Sleep disorders in Machado–Joseph disease: A dopamine transporter imaging study

Specific Biomarkers in Spinocerebellar Ataxia Type 3: A Systematic Review of Their Potential Uses in Disease Staging and Treatment Assessment

Spinocerebellar ataxia type 3 (SCA3) is the most common type of disease related to poly-glutamine (polyQ) repeats. Its hallmark pathology is related to the abnormal accumulation of ataxin 3 with a longer polyQ tract (polyQ-ATXN3). However, there are other mechanisms related to SCA3 progression that require identifying trait and state biomarkers for a more accurate diagnosis and prognosis. Moreover, the identification of potential pharmacodynamic targets and assessment of therapeutic efficacy necessitates valid biomarker profiles. The aim of this review was to identify potential trait and state biomarkers and their potential value in clinical trials. Our results show that, in SCA3, there are different fluid biomarkers involved in neurodegeneration, oxidative stress, metabolism, miRNA and novel genes. However, neurofilament light chain NfL and polyQ-ATXN3 stand out as the most prevalent in body fluids and SCA3 stages. A heterogeneity analysis of NfL revealed that it may be a valuable state biomarker, particularly when measured in plasma. Nonetheless, since it could be a more beneficial approach to tracking SCA3 progression and clinical trial efficacy, it is more convenient to perform a biomarker profile evaluation than to rely on only one.

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.

Sleep disorders among Aboriginal Australians with Machado-Joseph Disease: Quantitative results from a multiple methods study to assess the experience of people living with the disease and their caregivers

Background

Machado-Joseph Disease (MJD), or Spinocerebellar Ataxia Type 3 (SCA3), is a genetic disorder that causes progressive muscle weakness, loss of motor control, ataxia and permanent physical disability. Sleep disturbances are associated with MJD but remain poorly understood.

Objective

To investigate frequency and characteristics of sleep disorders and their association with health-related quality of life and psychosocial wellbeing for Aboriginal Australians living with MJD.

Methods

A convenience sample of MJD participants n = 24 participated in a semi-attended, ambulatory diagnostic sleep study to capture polysomnography, actigraphy and sleep diary data. Self-report measures collected were the Pittsburgh Sleep Quality Index (PSQI), STOP-BANG Questionnaire for Obstructive Sleep Apnoea (OSA), International Restless Legs Syndrome Study Group rating scale (IRLS), Kessler-5 (K5) and EuroQoL-5 Dimension (EQ5D). Caregivers (n = 22) reported EQ-5D, K5 and bed partners’ sleep behaviour (Mayo Sleep Questionnaire-Informant). Environmental factors were measured.

Results

We observed Nocturia, Sleep Related Leg Cramps, OSA, REM Behaviour Disorder, and RLS, respectively in 100%, 71%, 47%, 43%, and 33% of participants with a significant positive correlation between Body mass index (BMI) and Apnoea hypopnea index (AHI). The majority of sleep was spent in non-rapid eye movement sleep (NREM)-N2 stage (77.8% (67.7, 81.6)). Overcrowding (92%) and overnight care needs (42%) interrupted sleep. MJD participants and caregivers reported high psychological distress (K5 median 12.5 IQR 7, 16.5 & 8 IQR 6, 12 respectively).

Conclusion

Poor sleep quality and sleep disturbances are prevalent among this cohort. Disease manifestations and environmental factors are driving factors. Larger sample sizes are required to predict risk factors and confirm observed associations.

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Aboriginal People living with MJD in Australia experience numerous sleep disorders.

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Majority of sleep was spent in non-rapid eye movement sleep.

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Overcrowding and overnight care needs interrupt sleep.

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MJD participants and caregivers reported high psychological distress.

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.

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.

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.

99mTc-TRODAT-1 SPECT as a Potential Neuroimaging Biomarker in Patients With Restless Legs Syndrome

BACKGROUND

Restless legs syndrome (RLS) is a neurological sensory motor disorder of which pathophysiology remains sketchy. The present study was aimed to determine the diagnostic accuracy and potential of SPECT-TRODAT imaging in discriminating patients with RLS from normal individuals.

PATIENTS AND METHODS

A total of 34 subjects, 22 diagnosed with RLS and 12 classified as normal, were enrolled. Brain SPECT images were acquired 180 minutes after IV injection of 740 to 925 MBq (20-25 mCi) 99mTc-TRODAT-1 using a double-headed γ-camera equipped with high-resolution fan-beam collimators. Regions of interest were drawn over the whole striatum, caudate, and putamen nucleus of each hemisphere on composite images of the 9 slices with the highest basal ganglia activity. The brain SPECT 99mTc-TRODAT-1 imaging was compared with early-stage RLS patients and healthy volunteers groups.

