Sleep disorders in multiple system atrophy

Neurologic Disorders in Women and Sleep

Sleep disorders in women remain underrecognized and underdiagnosed mainly because of gender bias in researching and characterizing sleep disorders in women. Symptoms of common sleep disorders are frequently missed in the general female population and are expected to be further overlooked because of overlapping symptoms in women with neurologic disorders. Given the bidirectional relationship with sleep and neurologic disorders, it remains critical to be aware of the presentation and impact of sleep disorders in this patient population. This article reviews available data on sleep disorders in women with neurologic disorders and discusses their distinctive features.

Autonomic failure: Clinicopathologic, physiologic, and genetic aspects

Over the past century, generations of neuroscientists, pathologists, and clinicians have elucidated the underlying causes of autonomic failure found in neurodegenerative, inherited, and antibody-mediated autoimmune disorders, each with pathognomonic clinicopathologic features. Autonomic failure affects central autonomic nervous system components in the α-synucleinopathy, multiple system atrophy, characterized clinically by levodopa-unresponsive parkinsonism or cerebellar ataxia, and pathologically by argyrophilic glial cytoplasmic inclusions (GCIs). Two other central neurodegenerative disorders, pure autonomic failure characterized clinically by deficits in norepinephrine synthesis and release from peripheral sympathetic nerve terminals; and Parkinson's disease, with early and widespread autonomic deficits independent of the loss of striatal dopamine terminals, both express Lewy pathology. The rare congenital disorder, hereditary sensory, and autonomic neuropathy type III (or Riley-Day, familial dysautonomia) causes life-threatening autonomic failure due to a genetic mutation that results in loss of functioning baroreceptors, effectively separating afferent mechanosensing neurons from the brain. Autoimmune autonomic ganglionopathy caused by autoantibodies targeting ganglionic α3-acetylcholine receptors instead presents with subacute isolated autonomic failure affecting sympathetic, parasympathetic, and enteric nervous system function in various combinations. This chapter is an overview of these major autonomic disorders with an emphasis on their historical background, neuropathological features, etiopathogenesis, diagnosis, and treatment.

Multiple system atrophy

Multiple system atrophy (MSA) is a rare neurodegenerative disease that is characterized by neuronal loss and gliosis in multiple areas of the central nervous system including striatonigral, olivopontocerebellar and central autonomic structures. Oligodendroglial cytoplasmic inclusions containing misfolded and aggregated α-synuclein are the histopathological hallmark of MSA. A firm clinical diagnosis requires the presence of autonomic dysfunction in combination with parkinsonism that responds poorly to levodopa and/or cerebellar ataxia. Clinical diagnostic accuracy is suboptimal in early disease because of phenotypic overlaps with Parkinson disease or other types of degenerative parkinsonism as well as with other cerebellar disorders. The symptomatic management of MSA requires a complex multimodal approach to compensate for autonomic failure, alleviate parkinsonism and cerebellar ataxia and associated disabilities. None of the available treatments significantly slows the aggressive course of MSA. Despite several failed trials in the past, a robust pipeline of putative disease-modifying agents, along with progress towards early diagnosis and the development of sensitive diagnostic and progression biomarkers for MSA, offer new hope for patients.

The orexin/hypocretin system in neuropsychiatric disorders: Relation to signs and symptoms

Hypocretin-1 and 2 (or orexin A and B) are neuropeptides exclusively produced by a group of neurons in the lateral and dorsomedial hypothalamus that project throughout the brain. In accordance with this, the two different hypocretin receptors are also found throughout the brain. The hypocretin system is mainly involved in sleep-wake regulation, but also in reward mechanisms, food intake and metabolism, autonomic regulation including thermoregulation, and pain. The disorder most strongly linked to the hypocretin system is the primary sleep disorder narcolepsy type 1 caused by a lack of hypocretin signaling, which is most likely due to an autoimmune process targeting the hypocretin-producing neurons. However, the hypocretin system may also be affected, but to a lesser extent and less specifically, in various other neurological disorders. Examples are neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's disease, immune-mediated disorders such as multiple sclerosis, neuromyelitis optica, and anti-Ma2 encephalitis, and genetic disorders such as type 1 diabetus mellitus and Prader-Willi Syndrome. A partial hypocretin deficiency may contribute to the sleep features of these disorders.

Chronic Respiratory Diseases and Neurodegenerative Disorders: A Primer for the Practicing Clinician

Chronic respiratory disorders represent a world epidemic. Their incidence and prevalence in the world population is increasing, and especially among elderly subjects, they are commonly associated with other pathologies, often generating a status of high clinical complexity. Neurology, internal medicine, and pneumology specialists should be aware of the common background of these disorders in order to treat correctly the patient's comorbid state and optimize the treatment considering potential overlaps. In this review, we aimed to focus on the relationships between chronic respiratory disorders and chronic neurodegenerative diseases at different levels; we review the shared risk factors and the interactions between disorders, the indications to explore respiratory function in neurodegenerative diseases, pathology-pathology and drug-pathology interactions in patients affected by both chronic neurologic and respiratory diseases.

Current Management and Emerging Therapies in Multiple System Atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease variably associated with motor, nonmotor, and autonomic symptoms, resulting from putaminal and cerebellar degeneration and associated with glial cytoplasmic inclusions enriched with α-synuclein in oligodendrocytes and neurons. Although symptomatic treatment of MSA can provide significant improvements in quality of life, the benefit is often partial, limited by adverse effects, and fails to treat the underlying cause. Consistent with the multisystem nature of the disease and evidence that motor symptoms, autonomic failure, and depression drive patient assessments of quality of life, treatment is best achieved through a coordinated multidisciplinary approach driven by the patient's priorities and goals of care. Research into disease-modifying therapies is ongoing with a particular focus on synuclein-targeted therapies among others. This review focuses on both current management and emerging therapies for this devastating disease.

