At posterior sites, a similar effect was observed for images without implied movement. The late positive potential (LPP; 500-1000 ms) was significant for emotion (at frontal sites) and movement (at frontal, central, and posterior sites), as well as for their interaction (at parietal sites), with larger LPPs for negative vs. neutral images with movement only. Together, these results suggest that the perception of emotion and movement interact at later stages of visual perception.
- Published
- 2024
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23. Trichotillomania: a perspective synthesised from neuroscience and lived experience.
- Author
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Mackay CE
- Subjects
- Animals, Anxiety, Grooming, Nail Biting, Trichotillomania therapy, Neurosciences
- Abstract
Trichotillomania, or hair-pulling disorder, is one of a family of disorders called body-focused repetitive behaviours (BFRBs), which also include disordered skin-picking (dermotillomania) and nail-biting (onychophagia). The disorders affect 1%-2% of the population, cause high levels of distress and have high levels of comorbidity with other psychiatric diagnoses. The key facts and figures are briefly reviewed and some important points are further explored: (1) BFRBs are associated with psychological distress, but are distinct from other diagnoses, (2) The pathological behaviours mirror excessive self-grooming behaviours in other species, and may relate to immune-system mediated feedback loops, and (3) The resulting behaviours are stigmatised and cause intense shame and isolation for those who suffer, which might in itself maintain the feedback loop. These observations lead to the hypothesis that the core disorder is one of pathological grooming, which may have a basis in an immune response, with shame being both a consequence and a maintainer of the disorder. The major barrier to testing the hypotheses and potential interventions remains the stigma that keeps these disorders, and those who suffer from them, in the shadows., Competing Interests: Competing interests: CM is supported by the NIHR Oxford Health Biomedical Research Centre, and is a co-founder/shareholder of Exprodo Software Ltd., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. Published by BMJ.)
- Published
- 2023
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24. Oxford brain health clinic: protocol and research database.
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O'Donoghue MC, Blane J, Gillis G, Mitchell R, Lindsay K, Semple J, Pretorius PM, Griffanti L, Fossey J, Raymont V, Martos L, and Mackay CE
- Subjects
- Humans, Magnetic Resonance Imaging, Memory Disorders, Clinical Protocols, Brain diagnostic imaging, Research
- Abstract
Introduction: Despite major advances in the field of neuroscience over the last three decades, the quality of assessments available to patients with memory problems in later life has barely changed. At the same time, a large proportion of dementia biomarker research is conducted in selected research samples that often poorly reflect the demographics of the population of patients who present to memory clinics. The Oxford Brain Health Clinic (BHC) is a newly developed clinical assessment service with embedded research in which all patients are offered high-quality clinical and research assessments, including MRI, as standard., Methods and Analysis: Here we describe the BHC protocol, including aligning our MRI scans with those collected in the UK Biobank. We evaluate rates of research consent for the first 108 patients (data collection ongoing) and the ability of typical psychiatry-led NHS memory-clinic patients to tolerate both clinical and research assessments., Ethics and Dissemination: Our ethics and consenting process enables patients to choose the level of research participation that suits them. This generates high rates of consent, enabling us to populate a research database with high-quality data that will be disseminated through a national platform (the Dementias Platform UK data portal)., Competing Interests: Competing interests: CEM is a cofounder and shareholder of Exprodo Software, which was used to develop the BHC database. CEM serves on a Biogen Brain Health Consortium (unpaid). No other competing interests to report., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)
- Published
- 2023
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25. Vasodilators mobilize SK3 channels in endothelial cells to produce arterial relaxation.
- Author
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Peixoto-Neves D, Yadav S, MacKay CE, Mbiakop UC, Mata-Daboin A, Leo MD, and Jaggar JH
- Subjects
- Endothelial Cells metabolism, Small-Conductance Calcium-Activated Potassium Channels metabolism, Arteries metabolism, Vasodilation, Acetylcholine metabolism, Endothelium, Vascular metabolism, Vasodilator Agents pharmacology, TRPV Cation Channels metabolism
- Abstract
Endothelial cells (ECs) line the lumen of all blood vessels and regulate functions, including contractility. Physiological stimuli, such as acetylcholine (ACh) and intravascular flow, activate transient receptor potential vanilloid 4 (TRPV4) channels, which stimulate small (SK3)- and intermediate (IK)-conductance Ca
2+ -activated potassium channels in ECs to produce vasodilation. Whether physiological vasodilators also modulate the surface abundance of these ion channels in ECs to elicit functional responses is unclear. Here, we show that ACh and intravascular flow stimulate rapid anterograde trafficking of an intracellular pool of SK3 channels in ECs of resistance-size arteries, which increases surface SK3 protein more than two-fold. In contrast, ACh and flow do not alter the surface abundance of IK or TRPV4 channels. ACh triggers SK3 channel trafficking by activating TRPV4-mediated Ca2+ influx, which stimulates Rab11A, a Rab GTPase associated with recycling endosomes. Superresolution microscopy data demonstrate that SK3 trafficking specifically increases the size of surface SK3 clusters which overlap with TRPV4 clusters. We also show that Rab11A-dependent trafficking of SK3 channels is an essential contributor to vasodilator-induced SK current activation in ECs and vasorelaxation. In summary, our data demonstrate that vasodilators activate Rab11A, which rapidly delivers an intracellular pool of SK3 channels to the vicinity of surface TRPV4 channels in ECs. This trafficking mechanism increases surface SK3 cluster size, elevates SK3 current density, and produces vasodilation. These data also demonstrate that SK3 and IK channels are differentially regulated by trafficking-dependent and -independent signaling mechanisms in endothelial cells.- Published
- 2023
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26. Neflamapimod inhibits endothelial cell activation, adhesion molecule expression, leukocyte attachment and vascular inflammation by inhibiting p38 MAPKα and NF-κB signaling.
- Author
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Menon SN, Zerin F, Ezewudo E, Simon NP, Menon SN, Daniel ML, Green AJ, Pandey A, Mackay CE, Hafez S, Moniri NH, and Hasan R
- Subjects
- Rats, Animals, Lipopolysaccharides toxicity, Vascular Cell Adhesion Molecule-1 metabolism, Cell Adhesion Molecules metabolism, Leukocytes, Cell Adhesion, Protein Kinase Inhibitors pharmacology, Inflammation drug therapy, Inflammation metabolism, Endothelium, Vascular metabolism, Intercellular Adhesion Molecule-1 metabolism, NF-kappa B metabolism, Endothelial Cells metabolism
- Abstract
Neflamapimod, a selective inhibitor of the alpha isoform of p38 mitogen-activated protein kinase (MAPKα), was investigated for its potential to inhibit lipopolysaccharide (LPS)-induced activation of endothelial cells (ECs), adhesion molecule induction, and subsequent leukocyte attachment to EC monolayers. These events are known to contribute to vascular inflammation and cardiovascular dysfunction. Our results demonstrate that LPS treatment of cultured ECs and rats leads to significant upregulation of adhesion molecules, both in vitro and in vivo, which can be effectively inhibited by neflamapimod treatment. Western blotting data further reveals that neflamapimod inhibits LPS-induced phosphorylation of p38 MAPKα and the activation of NF-κB signaling in ECs. Additionally, leukocyte adhesion assays demonstrate a substantial reduction in leukocyte attachment to cultured ECs and the aorta lumen of rats treated with neflamapimod. Consistent with vascular inflammation, LPS-treated rat arteries exhibit significantly diminished vasodilation response to acetylcholine, however, arteries from rats treated with neflamapimod maintain their vasodilation capacity, demonstrating its ability to limit LPS-induced vascular inflammation. Overall, our data demonstrate that neflamapimod effectively inhibits endothelium activation, adhesion molecule expression, and leukocyte attachment, thereby reducing vascular inflammation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
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27. A systematic review of the association between dementia risk factors and cerebrovascular reactivity.
