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Background: McLeod syndrome (MLS) and chorea-acanthocytosis (ChAc) are exceedingly rare diseases characterized by a variety of movement disorders including chorea, dystonia, and Parkinsonism. Genetic analysis plays a key role in early and accurate diagnosis, but relevant variants are still under investigation. This study aims to explore new pathogenic variants in Chinese patients with MLS and ChAc and to conduct a comprehensive analysis of the clinical heterogeneity among these patients., Methods: Eighteen Chinese patients who presented with choreatic movements with negative HTT genetic testing were identified and underwent targeted next-generation sequencing, verified by Sanger sequencing., Results: Two novel XK variants (c.970A>T, c.422_423del) were identified in three index MLS patients and six novel VPS13A variants (c.9219C>A, c.3467T>A, c.4208dup, c.9243_9246del, c.5364del, c.556-290_697-483del) in five index ChAc patients. One copy number variant of VPS13A (g.79827595_79828762del/c.556-290_697-483del) was firstly described in Chinese population., Conclusion: As the currently largest descriptive study of MLS and ChAc patients in China, this study expands on the clinical and genetic spectrum of XK and VPS13A, contributing to the clinical diagnosis of MLS and ChAc., (© 2024 The Author(s). Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Huntington disease (HD)-like 2 (HDL2) is a rare genetic disease caused by an expanded trinucleotide repeat in the JPH3 gene (encoding junctophilin 3) that shows remarkable clinical similarity to HD. To date, HDL2 has been reported only in patients with definite or probable African ancestry. A single haplotype background is shared by patients with HDL2 from different populations, supporting a common African origin for the expansion mutation. Nevertheless, outside South Africa, reports of patients with HDL2 in Africa are scarce, probably owing to limited clinical services across the continent. Systematic comparisons of HDL2 and HD have revealed closely overlapping motor, cognitive and psychiatric features and similar patterns of cerebral and striatal atrophy. The pathogenesis of HDL2 remains unclear but it is proposed to occur through several mechanisms, including loss of protein function and RNA and/or protein toxicity. This Review summarizes our current knowledge of this African-specific HD phenocopy and highlights key areas of overlap between HDL2 and HD. Given the aforementioned similarities in clinical phenotype and pathology, an improved understanding of HDL2 could provide novel insights into HD and other neurodegenerative and/or trinucleotide repeat expansion disorders., (© 2023. Springer Nature Limited.)

Pathogenic variants in ARX lead to a variety of phenotypes with intellectual disability being a uniform feature. Other features can include severe epilepsy, spasticity, movement disorders, agenesis of the corpus callosum, lissencephaly, hydranencephaly and ambiguous genitalia in males. We present the first report of monozygotic female twins with a de novo ARX pathogenic variant (c.1406_1415del; p. Ala469Aspfs*20), predicted to result in a truncated ARX protein missing the important regulatory Aristaless domain. The twins presented with profound developmental delay and seizures, consistent with the known genotype-phenotype correlation. Twin 2's features were significantly more severe. She also developed chorea; the first time this movement disorder has been seen in an ARX variant other than an expansion of the first polyalanine tract. Differential X-chromosome inactivation was the most likely explanation for the differing severities but could not be conclusively proven., (Crown Copyright © 2021. Published by Elsevier Masson SAS. All rights reserved.)

Paroxysmal dyskinesias (PD) are rare movement disorders characterized by recurrent attacks of dystonia, chorea, athetosis, or their combination, with large phenotypic and genetic heterogeneity. 3-Hydroxy-isobutyryl-CoA hydrolase ( HIBCH ) deficiency is a neurodegenerative disease characterized in most patients by a continuous decline in psychomotor abilities or a secondary regression triggered by febrile infections and metabolic crises.We describe two PD patients from two pedigrees, both carrying a homozygous c.913A > G, p.Thr305Ala mutation in the HIBCH gene, associated with an unusual clinical presentation. The first patient presented in the second year of life with right paroxysmal hemidystonia lasting for 30 minutes, without any loss of consciousness and without any triggering factor. The second patient has presented since the age of 3 recurrent exercise-induced PD episodes which have been described as abnormal equinovarus, contractures of the lower limbs, lasting for 1 to 4 hours, associated with choreic movements of the hands. Their neurological examination and metabolic screening were normal, while brain magnetic resonance imaging showed abnormal signal of the pallidi.We suggest that HIBCH deficiency, through the accumulation of metabolic intermediates of the valine catabolic pathway, leads to a secondary defect in respiratory chain activity and pyruvate dehydrogenase ( PDH ) activity and to a broad phenotypic spectrum ranging from Leigh syndrome to milder phenotypes. The two patients presented herein expand the spectrum of the disease to include unusual paroxysmal phenotypes and HIBCH deficiency should be considered in the diagnostic strategy of PD to enable adequate preventive treatment., Competing Interests: None of the authors has any conflict of interest to disclose., (Thieme. All rights reserved.)

