Movement disorders in spinocerebellar ataxias in a cohort of Brazilian patients

Myoclonus-Ataxia Syndromes: A Diagnostic Approach

Background

A myriad of disorders combine myoclonus and ataxia. Most causes are genetic and an increasing number of genes are being associated with myoclonus-ataxia syndromes (MAS), due to recent advances in genetic techniques. A proper etiologic diagnosis of MAS is clinically relevant, given the consequences for genetic counseling, treatment, and prognosis.

Objectives

To review the causes of MAS and to propose a diagnostic algorithm.

Methods

A comprehensive and structured literature search following PRISMA criteria was conducted to identify those disorders that may combine myoclonus with ataxia.

Results

A total of 135 causes of combined myoclonus and ataxia were identified, of which 30 were charted as the main causes of MAS. These include four acquired entities: opsoclonus-myoclonus-ataxia syndrome, celiac disease, multiple system atrophy, and sporadic prion diseases. The distinction between progressive myoclonus epilepsy and progressive myoclonus ataxia poses one of the main diagnostic dilemmas.

Conclusions

Diagnostic algorithms for pediatric and adult patients, based on clinical manifestations including epilepsy, are proposed to guide the differential diagnosis and corresponding work-up of the most important and frequent causes of MAS. A list of genes associated with MAS to guide genetic testing strategies is provided. Priority should be given to diagnose or exclude acquired or treatable disorders.

Childhood-Onset Spinocerebellar Ataxia 3: Tongue Dystonia as an Early Manifestation

Background

Dystonia is a relatively common feature of spinocerebellar ataxia 3 (SCA3). Childhood onset of SCA3 is rare and typically associated with either relatively large, or homozygous, CAG repeat expansions.

Case report

We describe a 10-year-old girl with SCA3, who presented with tongue dystonia in addition to limb dystonia and gait ataxia due to a heterozygous expansion of 84 repeats in ATXN3.

Discussion

Diagnosis of the SCAs can be challenging, and even more so in children. Tongue dystonia has not previously been documented in SCA3.

The Geographic Diversity of Spinocerebellar Ataxias (SCAs) in the Americas: A Systematic Review

Background

The frequency and presentation of each of the most common forms of spinocerebellar ataxias (SCAs) varies widely. In the case of the Americas, this diversity is particularly dynamic given additional social, demographic, and cultural characteristics.

Objective

To describe the regional prevalence and clinical phenotypes of SCAs throughout the continent.

Methods

A literature search was performed in both MEDLINE and LILACS databases. The research was broadened to include the screening of reference lists of systematic review articles for additional studies. Investigations dating from the earliest available through 2019. Only studies in English, Portuguese, and Spanish were included. We analyzed publications with genetically confirmed cases only, ranging from robust samples with epidemiological data to case reports and case series from each country or regions.

Results

Overall, SCA3 is the most common form in the continent. Region-specific prevalence and ranking of the common forms vary. On the other hand, region-specific phenotypic variations were not consistently found based on the available literature analyzed, with the exception of the absence of epilepsy in SCA10 consistently described in a particular cluster of cases in South Brazil.

Conclusion

Systematic, multinational studies analyzing in detail the true frequencies of SCAs across the Americas as well as distinct clinical signs and clues of each form would be ideal to look for these potential variations.

The influence of initial symptoms on phenotypes in spinocerebellar ataxia type 3

Background

Spinocerebellar ataxia type 3 (SCA3) is a rare, inherited form of ataxia that leads to progressive neurodegeneration. The initial symptoms could affect clinical phenotypes in neurodegenerative diseases, such as Parkinson's disease and amyotrophic lateral sclerosis. However, the contribution of initial symptoms to the phenotypes of SCA3 has been scarcely investigated.

Methods

In the present study, 143 SCA3 patients from China were recruited and divided into two groups of gait‐onset and non‐gait‐onset. For determining the influences of initial symptoms on age at onset (AAO), the severity and progression of ataxia, and the possible factors affecting the initial symptoms, multivariable linear regression, and multivariate logistic regression were performed.

Results

We found that the frequency of gait‐onset was 87.41%, and the frequency of non‐gait‐onset was 12.59% (diplopia: 7.69%, dysarthria: 4.20%, dystonia: 0.70%). Compared to the non‐gait‐onset group, the gait‐onset group had significantly more severe ataxia (p = 0.046), while the initial symptoms had no effect on AAO (p = 0.109) and progression of ataxia (p = 0.265). We failed to find the existence of any factors affecting initial symptoms.

Conclusion

These findings collectively suggested that initial symptoms influenced phenotypes in SCA3 and that neurodegeneration in different parts of brain may induce different disease severity in SCA3.