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Wang C, Reid G, Mackay CE, Hayes G, Bulte DP, and Suri S
- Subjects
- Humans, Brain blood supply, Risk Factors, Magnetic Resonance Imaging methods, Cerebrovascular Circulation physiology, Stroke, Dementia complications
- Abstract
Cumulative evidence suggests that impaired cerebrovascular reactivity (CVR), a regulatory response critical for maintaining neuronal health, is amongst the earliest pathological changes in dementia. However, we know little about how CVR is affected by dementia risk, prior to disease onset. Understanding this relationship would improve our knowledge of disease pathways and help inform preventative interventions. This systematic review investigates 59 studies examining how CVR (measured by magnetic resonance imaging) is affected by modifiable, non-modifiable, and clinical risk factors for dementia. We report that non-modifiable risk (older age and apolipoprotein ε4), some modifiable factors (diabetes, traumatic brain injury, hypertension) and some clinical factors (stroke, carotid artery occlusion, stenosis) were consistently associated with reduced CVR. We also note a lack of conclusive evidence on how other behavioural factors such as physical inactivity, obesity, or depression, affect CVR. This review explores the biological mechanisms underpinning these brain-behaviour associations, highlights evident gaps in the literature, and identifies the risk factors that could be managed to preserve CVR in an effort to prevent dementia., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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28. Inter- and intra-individual variation in brain structural-cognition relationships in aging.
- Author
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Patel R, Mackay CE, Jansen MG, Devenyi GA, O'Donoghue MC, Kivimäki M, Singh-Manoux A, Zsoldos E, Ebmeier KP, Chakravarty MM, and Suri S
- Subjects
- Aged, Aging, Anisotropy, Humans, Magnetic Resonance Imaging, Middle Aged, Neuropsychological Tests, Brain diagnostic imaging, Cognition
- Abstract
The sources of inter- and intra-individual variability in age-related cognitive decline remain poorly understood. We examined the association between 20-year trajectories of cognitive decline and multimodal brain structure and morphology in older age. We used the Whitehall II Study, an extensively characterised cohort with 3T brain magnetic resonance images acquired at older age (mean age = 69.52 ± 4.9) and 5 repeated cognitive performance assessments between mid-life (mean age = 53.2 ±4.9 years) and late-life (mean age = 67.7 ± 4.9). Using non-negative matrix factorization, we identified 10 brain components integrating cortical thickness, surface area, fractional anisotropy, and mean and radial diffusivities. We observed two latent variables describing distinct brain-cognition associations. The first describes variations in 5 structural components associated with low mid-life performance across multiple cognitive domains, decline in reasoning, but maintenance of fluency abilities. The second describes variations in 6 structural components associated with low mid-life performance in fluency and memory, but retention of multiple abilities. Expression of latent variables predicts future cognition 3.2 years later (mean age = 70.87 ± 4.9). This data-driven approach highlights brain-cognition relationships wherein individuals degrees of cognitive decline and maintenance across diverse cognitive functions are both positively and negatively associated with markers of cortical structure., (Copyright © 2022. Published by Elsevier Inc.)
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- 2022
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29. Macrostructural brain alterations at midlife are connected to cardiovascular and not inherited risk of future dementia: the PREVENT-Dementia study.
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Dounavi ME, Newton C, Jenkins N, Mak E, Low A, Muniz-Terrera G, Williams GB, Lawlor B, Naci L, Malhotra P, Mackay CE, Koychev I, Ritchie K, Ritchie CW, Su L, and O'Brien JT
- Subjects
- Adult, Atrophy pathology, Brain diagnostic imaging, Brain pathology, Cerebral Cortical Thinning, Humans, Magnetic Resonance Imaging, Middle Aged, Alzheimer Disease complications, Apolipoprotein E4 genetics
- Abstract
Background: Macrostructural brain alterations in the form of brain atrophy or cortical thinning typically occur during the prodromal Alzheimer's disease stage. Mixed findings largely dependent on the age of the examined cohorts have been reported during the preclinical, asymptomatic disease stage. In the present study, our aim was to examine the association of midlife dementia risk with brain macrostructural alterations., Methods: Structural 3T MRI scans were acquired for 647 cognitively normal middle-aged (40-59 years old) participants in the PREVENT-Dementia study. Cortical thickness, volumes of subcortical structures, the hippocampus and hippocampal subfields were quantified using Freesurfer version 7.1. The clarity of the hippocampal molecular layer was evaluated based on T2-weighted hippocampal scans. Associations of structural measures with apolipoprotein ε4 (APOE4) genotype and dementia family history (FHD), were investigated using linear regression. Correlations between the CAIDE dementia risk score (incorporating information about blood pressure, cholesterol, physical activity, body mass index, education, age and sex) and structural measures were further investigated., Results: A higher CAIDE score was associated with thinner cortex and a larger hippocampal fissure. APOE4 genotype was associated with reduced molecular layer clarity., Conclusions: Our findings suggest that a higher CAIDE score is associated with widespread cortical thinning. Conversely, APOE4 carriers and participants with FHD do not demonstrate prominent macrostructural alterations at this age range. These findings indicate that cardiovascular and not inherited risk factors for dementia are associated with macrostructural brain alterations at midlife., (© 2022. The Author(s).)
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- 2022
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30. Association of cerebral small vessel disease burden with brain structure and cognitive and vascular risk trajectories in mid-to-late life.
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Jansen MG, Griffanti L, Mackay CE, Anatürk M, Melazzini L, Lange AG, Filippini N, Zsoldos E, Wiegertjes K, Leeuw FE, Singh-Manoux A, Kivimäki M, Ebmeier KP, and Suri S
- Subjects
- Adult, Aged, Brain diagnostic imaging, Cognition physiology, Female, Humans, Magnetic Resonance Imaging, Male, Retrospective Studies, Cerebral Small Vessel Diseases complications, Cerebral Small Vessel Diseases diagnostic imaging, Cognitive Dysfunction etiology, White Matter diagnostic imaging
- Abstract
We characterize the associations of total cerebral small vessel disease (SVD) burden with brain structure, trajectories of vascular risk factors, and cognitive functions in mid-to-late life. Participants were 623 community-dwelling adults from the Whitehall II Imaging Sub-study with multi-modal MRI (mean age 69.96, SD = 5.18, 79% men). We used linear mixed-effects models to investigate associations of SVD burden with up to 25-year retrospective trajectories of vascular risk and cognitive performance. General linear modelling was used to investigate concurrent associations with grey matter (GM) density and white matter (WM) microstructure, and whether these associations were modified by cognitive status (Montreal Cognitive Asessment [MoCA] scores of < 26 vs. ≥ 26). Severe SVD burden in older age was associated with higher mean arterial pressure throughout midlife (β = 3.36, 95% CI [0.42-6.30]), and faster cognitive decline in letter fluency (β = -0.07, 95% CI [-0.13--0.01]), and verbal reasoning (β = -0.05, 95% CI [-0.11--0.001]). Moreover, SVD burden was related to lower GM volumes in 9.7% of total GM, and widespread WM microstructural decline (FWE-corrected p < 0.05). The latter association was most pronounced in individuals who demonstrated cognitive impairments on MoCA (MoCA < 26; F
3,608 = 2.14, p = 0.007). These findings highlight the importance of managing midlife vascular health to preserve brain structure and cognitive function in old age.- Published
- 2022
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31. A plasma membrane-localized polycystin-1/polycystin-2 complex in endothelial cells elicits vasodilation.