Background: Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early-onset non-progressive involuntary movements. Although NKX2-1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2-1 gene, indicating that mutations of non-coding regulatory elements of NKX2-1 may also play a role., Methods and Results: By using whole-genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2-1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2-1 on chromosome 14q13.2-q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non-coding sequences., Conclusion: We propose that the deletion of potential regulatory elements necessary for NKX2-1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease-causing mechanism for BHC., (© 2021 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Background: Our aim in this study was to evaluate the efficacy of magnetic resonance imaging (MRI) studies in the detection of brain regions effected by Sydenham chorea and to determine whether they provided data regarding the pathogenesis of Sydenham chorea. To this end, we assessed basal ganglia structures in Sydenham chorea patients and control group by quantitative MRI volumetric analysis., Methods: Patients with a recent onset of chorea and control subjects matched for age and gender were included in the study. Medical history, laboratory tests, and physical and neurologic examinations were reviewed. All MRIs were considered within normal limits. High-resolution T1-weighted 3D magnetization-prepared rapid acquisition of gradient echo scans were used for quantitative volumetric assessment of the brain via the "volBrain" method., Results: Twenty-four subjects with Sydenham chorea (16 girls and 8 boys, aged between 7 and 16 years) and 35 control subjects were evaluated. Mean age was 11.25 ± 2.89 years for Sydenham chorea patients and 10.58 ± 2.53 years for the controls. No significant difference was found relative to globus pallidus, caudate, and thalamic volumes between patients with Sydenham chorea and controls. The relative mean total, left, and right putamen volumes were significantly larger in patients with Sydenham chorea compared to controls ( P = .003, P = .018, P = .001, respectively)., Conclusion: Selective neuroanatomic differences in putamen among other basal ganglia structures and significant increases in size are consistent with a hypothesis of a cross-reactive antibody-mediated inflammation of the putamen as being the pathophysiologic mechanism for this disorder.

Cerebral infarction as well as other thromboses, headaches, and visual complaints are well-known symptoms of polycythemia vera. However, chorea and neuropsychiatric disturbances are less recognized consequences of this chronic disease. Whereas chorea is a rare but acknowledged symptom of polycythemia vera, neuropsychiatric symptoms have only sporadically been reported. We depict 2 patients with an unusual presentation of polycythemia vera. Our first patient presented with right-sided hemiballism and psychosis, and the second patient had a long diagnostic trajectory of unexplained chorea. In both cases diagnosis of JAK2 positive polycythemia vera was established, and in both cases remarkable recovery occurred after the initiation of phlebotomies. The underlying pathophysiology of these symptoms has not been clearly elucidated. Because of the unfamiliarity of the link between especially neuropsychiatric symptoms and polycythemia, current reported numbers are probably an underestimation. Benefit of treatment appears to be large. We seek to create more awareness among physicians about this phenomenon., (© 2021 S. Karger AG, Basel.)

Background: Mutations in SQSTM1 gene have been recently identified as a rare cause of progressive childhood neurodegenerative disorder. So far, only 25 patients from 10 unrelated families were reported., Methods and Results: We report on the first Tunisian case of an 11-year-old girl with cerebellar ataxia, chorea and ophthalmoparesis. Brain MRI was normal. Whole-exome sequencing revealed a homozygous mutation c.823_824del(p.Ser275Phefs*17) in SQSTM1 gene (GenBank: NM_003900.4)., Conclusion: By pooling our data to the data of literature, we delineated the phenotypic spectrum and stressed on genetic heterogeneity of this rare neurodegenerative disease., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Cause of complex dyskinesia remains elusive in some patients. A homozygous missense variant leading to drastic decrease of PDE2A enzymatic activity was reported in one patient with childhood-onset choreodystonia preceded by paroxysmal dyskinesia and associated with cognitive impairment and interictal EEG abnormalities. Here, we report three new cases with biallelic PDE2A variants identified by trio whole-exome sequencing. Mitochondria network was analyzed after Mitotracker™ Red staining in control and mutated primary fibroblasts. Analysis of retrospective video of patients' movement disorder and refinement of phenotype was carried out. We identified a homozygous gain of stop codon variant c.1180C>T; p.(Gln394*) in PDE2A in siblings and compound heterozygous variants in young adult: a missense c.446C>T; p.(Pro149Leu) and splice-site variant c.1922+5G>A predicted and shown to produce an out of frame transcript lacking exon 22. All three patients had cognitive impairment or developmental delay. The phenotype of the two oldest patients, aged 9 and 26, was characterized by childhood-onset refractory paroxysmal dyskinesia initially misdiagnosed as epilepsy due to interictal EEG abnormalities. The youngest patient showed a proven epilepsy at the age of 4 months and no paroxysmal dyskinesia at 15 months. Interestingly, analysis of the fibroblasts with the biallelic variants in PDE2A variants revealed mitochondria network morphology changes. Together with previously reported case, our three patients confirm that biallelic PDE2A variants are a cause of childhood-onset refractory paroxysmal dyskinesia with cognitive impairment, sometimes associated with choreodystonia and interictal baseline EEG abnormalities or epilepsy.