An update on MSA: premotor and non-motor features open a window of opportunities for early diagnosis and intervention

In this review, we describe the wide clinical spectrum of features that can be seen in multiple system atrophy (MSA) with a focus on the premotor phase and the non-motor symptoms providing an up-to-date overview of the current understanding in this fast-growing field. First, we highlight the non-motor features at disease onset when MSA can be indistinguishable from pure autonomic failure or other chronic neurodegenerative conditions. We describe the progression of clinical features to aid the diagnosis of MSA early in the disease course. We go on to describe the levels of diagnostic certainty and we discuss MSA subtypes that do not fit into the current diagnostic criteria, highlighting the complexity of the disease as well as the need for revised diagnostic tools. Second, we describe the pathology, clinical description, and investigations of cardiovascular autonomic failure, urogenital and sexual dysfunction, orthostatic hypotension, and respiratory and REM-sleep behavior disorders, which may precede the motor presentation by months or years. Their presence at presentation, even in the absence of ataxia and parkinsonism, should be regarded as highly suggestive of the premotor phase of MSA. Finally, we discuss how the recognition of the broader spectrum of clinical features of MSA and especially the non-motor features at disease onset represent a window of opportunity for disease-modifying interventions.

Sleep-Induced Glottis Closure in Multiple System Atrophy Evaluated by Four-Dimensional Computed Tomography

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder. Since patients with MSA often have sleep-related respiratory disorders including upper-airway obstruction and/or central sleep disturbance, appropriate evaluation of the upper airway especially during sleep may be indispensable. Fiberoptic laryngoscopy during diazepam-induced sleep has been reported for upper-airway obstruction verification. However, some patients cannot endure the uncomfortable sensation of the fiberscope. To address these issues, we devised a protocol of four four-dimensional computed tomography (4D-CT) for upper-airway evaluation during sleep. Here, we report the case of patient with MSA who was evaluated for upper-airway obstruction during sleep using 4D-CT. A 46-year-old man (height 1.60 m, weight 79 kg) was admitted to our neurological department for tracheal intubation because of a sudden onset of respiratory failure occurring at night. At the age of 45 years, he was diagnosed as MSA with predominant parkinsonism. As pulmonary disease had been excluded and his swallowing was normal, our differential diagnoses were central sleep apnea or obstructive sleep apnea related to his MSA or obstructive sleep apnea (SA) related to his obesity. A tracheostomy was done to maintain the airway after extubation. Polysomnography showed obstructive SA and not central SA. Awake fiberoptic laryngoscopy showed no upper airway obstruction but bilateral vocal abduction impairment (BVAI) during inspiration. To assess the spatial and temporal conditions of the upper respiratory tract—the patient could not tolerate sleep laryngoscopy—we carried out a 4D-CT. Reconstructed 4D-CT images of respiration during sleep showed clear abnormalities: glottis closure at the terminal stage of inspiration and subsequent velopharyngeal closure. As glottis closure does not occur normally in obesity patients, the cause of the respiratory failure in this patient was considered MSA-related sleep-induced airway obstruction. We decided to keep the tracheostoma, because BVAI in patients with MSA may be getting worse, although central apnea after tracheostomy may cause sudden central origin-related death; 4 months postoperatively, the patient had experienced no further airway-related complications. This report indicates that 4D-CT sequential upper-airway assessment during sleep is useful for determining the abnormalities causing obstructive SA in patients with MSA.

Heightened risk of early vocal fold motion impairment onset and dysphagia in the parkinsonian variant of multiple system atrophy: a comparative study

Objective

We compared differences in frequency and timing of onset of the following clinical events between the cerebellar and parkinsonian variants of multiple system atrophy (MSA-C and MSA-P, respectively): type of operation including tracheostomy and/or aspiration prevention surgery, vocal fold motion impairment (VFMI), sleep apnea (SA), introduction of mechanical ventilation (MV), and dysphagia. The risks of these events cooccurring with either MSA-C or MSA-P were compared.

Methods

We retrospectively assessed clinical outcomes only of patients with MSA who presented at the Department of Otolaryngology of the University of Tokyo Hospital between 2008 and 2018. The proportion and timing of onset events between MSA-C and MSA-P and risks of onset were compared using chi-square tests and Cox proportional hazard models adjusted for age, sex, and disease severity, respectively.

Results

We identified 113 patients (median age: 60 years, 72 men [64%]). The frequency and timing of VFMI, SA, MV, dysphagia, and surgeries were 55 patients (49%) and 76 (95% CI 61–91) months after MSA onset, 85 (75%) and 41 (32–50), 36 (32%) and 100 (73–127), 77 (68%) and 43 (36–50), and 25 (22%) and 102 (84–120), respectively. Twenty-seven patients (24%) had MSA-P and higher risk of VFMI (p < .001), SA (p = .030), and dysphagia (p = .017) than did patients with MSA-C.

Conclusion

While MSA-P is less common, it may involve heightened risk of VFMI and dysphagia early onset. Thus, careful follow-up for VFMI, SA, and dysphagia may be needed for these patients.

Criteria for Rating Diagnostic Accuracy Studies

Class II.