To investigate the contribution of initial symptoms to the phenotypes of spinocerebellar ataxia type 3 (SCA3), 143 SCA3 patients from China were recruited and divided into two groups of gait‐onset and non‐gait‐onset. We found that compared to the group of non‐gait‐onset, the group of gait‐onset had significantly more severe ataxia. Our finding suggested that initial symptoms influenced phenotypes in SCA3 and that neurodegeneration in different parts of brain may induce different severity in SCA3.

Extra-Cerebellar Signs and Non-motor Features in Chinese Patients With Spinocerebellar Ataxia Type 3

Objectives: Our study attempted to systematically explore the prevalence of extra-cerebellar signs and non-motor symptoms, such as anxiety, depression, fatigue, excessive daytime sleepiness (EDS) and sleep disturbances in a cohort of Chinese patients with spinocerebellar ataxia type 3 (SCA3), and further investigated the correlations between non-motor symptoms and clinical characteristics in SCA3 patients.

Methods: This study included 68 molecular-proven SCA3 patients. Extra-cerebellar signs were evaluated with the Inventory of Non-Ataxia Symptoms (INAS). The INAS count indicated the number of non-ataxia signs in each patient. The severity of ataxia, fatigue, EDS, sleep quality, anxiety, and depression were assessed using the Scale for the assessment and rating of ataxia (SARA), Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Rating Scale (HAMA), and the Hamilton Depression Rating Scale (HAMD) (24 items), respectively.

Results: Extra-cerebellar signs were detected in 91.2% of all SCA3 patients and the mean total INAS count was 2.72 ± 1.88. Rigidity was the most frequent extra-cerebellar sign (47.1%, N = 32). Sensory symptoms (2.9%, N = 2) and chorea (5.9%, N = 4) were rare, and myoclonus (0%) was not found in this cohort. High frequencies of sleep disturbances (64.7%), fatigue (52.9%), depression (48.5%), and anxiety (42.6%) were detected in SCA3 patients. The Spearman correlation indicated that the HAMD score was associated with the CAG repeat length and HAMA score, while the PSQI score was correlated with the SARA and FSS score. In addition, multivariate linear regression analysis showed that the CAG repeat length, age of onset, sleep disturbances and depression were significant predictors of fatigue in SCA3 patients.

Conclusions: Our study indicates that the vast majority of SCA3 patients display extra-cerebellar signs. Except for EDS, anxiety, depression, fatigue and impaired sleep quality are present in SCA3 patients. The CAG repeat length, age of onset, sleep disturbances and depression are predictors of fatigue in SCA3 patients.

Facial grimacing and clinical correlates in spinocerebellar ataxia type 3

INTRODUCTION

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is the most common spinocerebellar ataxia (SCA) worldwide. SCA3 presents with cerebellar ataxia in association with pyramidal signs, peripheral amyotrophy, nystagmus, ophthalmoparesis, fasciculations of the face and tongue, dystonia and parkinsonism. Oromandibular dystonia (OMD) with facial grimacing (FG) in SCA3 has seldom been reported in the literature and in series of SCA3 patients.

METHODS

We evaluated 104 patients with SCA (59 patients with SCA3, 20 with SCA2, 20 with SCA7 and 5 with SCA6) and assessed dystonia frequency and types.

RESULTS

Thirteen cases of SCA3, one of SCA2 and two of SCA7 had dystonia. OMD in the form of FG was present in seven SCA3 patients (11.9%). Patients with FG were significantly younger, had earlier disease onset and a significantly higher CAG repetition length when compared to the SCA3 sample. Parkinsonism, dysphagia and pyramidal signs were significantly more frequent in the FG group than the non-FG group of the SCA3 sample.

CONCLUSION

Patients with SCA3 presenting with FG are younger, with earlier disease onset and higher CAG repetition length. They present with parkinsonism, dysphagia and pyramidal signs more frequently than SCA3 patients without FG.

Huntington's disease-like disorders in Latin America and the Caribbean

Diseases with a choreic phenotype can be due to a variety of genetic etiologies. As testing for Huntington's disease (HD) becomes more available in previously resource-limited regions, it is becoming apparent that there are patients in these areas with other rare genetic conditions which cause an HD-like phenotype. Documentation of the presence of these conditions is important in order to provide appropriate diagnostic and clinical care for these populations. Information for this article was gathered in two ways; the literature was surveyed for publications reporting a variety of genetic choreic disorders, and movement disorders specialists from countries in Latin America and the Caribbean were contacted regarding their experiences with chorea of genetic etiology. Here we discuss the availability of molecular diagnostics for HD and for other choreic disorders, along with a summary of the published reports of affected subjects, and authors' personal experiences from the regions. While rare, patients affected by non-HD genetic choreas are evidently present in Latin America and the Caribbean. HD-like 2 is particularly prevalent in countries where the population has African ancestry. The incidence of other conditions is likely determined by other variations in ethnic background and settlement patterns. As genetic resources and awareness of these disorders improve, more patients are likely to be identified, and have the potential to benefit from education, support, and ultimately molecular therapies.

