Sleep symptoms and their clinical correlates in Machado-Joseph disease

The frequency of non-motor symptoms in SCA3 and their association with disease severity and lifestyle factors

BACKGROUND

Non-motor symptoms (NMS) are a substantial burden for patients with SCA3. There are limited data on their frequency, and their relation with disease severity and activities of daily living is not clear. In addition, lifestyle may either influence or be affected by the occurrence of NMS.

OBJECTIVE

To characterize NMS in SCA3 and investigate possible associations with disease severity and lifestyle factors.

METHODS

In a prospective cohort study, we performed a cross-sectional analysis of NMS in 227 SCA3 patients, 42 pre-ataxic mutation carriers, and 112 controls and tested for associations with SARA score, activities of daily living, and the lifestyle factors alcohol consumption, smoking and physical activity.

RESULTS

Sleep disturbance, restless legs syndrome, mild cognitive impairment, depression, bladder dysfunction and pallhypesthesia were frequent among SCA3 patients, while mainly absent in pre-ataxic mutation carriers. Except for restless legs syndrome, NMS correlated significantly with disease severity and activities of daily living. Alcohol abstinence was associated with bladder dysfunction. Patients with higher physical activity showed less cognitive impairment and fewer depressive symptoms, but these differences were not significant.

CONCLUSION

This study revealed a clear association between disease severity and NMS, likely driven by the progression of the widespread neurodegenerative process. Associations between lifestyle and NMS can probably be attributed to the influence of NMS on lifestyle.

The Homogeneous Azorean Machado-Joseph Disease Cohort: Characterization and Contributions to Advances in Research

Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) is the most common autosomal dominant ataxia worldwide. MJD is characterized by late-onset progressive cerebellar ataxia associated with variable clinical findings, including pyramidal signs and a dystonic-rigid extrapyramidal syndrome. In the Portuguese archipelago of the Azores, the worldwide population cluster for this disorder (prevalence of 39 in 100,000 inhabitants), a cohort of MJD mutation carriers belonging to extensively studied pedigrees has been followed since the late 1990s. Studies of the homogeneous Azorean MJD cohort have been contributing crucial information to the natural history of this disease as well as allowing the identification of novel molecular biomarkers. Moreover, as interventional studies for this globally rare and yet untreatable disease are emerging, this cohort should be even more important for the recruitment of trial participants. In this paper, we profile the Azorean cohort of MJD carriers, constituted at baseline by 20 pre-ataxic carriers and 52 patients, which currently integrates the European spinocerebellar ataxia type 3/Machado-Joseph disease Initiative (ESMI), a large European longitudinal MJD cohort. Moreover, we summarize the main studies based on this cohort and highlight the contributions made to advances in MJD research. Knowledge of the profile of the Azorean MJD cohort is not only important in the context of emergent interventional trials but is also pertinent for the implementation of adequate interventional measures, constituting relevant information for Lay Associations and providing data to guide healthcare decision makers.

Sleep Alterations in a Mouse Model of Spinocerebellar Ataxia Type 3

Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disorder showing progressive neuronal loss in several brain areas and a broad spectrum of motor and non-motor symptoms, including ataxia and altered sleep. While sleep disturbances are known to play pathophysiologic roles in other neurodegenerative disorders, their impact on SCA3 is unknown. Using spectrographic measurements, we sought to quantitatively characterize sleep electroencephalography (EEG) in SCA3 transgenic mice with confirmed disease phenotype. We first measured motor phenotypes in 18-31-week-old homozygous SCA3 YACMJD84.2 mice and non-transgenic wild-type littermate mice during lights-on and lights-off periods. We next implanted electrodes to obtain 12-h (zeitgeber time 0-12) EEG recordings for three consecutive days when the mice were 26-36 weeks old. EEG-based spectroscopy showed that compared to wild-type littermates, SCA3 homozygous mice display: (i) increased duration of rapid-eye movement sleep (REM) and fragmentation in all sleep and wake states; (ii) higher beta power oscillations during REM and non-REM (NREM); and (iii) additional spectral power band alterations during REM and wake. Our data show that sleep architecture and EEG spectral power are dysregulated in homozygous SCA3 mice, indicating that common sleep-related etiologic factors may underlie mouse and human SCA3 phenotypes.