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The onset of vocal fold motion impairment varies in multiple system atrophy types

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The sleep-apnea onset is relatively early in parkinsonian multiple system atrophy

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The onset of dysphagia is relatively early in parkinsonian multiple system atrophy

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Respiratory clinical events are more common in parkinsonian multiple system atrophy

Diagnosis and Differential Diagnosis of Parkinson Disease

Parkinsonism is one of the most common neurologic disorders in the aging population. Although Parkinson disease (PD) is the most common cause, there is a lengthy differential diagnosis. The diagnosis of PD hinges on recognizing its typical features, including bradykinesia, rest tremor, unilateral onset, cogwheel rigidity, and beneficial and sustained response to levodopa. Equally important is to be familiar with the "red flags," which are features not expected with PD and suggest an alternative diagnosis, usually a parkinsonian syndrome. In general, it is best to have the diagnosis confirmed by a neurologist, especially one with expertise in movement disorders.

Vocal Fold "Paralysis": An Early Sign in Multiple System Atrophy

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by a cerebellar syndrome, autonomic dysfunction, and extrapyramidal signs. Extrapyramidal signs may manifest as parkinsonism as well as dystonia, which is the involuntary contraction of a muscle(s) resulting in an abnormal posture. MSA belongs to a family of diseases known as α-synucleinopathies which are associated with dream enactment reflecting REM sleep behavior disorder (RBD). In patients with MSA, dystonia or paresis may involve the laryngeal muscles resulting in vocal fold hypomobility. We identified four individuals presenting with vocal complaints and subsequently diagnosed with vocal fold "paralysis." Within one year, each patient developed neurologic symptoms and upon evaluation by a movement disorders specialist was diagnosed with probable MSA. Our findings highlight the importance of screening by otolaryngologists when patients are diagnosed with vocal fold hypomobility. Specifically, patients should be assessed for RBD by questioning others if he/she acts out their dreams. The presence of RBD raises clinical suspicion for a synucleinopathy such as MSA. Untreated patients with MSA experiencing nocturnal stridor and breathing disorders have an increased risk for sudden death. Therefore, early evaluation by a movement disorders specialist to promptly diagnose MSA may have a substantial effect on morbidity and mortality in this high-risk patient population.

The Diagnosis and Natural History of Multiple System Atrophy, Cerebellar Type

The objective of this study was to identify key features differentiating multiple system atrophy cerebellar type (MSA-C) from idiopathic late-onset cerebellar ataxia (ILOCA). We reviewed records of patients seen in the Massachusetts General Hospital Ataxia Unit between 1992 and 2013 with consensus criteria diagnoses of MSA-C or ILOCA. Twelve patients had definite MSA-C, 53 had possible/probable MSA-C, and 12 had ILOCA. Autonomic features, specifically urinary urgency, frequency, and incontinence with erectile dysfunction in males, differentiated MSA-C from ILOCA throughout the disease course (p = 0.005). Orthostatic hypotension developed later and differentiated MSA-C from ILOCA (p < 0.01). REM sleep behavior disorder (RBD) occurred early in possible/probable MSA-C (p < 0.01). Late MSA-C included pathologic laughing and crying (PLC, p < 0.01), bradykinesia (p = 0.01), and corticospinal findings (p = 0.01). MRI distinguished MSA-C from ILOCA by atrophy of the brainstem (p < 0.01) and middle cerebellar peduncles (MCP, p = 0.02). MSA-C progressed faster than ILOCA: by 6 years, MSA-C walker dependency was 100 % and ILOCA 33 %. MSA-C survival was 8.4 ± 2.5 years. Mean length of ILOCA illness to date is 15.9 ± 6.4 years. A sporadic onset, insidiously developing cerebellar syndrome in midlife, with autonomic features of otherwise unexplained bladder dysfunction with or without erectile dysfunction in males, and atrophy of the cerebellum, brainstem, and MCP points strongly to MSA-C. RBD and postural hypotension confirm the diagnosis. Extrapyramidal findings, corticospinal tract signs, and PLC are helpful but not necessary for diagnosis. Clarity in early MSA-C diagnosis can prevent unnecessary investigations and facilitate therapeutic trials.

Distinct Parameters in the EEG of the PLP α-SYN Mouse Model for Multiple System Atrophy Reinforce Face Validity

Multiple system atrophy (MSA) is a neurodegenerative movement disorder characterized by parkinsonian symptoms and cerebellar symptoms. Sleep disturbances also play a crucial role in MSA. One of the most convincing animal models in MSA research is the PLP α-SYN model, but to date no studies on sleep disturbances in this mouse model, frequently found in MSA patients are available. We identified spectral shifts within the EEG of the model, strikingly resembling results of clinical studies. We also characterized muscle activity during REM sleep, which is one of the key symptoms in REM sleep behavioral disorder. Spectral shifts and REM sleep-linked muscle activity were age dependent, supporting Face Validity of the PLP α-SYN model. We also strongly suggest our findings to be critically evaluated for Predictive Validity in future studies. Currently, research on MSA lacks potential compounds attenuating or curing MSA. Future drugs must prove its potential in animal models, for this our study provides potential biomarkers.

Current Treatment of Multiple System Atrophy

OPINION STATEMENT

Treatment of patients with multiple system atrophy (MSA) is complex and purely symptomatic to date. No disease-modifying treatment is available so far, leaving a survival time of usually less than 10 years after diagnosis is made. Clinically, two forms of movement disorders characterize this disease, either a hypokinetic rigid parkinsonian movement disorder in MSA of the parkinsonian type or ataxia in MSA of the cerebellar type. In both variants of the disease, autonomic symptoms are mandatory for establishing the diagnosis of MSA. While hypokinetic rigid symptoms of patients with MSA of the parkinsonian type can respond to some extent to dopaminergic treatment, no effective symptomatic treatment for the cerebellar symptoms is available so far. Particular attention should be paid to autonomic symptoms, as these symptoms are known to strongly affect the patients' quality of life. Here, we discuss the current state of the art in MSA treatment.