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MacKay CE, Floen M, Leo MD, Hasan R, Garrud TAC, Fernández-Peña C, Singh P, Malik KU, and Jaggar JH
- Subjects
- Animals, Cell Membrane metabolism, Endothelial Cells metabolism, Mice, Mice, Knockout, Polycystic Kidney Diseases, TRPP Cation Channels metabolism, Vasodilation
- Abstract
Polycystin-1 (PC-1, PKD1), a receptor-like protein expressed by the Pkd1 gene, is present in a wide variety of cell types, but its cellular location, signaling mechanisms, and physiological functions are poorly understood. Here, by studying tamoxifen-inducible, endothelial cell (EC)-specific Pkd1 knockout ( Pkd1 ecKO) mice, we show that flow activates PC-1-mediated, Ca
2+ -dependent cation currents in ECs. EC-specific PC-1 knockout attenuates flow-mediated arterial hyperpolarization and vasodilation. PC-1-dependent vasodilation occurs over the entire functional shear stress range and via the activation of endothelial nitric oxide synthase (eNOS) and intermediate (IK)- and small (SK)-conductance Ca2+ -activated K+ channels. EC-specific PC-1 knockout increases systemic blood pressure without altering kidney anatomy. PC-1 coimmunoprecipitates with polycystin-2 (PC-2, PKD2), a TRP polycystin channel, and clusters of both proteins locate in nanoscale proximity in the EC plasma membrane. Knockout of either PC-1 or PC-2 ( Pkd2 ecKO mice) abolishes surface clusters of both PC-1 and PC-2 in ECs. Single knockout of PC-1 or PC-2 or double knockout of PC-1 and PC-2 ( Pkd1 / Pkd2 ecKO mice) similarly attenuates flow-mediated vasodilation. Flow stimulates nonselective cation currents in ECs that are similarly inhibited by either PC-1 or PC-2 knockout or by interference peptides corresponding to the C-terminus coiled-coil domains present in PC-1 or PC-2. In summary, we show that PC-1 regulates arterial contractility through the formation of an interdependent signaling complex with PC-2 in ECs. Flow stimulates PC-1/PC-2 clusters in the EC plasma membrane, leading to eNOS, IK channel, and SK channel activation, vasodilation, and a reduction in blood pressure., Competing Interests: CM, MF, ML, RH, TG, CF, PS, KM, JJ No competing interests declared, (© 2022, MacKay et al.)- Published
- 2022
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32. Author Correction: Mapping brain structural differences and neuroreceptor correlates in Parkinson's disease visual hallucinations.
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Vignando M, Ffytche D, Lewis SJG, Lee PH, Chung SJ, Weil RS, Hu MT, Mackay CE, Griffanti L, Pins D, Dujardin K, Jardri R, Taylor JP, Firbank M, McAlonan G, Mak HKF, Ho SL, and Mehta MA
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- 2022
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33. Mapping brain structural differences and neuroreceptor correlates in Parkinson's disease visual hallucinations.
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Vignando M, Ffytche D, Lewis SJG, Lee PH, Chung SJ, Weil RS, Hu MT, Mackay CE, Griffanti L, Pins D, Dujardin K, Jardri R, Taylor JP, Firbank M, McAlonan G, Mak HKF, Ho SL, and Mehta MA
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- Aged, Bayes Theorem, Brain diagnostic imaging, Cerebral Cortex, Female, Hippocampus, Humans, Male, Middle Aged, Brain Mapping, Hallucinations, Parkinson Disease, Sensory Receptor Cells
- Abstract
Parkinson's psychosis (PDP) describes a spectrum of symptoms that may arise in Parkinson's disease (PD) including visual hallucinations (VH). Imaging studies investigating the neural correlates of PDP have been inconsistent in their findings, due to differences in study design and limitations of scale. Here we use empirical Bayes harmonisation to pool together structural imaging data from multiple research groups into a large-scale mega-analysis, allowing us to identify cortical regions and networks involved in VH and their relation to receptor binding. Differences of morphometrics analysed show a wider cortical involvement underlying VH than previously recognised, including primary visual cortex and surrounding regions, and the hippocampus, independent of its role in cognitive decline. Structural covariance analyses point to the involvement of the attentional control networks in PD-VH, while associations with receptor density maps suggest neurotransmitter loss may be linked to the cortical changes., (© 2022. The Author(s).)
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- 2022
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34. Adapting UK Biobank imaging for use in a routine memory clinic setting: The Oxford Brain Health Clinic.
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Griffanti L, Gillis G, O'Donoghue MC, Blane J, Pretorius PM, Mitchell R, Aikin N, Lindsay K, Campbell J, Semple J, Alfaro-Almagro F, Smith SM, Miller KL, Martos L, Raymont V, and Mackay CE
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- Humans, Magnetic Resonance Imaging, Atrophy pathology, United Kingdom, Biological Specimen Banks, Brain diagnostic imaging, Brain pathology
- Abstract
The Oxford Brain Health Clinic (BHC) is a joint clinical-research service that provides memory clinic patients and clinicians access to high-quality assessments not routinely available, including brain MRI aligned with the UK Biobank imaging study (UKB). In this work we present how we 1) adapted the UKB MRI acquisition protocol to be suitable for memory clinic patients, 2) modified the imaging analysis pipeline to extract measures that are in line with radiology reports and 3) explored the alignment of measures from BHC patients to the largest brain MRI study in the world (ultimately 100,000 participants). Adaptations of the UKB acquisition protocol for BHC patients include dividing the scan into core and optional sequences (i.e., additional imaging modalities) to improve patients' tolerance for the MRI assessment. We adapted the UKB structural MRI analysis pipeline to take into account the characteristics of a memory clinic population (e.g., high amount of white matter hyperintensities and hippocampal atrophy). We then compared the imaging derived phenotypes (IDPs) extracted from the structural scans to visual ratings from radiology reports, non-imaging factors (age, cognition) and to reference distributions derived from UKB data. Of the first 108 BHC attendees (August 2020-November 2021), 92.5 % completed the clinical scans, 88.0 % consented to use of data for research, and 43.5 % completed the additional research sequences, demonstrating that the protocol is well tolerated. The high rates of consent to research makes this a valuable real-world quality research dataset routinely captured in a clinical service. Modified tissue-type segmentation with lesion masking greatly improved grey matter volume estimation. CSF-masking marginally improved hippocampal segmentation. The IDPs were in line with radiology reports and showed significant associations with age and cognitive performance, in line with the literature. Due to the age difference between memory clinic patients of the BHC (age range 65-101 years, average 78.3 years) and UKB participants (44-82 years, average 64 years), additional scans on elderly healthy controls are needed to improve reference distributions. Current and future work aims to integrate automated quantitative measures in the radiology reports and evaluate their clinical utility., Competing Interests: Declaration of Competing Interest CEM is a co-founder and shareholder of Exprodo Software, which was used to develop the BHC database. CEM serves on a Biogen Brain Health Consortium (unpaid). No other competing interests to report., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2022
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35. International Multicenter Analysis of Brain Structure Across Clinical Stages of Parkinson's Disease.
