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Cerebellum (London, England) Apr 2022Spinocerebellar ataxia type 3 (SCA3), the commonest dominantly inherited ataxia worldwide, is characterized by disruption in the cerebellar-cerebral and... (Review)
Review
Spinocerebellar ataxia type 3 (SCA3), the commonest dominantly inherited ataxia worldwide, is characterized by disruption in the cerebellar-cerebral and striatal-cortical networks. Findings on SCA3-associated cognitive impairments are mixed. The classification models, tests and scoring systems used, language, culture, ataxia severity, and depressive symptoms are all potential confounders in neuropsychological assessments and may have contributed to the heterogeneity of the neurocognitive profile of SCA3. We conducted a systematic review of studies evaluating neurocognitive function in SCA3 patients. Of 1304 articles identified, 15 articles met the eligibility criteria. All articles were of excellent quality according to the National Institutes of Health quality assessment tool for case-control studies. In line with the disrupted cerebellar-cerebral and striatal-cortical networks in SCA3, this systematic review found that the neurocognitive profile of SCA3 is characterized by a core impairment of executive function that affects processes such as nonverbal reasoning, executive aspects of language, and recall. Conversely, neurocognitive domains such as general intelligence, verbal reasoning, semantic aspect of language, attention/processing speed, recognition, and visuospatial perception and construction are relatively preserved. This review highlights the importance of evaluating neurocognitive function in SCA3 patients. Considering the negative impact of cognitive and affective impairment on quality of life, this review points to the profound impairments that existing or future treatments should prioritize.
Topics: Ataxia; Executive Function; Humans; Machado-Joseph Disease; Neuropsychological Tests; Quality of Life
PubMed: 34231180
DOI: 10.1007/s12311-021-01282-3 -
European Journal of Ophthalmology May 2022This study aims to present a family with two children with MSS who presented with different ophthalmic features. We also aim to review MSS patients' ocular...
PURPOSE
This study aims to present a family with two children with MSS who presented with different ophthalmic features. We also aim to review MSS patients' ocular manifestations to provide a basis for future clinical trials and improve MSS patients' ophthalmologic care.
CASE DESCRIPTION
Both patients presented with global developmental delay, microcephaly, cerebellar ataxia, and myopathy. The older sibling had developed bilateral cataracts at the age of six. Her 2 years younger sister interestingly showed bilateral hyperopic refractive error without cataracts yet. Mendeliome sequencing unraveled a novel homozygous frameshift mutation in the gene (, NM_022464.5, c.1042dupG, p.E348Gfs*4), causing MSS. A systematic literature review revealed that cataracts appear in 96% of MSS cases with a mean onset at 3.2 years. Additional frequent ocular features were strabismus (51.6%) and nystagmus (45.2%).
CONCLUSION
-related MSS is associated with marked clinical variability. Cataracts can develop later than neuromuscular features and cognitive signs. Since cataract is a relatively late finding, patients may refer to ophthalmologists for other reasons such as refractive errors, strabismus, or nystagmus. Molecular genetic testing for is essential to facilitate early diagnosis in patients with suspected MSS.
Topics: Cataract; Female; Genetic Association Studies; Guanine Nucleotide Exchange Factors; Humans; Spinocerebellar Degenerations; Strabismus
PubMed: 34075802
DOI: 10.1177/11206721211021291 -
Spinocerebellar ataxia type 2 from an evolutionary perspective: Systematic review and meta-analysis.Clinical Genetics Sep 2021Dominant diseases due to expanded CAG repeat tracts, such as spinocerebellar ataxia type 2 (SCA2), are prone to anticipation and worsening of clinical picture in... (Meta-Analysis)
Meta-Analysis
Dominant diseases due to expanded CAG repeat tracts, such as spinocerebellar ataxia type 2 (SCA2), are prone to anticipation and worsening of clinical picture in subsequent generations. There is insufficient data about selective forces acting on the maintenance of these diseases in populations. We made a systematic review and meta-analysis on the effect of the CAG length over age at onset, instability of transmissions, anticipation, de novo or sporadic cases, fitness, segregation of alleles, and ancestral haplotypes. The correlation between CAG expanded and age at onset was r = 0.577, and transmission of the mutant allele was associated with an increase of 2.42 CAG repeats in the next generation and an anticipation of 14.62 years per generation, on average. One de novo and 18 sporadic cases were detected. Affected SCA2 individuals seem to have more children than controls. The expanded allele was less segregated than the 22-repeat allele in children of SCA2 subjects. Several ancestral SCA2 haplotypes were published. Data suggest that SCA2 lineages may tend to disappear eventually, due to strong anticipation phenomena. Whether or not the novel cases come from common haplotypes associated with a predisposition to further expansions is a question that needs to be addressed by future studies.