Neurophysiological features in spinocerebellar ataxia type 2: Prospects for novel biomarkers

Electrophysiological biomarkers are useful to assess the degeneration and progression of the nervous system in pre-ataxic and ataxic stages of the Spinocerebellar Ataxia Type 2 (SCA2). These biomarkers are essentially defined by their clinical significance, discriminating patients and/or preclinical subjects from healthy controls in cross-sectional studies, their significant changes over time in longitudinal studies, and their correlation with the cytosine-guanine-adenine (CAG) repeat expansion and/or clinical ataxia scores, time of evolution and time to ataxia onset. We classified electrophysiological biomarkers into three main types: (1) preclinical, (2) disease progression and (3) genetic damage. We review the data that identify sural nerve potential amplitude, maximum saccadic velocity, sleep efficiency, rapid eye movement (REM) sleep percentage, K-complex density, REM sleep without atonia percentage, corticomuscular coherence, central motor conduction time, visual P300 latency, and antisaccadic error correction latency as reliable preclinical, progression and/or genetic damage biomarkers of SCA2. These electrophysiological biomarkers will facilitate the conduction of clinical trials that test the efficacy of emerging treatments in SCA2.

Which Factors in Spinocerebellar Ataxia Type 3 Patients Are Associated with Restless Legs Syndrome/Willis-Ekbom Disease?

There is evidence of a higher prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) in individuals with spinocerebellar ataxia type 3 (SCA3), although the factors underlying this association remain unknown. The present study aimed to determine the prevalence of RLS/WED in SCA3 patients and to investigate which factors of SCA3 patients are associated with presence of RLS/WED. From February to August of 2006, we carried out clinical interviews in 40 controls and 40 SCA3 patients, diagnosed and followed up at Faculty of Medicine of Ribeirão Preto, University of São Paulo. Twenty-seven SCA3 patients were submitted to a detailed clinical protocol, electroneuromyography, blood work up, polysomnography (PSG), suggested immobilization test (SIT), and magnetic resonance image (MRI). RLS/WED was found in 27.5% of SCA3 patients and 2.5% of normal controls (p = 0.003). The factors related to RLS/WED in SCA3 patients were female gender, age at start of the symptoms of ataxia after 30 years, presence of peripheral neuropathy, and documented iron deficiency. Among SCA3 patients, those with RLS showed higher values of maximal discomfort level and discomfort level sum compared to non-RLS individuals on SIT. There is a relation between RLS/WED and SCA3, which seems to be resultant of different factors whose identification could improve the quality of assistance to those patients as well as to promote a better comprehension of the pathophysiology of both RLS/WED and SCA3.

Nonmotor symptoms in spinocerebellar ataxias (SCAs)

Nonmotor symptoms (NMS) have been increasingly recognized in a number of neurodegenerative diseases with a burden of disability that parallels or even surpasses that induced by motor symptoms. As NMS have often been poorly recognized and inadequately treated, much of the most recent developments in the investigation of these disorders has focused on the recognition and quantification of NMS, which will form the basis of improved clinical care for these complex cases. NMS have been only sparsely investigated in a limited number of spinocerebellar ataxias (SCAs), particularly SCA3, and have not been systematically reviewed for other forms of SCAs. The aim of the present study was to review the available literature on the presence of NMS among different types of SCAs.

Abnormal Findings in Polysomnographic Recordings of Patients with Spinocerebellar Ataxia Type 2 (SCA2)

Spinocerebellar ataxia type 2 (SCA2) is characterized by a progressive cerebellar syndrome, and additionally saccadic slowing, cognitive dysfunction, and sleep disorders. The aim of this study was to assess the frequency of abnormal findings in sleep recordings of patients with SCA2. Seventeen patients with genetically confirmed SCA2 from the Movement Disorders Outpatient group of the Hospital de Clínicas da UFPR were evaluated with a structured medical interview and the Scale for the Assessment and Rating of Ataxia (SARA). Polysomnographic recordings were performed and sleep stages were scored according to standard criteria. There were 10 male subjects and 7 females, aged 24-66 years (mean 47.44). A sex- and age-matched control group of healthy subjects was used for comparison. There was a reduction of rapid eye movement (REM) sleep in 12 (70.58%), increased REM latency in 9 (52.94%), increased obstructive sleep apnea-index in 14 (82.35%), absent REM density (REM density was calculated as the total number of 3-s miniepochs of REM sleep with at least 1 REM per minute) in 13 (76.47%), and markedly reduced REM density in 4 (23.52%). There was an indirect correlation according to the SARA scale and the REM density decrease (r = - 0.6; P = < 0.001); and with a disease progression correlating with a reduction in the REM density (r = - 0.52, P = 0.03). In SCA2, changes occur mainly REM sleep. The absence/decrease of REM sleep density, even in oligosymptomatic patients, and the correlation of this finding with disease time and with the SARA scale were the main findings of the study.