Four female Shetland Sheepdogs with hypertonic paroxysmal dyskinesia, mainly triggered by exercise and stress, were investigated in a retrospective multi-center investigation aiming to characterize the clinical phenotype and its underlying molecular etiology. Three dogs were closely related and their pedigree suggested autosomal dominant inheritance. Laboratory diagnostic findings included mild lactic acidosis and lactaturia, mild intermittent serum creatine kinase (CK) elevation and hypoglycemia. Electrophysiological tests and magnetic resonance imaging of the brain were unremarkable. A muscle/nerve biopsy revealed a mild type II fiber predominant muscle atrophy. While treatment with phenobarbital, diazepam or levetiracetam did not alter the clinical course, treatment with a gluten-free, home-made fresh meat diet in three dogs or a tryptophan-rich, gluten-free, seafood-based diet, stress-reduction, and acetazolamide or zonisamide in the fourth dog correlated with a partial reduction in, or even a complete absence of, dystonic episodes. The genomes of two cases were sequenced and compared to 654 control genomes. The analysis revealed a case-specific missense variant, c.1658G>A or p.Arg553Gln, in the PCK2 gene encoding the mitochondrial phosphoenolpyruvate carboxykinase 2. Sanger sequencing confirmed that all four cases carried the mutant allele in a heterozygous state. The mutant allele was not found in 117 Shetland Sheepdog controls and more than 500 additionally genotyped dogs from various other breeds. The p.Arg553Gln substitution affects a highly conserved residue in close proximity to the GTP-binding site of PCK2. Taken together, we describe a new form of paroxysmal exercise-induced dyskinesia (PED) in dogs. The genetic findings suggest that PCK2:p.Arg553Gln should be further investigated as putative candidate causal variant.

Mutations in RNF216 have been found to be associated with autosomal recessive Huntington-like disorder. Here, we describe a patient with Huntington-like disorder caused by a novel de novo RNF216 mutation. The patient started to have choreatic movements of both hands, slowly progressing to head, face, and four extremities, with prominent cognitive deterioration. White matter lesions in cerebral hemispheres and brainstem, cerebellar atrophy, and low gonadotropin serum levels have been demonstrated. We have identified a homozygous deletion of exon 2 in the RNF216 gene by whole-exome sequencing. Our findings increased genetic knowledge of autosomal recessive Huntington-like disorder and extended the ethnic distribution of RNF216 mutations., (© 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Purpose : To describe and distinguish clinical phenotypes with the overlapping feature of optic atrophy caused by distinct mutations in the same gene, OPA3. We report 3 affected siblings in a consanguineous family harboring a novel OPA3 mutation causing 3-methylglutaconic aciduria type III with optic atrophy. Methods : Retrospective case series. Results : Three siblings (2 male, 1 female) among 6 children in a consanguineous Afghani family developed decreased vision from early childhood. Both parents and all extended family members were unaffected. All 3 affected siblings suffered from severe visual impairment ranging from visual acuities of 20/150 to counting fingers. All had spastic lower extremity weakness and ataxia. Two of the three affected siblings also had a history of seizures, and the female sibling had limited cognition with diffuse atrophic changes on brain MRI. Two of the three individuals also had migraine-like headaches. Urine organic acid analysis revealed mildly elevated 3-methylglutaconic acid for the male siblings. Whole exome sequencing and subsequent PCR confirmation revealed a novel variant in OPA3 (intron1, c.142 + 2_142 + 3dupTG), affecting the consensus sequence of the splice site, for which all 3 clinically affected siblings were homozygous. Discussion : Mutations in OPA3 can cause optic atrophy in a dominant pattern of inheritance associated with cataract or in a recessive pattern associated with spastic paresis and ataxia. The novel recessive mutation and clinical presentations described herein further support how different mutation types affecting OPA3 can produce distinct clinical phenotypes and underscore the critical and susceptible role of mitochondrial health in optic nerve function.

Huntington's Disease-Like 2 (HDL2), caused by a CTG/CAG expansion in JPH3 on chromosome 16q24, is the most common Huntington's Disease (HD) phenocopy in populations with African ancestry. Qualitatively, brain MRIs of HDL2 patients have been indistinguishable from HD. To determine brain regions most affected in HDL2 a cross-sectional study using MRI brain volumetry was undertaken to compare the brains of nine HDL2, 11 HD and nine age matched control participants. Participants were ascertained from the region in South Africa with the world's highest HDL2 incidence. The HDL2 and HD patient groups showed no significant differences with respect to mean age at MRI, disease duration, abnormal triplet repeat length, or age at disease onset. Overall, intracerebral volumes were smaller in both affected groups compared to the control group. Comparing the HDL2 and HD groups across multiple covariates, cortical and subcortical volumes were similar with the exception that the HDL2 thalamic volumes were smaller. Consistent with other similarities between the two diseases, these results indicate a pattern of neurodegeneration in HDL2 that is remarkably similar to HD. However smaller thalamic volumes in HDL2 raises intriguing questions into the pathogenesis of both disorders, and how these volumetric differences relate to their respective phenotypes., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Hyperglycemia-associated chorea-ballism (HCB) is an infrequent neurological syndrome occurring predominantly in elderly females and in the setting of non-ketotic hyperglycemia (NKH). A systematic review was conducted in accordance with the PRISMA statement. Studies published between 1980 and 2018 that reported demographic, clinical, laboratory and imaging features from patients with HCB were screened. 136 studies describing 286 patients were included in the analysis. The patients included had a median age of 72 years; those with ketotic hyperglycemia (KH) were older (p<0.001). Women and NKH patients were the most frequently affected (63% and 92%, respectively). The median glucose level at admission was 420 mg/dL (IQR 328-535), and was significantly higher in KH (p=0.009). Moreover, the absence of a clear lesion on imaging studies and the finding of bilateral imaging evidence of lesions were each more frequent in the KH group (p=0.036 and p=0.008, respectively). 48 cases (19.4%) presented with bilateral CT/MRI lesions, having higher values of plasma osmolarity compared with the patients with unilateral lesions (p=0.011). Every patient received hypoglycemic treatment, but only 174 (60.84%) were prescribed neuroleptics. 213 patients (84.86%) showed a total recovery, after a median of 14 days (IQR 3-31). Bilateral chorea-ballism was supported by bilateral imaging evidence of involvement in only 60% of the cases (positive predictive value). Patients not prescribed neuroleptics, with negative lentiform nucleus involvement, and age within the third tertile (≥ 78 years) had an odds ratio of 6.6 (CI 95% 1.18-141.10) for a complete clinical recovery. Significant differences were identified between types of hyperglycemia and regarding the clinical and imaging laterality features. Furthermore, the predictor variables evaluated showed potential utility for assessing the prognosis of HCB patients.