Comparison Study of Polysomnographic Features in Multiple System Atrophy-cerebellar Types Combined with and without Rapid Eye Movement Sleep Behavior Disorder

Background:

The brain stem is found to be impaired in multiple system atrophy-cerebellar types (MSA-C). Rapid eye movement (REM) sleep behavior disorder (RBD) is reported as a marker of progressive brain stem dysfunction. Few systematic studies about the sleep disturbances in MSA-C patients combined with or without RBD were reported. This study aimed to explore the polysomnographic (PSG) features of sleep disturbances between MSA-C patients with and without RBD.

Methods:

Totally, 46 MSA-C patients (23 with RBD, and 23 without RBD) were enrolled in this study. All patients underwent a structured interview for their demographic data, history of sleep pattern, and movement disorders; and then, overnight video-PSG was performed in each patient. All the records were evaluated by specialists at the Sleep Medicine Clinic for RBD and the Movement Disorder Clinic for MSA-C. The Student's t-test, Mann-Whitney U-test for continuous variables, and the Chi-square test for categorical variables were used in this study.

Results:

MSA-C patients with RBD had younger visiting age (52.6 ± 7.4 vs. 56.7 ± 6.0 years, P = 0.046) and shorter duration of the disease (12.0 [12.0, 24.0] vs. 24.0 [14.0, 36.0] months, P = 0.009) than MSA-C patients without RBD. MSA-C with RBD had shorter REM sleep latency (111.7 ± 48.2 vs. 157.0 ± 68.8 min, P = 0.042), higher percentage of REM sleep (14.9% ±4.0% vs. 10.0% ± 3.2%, P = 0.019), and lower Stage I (9.5% ±7.2% vs. 15.9% ±8.0%, P = 0.027) than MSA-C without RBD. Moreover, MSA-C patients with RBD had more decreased sleep efficiency (52.4% ±12.6% vs. 65.8% ±15.9%, P = 0.029) than that without RBD.

Conclusions:

In addition to the RBD, MSA-C patients with RBD had other more severe sleep disturbances than those without RBD. The sleep disorders of MSA patients might be associated with the progress of the disease.

[Expanding concept of clinical conditions and symptoms in multiple system atrophy]

Multiple system atrophy (MSA) is an adult-onset, progressive neurodegenerative disorder. MSA patients show various phenotypes during the course of their illness including parkinsonism, cerebellar ataxia, autonomic failure, and pyramidal signs. MSA is classified into the parkinsonian (MSA-P) or cerebellar (MSA-C) variant depending on the clinical motor phenotype at presentation. MSA-P and MSA-C are predominant in Western countries and Japan, respectively. The mean age at onset is 55 to 60 years. Prognosis ranges from 6 to 10 years, but some cases survive for more than 15 years. Early and severe autonomic failure is a poor prognostic factor. MSA patients sometimes present with isolated autonomic failure or motor symptoms/signs, and the median duration from onset to the concomitant appearance of motor and autonomic symptoms was approximately 2 years in our previous study. As the presence of the combination of motor and autonomic symptoms is essential for the current diagnostic criteria, early diagnosis is difficult when patients present with isolated autonomic failure or motor symptoms/signs. We experienced MSA patients who died before presentation of the motor symptoms/signs diagnostic for MSA (i.e., premotor MSA). Detection of the nature of autonomic failure consistent with MSA and identification of the dysfunctional anatomical sites may increase the probability of a diagnosis of premotor MSA. Dementia is another problem in MSA. Although dementia had been thought to be rare in MSA, frontal lobe dysfunction is observed frequently during the early course of the illness. Magnetic resonance imaging can show progressive cerebral atrophy in longstanding cases. More recently, MSA patients presenting with frontotemporal dementia preceding the presence of motor and autonomic manifestations diagnostic of MSA have been reported. Novel diagnostic criteria based on an expanding concept of the clinical conditions and symptoms of MSA will be needed for the development of disease-modifying therapies and better management.

Current Concepts in the Treatment of Multiple System Atrophy

MSA is a progressive neurodegenerative disorder characterized by autonomic failure and a variable combination of poor levodopa-responsive parkinsonism and cerebellar ataxia (CA). Current therapeutic management is based on symptomatic treatment. Almost one third of MSA patients may benefit from l-dopa for the symptomatic treatment of parkinsonism, whereas physiotherapy remains the best therapeutic option for CA. Only midodrine and droxidopa were found to be efficient for neurogenic hypotension in double-blind, controlled studies, whereas other symptoms of autonomic failure may be managed with off-label treatments. To date, no curative treatment is available for MSA. Recent results of neuroprotective and -restorative trials have provided some hope for future advances. Considerations for future clinical trials are also discussed in this review.

Cognitive and sleep features of multiple system atrophy: review and prospective study

BACKGROUND

The profile and degree of cognitive impairment in Multiple System Atrophy (MSA) and the impact of sleep disorders, REM sleep behavior disorder (RBD) in particular, in parkinsonism-related cognitive deficits are currently being debated.

SUMMARY

We reviewed the cognitive, affective and sleep findings in MSA and also carried out a longitudinal investigation of 10 MSA patients. At the first evaluation, 3 patients showed isolated cognitive deficits. After a mean of 16 months, these patients remained unchanged, while 1 patient worsened from a normal condition. No significant differences emerged when the cognitive, affective and video-polysomnographic findings of MSA-P and MSA-C were compared. Depression was present in half of the patients, although it did not influence their cognitive performance. Comparisons between the first and second evaluation data showed significant worsening in visual attention and in ADL/IADL and UMSARS.

KEY MESSAGES

Isolated cognitive deficits are evidenced in a minority of MSA patients with the absence of a clear-cut diagnosis of dementia in the early stages of the disease. Attention and executive functions are often impaired. This study with a short follow-up period showed that RBD, although present in almost all patients affected by MSA, does not appear a clear early marker of cognitive impairment. Future longer-term studies with a larger patient sample are thus encouraged.