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Laansma MA, Bright JK, Al-Bachari S, Anderson TJ, Ard T, Assogna F, Baquero KA, Berendse HW, Blair J, Cendes F, Dalrymple-Alford JC, de Bie RMA, Debove I, Dirkx MF, Druzgal J, Emsley HCA, Garraux G, Guimarães RP, Gutman BA, Helmich RC, Klein JC, Mackay CE, McMillan CT, Melzer TR, Parkes LM, Piras F, Pitcher TL, Poston KL, Rango M, Ribeiro LF, Rocha CS, Rummel C, Santos LSR, Schmidt R, Schwingenschuh P, Spalletta G, Squarcina L, van den Heuvel OA, Vriend C, Wang JJ, Weintraub D, Wiest R, Yasuda CL, Jahanshad N, Thompson PM, and van der Werf YD
- Subjects
- Brain diagnostic imaging, Brain pathology, Humans, Magnetic Resonance Imaging, Neuroimaging, Thalamus pathology, Parkinson Disease complications
- Abstract
Background: Brain structure abnormalities throughout the course of Parkinson's disease have yet to be fully elucidated., Objective: Using a multicenter approach and harmonized analysis methods, we aimed to shed light on Parkinson's disease stage-specific profiles of pathology, as suggested by in vivo neuroimaging., Methods: Individual brain MRI and clinical data from 2357 Parkinson's disease patients and 1182 healthy controls were collected from 19 sources. We analyzed regional cortical thickness, cortical surface area, and subcortical volume using mixed-effects models. Patients grouped according to Hoehn and Yahr stage were compared with age- and sex-matched controls. Within the patient sample, we investigated associations with Montreal Cognitive Assessment score., Results: Overall, patients showed a thinner cortex in 38 of 68 regions compared with controls (d
max = -0.20, dmin = -0.09). The bilateral putamen (dleft = -0.14, dright = -0.14) and left amygdala (d = -0.13) were smaller in patients, whereas the left thalamus was larger (d = 0.13). Analysis of staging demonstrated an initial presentation of thinner occipital, parietal, and temporal cortices, extending toward rostrally located cortical regions with increased disease severity. From stage 2 and onward, the bilateral putamen and amygdala were consistently smaller with larger differences denoting each increment. Poorer cognition was associated with widespread cortical thinning and lower volumes of core limbic structures., Conclusions: Our findings offer robust and novel imaging signatures that are generally incremental across but in certain regions specific to disease stages. Our findings highlight the importance of adequately powered multicenter collaborations. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)- Published
- 2021
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36. Adapting the UK Biobank Brain Imaging Protocol and Analysis Pipeline for the C-MORE Multi-Organ Study of COVID-19 Survivors.
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Griffanti L, Raman B, Alfaro-Almagro F, Filippini N, Cassar MP, Sheerin F, Okell TW, Kennedy McConnell FA, Chappell MA, Wang C, Arthofer C, Lange FJ, Andersson J, Mackay CE, Tunnicliffe EM, Rowland M, Neubauer S, Miller KL, Jezzard P, and Smith SM
- Abstract
SARS-CoV-2 infection has been shown to damage multiple organs, including the brain. Multiorgan MRI can provide further insight on the repercussions of COVID-19 on organ health but requires a balance between richness and quality of data acquisition and total scan duration. We adapted the UK Biobank brain MRI protocol to produce high-quality images while being suitable as part of a post-COVID-19 multiorgan MRI exam. The analysis pipeline, also adapted from UK Biobank, includes new imaging-derived phenotypes (IDPs) designed to assess the possible effects of COVID-19. A first application of the protocol and pipeline was performed in 51 COVID-19 patients post-hospital discharge and 25 controls participating in the Oxford C-MORE study. The protocol acquires high resolution T
1 , T2 -FLAIR, diffusion weighted images, susceptibility weighted images, and arterial spin labelling data in 17 min. The automated imaging pipeline derives 1,575 IDPs, assessing brain anatomy (including olfactory bulb volume and intensity) and tissue perfusion, hyperintensities, diffusivity, and susceptibility. In the C-MORE data, IDPs related to atrophy, small vessel disease and olfactory bulbs were consistent with clinical radiology reports. Our exploratory analysis tentatively revealed some group differences between recovered COVID-19 patients and controls, across severity groups, but not across anosmia groups. Follow-up imaging in the C-MORE study is currently ongoing, and this protocol is now being used in other large-scale studies. The protocol, pipeline code and data are openly available and will further contribute to the understanding of the medium to long-term effects of COVID-19., Competing Interests: BR reports grants from NIHR Oxford Biomedical Research Centre, grants from United Kingdom Research Innovation Award, and Oxford British Heart Foundation Centre for Research Excellence during the conduct of the study. MPC reports grants from NIHR Oxford Biomedical Research Centre, during the conduct of the study. ET reports grants from NIHR Oxford Biomedical Research Centre, during the conduct of the study; shareholding in Perspectum, outside the submitted work. TO reports grants from Wellcome Trust/Royal Society, during the conduct of the study; personal fees from SBGNeuro, personal fees from Oxford University Press, personal fees from Siemens Healthineers, outside the submitted work; In addition, outside the submitted work, TO has a patent Combined angiography and perfusion using radial imaging and arterial spin labelling pending, a patent (with PJ) Off-resonance Correction for Pseudo-continuous Arterial Spin Labelling pending, a patent Estimation of blood flow rates issued, a patent (with MAC) Fast analysis method for non-invasive imaging of blood flow using vessel-encoded arterial spin labelling with royalties paid by Siemens Healthineers, and a patent (with PJ and MAC) Quantification of blood volume flow rates from dynamic angiography data with royalties paid by Siemens Healthineers. MAC reports personal fees from Oxford University Press and Springer-Nature, outside submitted work. SN reports grants from Oxford NIHR Biomedical Research Centre, grants from UKRI, during the conduct of the study; personal fees, and others from Perspectum Diagnostics, outside the submitted work. PJ reports grants from Oxford NIHR Biomedical Research Centre and salary support from the Dunhill Medical Trust. LG, FA-A, MAC, JA, and SS receive royalties from licencing of FSL to non-academic, commercial entities. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Griffanti, Raman, Alfaro-Almagro, Filippini, Cassar, Sheerin, Okell, Kennedy McConnell, Chappell, Wang, Arthofer, Lange, Andersson, Mackay, Tunnicliffe, Rowland, Neubauer, Miller, Jezzard and Smith.)- Published
- 2021
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37. Integrating large-scale neuroimaging research datasets: Harmonisation of white matter hyperintensity measurements across Whitehall and UK Biobank datasets.
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Bordin V, Bertani I, Mattioli I, Sundaresan V, McCarthy P, Suri S, Zsoldos E, Filippini N, Mahmood A, Melazzini L, Laganà MM, Zamboni G, Singh-Manoux A, Kivimäki M, Ebmeier KP, Baselli G, Jenkinson M, Mackay CE, Duff EP, and Griffanti L
- Subjects
- Adult, Aged, Aged, 80 and over, Biological Specimen Banks, Female, Humans, Longitudinal Studies, Male, Middle Aged, United Kingdom, Aging, Biomedical Research, Datasets as Topic, Leukoaraiosis diagnostic imaging, Multicenter Studies as Topic, Neuroimaging
- Abstract
Large scale neuroimaging datasets present the possibility of providing normative distributions for a wide variety of neuroimaging markers, which would vastly improve the clinical utility of these measures. However, a major challenge is our current poor ability to integrate measures across different large-scale datasets, due to inconsistencies in imaging and non-imaging measures across the different protocols and populations. Here we explore the harmonisation of white matter hyperintensity (WMH) measures across two major studies of healthy elderly populations, the Whitehall II imaging sub-study and the UK Biobank. We identify pre-processing strategies that maximise the consistency across datasets and utilise multivariate regression to characterise study sample differences contributing to differences in WMH variations across studies. We also present a parser to harmonise WMH-relevant non-imaging variables across the two datasets. We show that we can provide highly calibrated WMH measures from these datasets with: (1) the inclusion of a number of specific standardised processing steps; and (2) appropriate modelling of sample differences through the alignment of demographic, cognitive and physiological variables. These results open up a wide range of applications for the study of WMHs and other neuroimaging markers across extensive databases of clinical data., Competing Interests: Declaration of Competing Interest M.J. receives royalties from licensing of FSL to non-academic, commercial entities., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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38. Study Protocol: The Heart and Brain Study.