Purpose of Review: This review will discuss the expanding clinical spectrum of paroxysmal movement disorders and therapeutic options in light of emerging genotypic heterogeneity in these conditions., Recent Findings: Paroxysmal movement disorders comprise a heterogeneous group of rare neurological conditions characterized by intermittent episodes of abnormal movement associated with various triggers. As the clinical and genotypic spectrum of these disorders evolves, so also has the range of therapeutic options. Triheptanoin has recently been shown to be a very promising alternative to the ketogenic diet in paroxysmal exercise-induced dyskinesia. Four-aminopyridine is now considered first-line symptomatic therapy for episodic ataxia type-2, with pre-clinical findings indicating cerebellar neuroprotection., Summary: In light of the newly emerging therapies, careful clinical phenotyping is needed to ensure diagnostic precision and timely initiation of appropriate therapies.

Frontotemporal dementia (FTD) is clinically characterized by behavioral changes, language impairment, and executive dysfunction. FTD usually belongs to the frontotemporal lobar degeneration (FTLD) disease group, and its familial forms are dominantly inherited and linked to a group of genes relevant to frontal and temporal brain pathology, such as MAPT, GRN, C9ORF72, TARDBP, CHMP2B, VCP, and FUS. However, FTD can also be associated with different clinical or pathological phenotypes caused by mutations in other genes, whose heredity can be dominant or recessive. In this work we report on a familial case of FTD characterized by behavioral changes and aphasia, very early onset and very long duration, choreic movements, and white matter lesions at magnetic resonance imaging. We performed a wide-range genetic analysis, using a next generation sequencing approach, to evaluate a number of genes involved in neurodegeneration. We found a previously unreported compound heterozygous mutation in TREM2, that is commonly associated with the recessively inherited Nasu-Hakola disease. We discuss the differential diagnosis to be taken into account in cases of FTD presenting with atypical features.

We retrospectively studied the clinical presentation, treatment modalities and outcome in 16 patients with heterozygous NKX2-1 mutation associated with chronic lung disease. Twelve different NKX2-1 mutations, including 4 novel mutations, were identified in the 16 patients. Nine patients presented with brain-lung-thyroid syndrome, 3 had neurological and lung symptoms and 4 had only pulmonary symptoms. Ten patients had neonatal respiratory distress, and 6 of them developed infiltrative lung disease (ILD). The other patients were diagnosed with ILD in childhood (n = 3) or in adulthood (n = 3). The median age at diagnosis was 36 months (IQ 3.5-95). Patient testing included HRCT (n = 13), BALF analysis (n = 6), lung biopsies (n = 3) and lung function tests (n = 6). Six patients required supplemental oxygen support with a median duration of 18 months (IQ 2.5-29). All symptomatic ILD patients (n = 12) benefited from a treatment consisting of steroids, azithromycin (n = 9), and/or hydroxychloroquine (n = 4). The median follow-up was 36 months (IQ 24-71.5). One patient died of respiratory failure at 18 months and another is waiting for lung transplantation. In summary, the initial diagnosis was based on clinical presentation and radiological features, but the presentation was heterogeneous. Definitive diagnosis required genetic analysis, which should be performed, even in absence of neurological or thyroid symptoms., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: Hyperglycemia can induce hemichorea-hemiballism, especially in elderly type II diabetics. CT and MRI findings include hyperdensity and T1-shortening in the contralateral lentiform nucleus, respectively. This study explores the associated imaging findings on T2*-based sequences., Methods: Six patients with clinically documented hyperglycemia-induced hemichorea-hemiballism who had undergone MR imaging with a T2*-based sequence (T2* gradient echo or susceptibility-weighted imaging) were included in this retrospective case series., Results: All six patients demonstrated T1-shortening contralateral to their hemichorea-hemiballism. T2*-based sequences demonstrated unilateral hypointense signal within the striatum in four patients. One patient had mild bilateral striatal hyperintensities, while another did not show significant signal changes., Conclusion: It is important for the radiologist to be aware of the signal changes that can be seen on T2*-based sequences in hyperglycemia-induced hemochorea-hemiballism., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Purpose of Review: Huntington's disease-like 2 (HDL2) is a rare, progressive, autosomal dominant neurodegenerative disorder that genetically, clinically, and pathologically closely resembles Huntington's disease. We review HDL2 pathogenic mechanisms and examine the implications of these mechanisms for Huntington's disease and related diseases., Recent Findings: HDL2 is caused by a CTG/CAG repeat expansion in junctophilin-3. Available data from cell and animal models and human brain suggest that HDL2 is a complex disease in which transcripts and proteins expressed bidirectionally from the junctophilin-3 locus contribute to pathogenesis through both gain-and loss-of-function mechanisms. Recent advances indicate that the pathogenesis of Huntington's disease is equally complex, despite the emphasis on toxic gain-of-function properties of the mutant huntingtin protein., Summary: Studies examining in parallel the genetic, clinical, neuropathological, and mechanistic similarities between Huntington's disease and HDL2 have begun to identify points of convergence between the pathogenic pathways of the two diseases. Comparisons to other diseases that are phenotypically or genetically related to Huntington's disease and HDL2 will likely reveal additional common pathways. The ultimate goal is to identify shared therapeutic targets and eventually develop therapies that may, at least in part, be effective across multiple similar rare diseases, an essential approach given the scarcity of resources for basic and translational research.