Visual signs and symptoms of multiple system atrophy

Multiple system atrophy (MSA) is a rare movement disorder and a member of the 'parkinsonian syndromes', which also include Parkinson's disease (PD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB) and corticobasal degeneration (CBD). Multiple system atrophy is a complex syndrome, in which patients exhibit a variety of signs and symptoms, including parkinsonism, ataxia and autonomic dysfunction. It can be difficult to separate MSA from the other parkinsonian syndromes but if ocular signs and symptoms are present, they may aid differential diagnosis. Typical ocular features of MSA include blepharospasm, excessive square-wave jerks, mild to moderate hypometria of saccades, impaired vestibular-ocular reflex (VOR), nystagmus and impaired event-related evoked potentials. Less typical features include slowing of saccadic eye movements, the presence of vertical gaze palsy, visual hallucinations and an impaired electroretinogram (ERG). Aspects of primary vision such as visual acuity, colour vision or visual fields are usually unaffected. Management of the disease to deal with problems of walking, movement, daily tasks and speech problems is important in MSA. Optometrists can work in collaboration with the patient and health-care providers to identify and manage the patient's visual deficits. A more specific role for the optometrist is to correct vision to prevent falls and to monitor the anterior eye to prevent dry eye and control blepharospasm.

A microstructural study of sleep instability in drug-naive patients with schizophrenia and healthy controls: sleep spindles, rapid eye movements, and muscle atonia

This study aimed at characterizing the functional stability of sleep in schizophrenia by quantifying dissociated stages of sleep (DSS), and to explore their correlation with psychopathology. The sleep of 10 first-break, drug-naive young adults with schizophrenia and 10 controls was recorded. Four basic DSS patterns were scored: 1) the transitional EEG-mixed intermediate stage (EMIS); 2) Rapid-eye-movement (REM) sleep without rapid eye movement (RSWR); 3) REM sleep without atonia (RSWA); and 4) non-REM sleep with rapid eye movements. An intermediate sleep (IS) score was calculated by summing EMIS and RSWR scores, and the durations of intra-REM sleep periods IS (IRSPIS) and IS scored "at the expense" of REM sleep (ISERS) were determined. Patients were administered the Brief Psychiatric Rating Scale (BPRS) at the time of recording. Proportions of each DSS variables over total sleep time and proportions of IRSPIS and ISERS over REM sleep duration were compared between patients and controls. Correlation coefficients between DSS variables and BPRS total scores were calculated. The proportion of total DSS did not differ between patients and controls. Among DSS subtypes, RSWA was significantly increased in patients while other comparisons showed no significant differences. Significant positive correlations were found between BPRS scores and proportions of DSS, IS, RSWR, IRSPIS and ISERS over total sleep and REM sleep durations. These results demonstrate the functional instability of REM sleep in first-break, drug naive young adults with schizophrenia and unveil a pattern reminiscent of REM sleep behavior disorder. The significant correlation suggests that schizophrenia and REM sleep share common neuronal control mechanisms.

Breathing variability and brainstem serotonergic loss in a genetic model of multiple system atrophy

Breathing disorders like sleep apnea, stridor, and dysrythmic breathing are frequent in patients with multiple system atrophy (MSA). These observations have been related to neurodegeneration in several pontomedullary respiratory nuclei and may explain the occurrence of sudden death. In this study, we sought to determine whether these functional and neuropathological characteristics could be replicated in a transgenic model of MSA. Mice expressing human wild-type α-synuclein under the control of the proteolipid promoter (PLP-αSYN) were compared with age-matched controls. Using whole-body, unrestrained plethysmography, the following breathing parameters were measured: inspiratory and expiratory times, tidal volume, expiratory volume, peak inspiratory and expiratory flows, and respiratory frequency. For each category, the mean, coefficient of variation, and irregularity score were analyzed. Brains were then processed for stereological cell counts of pontomedullary respiratory nuclei. A significant increase in the coefficient of variation and irregularity score was observed for inspiratory time, tidal volume, and expiratory volume in PLP-αSYN mice (P < 0.05). Glial cytoplasmic inclusions were found in the medullary raphe of PLP-αSYN mice, together with a loss of serotonergic immunoreactivity in the raphe obscurus (P < 0.001) and pallidus (P < 0.01). There was a negative correlation between α-synuclein burden and raphe pallidus cell counts (P < 0.05). There was no significant neuronal loss in the pre-Botzinger complex. The PLP-αSYN mouse model replicates the breathing variability and part of the neuronal depletion in pontomedullary respiratory nuclei observed in patients with MSA. Our findings support the use of this model for future candidate drugs in the breathing disorders observed in MSA.

Clinical and polysomnographic features of patients with multiple system atrophy in Southwest China

PURPOSE

The association between clinical features and polysomnographic variables of Chinese patients with multiple-system atrophy (MSA) remains largely unknown.

METHODS

This study assessed 30 patients with MSA from Southwest China using the Unified Multiple-System Atrophy Rating Scale (UMSARS). Each patient also underwent video-polysomnography. Twenty age and gender matched healthy volunteers were performed video-polysomnography as control group.