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Suri S, Bulte D, Chiesa ST, Ebmeier KP, Jezzard P, Rieger SW, Pitt JE, Griffanti L, Okell TW, Craig M, Chappell MA, Blockley NP, Kivimäki M, Singh-Manoux A, Khir AW, Hughes AD, Deanfield JE, Jensen DEA, Green SF, Sigutova V, Jansen MG, Zsoldos E, and Mackay CE
- Abstract
Background: It is well-established that what is good for the heart is good for the brain. Vascular factors such as hypertension, diabetes, and high cholesterol, and genetic factors such as the apolipoprotein E4 allele increase the risk of developing both cardiovascular disease and dementia. However, the mechanisms underlying the heart-brain association remain unclear. Recent evidence suggests that impairments in vascular phenotypes and cerebrovascular reactivity (CVR) may play an important role in cognitive decline. The Heart and Brain Study combines state-of-the-art vascular ultrasound, cerebrovascular magnetic resonance imaging (MRI) and cognitive testing in participants of the long-running Whitehall II Imaging cohort to examine these processes together. This paper describes the study protocol, data pre-processing and overarching objectives., Methods and Design: The 775 participants of the Whitehall II Imaging cohort, aged 65 years or older in 2019, have received clinical and vascular risk assessments at 5-year-intervals since 1985, as well as a 3T brain MRI scan and neuropsychological tests between 2012 and 2016 (Whitehall II Wave MRI-1). Approximately 25% of this cohort are selected for the Heart and Brain Study , which involves a single testing session at the University of Oxford (Wave MRI-2). Between 2019 and 2023, participants will undergo ultrasound scans of the ascending aorta and common carotid arteries, measures of central and peripheral blood pressure, and 3T MRI scans to measure CVR in response to 5% carbon dioxide in air, vessel-selective cerebral blood flow (CBF), and cerebrovascular lesions. The structural and diffusion MRI scans and neuropsychological battery conducted at Wave MRI-1 will also be repeated. Using this extensive life-course data, the Heart and Brain Study will examine how 30-year trajectories of vascular risk throughout midlife (40-70 years) affect vascular phenotypes, cerebrovascular health, longitudinal brain atrophy and cognitive decline at older ages., Discussion: The study will generate one of the most comprehensive datasets to examine the longitudinal determinants of the heart-brain association. It will evaluate novel physiological processes in order to describe the optimal window for managing vascular risk in order to delay cognitive decline. Ultimately, the Heart and Brain Study will inform strategies to identify at-risk individuals for targeted interventions to prevent or delay dementia., Competing Interests: JD reports provision of medical consulting for the Brain Protection Company Ltd. MC has received royalties for the commercial licensing of FSL and VEASL software tools. TO has received royalties for the commercial licensing of a patent relating to VEASL analysis. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Suri, Bulte, Chiesa, Ebmeier, Jezzard, Rieger, Pitt, Griffanti, Okell, Craig, Chappell, Blockley, Kivimäki, Singh-Manoux, Khir, Hughes, Deanfield, Jensen, Green, Sigutova, Jansen, Zsoldos and Mackay.)
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- 2021
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39. Subjective Cognitive Complaints Given in Questionnaire: Relationship With Brain Structure, Cognitive Performance and Self-Reported Depressive Symptoms in a 25-Year Retrospective Cohort Study.
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Topiwala A, Suri S, Allan C, Zsoldos E, Filippini N, Sexton CE, Mahmood A, Singh-Manoux A, Mackay CE, Kivimäki M, and Ebmeier KP
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- Aged, Aged, 80 and over, Brain anatomy & histology, Brain pathology, Depression physiopathology, Female, Gray Matter anatomy & histology, Gray Matter pathology, Gray Matter physiopathology, Humans, Male, Neuropsychological Tests, Retrospective Studies, White Matter anatomy & histology, White Matter pathology, White Matter physiopathology, Brain physiopathology, Cognition, Cognitive Dysfunction physiopathology, Depression psychology, Health Surveys, Memory Disorders physiopathology, Self Report
- Abstract
Background: Subjective cognitive complaints are common but it is unclear whether they indicate an underlying pathological process or reflect affective symptoms., Method: 800 community-dwelling older adults were drawn from the Whitehall II cohort. Subjective cognitive complaint inquiry for memory and concentration, a range of neuropsychological tests and multimodal MRI were performed in 2012-2016. Subjective complaints were again elicited after 1 year. Group differences in grey and white matter, between those with and without subjective complaints, were assessed using voxel-based morphometry and tract-based spatial statistics, respectively. Mixed effects models assessed whether cognitive decline or depressive symptoms (over a 25-year period) were associated with later subjective complaints. Analyses were controlled for potential confounders and multiple comparisons., Results: Mean age of the sample at scanning was 69.8 years (±5.1, range: 60.3-84.6). Subjective memory complaints were common (41%) and predicted further similar complaints later (mean 1.4 ± 1.4 years). There were no group differences in grey matter density or white matter integrity. Subjective complaints were not cross-sectionally or longitudinally associated with objectively assessed cognition. However, those with subjective complaints reported higher depressive symptoms ("poor concentration": odds ratio = 1.12, 95% CI 1.07-1.18; "poor memory": odds ratio = 1.18, 1.12-1.24)., Conclusions: In our sample subjective complaints were consistent over time and reflected depressive symptoms but not markers of neurodegenerative brain damage or concurrent or future objective cognitive impairment. Clinicians assessing patients presenting with memory complaints should be vigilant for affective disorders. These results question the rationale for including subjective complaints in a spectrum with Mild Cognitive Impairment diagnostic criteria., (Copyright © 2020. Published by Elsevier Inc.)
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- 2021
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40. White matter hyperintensities classified according to intensity and spatial location reveal specific associations with cognitive performance.
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Melazzini L, Mackay CE, Bordin V, Suri S, Zsoldos E, Filippini N, Mahmood A, Sundaresan V, Codari M, Duff E, Singh-Manoux A, Kivimäki M, Ebmeier KP, Jenkinson M, Sardanelli F, and Griffanti L
- Subjects
- Aged, Cognition, Humans, Magnetic Resonance Imaging, Cognitive Dysfunction diagnostic imaging, Leukoaraiosis, White Matter diagnostic imaging
- Abstract
White matter hyperintensities (WMHs) on T
2 -weighted images are radiological signs of cerebral small vessel disease. As their total volume is variably associated with cognition, a new approach that integrates multiple radiological criteria is warranted. Location may matter, as periventricular WMHs have been shown to be associated with cognitive impairments. WMHs that appear as hypointense in T1 -weighted images (T1 w) may also indicate the most severe component of WMHs. We developed an automatic method that sub-classifies WMHs into four categories (periventricular/deep and T1 w-hypointense/nonT1 w-hypointense) using MRI data from 684 community-dwelling older adults from the Whitehall II study. To test if location and intensity information can impact cognition, we derived two general linear models using either overall or subdivided volumes. Results showed that periventricular T1 w-hypointense WMHs were significantly associated with poorer performance in the trail making A (p = 0.011), digit symbol (p = 0.028) and digit coding (p = 0.009) tests. We found no association between total WMH volume and cognition. These findings suggest that sub-classifying WMHs according to both location and intensity in T1 w reveals specific associations with cognitive performance., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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41. Associations between arterial stiffening and brain structure, perfusion, and cognition in the Whitehall II Imaging Sub-study: A retrospective cohort study.