Topics: Age of Onset; Ataxin-2; Evolution, Molecular; Genomic Instability; Haplotypes; Humans; Spinocerebellar Ataxias; Trinucleotide Repeat Expansion
PubMed: 33960424
DOI: 10.1111/cge.13978 -
Journal of Clinical Neurology (Seoul,... Apr 2021Premanifest mutation carriers with spinocerebellar ataxia (SCA) can exhibit subtle abnormalities before developing ataxia. We summarized the preataxic manifestations of... (Review)
Review
BACKGROUND AND PURPOSE
Premanifest mutation carriers with spinocerebellar ataxia (SCA) can exhibit subtle abnormalities before developing ataxia. We summarized the preataxic manifestations of SCA1, -2, -3, and -6, and their associations with ataxia onset.
METHODS
We included studies of the premanifest carriers of SCA published between January 1998 and December 2019 identified in Scopus and PubMed by searching for terms including 'spinocerebellar ataxia' and several synonyms of 'preataxic manifestation'. We systematically reviewed the results obtained in studies categorized based on clinical, imaging, and laboratory markers.
RESULTS
We finally performed a qualitative analysis of 48 papers. Common preataxic manifestations appearing in multiple SCA subtypes were muscle cramps, abnormal muscle reflexes, instability in gait and posture, lower Composite Cerebellar Functional Severity scores, abnormalities in video-oculography and transcranial magnetic stimulation, and gray-matter loss and volume reduction in the brainstem and cerebellar structures. Also, decreased sensory amplitudes in nerve conduction studies were observed in SCA2. Eotaxin and neurofilament light-chain levels were revealed as sensitive blood biomarkers in SCA3. Concerning potential predictive markers, hyporeflexia and abnormalities of somatosensory evoked potentials showed correlations with the time to ataxia onset in SCA2 carriers. However, no longitudinal data were found for the other SCA gene carriers.
CONCLUSIONS
Our results suggest that preataxic manifestations vary among SCA1, -2, -3, and -6, with some subtypes sharing specific features. Combining various markers into a standardized index for premanifest carriers may be useful for early screening and assessing the risk of disease progression in SCA carriers.
PubMed: 33835738
DOI: 10.3988/jcn.2021.17.2.187 -
Movement Disorders Clinical Practice Apr 2021Neuroimaging has been used to support a diagnosis of possible multiple system atrophy (MSA). Only blood pressure changes upon standing are included in the second... (Review)
Review
BACKGROUND
Neuroimaging has been used to support a diagnosis of possible multiple system atrophy (MSA). Only blood pressure changes upon standing are included in the second consensus criteria but other autonomic function tests (AFT) are also useful to diagnose widespread and progressive autonomic failure typical of MSA. Additional diagnostic tools are of interest to improve accuracy of MSA diagnosis.
OBJECTIVES
To assess the utility of diagnostic tools beyond brain imaging and AFT in enhancing a laboratory-supported diagnosis of MSA to support the upcoming revision of the consensus criteria.
METHODS
The International Parkinson and Movement Disorders Society MSA Study Group (MoDiMSA) performed a systematic review of original papers on biomarkers, sleep studies, genetic, neuroendocrine, neurophysiological, neuropsychological and other tests including olfactory testing and acute levodopa challenge test published before August 2019.