Dystonia in Patients with Spinocerebellar Ataxia 3 - Machado-Joseph disease: An Underestimated Diagnosis?

Background

Spinocerebellar Ataxia type 3 (SCA3) or Machado-Joseph Disease (MJD) is characterized by cerebellar, central and peripheral symptoms, including movement disorders. Dystonia can be classified as hereditary and neurodegenerative when present in SCA3.

Objective

The objective of this study was to evaluate the dystonia characteristics in patients with MJD.

Method

We identified all SCA3 patients with dystonia from the SCA3 HC-UFPR database, between December 2015 and December 2016.Their medical records were reviewed to verify the diagnosis of dystonia and obtain demographic and clinical data. Standardized evaluation was carried out through the classification of Movement Disorders Society of 2013 and Burke Fahn-Marsden scale (BFM).

Results

Amongst the presenting some common characteristics, 381 patients with SCA3, 14 (3.7%) subjects presented dystonia: 5 blepharospasm, 1 cervical dystonia, 3 oromandibular, 3 multifocal and 2 generalized dystonia. Regarding dystonia's subtypes, 71.4% had SCA3 subtype I and 28.6% SCA3 subtype II. The average age of the disease onset was 40±10.7 years; the SCA3 disease duration was 11.86± 6.13 years; the CAG repeat lengths ranged from 75 to 78, and the BFM scores ranged from 1.0 to 40. There was no correlation between the dystonia severity and CAG repeat lengths or the SCA3 clinical evolution.

Conclusion

Dystonia in SCA3 is frequent and displays highly variable clinical profiles and severity grades. Dystonia is therefore a present symptom in SCA3, which may precede the SCA3 classic symptoms. Dystonia diagnosis is yet to be properly recognized within SCA3 patient.

Dystonia and ataxia progression in spinocerebellar ataxias

BACKGROUND

Dystonia is a common feature in spinocerebellar ataxias (SCAs). Whether the presence of dystonia is associated with different rate of ataxia progression is not known.

OBJECTIVES

To study clinical characteristics and ataxia progression in SCAs with and without dystonia.

METHODS

We studied 334 participants with SCA 1, 2, 3 and 6 from the Clinical Research Consortium for Spinocerebellar Ataxias (CRC-SCA) and compared the clinical characteristics of SCAs with and without dystonia. We repeatedly measured ataxia progression by the Scale for Assessment and Rating of Ataxia every 6 months for 2 years. Regression models were employed to study the association between dystonia and ataxia progression after adjusting for age, sex and pathological CAG repeats. We used logistic regression to analyze the impact of different repeat expansion genes on dystonia in SCAs.

RESULTS

Dystonia was most commonly observed in SCA3, followed by SCA2, SCA1, and SCA6. Dystonia was associated with longer CAG repeats in SCA3. The CAG repeat number in TBP normal alleles appeared to modify the presence of dystonia in SCA1. The presence of dystonia was associated with higher SARA scores in SCA1, 2, and 3. Although relatively rare in SCA6, the presence of dystonia was associated with slower progression of ataxia.

CONCLUSIONS

The presence of dystonia is associated with greater severity of ataxia in SCA1, 2, and 3, but predictive of a slower progression in SCA6. Complex genetic interactions among repeat expansion genes can lead to diverse clinical symptoms and progression in SCAs.