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Suri S, Chiesa ST, Zsoldos E, Mackay CE, Filippini N, Griffanti L, Mahmood A, Singh-Manoux A, Shipley MJ, Brunner EJ, Kivimäki M, Deanfield JE, and Ebmeier KP
- Subjects
- Age Factors, Aged, Aged, 80 and over, Brain diagnostic imaging, Carotid-Femoral Pulse Wave Velocity, Cerebrovascular Disorders diagnostic imaging, Cerebrovascular Disorders epidemiology, Cognitive Aging, Cognitive Dysfunction diagnosis, Cognitive Dysfunction epidemiology, Executive Function, Female, Humans, London epidemiology, Magnetic Resonance Imaging, Male, Memory, Short-Term, Middle Aged, Neuropsychological Tests, Peripheral Arterial Disease diagnosis, Peripheral Arterial Disease epidemiology, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Brain blood supply, Cerebrovascular Circulation, Cerebrovascular Disorders physiopathology, Cognition, Cognitive Dysfunction psychology, Peripheral Arterial Disease physiopathology, Vascular Stiffness
- Abstract
Background: Aortic stiffness is closely linked with cardiovascular diseases (CVDs), but recent studies suggest that it is also a risk factor for cognitive decline and dementia. However, the brain changes underlying this risk are unclear. We examined whether aortic stiffening during a 4-year follow-up in mid-to-late life was associated with brain structure and cognition in the Whitehall II Imaging Sub-study., Methods and Findings: The Whitehall II Imaging cohort is a randomly selected subset of the ongoing Whitehall II Study, for which participants have received clinical follow-ups for 30 years, across 12 phases. Aortic pulse wave velocity (PWV) was measured in 2007-2009 (Phase 9) and at a 4-year follow-up in 2012-2013 (Phase 11). Between 2012 and 2016 (Imaging Phase), participants received a multimodal 3T brain magnetic resonance imaging (MRI) scan and cognitive tests. Participants were selected if they had no clinical diagnosis of dementia and no gross brain structural abnormalities. Voxel-based analyses were used to assess grey matter (GM) volume, white matter (WM) microstructure (fractional anisotropy (FA) and diffusivity), white matter lesions (WMLs), and cerebral blood flow (CBF). Cognitive outcomes were performance on verbal memory, semantic fluency, working memory, and executive function tests. Of 542 participants, 444 (81.9%) were men. The mean (SD) age was 63.9 (5.2) years at the baseline Phase 9 examination, 68.0 (5.2) at Phase 11, and 69.8 (5.2) at the Imaging Phase. Voxel-based analysis revealed that faster rates of aortic stiffening in mid-to-late life were associated with poor WM microstructure, viz. lower FA, higher mean, and radial diffusivity (RD) in 23.9%, 11.8%, and 22.2% of WM tracts, respectively, including the corpus callosum, corona radiata, superior longitudinal fasciculus, and corticospinal tracts. Similar voxel-wise associations were also observed with follow-up aortic stiffness. Moreover, lower mean global FA was associated with faster rates of aortic stiffening (B = -5.65, 95% CI -9.75, -1.54, Bonferroni-corrected p < 0.0125) and higher follow-up aortic stiffness (B = -1.12, 95% CI -1.95, -0.29, Bonferroni-corrected p < 0.0125). In a subset of 112 participants who received arterial spin labelling scans, faster aortic stiffening was also related to lower cerebral perfusion in 18.4% of GM, with associations surviving Bonferroni corrections in the frontal (B = -10.85, 95% CI -17.91, -3.79, p < 0.0125) and parietal lobes (B = -12.75, 95% CI -21.58, -3.91, p < 0.0125). No associations with GM volume or WMLs were observed. Further, higher baseline aortic stiffness was associated with poor semantic fluency (B = -0.47, 95% CI -0.76 to -0.18, Bonferroni-corrected p < 0.007) and verbal learning outcomes (B = -0.36, 95% CI -0.60 to -0.12, Bonferroni-corrected p < 0.007). As with all observational studies, it was not possible to infer causal associations. The generalisability of the findings may be limited by the gender imbalance, high educational attainment, survival bias, and lack of ethnic and socioeconomic diversity in this cohort., Conclusions: Our findings indicate that faster rates of aortic stiffening in mid-to-late life were associated with poor brain WM microstructural integrity and reduced cerebral perfusion, likely due to increased transmission of pulsatile energy to the delicate cerebral microvasculature. Strategies to prevent arterial stiffening prior to this point may be required to offer cognitive benefit in older age., Trial Registration: ClinicalTrials.gov NCT03335696., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: JED reports provision of medical consulting for the Brain Protection Company Ltd. The remaining authors have declared that no competing interests exist.
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- 2020
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42. Association of trajectories of depressive symptoms with vascular risk, cognitive function and adverse brain outcomes: The Whitehall II MRI sub-study.
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Demnitz N, Anatürk M, Allan CL, Filippini N, Griffanti L, Mackay CE, Mahmood A, Sexton CE, Suri S, Topiwala AG, Zsoldos E, Kivimäki M, Singh-Manoux A, and Ebmeier KP
- Subjects
- Brain diagnostic imaging, Cognition, Magnetic Resonance Imaging, Neuropsychological Tests, Depression diagnostic imaging, Depression epidemiology, White Matter diagnostic imaging
- Abstract
Background: Trajectories of depressive symptoms over the lifespan vary between people, but it is unclear whether these differences exhibit distinct characteristics in brain structure and function., Methods: In order to compare indices of white matter microstructure and cognitive characteristics of groups with different trajectories of depressive symptoms, we examined 774 participants of the Whitehall II Imaging Sub-study, who had completed the depressive subscale of the General Health Questionnaire up to nine times over 25 years. Twenty-seven years after the first examination, participants underwent magnetic resonance imaging to characterize white matter hyperintensities (WMH) and microstructure and completed neuropsychological tests to assess cognition. Twenty-nine years after the first examination, participants completed a further cognitive screening test., Outcomes: Using K-means cluster modelling, we identified five trajectory groups of depressive symptoms: consistently low scorers ("low"; n = 505, 62·5%), a subgroup with an early peak in depression scores ("early"; n = 123, 15·9%), intermediate scorers ("middle"; n = 89, 11·5%), a late symptom subgroup with an increase in symptoms towards the end of the follow-up period ("late"; n = 29, 3·7%), and consistently high scorers ("high"; n = 28, 3·6%). The late, but not the consistently high scorers, showed higher mean diffusivity, larger volumes of WMH and impaired executive function. In addition, the late subgroup had higher Framingham Stroke Risk scores throughout the follow-up period, indicating a higher load of vascular risk factors., Interpretation: Our findings suggest that tracking depressive symptoms in the community over time may be a useful tool to identify phenotypes that show different etiologies and cognitive and brain outcomes., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
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- 2020
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43. Associations Between Longitudinal Trajectories of Cognitive and Social Activities and Brain Health in Old Age.