RESULT

SPECT imaging in RLS patients showed reduced radioactivity accumulation in the striatum profile. The major abnormal result observed is the significantly reduced uptake in striatal dopamine transporter density and activity. The symmetric striatal uptake was observed, and striatum dopamine transporter destiny was more impaired in patients with RLS disease. SPECT images also showed significant differences between patients and volunteers.

CONCLUSIONS

This study supports that symptoms of restless legs resulted from the striatum of the brain dopaminergic system dysfunction.

Polysomnography findings in spinocerebellar ataxia type 6

Spinocerebellar ataxia type 6 (SCA6) is usually described as a pure ataxia syndrome. However, SCA6 patients may have sleep complaints. In this paper, sleep disorders were investigated in patients with SCA6. Twelve SCA6 patients and 12 subjects matched by gender, age and body mass index (control group) underwent polysomnography and clinical investigation for sleep disorders. SCA6 had a higher frequency of snoring (P = 0.01), a higher index of awakening due to respiratory events (P = 0.003) and central apnea events during sleep (P = 0.024), a longer sleep Stage N1 (P = 0.02) and a lower sleep Stage N3 (P = 0.05) in SCA6 patients than in control subjects. SCA6 patients had a reduction in slow wave sleep and a higher frequency of snoring and respiratory disorders during sleep when compared to the control group.

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.

Sleep and sleep disorders in rare hereditary diseases: a reminder for the pediatrician, pediatric and adult neurologist, general practitioner, and sleep specialist

Although sleep abnormalities in general and sleep-related breathing disorders (SBD) in particular are quite common in healthy children; their presence is notably under-recognized. Impaired sleep is a frequent problem in subjects with inborn errors of metabolism as well as in a variety of genetic disorders; however, they are commonly either missed or underestimated. Moreover, the complex clinical presentation and the frequently life-threatening symptoms are so overwhelming that sleep and its quality may be easily dismissed. Even centers, which specialize in rare genetic-metabolic disorders, are expected to see only few patients with a particular syndrome, a fact that significantly contributes to the under-diagnosis and treatment of impaired sleep in this particular population. Many of those patients suffer from reduced life quality associated with a variable degree of cognitive impairment, which may be worsened by poor sleep and abnormal ventilation during sleep, abnormalities which can be alleviated by proper treatment. Even when such problems are detected, there is a paucity of publications on sleep and breathing characteristics of such patients that the treating physician can refer to. In the present paper, we provide an overview of sleep and breathing characteristics in a number of rare genetic–metabolic disorders with the hope that it will serve as a reminder for the medical professional to look for possible impaired sleep and SBD in their patients and when present to apply the appropriate evaluation and treatment options.

Neurophysiological studies and non-motor symptoms prior to ataxia in a patient with machado-joseph disease: trying to understand the natural history of brain degeneration

Spinocerebellar ataxia type 3 or Machado-Joseph disease is the most common spinocerebellar ataxia. In this neurological disease, anatomical, physiological, clinical, and functional neuroimaging demonstrate a degenerative process besides the cerebellum. We performed neurophysiological and neuroimaging studies-polysomnography, transcranial sonography, vestibular-evoked myogenic potential, single-photon emission computed tomography (SPECT) with (99m)Tc-TRODAT-1, and a formal neuropsychological evaluation in a patient with sleep complaints and positive testing for Machado-Joseph disease, without cerebellar atrophy, ataxia, or cognitive complaints. Polysomnography disclosed paradoxical high amplitude of submental muscle, characterizing REM sleep without atonia phenomenon. Transcranial sonography showed hyperechogenicity of the substantia nigra. There was an absence of vestibular-evoked myogenic potentials on both sides in the patient under study, in opposite to 20 healthy subjects. Brain imaging SPECT with (99m)Tc-TRODAT-1 demonstrated a significant lower DAT density than the average observed in six healthy controls. Electroneuromyography was normal. Neuropsychological evaluation demonstrated visuospatial and memory deficits. Impairment of midbrain cholinergic and pontine noradrenergic systems, dysfunction of the pre-synaptic nigrostriatal system, changes in echogenicity of the substantia nigra, and damage to vestibulo-cervical pathways are supposed to occur previous to cerebellar involvement in Machado-Joseph disease.