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.

Nonmotor Symptoms in Patients with Spinocerebellar Ataxia Type 10

Nonmotor symptoms (NMS) have been described in several neurodegenerative diseases but have not been systematically evaluated in spinocerebellar ataxia type 10 (SCA10). The objective of the study is to compare the frequency of NMS in patients with SCA10, Machado-Joseph disease (MJD), and healthy controls. Twenty-eight SCA10, 28 MJD, and 28 healthy subjects were prospectively assessed using validated screening tools for chronic pain, autonomic symptoms, fatigue, sleep disturbances, psychiatric disorders, and cognitive function. Chronic pain was present with similar prevalence among SCA10 patients and healthy controls but was more frequent in MJD. Similarly, autonomic symptoms were found in SCA10 in the same proportion of healthy individuals, while the MJD group had higher frequencies. Restless legs syndrome and REM sleep behavior disorder were uncommon in SCA10. The mean scores of excessive daytime sleepiness were worse in the SCA10 group. Scores of fatigue were higher in the SCA10 sample compared to healthy individuals, but better than in the MJD. Psychiatric disorders were generally more prevalent in both spinocerebellar ataxias than among healthy controls. The cognitive performance of healthy controls was better compared with SCA10 patients and MJD, which showed the worst scores. Although NMS were present among SCA10 patients in a higher proportion compared to healthy controls, they were more frequent and severe in MJD. In spite of these comparisons, we were able to identify NMS with significant functional impact in patients with SCA10, indicating the need for their systematic screening aiming at optimal treatment and improvement in quality of life.

Sleep apnea in Machado-Joseph disease: a clinical and polysomnographic evaluation

OBJECTIVE/BACKGROUND

Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3) is the most common type of autosomal dominant spinocerebellar ataxia (SCA). Sleep disorders have been described as frequent non-motor symptoms in MJD, and with marked impairment on quality of life. However, few studies have evaluated the frequency and characteristics of sleep apnea in MJD.

PATIENTS/METHODS

This study analyzed the prevalence of sleep apnea in 47 patients with MJD by using polysomnography. Clinical variables such as age, age at onset of symptoms, duration of symptoms (at time of evaluation), body index mass, ataxia scales severity and CAG repeat length were compared with polysomnographic findings.

RESULTS

Thirty four percent of MJD patients had OSAS, and 42.5% had excessive daytime somnolence. There were no differences considering ataxia severity, CAG repetition length or other clinical variable.

CONCLUSIONS

Patients with MJD have high frequency of obstructive sleep apnea, and this sleep disorder is not correlated with ataxia severity, CAG repetition length or other clinical variable.

Sleep disorders in spinocerebellar ataxia type 10

As sleep disturbances have been reported in spinocerebellar ataxias (SCAs), including types SCA1, SCA2, SCA3, SCA6 and SCA13, identification and management of these disturbances can help minimise their impact on SCA patients' overall body functions and quality of life. To our knowledge, there are no studies that investigate sleep disturbances in SCA10. Therefore, the aim of this study was to assess sleep disturbances in patients with SCA10. Twenty-three SCA10 patients and 23 healthy controls were recruited. Patients were evaluated in terms of their demographic and clinical data, including disease severity (Scale for the Assessment and Rating of Ataxia, SARA) and excessive daytime sleepiness (Epworth Sleepiness Scale, ESS), and underwent polysomnography. SCA10 patients had longer rapid eye movement (REM) sleep (p = .04) and more REM arousals than controls (p< .0001). There was a correlation of REM sleep onset with the age of onset of symptoms (r = .459), and with disease duration (r = -.4305). There also was correlation between the respiratory disturbance index (RDI) and SARA (r = -.4013), and a strong indirect correlation between arousal index and age at onset of symptoms (r = -.5756). In conclusion, SCA10 patients had sleep abnormalities that included more REM arousals and higher RDI than controls. Our SCA10 patients had sleep disorders related to shorter disease duration and lower severity of ataxia, in a pattern similar to that of other neurodegenerative diseases.