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Anatürk M, Suri S, Zsoldos E, Filippini N, Mahmood A, Singh-Manoux A, Kivimäki M, Mackay CE, Ebmeier KP, and Sexton CE
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- Aged, Aged, 80 and over, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Prospective Studies, Aging physiology, Brain diagnostic imaging, Brain physiology, Cognition physiology, Leisure Activities, Social Behavior
- Abstract
Importance: Prior neuroimaging studies have found that late-life participation in cognitive (eg, reading) and social (eg, visiting friends and family) leisure activities are associated with magnetic resonance imaging (MRI) markers of the aging brain, but little is known about the neural and cognitive correlates of changes in leisure activities during the life span., Objectives: To examine trajectories of cognitive and social activities from midlife to late life and evaluate whether these trajectories are associated with brain structure, functional connectivity, and cognition., Design, Setting, and Participants: This prospective cohort included participants enrolled in the Whitehall II study and its MRI substudy based in the UK. Participants provided information on their leisure activities at 5 times during calendar years 1997 to 1999, 2002 to 2004, 2006, 2007 to 2009, and 2011 to 2013 and underwent MRI and cognitive battery testing from January 1, 2012, to December 31, 2016. Data analysis was performed from October 7, 2017, to July 15, 2019., Main Outcome and Measures: Growth curve models and latent class growth analysis were used to identify longitudinal trajectories of cognitive and social activities. Multiple linear regression was used to evaluate associations between activity trajectories and gray matter, white matter microstructure, functional connectivity, and cognition., Results: A total of 574 individuals (468 [81.5%] men; mean [SD] age, 69.9 [4.9] years; median Montreal Cognitive Assessment score, 28 [interquartile range, 26-28]) were included in the present analysis. During a mean (SD) of 15 (4.2) years, cognitive and social activity levels increased during midlife before reaching a plateau in late life. Both baseline (global cognition: unstandardized β [SE], 0.955 [0.285], uncorrected P = .001; executive function: β [SE], 1.831 [0.499], uncorrected P < .001; memory: β [SE], 1.394 [0.550], uncorrected P = .01; processing speed: β [SE], 1.514 [0.528], uncorrected P = .004) and change (global cognition: β [SE], -1.382 [0.492], uncorrected P = .005, executive function: β [SE], -2.219 [0.865], uncorrected P = .01; memory: β [SE], -2.355 [0.948], uncorrected P = .01) in cognitive activities were associated with multiple domains of cognition as well as global gray matter volume (β [SE], -0.910 [0.388], uncorrected P = .02). Baseline (β [SE], 1.695 [0.525], uncorrected P = .001) and change (β [SE], 2.542 [1.026], uncorrected P = .01) in social activities were associated only with executive function, in addition to voxelwise measures of functional connectivity that involved sensorimotor (quadratic change in social activities: number of voxels, 306; P = 0.01) and temporoparietal (linear change in social activities: number of voxels, 16; P = .02) networks. Otherwise, no voxelwise associations were found with gray matter, white matter, or resting-state functional connectivity. False discovery rate corrections for multiple comparisons suggested that the association between cognitive activity levels and executive function was robust (β [SE], 1.831 [0.499], false discovery rate P < .001)., Conclusions and Relevance: The findings suggest that a life course approach may delineate the association between leisure activities and cognitive and brain health and that interventions aimed at improving and maintaining cognitive engagement may be valuable for the cognitive health of community-dwelling older adults.
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- 2020
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44. Correction: Arterial smooth muscle cell PKD2 (TRPP1) channels regulate systemic blood pressure.
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Bulley S, Fernández-Peña C, Hasan R, Leo MD, Muralidharan P, MacKay CE, Evanson KW, Moreira-Junior L, Mata-Daboin A, Burris SK, Wang Q, Kuruvilla KP, and Jaggar JH
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- 2020
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45. Correction: Intravascular flow stimulates PKD2 (polycystin-2) channels in endothelial cells to reduce blood pressure.
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MacKay CE, Leo MD, Fernández-Peña C, Hasan R, Yin W, Mata-Daboin A, Bulley S, Gammons J, Mancarella S, and Jaggar JH
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- 2020
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46. Intravascular flow stimulates PKD2 (polycystin-2) channels in endothelial cells to reduce blood pressure.
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MacKay CE, Leo MD, Fernández-Peña C, Hasan R, Yin W, Mata-Daboin A, Bulley S, Gammons J, Mancarella S, and Jaggar JH
- Subjects
- Animals, Calcium Signaling, Hypertension genetics, Hypertension physiopathology, Intermediate-Conductance Calcium-Activated Potassium Channels metabolism, Male, Membrane Potentials, Mesenteric Arteries physiopathology, Mice, Knockout, Nitric Oxide metabolism, Nitric Oxide Synthase Type III metabolism, Phosphorylation, Regional Blood Flow, Small-Conductance Calcium-Activated Potassium Channels metabolism, TRPP Cation Channels deficiency, TRPP Cation Channels genetics, Arterial Pressure, Endothelial Cells metabolism, Hypertension metabolism, Mechanotransduction, Cellular, Mesenteric Arteries metabolism, TRPP Cation Channels metabolism, Vasodilation
- Abstract
PKD2 (polycystin-2, TRPP1), a TRP polycystin channel, is expressed in endothelial cells (ECs), but its physiological functions in this cell type are unclear. Here, we generated inducible, EC-specific Pkd2 knockout mice to examine vascular functions of PKD2. Data show that a broad range of intravascular flow rates stimulate EC PKD2 channels, producing vasodilation. Flow-mediated PKD2 channel activation leads to calcium influx that activates SK/IK channels and eNOS serine 1176 phosphorylation in ECs. These signaling mechanisms produce arterial hyperpolarization and vasodilation. In contrast, EC PKD2 channels do not contribute to acetylcholine-induced vasodilation, suggesting stimulus-specific function. EC-specific PKD2 knockout elevated blood pressure in mice without altering cardiac function or kidney anatomy. These data demonstrate that flow stimulates PKD2 channels in ECs, leading to SK/IK channel and eNOS activation, hyperpolarization, vasodilation and a reduction in systemic blood pressure. Thus, PKD2 channels are a major component of functional flow sensing in the vasculature., Competing Interests: CM, ML, CF, RH, WY, AM, SB, JG, SM, JJ No competing interests declared, (© 2020, MacKay et al.)
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- 2020
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47. Association of midlife stroke risk with structural brain integrity and memory performance at older ages: a longitudinal cohort study.
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Zsoldos E, Mahmood A, Filippini N, Suri S, Heise V, Griffanti L, Mackay CE, Singh-Manoux A, Kivimäki M, and Ebmeier KP
- Abstract
Cardiovascular health in midlife is an established risk factor for cognitive function later in life. Knowing mechanisms of this association may allow preventative steps to be taken to preserve brain health and cognitive performance in older age. In this study, we investigated the association of the Framingham stroke-risk score, a validated multifactorial predictor of 10-year risk of stroke, with brain measures and cognitive performance in stroke-free individuals. We used a large ( N = 800) longitudinal cohort of community-dwelling adults of the Whitehall II imaging sub-study with no obvious structural brain abnormalities, who had Framingham stroke risk measured five times between 1991 and 2013 and MRI measures of structural integrity, and cognitive function performed between 2012 and 2016 [baseline mean age 47.9 (5.2) years, range 39.7-62.7 years; MRI mean age 69.81 (5.2) years, range 60.3-84.6 years; 80.6% men]. Unadjusted linear associations were assessed between the Framingham stroke-risk score in each wave and voxelwise grey matter density, fractional anisotropy and mean diffusivity at follow-up. These analyses were repeated including socio-demographic confounders as well as stroke risk in previous waves to examine the effect of residual risk acquired between waves. Finally, we used structural equation modelling to assess whether stroke risk negatively affects cognitive performance via specific brain measures. Higher unadjusted stroke risk measured at each of the five waves over 20 years prior to the MRI scan was associated with lower voxelwise grey and white matter measures. After adjusting for socio-demographic variables, higher stroke risk from 1991 to 2009 was associated with lower grey matter volume in the medial temporal lobe. Higher stroke risk from 1997 to 2013 was associated with lower fractional anisotropy along the corpus callosum. In addition, higher stroke risk from 2012 to 2013, sequentially adjusted for risk measured in 1991-94, 1997-98 and 2002-04 (i.e. 'residual risks' acquired from the time of these examinations onwards), was associated with widespread lower fractional anisotropy, and lower grey matter volume in sub-neocortical structures. Structural equation modelling suggested that such reductions in brain integrity were associated with cognitive impairment. These findings highlight the importance of considering cerebrovascular health in midlife as important for brain integrity and cognitive function later in life (ClinicalTrials.gov Identifier: NCT03335696)., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain.)