The pathogenesis of HD and HDL2, similar progressive neurodegenerative disorders caused by expansion mutations, remains incompletely understood. No systematic quantitative proteomics studies, assessing global changes in HD or HDL2 human brain, were reported. To address this deficit, we used a stable isotope labeling-based approach to quantify the changes in protein abundances in the cortex of 12 HD and 12 control cases and, separately, of 6 HDL2 and 6 control cases. The quality of the tissues was assessed to minimize variability due to post mortem autolysis. We applied a robust median sweep algorithm to quantify protein abundance and performed statistical inference using moderated test statistics. 1211 proteins showed statistically significant fold changes between HD and control tissues; the differences in selected proteins were verified by Western blotting. Differentially abundant proteins were enriched in cellular pathways previously implicated in HD, including Rho-mediated, actin cytoskeleton and integrin signaling, mitochondrial dysfunction, endocytosis, axonal guidance, DNA/RNA processing, and protein transport. The abundance of 717 proteins significantly differed between control and HDL2 brain. Comparative analysis of the disease-associated changes in the HD and HDL2 proteomes revealed that similar pathways were altered, suggesting the commonality of pathogenesis between the two disorders.

This was an exploratory study comparing neuropsychological manifestations of Sydenham's chorea (SC), 6 months after initiation of treatment, in children who had received intravenous immunoglobulins as an adjunct to standard treatment, with those who had received standard treatment. We included a non-SC control group for comparison. We hypothesized that compared to controls, children with SC who had received prior intravenous immunoglobulins would demonstrate less pronounced impairments compared to those who had received standard care. We conducted a cross-sectional analysis of 17 children with -SC who had received treatment 6 months previously (9 treated with standard of care and 8 augmented with intravenous immunoglobulins) and 17 non-SC, medically well controls. The standard treatment group (n = 9) exhibited significant behavioral difficulties, including significantly poorer co-operation (p = 0.009) compared with the other augmented immunoglobulins and non-SC control groups, and increased impulsivity (p = 0.016) compared with non-SC controls. The standard treatment group scored significantly lower than the other two groups on a measure of executive functioning (p = 0.03). Children with SC may be more at risk for neuropsychological difficulties than non-SC, medically well children. Intravenous immunoglobulins may mitigate some of these impairments.

Two siblings born to non-consanguineous parents showed nystagmus and sudden opistotonic posturing from the early infancy, and subsequent developmental delay and marked choreiform movements with hypotonia in the childhood. The brother had a mild postnatal microcephaly. Brain MRI of the sister showed mild delay of myelination, dilated anterior horn and mild cerebellar atrophy. Whole exome sequencing (WES) revealed compound heterozygous mutations in MED17 gene in both siblings: c.1013-5A>G and c.1484T>G mutations transmitted from their father and mother, respectively. The c.1013-5A>G mutation caused insertion of 4 bases of intron 6 in the transcript, resulting in frameshift (p. Ser338Asnfs*15), and mutant transcript underwent nonsense-mediated mRNA decay in lymphoblastoid cells derived from two siblings. The c.1484T>G mutation substituted a leucine residue, which is highly conserved among the vertebrates, and was predicted to be damaging by in silico analysis programs. Both mutations were not registered in dbSNP data and in our 575 control exomes. These results suggest that the siblings' mutations are likely to be pathogenic. This is the second case report concerning MED17 mutations. Compared with the first reported cases of Caucasian Jewish origin, the clinical symptoms and courses are much milder and slower, respectively, in our cases. Genotype difference (a homozygous mutation versus compound heterozygous mutations) might explain these clinical differences between two cases, though early-onset nystagmus and later choreiform movements were unique in our cases. Clinical spectrum and phenotype-genotype correlations in this rare mutation should be further elucidated., (Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Hemichorea is a disorder characterized by abnormal, continuous, nonrhythmic, jerky, and distal movement involving one side of the body. It may result from cerebrovascular insult to basal ganglia, or from other causes including neoplasm, infection, and non-ketotic hyperglycemia. We report the clinical, laboratory, and neuroimaging data with treatment response of a Saudi woman who has diabetes with left side hemichorea, involving the face, and upper and lower extremities, with unilateral right striatal hyperintense signal changes in T1 weighted MRI, and a hyperglycemic state of longstanding uncontrolled diabetes. Literature review suggested a syndrome with a triad of symptoms: non-ketotic hyperglycemia, hemichorea, and T1 MRI striatal hyperintensities. As the number of internationally reported cases is still modest, reporting more patients will highlight aspects pertaining to the diagnosis and treatment of this condition. We present a patient who had a sustained therapeutic result from haloperidol and clonazepam.