Clinical Features of Machado-Joseph Disease

Machado-Joseph disease (MJD) also known as Spinocerebellar ataxia type 3, is a hereditary neurodegenerative disease associated with severe clinical manifestations and premature death. Although rare, it is the most common autosomal dominant spinocerebellar ataxia worldwide and has a distinct geographic distribution, reaching peak prevalence in certain regions of Brazil, Portugal and China. Due to its clinical heterogeneity, it was initially described as several different entities and as had many designations over the last decades. An accurate diagnosis become possible in 1994, after the identification of the MJD1 gene. Among its wide clinical spectrum, progressive cerebellar ataxia is normally present. Other symptoms include pyramidal syndrome, peripheral neuropathy, oculomotor abnormalities, extrapyramidal signs and sleep disorders. On the basis of the presence/absence of important extra-pyramidal signs, and the presence/absence of peripheral signs, five clinical types have been defined. Neuroimaging studies like MRI, DTI and MRS, can be useful as they can characterize structural and functional differences in specific subgroups of patients with MJD. There is no effective treatment for MJD. Symptomatic therapies are used to relieve some of the clinical symptoms and physiotherapy is also helpful in improving quality of live. Several clinical trials have been carried out using different molecules like sulfamethoxazole-trimethoprim, varenicline and lithium carbonate, but the results of these trials were negative or showed little benefit. Future studies sufficiently powered and adequately designed are warranted.

REM sleep behaviour disorder: not just a bad dream

Rapid eye movement (REM) sleep behaviour disorder (RBD) is a parasomnia characterised by the loss of the normal atonia during the REM stage of sleep, resulting in overt motor behaviours that usually represent the enactment of dreams. Patients will seek medical attention due to sleep-related injuries or unpleasant dream content. Idiopathic RBD which occurs independently of any other disease occurs in up to 2% of the older population. Meanwhile, secondary RBD is very common in association with certain neurodegenerative conditions. RBD can also occur in the context of antidepressant use, obstructive sleep apnoea and narcolepsy. RBD can be diagnosed with a simple screening question followed by confirmation with polysomnography to exclude potential mimics. Treatment for RBD is effective and involves treatment of underlying causes, modification of the sleep environment, and pharmacotherapy with either clonazepam or melatonin. An important finding in the past decade is the recognition that almost all patients with idiopathic RBD will ultimately go on to develop Parkinson disease or dementia with Lewy bodies. This suggests that idiopathic RBD represents a prodromal phase of these conditions. Physicians should be aware of the risk of phenoconversion. They should educate idiopathic RBD patients to recognise the symptoms of these conditions and refer as appropriate for further testing and enrolment into research trials focused on neuroprotective measures.

Sleep disorders in Machado-Joseph disease

PURPOSE OF REVIEW

This article provides a description on clinical features and pathophysiology of the main sleep disorders observed in Machado-Joseph disease (MJD).

RECENT FINDINGS

Pathological studies have clearly demonstrated that degenerative process in MJD is widespread in the nervous system, and not restricted to the cerebellum. Nonmotor manifestations are frequent and may include pain, cramps, dysautonomia, cognitive deficits, psychiatric manifestations, olfactory deficits, fatigue, nutritional issues, and sleep disorders.

SUMMARY

Sleep disorders are frequent in MJD, and include restless legs syndrome, rapid eye movement sleep behavior disorder, excessive daytime sleepiness, insomnia, sleep apnea, periodic limb movements during sleep, parasomnia, and others. Pathophysiological mechanisms related to sleep disorders in Machado-Joseph are complex and poorly understood. Considering that sleep complaints are a treatable condition, recognizing sleep disorders in MJD is relevant.

Spectrum of sleep disorders in a patient with spinocerebellar ataxia 13

We report the case of a 52-year-old female with spinocerebellar ataxia (SCA) 13. She presented with complaints of insomnia and had a history of restless legs syndrome. Her polysomnogram revealed that she had a significantly elevated periodic limb movement index, mild obstructive sleep apnea, and the absence of REM sleep. Sleep disorders have previously been described in patients with SCA 1, SCA 2, SCA 3, and SCA 6. To our knowledge, this is the first description of sleep disorders in a patient with SCA 13.