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- 2020
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48. Nigrosome 1 imaging in REM sleep behavior disorder and its association with dopaminergic decline.
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Barber TR, Griffanti L, Bradley KM, McGowan DR, Lo C, Mackay CE, Hu MT, and Klein JC
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- Aged, Cohort Studies, Female, Humans, Male, Middle Aged, Multimodal Imaging, Nortropanes, Single-Blind Method, Tomography, Emission-Computed, Single-Photon, Dopamine Plasma Membrane Transport Proteins metabolism, Magnetic Resonance Imaging methods, Magnetic Resonance Imaging standards, Neuroimaging methods, Neuroimaging standards, Parkinson Disease diagnostic imaging, Parkinson Disease metabolism, Parkinson Disease pathology, Pars Compacta diagnostic imaging, Pars Compacta pathology, Putamen diagnostic imaging, Putamen metabolism, REM Sleep Behavior Disorder diagnostic imaging, REM Sleep Behavior Disorder metabolism, REM Sleep Behavior Disorder pathology
- Abstract
Objectives: Rapid eye movement sleep behavior disorder (RBD) patients have a high risk of developing a Parkinsonian disorder, offering an opportunity for neuroprotective intervention. Predicting near-term conversion, however, remains a challenge. Dopamine transporter imaging, while informative, is expensive and not widely available. Here, we investigate the utility of susceptibility-weighted MRI (SWI) to detect abnormalities of the substantia nigra in RBD, and explore their association with striatal dopaminergic deficits., Methods: SWI of the substantia nigra was performed in 46 RBD patients, 27 Parkinson's patients, and 32 control subjects. Dorsal nigral hyperintensity (DNH) was scored by two blinded raters, and separately quantified using a semiautomated process. Forty-two RBD patients were also imaged with
123 I-ioflupane single-photon emission computed tomography (DaT SPECT/CT)., Results: Consensus visual DNH classification was possible in 87% of participants. 27.5% of RBD patients had lost DNH, compared with 7.7% of control subjects and 96% of Parkinson's patients. RBD patients lacking DNH had significantly lower putamen dopaminergic SPECT/CT activity compared to RBD patients with DNH present (specific uptake ratios 1.89 vs. 2.33, P = 0.002). The mean quantified DNH signal intensity declined in a stepwise pattern, with RBD patients having lower intensity than controls (0.837 vs. 0.877, P = 0.01) but higher than PD patients (0.837 vs. 0.765, P < 0.001)., Interpretation: Over one quarter of RBD patients have abnormal substantia nigra SWI reminiscent of Parkinson's, which is associated with a greater dopaminergic deficit. This modality may help enrich neuroprotective trials with early converters., (© 2019 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals, Inc on behalf of American Neurological Association.)- Published
- 2020
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49. Multimodal MRI of grey matter, white matter, and functional connectivity in cognitively healthy mutation carriers at risk for frontotemporal dementia and Alzheimer's disease.
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Feis RA, Bouts MJRJ, Dopper EGP, Filippini N, Heise V, Trachtenberg AJ, van Swieten JC, van Buchem MA, van der Grond J, Mackay CE, and Rombouts SARB
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- Aged, Alzheimer Disease genetics, Alzheimer Disease pathology, Brain diagnostic imaging, Brain pathology, Early Diagnosis, Female, Frontotemporal Dementia genetics, Frontotemporal Dementia pathology, Genetic Predisposition to Disease, Gray Matter pathology, Humans, Magnetic Resonance Imaging methods, Male, Middle Aged, Mutation, Neural Pathways pathology, White Matter pathology, Alzheimer Disease diagnostic imaging, Frontotemporal Dementia diagnostic imaging, Gray Matter diagnostic imaging, Neural Pathways diagnostic imaging, White Matter diagnostic imaging
- Abstract
Background: Frontotemporal dementia (FTD) and Alzheimer's disease (AD) are associated with divergent differences in grey matter volume, white matter diffusion, and functional connectivity. However, it is unknown at what disease stage these differences emerge. Here, we investigate whether divergent differences in grey matter volume, white matter diffusion, and functional connectivity are already apparent between cognitively healthy carriers of pathogenic FTD mutations, and cognitively healthy carriers at increased AD risk., Methods: We acquired multimodal magnetic resonance imaging (MRI) brain scans in cognitively healthy subjects with (n=39) and without (n=36) microtubule-associated protein Tau (MAPT) or progranulin (GRN) mutations, and with (n=37) and without (n=38) apolipoprotein E ε4 (APOE4) allele. We evaluated grey matter volume using voxel-based morphometry, white matter diffusion using tract-based spatial statistics (TBSS), and region-to-network functional connectivity using dual regression in the default mode network and salience network. We tested for differences between the respective carriers and controls, as well as for divergence of those differences. For the divergence contrast, we additionally performed region-of-interest TBSS analyses in known areas of white matter diffusion differences between FTD and AD (i.e., uncinate fasciculus, forceps minor, and anterior thalamic radiation)., Results: MAPT/GRN carriers did not differ from controls in any modality. APOE4 carriers had lower fractional anisotropy than controls in the callosal splenium and right inferior fronto-occipital fasciculus, but did not show grey matter volume or functional connectivity differences. We found no divergent differences between both carrier-control contrasts in any modality, even in region-of-interest analyses., Conclusions: Concluding, we could not find differences suggestive of divergent pathways of underlying FTD and AD pathology in asymptomatic risk mutation carriers. Future studies should focus on asymptomatic mutation carriers that are closer to symptom onset to capture the first specific signs that may differentiate between FTD and AD.
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- 2019
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50. SUMO1 modification of PKD2 channels regulates arterial contractility.
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Hasan R, Leo MD, Muralidharan P, Mata-Daboin A, Yin W, Bulley S, Fernandez-Peña C, MacKay CE, and Jaggar JH
- Abstract
PKD2 (polycystin-2, TRPP1) channels are expressed in a wide variety of cell types and can regulate functions, including cell division and contraction. Whether posttranslational modification of PKD2 modifies channel properties is unclear. Similarly uncertain are signaling mechanisms that regulate PKD2 channels in arterial smooth muscle cells (myocytes). Here, by studying inducible, cell-specific Pkd2 knockout mice, we discovered that PKD2 channels are modified by SUMO1 (small ubiquitin-like modifier 1) protein in myocytes of resistance-size arteries. At physiological intravascular pressures, PKD2 exists in approximately equal proportions as either nonsumoylated (PKD2) or triple SUMO1-modifed (SUMO-PKD2) proteins. SUMO-PKD2 recycles, whereas unmodified PKD2 is surface-resident. Intravascular pressure activates voltage-dependent Ca
2+ influx that stimulates the return of internalized SUMO-PKD2 channels to the plasma membrane. In contrast, a reduction in intravascular pressure, membrane hyperpolarization, or inhibition of Ca2+ influx leads to lysosomal degradation of internalized SUMO-PKD2 protein, which reduces surface channel abundance. Through this sumoylation-dependent mechanism, intravascular pressure regulates the surface density of SUMO-PKD2-mediated Na+ currents (INa ) in myocytes to control arterial contractility. We also demonstrate that intravascular pressure activates SUMO-PKD2, not PKD2, channels, as desumoylation leads to loss of INa activation in myocytes and vasodilation. In summary, this study reveals that PKD2 channels undergo posttranslational modification by SUMO1, which enables physiological regulation of their surface abundance and pressure-mediated activation in myocytes and thus control of arterial contractility.- Published
- 2019
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