RESULTS

Of the 30 patients, 23 (76.7 %) were classified as having MSA-C and seven (23.3 %) were diagnosed with MSA-P. The mean age of the patients at disease onset was 53.2 ± 8.5 years, and the mean duration of their disease was 3.6 ± 2.8 years. Twenty-one patients complained of sleep disorders. The mean scores of UMSARS-I, UMSARS-II, and UMSARS-IV of patients with MSA-P were significantly higher than those of patients with MSA-C. Polysomnography revealed that 29 patients had sleep architecture alteration. A longer duration of stage N1 sleep, a shorter REM sleep, as well as decreased sleep efficiency and total sleep time (TST) were detected. Twenty-one patients had obstructive sleep apnea. Patients with MSA-C demonstrated longer sleep onset latencies compared with patients with MSA-P. TST was negatively correlated with MSA duration, whereas sleep latency was positively correlated with MSA duration. Moreover, TST, and mean SaO2 were negatively correlated with motor disability.

CONCLUSIONS

Various sleep disorders are common in Chinese MSA patients. Sleep architecture and sleep-associated breathing disorders are predominant polysomnographic findings. Sleep quantity was reduced with disease progression.

Use of ramelteon for the treatment of secondary REM sleep behavior disorder

We used ramelteon to treat two patients with secondary REM sleep behavior disorder (RBD) complications along with neurodegenerative diseases including multiple system atrophy and Parkinson's disease. These two patients not only improved in terms of their clinical RBD symptoms but also exhibited a decrease in the proportion of REM sleep without atonia (from 8.5% to 3.5% and from 10.9% to 3.9% in the two patients). Although clonazepam is the standard first-line therapy for the treatment of RBD, ramelteon might be an effective treatment alternative in patients with RBD who cannot take clonazepam due to either ineffectiveness or adverse effects.

Multiple system atrophy: current and future approaches to management

Multiple system atrophy (MSA) is a rare neurodegenerative disorder without any effective treatment in slowing or stopping disease progression. It is characterized by poor levodopa responsive Parkinsonism, cerebellar ataxia, pyramidal signs and autonomic failure in any combination. Current therapeutic strategies are primarily based on dopamine replacement and improvement of autonomic failure. However, symptomatic management remains disappointing and no curative treatment is yet available. Recent experimental evidence has confirmed the key role of alpha-synuclein aggregation in the pathogenesis of MSA. Referring to this hypothesis, transgenic and toxic animal models have been developed to assess candidate drugs for MSA. The standardization of diagnosis criteria and assessment procedures will allow large multicentre clinical trials to be conducted. In this article we review the available symptomatic treatment, recent results of studies investigating potential neuroprotective drugs, and future approaches for the management in MSA.

Sleep disorders in neurodegenerative diseases

The aim of this review is to provide data on sleep disturbances in three categories of neurodegenerative disorders: synucleinopathies, tauopathies, and other diseases (this heterogeneous group includes also spinocerebellar degeneration and amyotrophic lateral sclerosis). Analysing and knowing sleep disorders in neurodegenerative diseases may offer important insights into the pathomechanism of some of these diseases and calls attention to the still insufficiently known 'sleep neurology'. The identification of sleep disorders in some neurodegenerative conditions may make their diagnosis easier and earlier; for example, rapid eye movements sleep behaviour disorder may precede any other clinical manifestation of synucleinopathies by more than 10 years.

New clinical findings in the fragile X-associated tremor ataxia syndrome (FXTAS)

The objective of this paper was to assess the phenotypic variance in patients with the Fragile X-associated Tremor Ataxia Syndrome (FXTAS) and to further elucidate genotype-phenotype correlations in the illness. A second goal was to generate hypotheses regarding symptom progression based on careful histories in our sample that can now be tested in ongoing longitudinal studies. The variability of clinical signs and symptom progression in FXTAS complicates our understanding of its phenotype and presents a series of problems in clinical trial design. Similarly, pre-motor and non-motor symptoms have not been adequately explored to answer outstanding questions regarding genotype-phenotype associations in FXTAS. This was a cross-sectional study of FMR1 premutation carriers from known fragile X syndrome pedigrees. We report on the first 50 subjects who have completed a full neurologic evaluation and a brain MRI. Subjects were selected on the basis of motor symptoms or abnormal results (>1 SD) on a quantitative instrument designed to detect mild tremor and ataxia (CATSYS 1994). A neuropsychological battery included the WAIS-III, COWA, and WCST. Statistical analysis used ANOVA and Fisher's exact test with p < 0.05. All FMR1 premutation carriers were men of mean age 65 ± 7 years. According to the diagnostic criteria of Jacquemont et al. (Am J Hum Genet 72(4):869-878, 2003), 21 subjects met criteria for definite FXTAS, 10 for probable, 9 for possible, and 10 were indeterminate. Duration of motor symptoms was significantly longer in the definitive group (8.6 ± 6) compared to the other groups (p < 0.01). The presentations in 40 subjects, excluding the indeterminate group, included: tremor 24, ataxia 5, memory symptoms 3, parkinsonism 2, and torticollis 1. The data suggest at least two dominant phenotypic presentations: (a) a tremor-dominant subtype in which the onset of ataxia is delayed; (b) a second in which ataxia is the dominant presentation from the outset. In both subtypes, once ataxia emerges it tends to track frontal cognitive changes (p < 0.01). The data support the view that FXTAS is a late-life neurodegenerative disorder with involvement of motor, non-motor, and cognitive systems. The results suggest at least two presentations with tremor- and ataxia-predominant phenotypes. In both, global cognitive decline appears to track ataxia. Prospective longitudinal studies are needed to validate this proposed evolution of FXTAS and its relevance to future clinical trials design.

Modelling progressive autonomic failure in MSA: where are we now?

