Pathological description of a non-motor variant of multiple system atrophy

CSF markers of neurodegeneration Alzheimer's and Lewy body pathology in isolated REM sleep behavior disorder

We investigated the biomarker profile of neurodegeneration, Alzheimer's and Lewy body pathology in the CSF of 148 polysomnography-confirmed patients with isolated REM sleep behavior disorder (IRBD), a condition that precedes Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We assessed misfolded α-synuclein (AS) by RT-QuIC assay, amyloid-beta peptides (Aβ42 and Aβ40), phosphorylated tau (p-tau), and total tau (t-tau) by CLEIA and neurofilament light chain (NfL) by ELISA. We detected AS in 75.3% of patients, pathologically decreased Aβ42/Aβ40 ratio in 22.5%, increased p-tau in 15.5%, increased t-tau in 14.9%, and elevated NfL in 14.7%. After a mean follow-up of 2.48 ± 2.75 years, 47 (38.1%) patients developed PD (n = 24) or DLB (n = 23). At CSF collection, AS positivity [HR 4.05 (1.26-12.99), p = 0.019], mild cognitive impairment [3.86 (1.96-7.61), p < 0.001], and abnormal DAT-SPECT [2.31 (1.09-4.91), p < 0.030] were independent predictors of conversion to PD and DLB. Among the other CSF markers, only elevated p-tau/Aβ42 was predictive of conversion, although only to DLB and not as an independent variable. In IRBD, CSF AS assessment by RT-QuIC provides an added value in defining the risk of short-term conversion to PD and DLB independent of clinical and instrumental investigations. Positive Alzheimer's disease (AD) pathology markers and elevated NfL occur in a subgroup of patients, but p-tau/Aβ42 is the only marker that predicts short-term conversion to DLB. Longer follow-up is needed to assess if AD biomarkers predict the later development of PD and DLB in IRBD.

A Systematic Review of the Spectrum and Prevalence of Non-motor Symptoms in Multiple System Atrophy

BACKGROUND

Patients with Multiple System Atrophy (MSA) frequently report non-motor symptoms, and several research groups have highlighted this.

OBJECTIVE

We systematically searched for and reviewed papers assessing prevalence of non-motor symptoms (NMS) in MSA patients as reported in the scientific literature.

METHODS

We performed a systematic review of studies of subjects with MSA (involving > 10 patients) who were assessed for NMS, published in the English literature in PUBMED and EMBASE databases from 1947-2022.

RESULTS

23 research papers, with data from 2648 clinically diagnosed and 171 pathologically verified cases of MSA were included, along with 238 controls. Mean age for MSA cases was 61.3 (9.2) years, mean disease duration 3.6 (2.7) years. 57.9% were male. Our analysis showed that the prevalence of cognitive issues in MSA varied widely (between 15-100%); dementia per se was uncommon, but assessment in advanced stages of MSA is impacted by unintelligible speech (which may be noted in a quarter of cases). The prevalence of depressive symptoms in MSA was between 44-88%. Sleep disturbances were reported by 17-89%, with REM-sleep behaviour disorder (RBD) rates as high as 75%. Pain was reported by 40-47% of patients: rheumatic or musculoskeletal sources of pain being commonest. Fatigue was reported by 29-60% of patients. Symptoms of autonomic failure in MSA were seen in 34-96.5% patients at baseline.

CONCLUSION

In routine clinical practice, NMS in MSA are under-recognised by clinicians. These impact hugely on patient quality of life and contribute to their overall morbidity. A methodical ascertainment of these complaints will address an unmet need, and lead to a more holistic approach of care for individuals with MSA.

Role of Oligodendrocyte Lineage Cells in Multiple System Atrophy

Multiple system atrophy (MSA) is a debilitating movement disorder with unknown etiology. Patients present characteristic parkinsonism and/or cerebellar dysfunction in the clinical phase, resulting from progressive deterioration in the nigrostriatal and olivopontocerebellar regions. MSA patients have a prodromal phase subsequent to the insidious onset of neuropathology. Therefore, understanding the early pathological events is important in determining the pathogenesis, which will assist with developing disease-modifying therapy. Although the definite diagnosis of MSA relies on the positive post-mortem finding of oligodendroglial inclusions composed of α-synuclein, only recently has MSA been verified as an oligodendrogliopathy with secondary neuronal degeneration. We review up-to-date knowledge of human oligodendrocyte lineage cells and their association with α-synuclein, and discuss the postulated mechanisms of how oligodendrogliopathy develops, oligodendrocyte progenitor cells as the potential origins of the toxic seeds of α-synuclein, and the possible networks through which oligodendrogliopathy induces neuronal loss. Our insights will shed new light on the research directions for future MSA studies.

Heterogeneity of Multiple System Atrophy: An Update

Multiple system atrophy (MSA) is a fatal, rapidly progressing neurodegenerative disease of uncertain etiology, clinically characterized by various combinations of Levodopa unresponsive parkinsonism, cerebellar, autonomic and motor dysfunctions. The morphological hallmark of this α-synucleinopathy is the deposition of aberrant α-synuclein in both glia, mainly oligodendroglia (glial cytoplasmic inclusions /GCIs/) and neurons, associated with glioneuronal degeneration of the striatonigral, olivopontocerebellar and many other neuronal systems. Typical phenotypes are MSA with predominant parkinsonism (MSA-P) and a cerebellar variant (MSA-C) with olivocerebellar atrophy. However, MSA can present with a wider range of clinical and pathological features than previously thought. In addition to rare combined or "mixed" MSA, there is a broad spectrum of atypical MSA variants, such as those with a different age at onset and disease duration, "minimal change" or prodromal forms, MSA variants with Lewy body disease or severe hippocampal pathology, rare forms with an unusual tau pathology or spinal myoclonus, an increasing number of MSA cases with cognitive impairment/dementia, rare familial forms, and questionable conjugal MSA. These variants that do not fit into the current classification of MSA are a major challenge for the diagnosis of this unique proteinopathy. Although the clinical diagnostic accuracy and differential diagnosis of MSA have improved by using combined biomarkers, its distinction from clinically similar extrapyramidal disorders with other pathologies and etiologies may be difficult. These aspects should be taken into consideration when revising the current diagnostic criteria. This appears important given that disease-modifying treatment strategies for this hitherto incurable disorder are under investigation.