Unlabelled: The authors present a Brazilian case series of eight patients with idiopathic very-late onset (mean 75.5 years old) cerebellar ataxia, featuring predominantly gait ataxia, associated with cerebellar atrophy., Method: 26 adult patients with a diagnosis of idiopathic late onset cerebellar ataxia were analyzed in a Brazilian ataxia outpatient clinic and followed regularly over 20 years. Among them, 8 elderly patients were diagnosed as probable very late onset cerebellar ataxia. These patients were evaluated with neurological, ophthalmologic and Mini-Mental Status examinations, brain MRI, and EMG., Results: 62.5% of patients were males, mean age was 81.9 years-old, and mean age of onset was 75.5 years. Gait cerebellar ataxia was observed in all patients, as well as, cerebellar atrophy on brain MRI. Mild cognitive impairment and visual loss, due to macular degeneration, were observed in 50% of cases. Chorea was concomitantly found in 3 patients., Conclusion: We believe that this condition is similar the one described by Marie-Foix-Alajouanine presenting with mild dysarthria, associated with gait ataxia, and some patients had cognitive dysfunction and chorea.

Background: Hemichorea is usually caused by a structural lesion in the contralateral basal ganglia or subthalamic nuclei or it develops as a form of a neurologic complication including hyperglycemia. We report a rare case of a patient who developed choreic movement in the right upper extremity associated with a contralateral middle cerebral artery (MCA) occlusion., Methods: A 76-year-old man presented with chorea in the right upper limb, known as monochorea, which occurred after recovery from losing consciousness while standing. He was found to have idiopathic orthostatic hypotension. His diffusion-weighted magnetic resonance imaging did not show signal changes indicative of acute ischemic lesions. A left carotid artery angiogram showed occlusion of the left MCA. (123)I-N-isopropyl-4-iodoamphetamine single-photon emission computed tomography of the brain showed marked hypoperfusion in the left MCA territory. His cerebrovascular reserve capacity determined using acetazolamide was relatively decreased in this territory. This decrease in cerebrovascular reserve capacity, however, did not require surgical treatment, such as extracranial-intracranial bypass surgery., Results: The recurrence of chorea was not observed after antiplatelet therapy and instruction on how to cope with orthostatic hypotension., Conclusions: It is considered that transient hemodynamic ischemia in the right basal ganglia-thalamocortical circuits because of the combination of MCA occlusion and hypotension was the underlying cause of the monochorea in this patient.Vascular imaging studies for early identification of occlusion or severe stenosis of cerebral major arteries should be carried out in patients acutely presenting with chorea, even in the absence of other clinical signs., (Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.)

Huntington disease (HD) is a progressive autosomal dominant neurodegenerative disorder, characterized by abnormal movements, cognitive decline, and psychiatric symptoms, caused by a CAG repeat expansion in the huntingtin (HTT) gene on chromosome 4p. A CAG/CTG repeat expansion in the junctophilin-3 (JPH3) gene on chromosome 16q24.2 causes a Huntington disease-like phenotype (HDL2). All patients to date with HDL2 have some African ancestry. The present study aimed to characterize the genetic basis of the Huntington disease phenotype in South Africans and to investigate the possible origin of the JPH3 mutation. In a sample of unrelated South African individuals referred for diagnostic HD testing, 62% (106/171) of white patients compared to only 36% (47/130) of black patients had an expansion in HTT. However, 15% (20/130) of black South African patients and no white patients (0/171) had an expansion in JPH3, confirming the diagnosis of Huntington disease like 2 (HDL2). Individuals with HDL2 share many clinical features with individuals with HD and are clinically indistinguishable in many cases, although the average age of onset and diagnosis in HDL2 is 5 years later than HD and individual clinical features may be more prominent. HDL2 mutations contribute significantly to the HD phenotype in South Africans with African ancestry. JPH3 haplotype studies in 31 families, mainly from South Africa and North America, provide evidence for a founder mutation and support a common African origin for all HDL2 patients. Molecular testing in individuals with an HD phenotype and African ancestry should include testing routinely for JPH3 mutations., (© 2015 Wiley Periodicals, Inc.)

Chorea may be secondary to hyperosmolar nonketotic hyperglycemia, but such situation has rarely been described in adolescents, particularly as the initial and single manifestation of type 1 diabetes. We describe a case of a previously healthy 14-year-old girl with sudden onset of choreic movements on her left upper and lower limbs. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed an area of hyperdensity/hyperintensity affecting the right striatum. Blood glucose was 349 mg/dL. Despite adequate glucose control, the involuntary movements persisted and haloperidol, later substituted with valproate, was prescribed, with satisfactory but not complete resolution of the chorea. In 2 other occasions, when the patient had an infection and subsequent hyperglycemia, the chorea relapsed. Although not common, hyperglycemia must be considered in the differential diagnosis of acute hemichorea-hemiballismus in children and adolescents, particularly because it is a potentially reversible cause., (© The Author(s) 2014.)