Multiple system atrophy (MSA) is a fatal late-onset α-synucleinopathy that presents with features of ataxia, Parkinsonism, and pyramidal dysfunction in any combination. Over the last decade, efforts have been made to develop preclinical MSA testbeds for novel interventional strategies. The main focus has been on murine analogues of MSA-linked motor features and their underlying brainstem, cerebellar and basal ganglia pathology. Although progressive autonomic failure (AF) is a prominent clinical feature of patients with MSA, reflecting a disruption of both central and peripheral autonomic networks controlling cardiovascular, respiratory, urogenital, gastrointestinal and sudomotor functions, attempts of modelling this aspect of the human disease have been limited. However, emerging evidence suggests that AF-like features may occur in transgenic MSA models reflecting α-synucleinopathy lesions in distributed autonomic networks. Further research is needed to fully characterize both autonomic and motor features in optimized preclinical MSA models.

Ventilatory and cardiovascular responses to hypercapnia and hypoxia in multiple-system atrophy

BACKGROUND

Loss of medullary sympathoexcitatory neurons may contribute to baroreflex failure, leading to orthostatic hypotension in multiple-system atrophy (MSA). The cardiovascular responses to chemoreflex activation in MSA have not been explored to date.

OBJECTIVES

To determine whether ventilatory and cardiovascular responses to hypercapnia and hypoxia during wakefulness are systematically impaired in MSA.

DESIGN

Case-control study.

SETTING

Mayo Clinic, Rochester, Minnesota.

PATIENTS

Sixteen patients with probable MSA (cases) and 14 age-matched control subjects (controls).

MAIN OUTCOME MEASURES

Minute ventilation, blood pressure, and heart rate responses to hypercapnia and hypoxia during wakefulness. Hypercapnia was induced by a rebreathing technique and was limited to a maximal expiratory partial pressure of carbon dioxide of 65 mm Hg. Hypoxia was induced by a stepwise increase in inspiratory partial pressure of nitrogen and was limited to a minimal arterial oxygen saturation of 80%. Ventilatory responses were assessed as slopes of the regression line relating minute ventilation to changes in arterial oxygen saturation and partial pressure of carbon dioxide.

RESULTS

In cases, ventilatory responses to hypercapnia and hypoxia were preserved, despite the presence of severe autonomic failure, while cardiovascular responses to these stimuli were impaired. Among cases, hypercapnia elicited a less robust increase in arterial pressure than among controls, and hypoxia elicited a depressor response rather than the normal pressor responses (P < .001 for both).

CONCLUSIONS

Ventilatory responses to hypercapnia and hypoxia during wakefulness may be preserved in patients with MSA, despite the presence of autonomic failure and impaired cardiovascular responses to these stimuli. A critical number of chemosensitive medullary neurons may need to be lost before development of impaired automatic ventilation during wakefulness in MSA, whereas earlier loss of medullary sympathoexcitatory neurons may contribute to the impaired cardiovascular responses in these patients.

Does multiple system atrophy itself affect sleep structure?

OBJECTIVES

Reports on sleep in multiple system atrophy (MSA) are rare and many confounding variables affect the results. Among them, obstructive sleep apnea and periodic limb movements during sleep are very common. We conducted this study to see the changes of sleep parameters originating from MSA itself without confounders.

METHODS

We compared polysomnographic variables of 15 MSA patients and 15 age-, gender-, apnea-hypopnea index-, and periodic limb movements index-matched controls. We also applied cyclic alternating pattern scoring in 7 MSA patients and 7 controls.

RESULTS

Total sleep time and sleep efficiency are decreased in MSA. Wake after sleep onset, sleep onset latency, and stage 2 latency are prolonged. There is no difference in the proportion of slow wave sleep and rapid eye movement sleep between MSA patients and the controls. Cyclic alternating pattern scoring shows no difference, either.

CONCLUSIONS

MSA itself does not affect the macro- and microstructures of sleep. However, patients with MSA sleep less and it cannot be explained by obstructive sleep apnea and periodic limb movements during sleep.

Dopamine cell loss in the periaqueductal gray in multiple system atrophy and Lewy body dementia

BACKGROUND

Experimental studies indicate that dopaminergic neurons in the ventral periaqueductal gray matter (PAG) are involved in maintenance of wakefulness. Excessive daytime sleepiness (EDS) is a common manifestation of multiple system atrophy (MSA) and dementia with Lewy bodies (DLB) but involvement of these neurons has not yet been explored.

METHODS

We sought to determine whether there is loss of dopaminergic neurons in the ventral PAG in MSA and DLB. We studied the midbrain obtained at autopsy from 12 patients (9 male, 3 female, age 61 +/- 3) with neuropathologically confirmed MSA, 12 patients (11 male, 1 female, age 79 +/- 4) with diagnosis of DLB and limbic or neocortical Lewy body disease, and 12 controls (7 male, 5 female, ages 67 +/- 4). Fifty-micron sections were immunostained for tyrosine hydroxylase (TH) or alpha-synuclein and costained with thionin. Cell counts were performed every 400 mum throughout the ventral PAG using stereologic techniques.

RESULTS

Compared to the total estimated cell numbers in controls (21,488 +/- 8,324 cells), there was marked loss of TH neurons in the ventral PAG in both MSA (11,727 +/- 5,984; p < 0.01) and DLB (5,163 +/- 1,926; p < 0.001) cases. Cell loss was more marked in DLB than in MSA. There were characteristic alpha-synuclein inclusions in the ventral PAG in both MSA and DLB.

CONCLUSIONS

There is loss of putative wake-active ventral periaqueductal gray matter dopaminergic neurons in both multiple system atrophy and dementia with Lewy bodies, which may contribute to excessive daytime sleepiness in these conditions.

Recent developments in multiple system atrophy

Multiple system atrophy (MSA) is a rare late onset neurodegenerative disorder which presents with autonomic failure and a complicated motor syndrome including atypical parkinsonism, ataxia and pyramidal signs. MSA is a glial alpha-synucleinopathy with rapid progression and currently poor therapeutic management. This paper reviews the clinical features, natural history and novel diagnostic criteria for MSA as well as contemporary knowledge on pathogenesis based on evidence from neuropathological studies and experimental models. An outline of the rationale for managing symptomatic deterioration in MSA is provided together with a summary of novel experimental therapeutic approaches to decrease disease progression.