RNA interference mitigates motor and neuropathological deficits in a cerebellar mouse model of Machado-Joseph disease

Machado-Joseph disease or Spinocerebellar ataxia type 3 is a progressive fatal neurodegenerative disorder caused by the polyglutamine-expanded protein ataxin-3. Recent studies demonstrate that RNA interference is a promising approach for the treatment of Machado-Joseph disease. However, whether gene silencing at an early time-point is able to prevent the appearance of motor behavior deficits typical of the disease when initiated before onset of the disease had not been explored. Here, using a lentiviral-mediated allele-specific silencing of mutant ataxin-3 in an early pre-symptomatic cerebellar mouse model of Machado-Joseph disease we show that this strategy hampers the development of the motor and neuropathological phenotypic characteristics of the disease. At the histological level, the RNA-specific silencing of mutant ataxin-3 decreased formation of mutant ataxin-3 aggregates, preserved Purkinje cell morphology and expression of neuronal markers while reducing cell death. Importantly, gene silencing prevented the development of impairments in balance, motor coordination, gait and hyperactivity observed in control mice. These data support the therapeutic potential of RNA interference for Machado-Joseph disease and constitute a proof of principle of the beneficial effects of early allele-specific silencing for therapy of this disease.

Dysautonomia is frequent in Machado-Joseph disease: clinical and neurophysiological evaluation

Autonomic dysfunction has been already described in patients with SCA3/MJD, but several important questions remain unanswered. The objectives of this study are to determine the frequency and the intensity of autonomic manifestations in SCA3/MJD, as well as to identify possible correlations between autonomic manifestations and genetic and clinical parameters. We have performed clinical and electrophysiological evaluations of 40 patients with SCA3/MJD and 38 healthy controls. We used the Scale for the Assessment and Rating of Ataxia (SARA) and the scales for Outcomes in Parkinson's Disease: Autonomic Questionnaire to quantify the severity of ataxia and autonomic complaints, respectively. We also studied heart rate variability at rest, during orthostatic challenge (30:15 ratio), Valsalva maneuver (Valsalva index), and deep breathing (E/I ratio). We evaluated spectral analyses of RR intervals at rest and the sympathetic skin response. Mean RR intervals at rest and the 30:15 ratio were different between patients and controls (811.8 versus 933.4 ms; p = 0.001 and 1.10 versus 1.15; p = 0.038, respectively). The Valsalva index and the E/I ratio were similar between the groups (p = 0.373 and p = 0.08). Spectral analysis presented distinct results in patients and controls, related to low- and high-frequency power (p < 0.001 and <0.001, respectively). We found cardiovascular and sympathetic sweat disautonomia in 30 % and 45 % of the patients with SCA3/MJD. Autonomic manifestations were related neither to genetic (CAG repeat length) nor clinical parameters (age, disease duration, SARA scores). Autonomic dysfunction is frequent and sometimes disabling in SCA3/MJD. We found evidence of both cardiovascular and sudomotor dysfunction in the disease.

Sleep disorders in machado-joseph disease: frequency, discriminative thresholds, predictive values, and correlation with ataxia-related motor and non-motor features

Sleep disorders are common complaints in patients with neurodegenerative diseases such as spinocerebellar ataxia type 3 (SCA3) or Machado-Joseph disease (MJD)--SCA3/MJD. We evaluated the frequency of sleep disorders in SCA3/MJD patients against controls matched by age and gender, and correlated data with demographic and clinical variables. The main sleep disorders evaluated were rapid eye movement (REM) sleep behavior disorder (RBD), restless leg syndrome (RLS), and excessive daytime sleepiness (EDS). We recruited 40 patients with clinical and molecular-proven SCA3/MJD and 38 controls. We used the following clinical scales to evaluate our primary outcome measures: RBD Screening Questionnaire, International RLS Rating Scale, and Epworth Sleepiness Scale. To evaluate ataxia-related motor and non-motor features, we applied the International Cooperative Ataxia Rating Scale, the Scale for the Assessment and Rating of Ataxia, and the Unified Parkinson's Disease Rating Scale part III. Psychiatric manifestations were tested with the Hamilton Anxiety Scale, and Beck Depression Inventory. The frequency of RBD and RLS were significantly higher in the SCA3/MJD group than in the control group (p < 0.001). There was no difference between both groups with regard to EDS. The accuracy of RDBSQ to discriminate between cases and controls was considered the best area under the ROC curve (0.86). Within-SCA3/MJD group analysis showed that anxiety and depression were significantly correlated with RDB, but not with RLS. Additionally, depression was considered the best predictive clinical feature for RDB and EDS.