Infections, and the resulting immune response to these infections, have recently received increased recognition as pathogenic mechanisms for neuropsychiatric disorders. Sydenham's chorea (SC), a widely recognized post-streptococcal autoimmune disorder, represents a model for this proposed pathogenesis. In SC, a dysregulated immune response to a streptococcal infection is hypothesized to result in inflammation of neuronal networks, particularly the basal ganglia nuclei. The resulting dysfunction in the basal ganglia nuclei are hypothesized to lead to a constellation of adventitious movements and psychiatric symptoms, which investigations have shown are amenable to immunomodulatory therapies. PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infections) has been proposed as a variant of SC, and is hypothesized to share a pathogenic mechanism, despite a unique symptom profile of predominantly psychiatric symptoms. In this review, we present the clinical aspects of both disorders, the data for potential shared etiopathogenesis between them, and the evidence for the therapeutic use of immunomodulatory therapies for the symptoms of SC and PANDAS. This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In South Africa, and worldwide, rheumatic fever represents a public health problem. Improved diagnosis and management of Sydenham chorea, a major manifestation of acute rheumatic fever is key to prevention of rheumatic heart disease. This article reviews Sydenham chorea from its original description to current opinions. Recommendations are founded on expert opinion as class 1 data is lacking. This South African perspective is relevant to resource-poor settings globally insofar as it provides diagnosis and management recommendations for primary- and secondary-level healthcare professionals who care for patients in such environments. Four basic tenets of care are recommended, namely, elimination of the streptococcal infection, symptomatic treatment, immunological treatment, and nonpharmacologic interventions. A user-friendly outcome measurement tool, viable for use in low-resource settings is presented. Introduction of this tool may lead to increased awareness of the neuropsychiatric manifestations of poststreptococcal movement disorders in Africa, where reports are limited., (© The Author(s) 2014.)

Chaining or cascading of different actions and responses is necessary to accomplish a goal. Yet, little is known about the functional neuroanatomical-electrophysiological mechanisms mediating these processes. Computational models suggest that medium spiny neurons (MSNs) play an important role in action cascading, but this assumption has hardly been tested relating neuroanatomical and electrophysiological parameters in a human model of circumscribed MSN dysfunction. As a possible human model of circumscribed MSN dysfunction, we investigate benign hereditary chorea in a case-control study applying bootstrap statistics. To investigate these mechanisms, we used a stop-change paradigm, where we apply mathematical constraints to describe the degree of how task goals are activated with more or less overlap during action cascading. We record event-related potentials and analyze neural synchronization processes. The results show that MSN dysfunctions lead to deficits in action cascading processes only when two response options seek simultaneous access to response selection resources. Attentional selection processes are not affected, but processes reflecting the transition between stimulus evaluation and responding are affected. The results underline computational models of MSN functioning and show that dysfunction in these networks leads to a more parallel and hence inefficient response selection.

Paroxysmal dyskinesias are episodic movement disorders characterized by muscle hypertonicity that can produce involuntary movements. Signs emanate from the central nervous system; consciousness is not impaired, ictal electroencephalography is normal, and there are no autonomic signs, distinguishing them from seizure disorders. In humans they are classified into 3 groups, each responding to different therapies. A mutation in the gene for brevican (BCAN) has been identified as the cause of Episodic Falling in Cavalier King Charles spaniels. Further elucidation of the genetic causes will enhance our ability to identify and treat these canine diseases., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The aim of this study was to identify the relative frequency of Huntington's disease (HD) and HD-like (HDL) disorders HDL1, HDL2, spinocerebellar ataxia type 2 (SCA2), SCA17, dentatorubral-pallidoluysian degeneration (DRPLA), benign hereditary chorea, neuroferritinopathy and chorea-acanthocytosis (CHAC), in a series of Brazilian families. Patients were recruited in seven centers if they or their relatives presented at least chorea, besides other findings. Molecular studies of HTT, ATXN2, TBP, ATN1, JPH3, FTL, NKX2-1/TITF1 and VPS13A genes were performed. A total of 104 families were ascertained from 2001 to 2012: 71 families from South, 25 from Southeast and 8 from Northeast Brazil. There were 93 HD, 4 HDL2 and 1 SCA2 families. Eleven of 104 index cases did not have a family history: 10 with HD. Clinical characteristics were similar between HD and non-HD cases. In HD, the median expanded (CAG)n (range) was 44 (40-81) units; R(2) between expanded HTT and age-at-onset (AO) was 0.55 (p=0.0001, Pearson). HDL2 was found in Rio de Janeiro (2 of 9 families) and Rio Grande do Sul states (2 of 68 families). We detected HD in 89.4%, HDL2 in 3.8% and SCA2 in 1% of 104 Brazilian families. There were no cases of HDL1, SCA17, DRPLA, neuroferritinopathy, benign hereditary chorea or CHAC. Only six families (5.8%) remained without diagnosis., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Benign hereditary chorea (BHC) is a rare autosomal dominant condition characterized by early onset, non-progressive chorea, usually caused by mutations in the thyroid transcription factor-1 gene (TITF1). We describe a novel mutation arising de novo in a proband presenting in infancy with delayed walking and ataxia. She later developed chorea, then hypothyroidism and a large cystic pituitary mass. Her daughter presented in infancy with delayed walking and ataxia and went on to develop non-progressive chorea and a hormonally inactive cystic pituitary mass. Mutational analysis of the whole coding region of the TITF1 gene was undertaken and compared with a population study of 160 control subjects. This showed that both affected subjects have a heterozygous A > T substitution at nucleotide 727 of the TITF1 gene changing lysine to a stop codon at residue 211. Genetic analysis of parents and siblings of the proband confirmed that the mutation arose de novo in the proband. The mutated lysine is an evolutionarily highly conserved amino acid in the protein homoeodomain (HD) where most point mutations associated with BHC are located. The range of mutations in BHC is reviewed with particular emphasis on pituitary abnormalities. Cystic pituitary masses and abnormalities of the sella turcica are reported in just 6.4 % of published cases. This is a new nonsense mutation associated with ataxia, benign chorea and pituitary abnormalities which further extends the phenotype of this condition. Mutational screening of TITF1 is important in cases of sporadic or dominant juvenile-onset ataxia, with mild chorea where no other cause is found, particularly if pituitary abnormalities are seen on imaging.