Clinical differential diagnosis of parkinsonism

Several clinical diagnostic criteria are available for differentiating Parkinson’s disease from the various forms of parkinsonism, but most clinical features have inadequate sensitivity and positive predictive value in the differential diagnosis of these conditions. Although a diagnosis of Parkinson’s disease can be a simple clinical exercise in typical patients with a positive response to dopaminergic treatment, the differential diagnosis versus other parkinsonian disorders can be challenging in some cases, particularly early in the disease. In this paper we have reviewed the motor and nonmotor clinical features that are helpful in the differential diagnosis of the most common forms of parkinsonism. A correct diagnosis in a parkinsonian patient is not simply an academic exercise, but it is crucial for planning any possible therapeutical intervention.

Sleep disorders in Parkinson's disease: an overview

Sleep disturbances are one of the most common of the nonmotor complications of Parkinson's disease (PD), and increase in frequency with advancing disease. The causes of sleep disturbance in PD are numerous, and many patients may have several factors that contribute. These disorders can be broadly categorized into those that involve nocturnal sleep and daytime manifestations such as excessive daytime sleepiness. Some sleep disorders, in particular REM sleep behavior disorder (RBD) and excessive daytime sleepiness (EDS) may arise as a primary manifestation of PD, reflecting the anatomic areas affected by the neurodegenerative process. Appropriate diagnosis of the sleep disturbance affecting a PD patient can lead to specific treatments that can consolidate nocturnal sleep and enhance daytime alertness.

Impaired cortical and autonomic arousal during sleep in multiple system atrophy

OBJECTIVE

Periodic limb movements during sleep (PLMS) in Restless Legs Syndrome (RLS) are associated with arousals and stereotyped EEG and heart rate (HR) changes. We investigated PLMS-related EEG and HR variations in multiple system atrophy (MSA) in order to detect possible abnormalities in cortical and autonomic arousal responses.

METHODS

Ten patients with MSA were contrasted against ten patients with primary RLS. Cortical (EEG) and autonomic (HR) variations associated with PLMS during NREM sleep were analysed by means of Fast Fourier Transform and HR analysis. In addition, we analysed the cyclic alternating pattern (CAP) during sleep, CAP representing a measure of the spontaneous arousal oscillations during NREM sleep.

RESULTS

PLMS in RLS were associated with tachycardia and spectral EEG variations, beginning about 2s before the onset of PLMS, and peaking 1-4s after. The HR and spectral EEG variations were strikingly reduced or absent in MSA. MSA patients also had significantly lower CAP rate compared to RLS patients.

CONCLUSIONS

Blunted HR and EEG spectral changes adjacent to PLMS indicated impaired cortical and autonomic arousal responses during sleep in MSA patients.

SIGNIFICANCE

PLMS, when present, may represent a useful means to study the arousal responses during sleep.

Health-related quality of life in sporadic adult-onset ataxia

Despite progressive disability in sporadic adult-onset ataxia (SAOA), little is known about patients' assessment of their ataxic disorder and its impact on health-related quality of life (Hr-QoL). This study investigated Hr-QoL by means of the following self-administered scales: Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Beck Depression Inventory (BDI), and the Medical Outcome Study Short Form (SF-36). Twenty-two unselected ataxia patients were included. Sleep-related complaints were found in 9 (41%) of 22 and symptoms of depression in 6 (38%) of 16 patients. Compared to a large german control group, SAOA patients had lower scores in all SF-36 dimensions except for bodily pain. The greatest impairment was found in the domain physical functioning, followed by the domains social functioning and role limitations (emotional problems). There was a significant negative correlation of all nonmotor SF-36 dimensions with the BDI score. Walking aid dependency was significantly correlated with poorer health status perception in several motor and nonmotor domains. In addition, impaired sleep quality was correlated with an impaired general health perception and with bodily pain. The study demonstrates a great impact of SAOA on Hr-QoL. Adequate treatment of depression, motor disability, and impaired sleep quality is essential to improve Hr-QoL in ataxic patients.

Involvement of hypocretin neurons in multiple system atrophy

Hypocretin/Orexin (Hcrt/Orx) neurons of the posterolateral hypothalamus have been implicated in control of sleep and autonomic function. Sleep disorders and autonomic failure are important manifestations of multiple system atrophy (MSA). We sought to determine whether Hcrt/Orx neurons were involved in this disorder. Hypothalamus was obtained from seven subjects with neuropathologically confirmed MSA, and seven age-matched controls. 50 mum sections obtained throughout the posterior hypothalamus were immunostained for Hcrt-1 and alpha-synuclein. In MSA, there was a marked reduction of the total numbers of Hcrt/Orx neurons compared to controls (1,009 +/- 190 cells in MSA vs. 3,206 +/- 185 in controls, P < 0.0001). There were abundant glial cytoplasmic inclusions in the area of distribution of Hcrt/Orx neurons in MSA. This is the first demonstration of loss of Hcrt/Orx neurons in MSA, which is consistent with a system degeneration of neurons involved in homeostatic function, including sleep and autonomic regulation, in this disorder.

Parkinsonian syndromes

The term parkinsonian syndromes refers to a group of disorders whose clinical features overlap those of idiopathic Parkinson's disease. The four major entities include three important neurodegenerations, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration, and a lacunar cerebrovascular disorder, vascular parkinsonism. This article reviews the epidemiology, pathology, clinical features, diagnosis, and management of these disorders.