Fatigue in spinocerebellar ataxia: patient self-assessment of an early and disabling symptom

OBJECTIVE

To identify the prevalence and severity of fatigue and predicting factors for severe fatigue in autosomal dominant spinocerebellar ataxia (SCA).

METHODS

We studied a cross-section of 123 patients with SCA. Six functional scales were used in a self-assessment: the Fatigue Severity Scale (FSS); the Beck Depression Inventory (BDI); the Rotterdam Handicap Scale (RHS); the Short Form-36 health survey, distinguishing a norm-based physical and mental component score (Nb-PCS and Nb-MCS); the Pittsburgh Sleep Quality Index (PSQI); and the Epworth Sleepiness Scale (ESS). A subset of 58 patients was clinically evaluated, measuring severity of ataxia with the Scale for the Assessment and Rating of Ataxia and cognitive functioning with the Mini-Mental State Examination.

RESULTS

Severe fatigue (FSS ≥5) was present in 69% of patients and FSS value correlated with the scores on RHS, Nb-PCS, Nb-MCS, BDI, PSQI, and ESS. There was no relation with disease duration, gender, or medication use. Multivariate analysis revealed that Nb-PCS and BDI were the best independent predictors for severe fatigue. Interestingly, the presence of visual symptoms was related to FSS value in the clinically evaluated subgroup.

CONCLUSION

Fatigue is a severe and disabling symptom in adult patients with SCA, even early in the course of disease. Physical functioning and depression are the strongest predictors of fatigue. In treatment strategies, all treatable factors for fatigue should be addressed, especially depression, visual symptoms, and sleeping disorders.

Sleep disorders in cerebellar ataxias

Cerebellar ataxias comprise a wide range of etiologies leading to central nervous system-related motor and non-motor symptoms. Recently, a large body of evidence has demonstrated a high frequency of non-motor manifestations in cerebellar ataxias, specially in autosomal dominant spinocerebellar ataxias (SCA). Among these non-motor dysfunctions, sleep disorders have been recognized, although still under or even misdiagnosed. In this review, we highlight the main sleep disorders related to cerebellar ataxias focusing on REM sleep behavior disorder (RBD), restless legs syndrome (RLS), periodic limb movement in sleep (PLMS), excessive daytime sleepiness (EDS), insomnia and sleep apnea.

Caring for Machado-Joseph disease: current understanding and how to help patients

Machado-Joseph disease or spinocerebellar ataxia 3 (MJD/SCA3) is a clinically heterogeneous, neurodegenerative disorder characterized by varying degrees of ataxia, ophthalmoplegia, peripheral neuropathy, pyramidal dysfunction and movement disorder. MJD/SCA3 is caused by a CAG repeat expansion mutation in the protein coding region of the ATXN3 gene located at chromosome 14q32.1. Current hypotheses regarding pathogenesis favor the view that mutated ataxin-3, with its polyglutamine expansion, is prone to adopt an abnormal conformation, engage in altered protein-protein interactions and aggregate. Expanded CAG repeat length correlates with the range and severity of the clinical manifestations and inversely correlates with age of disease onset. Though MJD/SCA3 is classically described as affecting the cerebellum, brainstem and basal ganglia, recent neuropathology and neuroimaging series demonstrate involvement of other areas such as the thalamus and cerebral cortex. Clinically, much emphasis has been placed in the description and recognition of the non-motor symptoms observed in these patients, such as pain, cramps, fatigue and depression. Currently, no disease modifying treatment exists for MJD/SCA3. Standard of care includes genetic counseling, exercise/physical therapy programs, and speech and swallow evaluation. Symptomatic treatment for clinical findings such as depression, sleep disorders, parkinsonism, dystonia, cramps, and pain is important to improve the quality of life for those with MJD/SCA3.