A 9-month-old intact female Yorkshire terrier dog was presented with episodic partial seizure-like cramping of the limbs. The patient's episodes began six months previously; the interval between episodes became shorter, and the duration of the episodes increased. Various tests including neurologic examination, blood examination, abdominal radiography, ultrasonographic examination, angiographic computed tomography (CT) and brain magnetic resonance imaging (MRI) detected no remarkable changes. After these tests were conducted, the patient's condition was suspected to be canine epileptoid cramping syndrome (CECS), which could be a form of paroxysmal dyskinesia (PD), and as a trial therapy, Science Diet k/d (Hill's Pet Nutrition, Topeka, KS, U.S.A.) was prescribed. The clinical signs were dramatically reduced after diet therapy, and we diagnosed the patient with CECS. This is the first case report of CECS in a Yorkshire terrier dog.

Movement disorders are common following cerebrovascular accidents and they can be hyperkinetic, including hemichorea and hemiballismus, or hypokinetic, as seen in parkinsonian disorders. Monochorea has also been reported due to stroke, albeit rarely. We report a 47-year-old gentleman who presented with a history of sudden onset choreiform movement of his left lower limb. On clinical examination his motor power was normal and there were no abnormal movements in any other limb. MRI of his brain was suggestive of an infarct in the right globus pallidus interna extending up to the posterior limb of the internal capsule. He was treated with clonazepam and trihexyphenidyl. His movements improved significantly within 3 months. Monochorea in a lower limb due to an infarct in the globus pallidus interna is unusual and highlights the complexity of the pathophysiology of chorea., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Despite improvements in socio-economic status and the standard of health care services, rheumatic fever continuous to occur in Saudi Arabia, although with decreasing frequency. The disease is most commonly observed in school-aged children, but can also occur in a younger age group. Carditis and arthritis are the major clinical symptoms on presentation of acute rheumatic fever in young children. Rheumatic chorea is infrequently reported in young children. Here, a case of Sydenham chorea, in a 5-year-old boy, is presented. Although rare, the diagnosis of Sydenham chorea should always be considered in young children with choreiform movements.

Diabetic chorea is characterized by acute hemichorea, as observed on striatal T1 magnetic resonance imaging (MRI), and is associated with hyperglycemia. Acute involuntary movements begin with the onset of hyperglycemia. This condition produces characteristic MR images, which are the key diagnostic feature. Contralateral T1 MRI hyperdensities have been observed in virtually all cases and are used as a diagnostic measure. In some cases, smaller, less dense lesions are seen on the ipsilateral side. The putamen is always involved, whereas the caudate and globus pallidus are involved occasionally. This lesion is usually well delineated and does not follow vascular distribution. Diffusion-weighted imaging (DWI) and the apparent diffusion coefficient show restricted diffusion on the corresponding side of the putamen. Increased susceptibility (hypodensity) is observed using susceptibility-weighted imaging (SWI). Perhaps the most parsimonious explanation for the imaging results is that they represent gemistocytes. Pathological studies have confirmed the presence of gemistocytes, and these findings are consistent with T1, T2, DWI, and SWI MRI sequence findings. The zinic-laden metallothionein protein in the gemistocytes is the primary reason for the diagnostic imaging findings. The first avenue of treatment is to address the underlying hyperglycemia. As the hyperglycemia decreases, the chorea improves over the subsequent days or weeks, in most cases. If the chorea is uncomfortable, disabling, or persistent, symptomatic therapy (e.g., administration of haloperidol, a dopamine antagonist) should be initiated.

Background: Sydenham's chorea, a major manifestation of rheumatic fever, is characterized by chorea, behavioral changes, and cognitive dysfunction. Perfusion changes in the basal ganglia are the most frequent imaging findings observed in patients with Sydenham's chorea., Methods: Twelve adult women with Sydenham's chorea in remission underwent brain single-photon emission computed tomography (SPECT). Their scans underwent a quantification process to evaluate the perfusion of Brodmann's areas of the frontal lobes and basal ganglia. The results were compared with the findings from a control group that was matched by age., Results: A pattern of hyperperfusion in the left putamen was observed in the patient group (P = 0.02). No significant difference was observed in relation to other brain regions., Conclusions: The findings of brain SPECT suggest that perfusion abnormalities of the basal ganglia may persist even after the remission of abnormal movements in patients with Sydenham's chorea., (© 2013 Movement Disorder Society.)