RESULTS
Evaluation of history of levodopa responsiveness and olfaction is useful in patients in whom MSA-parkinsonian subtype is suspected. Neuropsychological testing is useful to exclude dementia at time of diagnosis. Applicability of sphincter EMG is limited. When MSA-cerebellar subtype is suspected, a screening for the common causes of adult-onset progressive ataxia is useful, including spinocerebellar ataxias in selected patients. Diagnosing stridor and REM sleep behavior disorder is useful in both MSA subtypes. However, none of these tools are validated in large longitudinal cohorts of postmortem confirmed MSA cases.
CONCLUSIONS
Despite limited evidence, additional laboratory work-up of patients with possible MSA beyond imaging and AFT should be considered to optimize the clinical diagnostic accuracy.
PubMed: 33816659
DOI: 10.1002/mdc3.13158 -
Frontiers in Neuroscience 2021Iron has been increasingly implicated in the pathology of neurodegenerative diseases. In the past decade, development of the new magnetic resonance imaging technique,...
Iron has been increasingly implicated in the pathology of neurodegenerative diseases. In the past decade, development of the new magnetic resonance imaging technique, quantitative susceptibility mapping (QSM), has enabled for the more comprehensive investigation of iron distribution in the brain. The aim of this systematic review was to provide a synthesis of the findings from existing QSM studies in neurodegenerative diseases. We identified 80 records by searching MEDLINE, Embase, Scopus, and PsycInfo databases. The disorders investigated in these studies included Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Wilson's disease, Huntington's disease, Friedreich's ataxia, spinocerebellar ataxia, Fabry disease, myotonic dystrophy, pantothenate-kinase-associated neurodegeneration, and mitochondrial membrane protein-associated neurodegeneration. As a general pattern, QSM revealed increased magnetic susceptibility (suggestive of increased iron content) in the brain regions associated with the pathology of each disorder, such as the amygdala and caudate nucleus in Alzheimer's disease, the substantia nigra in Parkinson's disease, motor cortex in amyotrophic lateral sclerosis, basal ganglia in Huntington's disease, and cerebellar dentate nucleus in Friedreich's ataxia. Furthermore, the increased magnetic susceptibility correlated with disease duration and severity of clinical features in some disorders. Although the number of studies is still limited in most of the neurodegenerative diseases, the existing evidence suggests that QSM can be a promising tool in the investigation of neurodegeneration.
PubMed: 33679303
DOI: 10.3389/fnins.2021.618435 -
Cerebellum & Ataxias Feb 2021Spinocerebellar ataxia is a hereditary neurodegenerative disease characterized by changes in balance, locomotion and motor coordination. Stem cell therapies are... (Review)
Review
BACKGROUND
Spinocerebellar ataxia is a hereditary neurodegenerative disease characterized by changes in balance, locomotion and motor coordination. Stem cell therapies are currently being investigated as an alternative to delay the evolution of the disease, and some experimental studies have investigated the effect of stem cell treatment on spinocerebellar ataxia.
OBJECTIVES
The aim of this review was to investigate whether the application of stem cells produced an effect on functional recovery in individuals with spinocerebellar ataxia.
METHODS
The studies included in this review investigated the efficacy and safety of a protocol for the application of mesenchymal stem cells extracted from umbilical cord and adipose tissue. Two studies used intrathecal route for application and one study used intravenous route.
RESULTS
Studies have shown clinical improvement in the scores of the ICARS (International Cooperative Ataxia Rating Scale), ADL (Activities of Daily Living Scale), BBS (Berg Balance Scale) and SARA (Scale for the Assessment and Rating of Ataxia), but lacked statistical significance.
CONCLUSIONS
There was low evidence for recommending stem cell therapy in individuals with spinocerebellar ataxia, and no statistical difference was observed for improving functional recovery of patients. Further studies are needed with different designs, largest sample sizes and placebo control, to fully understand anticipated outcomes of cellular therapy for spinocerebellar ataxia.