Non-motor and Extracerebellar Features in Spinocerebellar Ataxia Type 2

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant degenerative disease. Pathological studies have demonstrated not only cerebellar and brainstem atrophy, but substantia nigra, motoneurons, basal ganglia, thalamus, and peripheral nerves involvement. These findings may explain non-motor and extra-cerebellar features in SCA2. We accessed the non-motor symptoms and extra-cerebellar signs in SCA2 patients in order to provide a better understanding on pathophysiological mechanisms and natural history of brain degeneration in the disease. Thirty-three SCA2 patients were evaluated and compared with 26 healthy subjects. We investigated the following variables: sleep disorders, cognitive deficit, olfactory impairment, urinary dysfunction, psychiatric symptoms, cramps, pain, movement disorders, and weight loss. SCA2 had a high frequency of REM sleep behavior disorder (48.48 %, N = 16) as well as excessive daytime sleepiness (42.42 %, N = 14). Chorea was present in 15.15 % (N = 5), dystonia in 27.27 % (N = 9), and parkinsonism in 27.27 % (N = 9). Slow saccadic pursuit was present in 87.87 % (N = 29) and ophtalmoparesis in 78.78 % (N = 26) of patients. Regarding sleep disorders, 18.18 % (N = 6) of patients had restless leg syndrome. Dysphagia was present in 39.39 % (N = 13), weight loss 24.24 % (N = 8), and urinary dysfunction 27.27 % (N = 9). Cramps was present in only 6 % of patients (N = 2). This study highlighted the high frequency of non-motor symptoms and extra-cerebellar signs in SCA2. Our findings demonstrate the widespread of nervous system involvement in SCA2 patients and contribute to better understand the natural history of brain degeneration in this genetic condition.

Evaluation of parkinsonism and striatal dopamine transporter loss in patients with spinocerebellar ataxia type 6

It is unclear whether patients with spinocerebellar ataxia type 6 (SCA6) have parkinsonism and striatal dopamine transporter (DAT) loss, based on previously small size studies without well-matched controls. A study with a larger number of patients and both age- and gender-matched healthy controls (HCs) is needed for a better answer to this question. Twelve genetically confirmed ataxic SCA6 patients (six male six female, age 65.3 ± 11.2 years), and eight age- and gender-matched HCs (five male three female, age 71.3 ± 8.6 years) were enrolled during 2013-2015 from tertiary movement disorders and ataxia clinics. Clinical assessment for parkinsonism, and qualitative and quantitative assessment of DAT level on DaTscan™ imaging were conducted in SCA6 patients compared to HCs. We found no convincing parkinsonism in SCA6 patients, given generalized bradykinesia in the context of significant ataxia in all, with mild symmetric rigidity in five without resting tremor. Furthermore, we found no striatal DAT loss in anterior, posterior, and total putamen and caudate on imaging, assessed independently by qualitative visual inspection in a blinded manner by the nuclear medicine specialist and movement disorder specialist (kappa = 1). Additional quantitative analysis on these areas did not reveal significant DAT loss either in SCA6 patients compared to HCs. We conclude that there is no convincing parkinsonism or DAT loss in SCA6 patients in this unique study with a larger than previously reported number of patients compared to both age- and gender-matched HCs, suggesting that dopaminergic dysfunction is not usually involved in SCA6.

SCA 6 with Writer's Cramp: The Phenotype Expanded

Spinocerebellar ataxia type 6 (SCA6) presents typically with a pure cerebellar syndrome. Only 1 SCA 6 patient with writer's cramp has been reported on and a family history of ataxia and writer's cramp has never been reported on. Two other SCA6 patients with a shoulder girdle/hand dystonia and unspecified upper-limb dystonia with a family history of ataxia have been reported on. We report on the largest family with SCA6 and writer's cramp. The proband developed dysarthria, ataxia, and writer's cramp by age 37. His father presented with ataxia at 55, followed by writer's cramp and dysarthria. The proband's brother developed ataxia at 41, followed by dysarthria and writer's cramp. A paternal uncle (deceased; not examined) and 58-yr-old brother both developed pure ataxia (genetic testing is pending). This large family with complex movement disorder demonstrates that it is important to consider SCA6 in a patient presenting with an ataxia and writer's cramp and supports cerebellum involvement in dystonia.

Primary and secondary ataxias

PURPOSE OF REVIEW

This article discusses recent advances in the understanding of clinical and genetic aspects of primary ataxias, including congenital, autosomal recessive, autosomal dominant, episodic, X-linked, and mitochondrial ataxias, as well as idiopathic degenerative and secondary ataxias.

RECENT FINDINGS

Many important observations have been published in recent years in connection with primary ataxias, particularly new loci and genes. The most commonly inherited ataxias may present with typical and atypical phenotypes. In the group of idiopathic degenerative ataxias, genes have been found in patients with multiple system atrophy type C. Secondary ataxias represent an important group of sporadic, cerebellar, and afferent/sensory ataxias.

SUMMARY

Knowledge of primary ataxias has been growing rapidly in recent years. Here we review different forms of primary ataxia, including inherited forms, which are subdivided into congenital, autosomal recessive cerebellar ataxias, autosomal dominant cerebellar ataxias, episodic ataxias, X-linked ataxias, and mitochondrial ataxias, as well as sporadic ataxias and idiopathic degenerative ataxias. Secondary or acquired ataxias are also reviewed and the most common causes are discussed.