PubMed: 33632326
DOI: 10.1186/s40673-021-00130-8 -
Clinical Genetics Mar 2021Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is a dominant neurodegenerative disease caused by the expansion of a CAG repeat tract in ATXN3.... (Meta-Analysis)
Meta-Analysis
Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is a dominant neurodegenerative disease caused by the expansion of a CAG repeat tract in ATXN3. Anticipation and worsening of clinical picture in subsequent generations were repeatedly reported, but there is no indication that SCA3/MJD frequency is changing. Thus, we performed a systematic review and meta-analysis on phenomena with potential effect on SCA3/MJD recurrency in populations: instability of CAG repeat transmissions, anticipation, fitness, and segregation of alleles. Transmission of the mutant allele was associated with an increase of 1.23 CAG repeats in the next generation, and the average change in age at onset showed an anticipation of 7.75 years per generation; but biased recruitments cannot be ruled out. Affected SCA3/MJD individuals had 45% more children than related controls. Transmissions from SCA3/MJD carriers showed that the expanded allele was segregated in 64% of their children. In contrast, transmissions from normal subjects showed that the minor allele was segregated in 54%. The present meta-analysis concluded that there is a segregation distortion favoring the expanded allele, among children of carriers. Therefore, further studies on transmissions and anticipation phenomena as well as more observations about fertility are required to clarify these selective forces over SCA3/MJD.
Topics: Age of Onset; Alleles; Ataxin-3; Gene Frequency; Genetic Predisposition to Disease; Haplotypes; Heterozygote; Humans; Machado-Joseph Disease; Meiosis; Recurrence; Trinucleotide Repeat Expansion
PubMed: 33219521
DOI: 10.1111/cge.13888 -
Rehabilitacion 2020Evidence of the effectiveness of rehabilitation interventions in spinocerebellar ataxia is scarce and variable. OBJECTIVES: The aim of this systematic review was to...
Evidence of the effectiveness of rehabilitation interventions in spinocerebellar ataxia is scarce and variable. OBJECTIVES: The aim of this systematic review was to gather the existing evidence on the effectiveness of these interventions. MATERIAL AND METHODS: To do this, we analysed all the clinical trials published to date and assessed their results in terms of improved balance, gait, and performance of daily activities after treatment. Significant improvements were found for posture (P<.008) and gait (P<.02), as well as a reduction in the scores for the SARAg&p subscale (gait and posture) and SCAFI 8MW index (gait speed) (P=.02). We also observed improvements in speech disorders (P=.02), depressive symptoms (P<.0001) and accidental falls (P<.005).
Topics: Accidental Falls; Clinical Trials as Topic; Depression; Gait Disorders, Neurologic; Humans; Occupational Therapy; Physical Therapy Modalities; Postural Balance; Speech Disorders; Spinocerebellar Ataxias
PubMed: 32441264
DOI: 10.1016/j.rh.2020.01.003 -
Brain Sciences Apr 2020The accumulation of abnormal protein aggregates represents a universal hallmark of neurodegenerative diseases (NDDs). Post-translational modifications (PTMs) regulate... (Review)
Review
The accumulation of abnormal protein aggregates represents a universal hallmark of neurodegenerative diseases (NDDs). Post-translational modifications (PTMs) regulate protein structure and function. Dysregulated PTMs may influence the propensity for protein aggregation in NDD-proteinopathies. To investigate this, we systematically reviewed the literature to evaluate effects of PTMs on aggregation propensity for major proteins linked to the pathogenesis and/or progression of NDDs. A search of PubMed, MEDLINE, EMBASE, and Web of Science Core Collection was conducted to retrieve studies that investigated an association between PTMs and protein aggregation in seven NDDs: Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), spinocerebellar ataxias, transmissible spongiform encephalopathy, and multiple sclerosis. Together, 1222 studies were identified, of which 69 met eligibility criteria. We identified that the following PTMs, in isolation or combination, potentially act as modulators of proteinopathy in NDDs: isoaspartate formation in Aβ, phosphorylation of Aβ or tau in AD; acetylation, 4-hydroxy-2-neonal modification, -GlcNAcylation or phosphorylation of α-synuclein in PD; acetylation or phosphorylation of TAR DNA-binding protein-43 in ALS, and SUMOylation of superoxide dismutase-1 in ALS; and phosphorylation of huntingtin in HD. The potential pharmacological manipulation of these aggregation-modulating PTMs represents an as-yet untapped source of therapy to treat NDDs.
PubMed: 32290481
DOI: 10.3390/brainsci10040232