A historical review of multiple system atrophy with a critical appraisal of cellular and animal models

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by striatonigral degeneration (SND), olivopontocerebellar atrophy (OPCA), and dysautonomia with cerebellar ataxia or parkinsonian motor features. Isolated autonomic dysfunction with predominant genitourinary dysfunction and orthostatic hypotension and REM sleep behavior disorder are common characteristics of a prodromal phase, which may occur years prior to motor-symptom onset. MSA is a unique synucleinopathy, in which alpha-synuclein (aSyn) accumulates and forms insoluble inclusions in the cytoplasm of oligodendrocytes, termed glial cytoplasmic inclusions (GCIs). The origin of, and precise mechanism by which aSyn accumulates in MSA are unknown, and, therefore, disease-modifying therapies to halt or slow the progression of MSA are currently unavailable. For these reasons, much focus in the field is concerned with deciphering the complex neuropathological mechanisms by which MSA begins and progresses through the course of the disease. This review focuses on the history, etiopathogenesis, neuropathology, as well as cell and animal models of MSA.

Magnetic resonance imaging abnormalities as a marker of multiple system atrophy in isolated rapid eye movement sleep behavior disorder

STUDY OBJECTIVES

Patients with isolated rapid eye movement (REM) sleep behavior disorder (IRBD) develop Parkinson disease (PD), dementia with Lewy bodies (DLB), or multiple system atrophy (MSA). Magnetic resonance imaging (MRI) is abnormal in MSA showing abnormalities in the putamen, cerebellum, and brainstem. Our objective was to evaluate the usefulness of MRI to detect MRI abnormalities in IRBD and predict development of MSA and not PD and DLB.

METHODS

In IRBD patients that eventually developed PD, DLB, and MSA, we looked for the specific structural MRI abnormalities described in manifest MSA (e.g. hot cross-bun sign, putaminal rim, and cerebellar atrophy). We compared the frequency of these MRI changes among groups of converters (PD, DLB, and MSA) and analyzed their ability to predict development of MSA. The clinical and radiological features of the IRBD patients that eventually converted to MSA are described in detail.

RESULTS

A total of 61 IRBD patients who underwent MRI phenoconverted to PD (n = 30), DLB (n = 26), and MSA (n = 5) after a median follow-up of 2.4 years from neuroimaging. MRI changes typical of MSA were found in four of the five (80%) patients who converted to MSA and in three of the 56 (5.4%) patients who developed PD or DLB. MRI changes of MSA had sensitivity of 80.0%, specificity of 94.6%, positive likelihood ratio of 14.9 (95% CI 4.6-48.8), and negative likelihood ratio of 0.2 (95% CI 0.04-1.2) to predict MSA.

CONCLUSIONS

In IRBD, conventional brain MRI is helpful to predict conversion to MSA. The specific MRI abnormalities of manifest MSA may be detected in its premotor stage.

Stridor during sleep: description of 81 consecutive cases diagnosed in a tertiary sleep disorders center

Study Objectives

To describe the characteristics of stridor during sleep (SDS) in a series of adults identified by video-polysomnography (V-PSG).

Methods

Retrospective clinical, V-PSG, laryngoscopic, and therapeutic data of patients diagnosed with SDS in a tertiary referral sleep disorders center between 1997 and 2017.

Results

A total of 81 patients were identified (56.8% males, age 61.8 ± 11.2 years). Related etiologies were multiple system atrophy (MSA), amyotrophic lateral sclerosis, spinocerebellar ataxia type 1, anti-IgLON5 disease, fatal familial insomnia, brainstem structural lesions, vagus nerve stimulation, recurrent laryngeal nerve injury, the effect of radiotherapy on the vocal cords, cervical osteophytes, and others. Stridor during wakefulness coexisted in 13 (16%) patients and in MSA was only seen in the parkinsonian form. Laryngoscopy during wakefulness in 72 (88.9%) subjects documented vocal cord abductor impairment in 65 (90.3%) and extrinsic lesions narrowing the glottis in 2 (2.4%). The mean apnea–hypopnea index (AHI) was 21.4 ± 18.6 and CT90 was 11.5 ± 19.1. Obstructive AHI &gt; 10 occurred in 52 (64.2%) patients and central apnea index &gt;10 in 2 (2.4%). CPAP abolished SDS, obstructive apneic events and oxyhemoglobin desaturations in 58 of 60 (96.7%) titrated patients with optimal pressure of 9.0 ± 2.3 cm H20. Tracheostomy in 19 (23.4%) and cordotomy in 3 (3.7%) subjects also eliminated SDS.

Conclusions

SDS in adults is linked to conditions that damage the brainstem, recurrent laryngeal nerve, and vocal cords. V-PSG frequently detects obstructive sleep apnea and laryngoscopy usually shows vocal cord abductor dysfunction. CPAP, tracheostomy, and laryngeal surgery abolish SDS.

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.

Laryngeal Movement Disorders in Multiple System Atrophy: A Diagnostic Biomarker?

Background

Multiple system atrophy (MSA) is a rare neurodegenerative disorder, and its parkinsonian variant can be difficult to delineate from Parkinson's disease (PD). Despite laryngeal dysfunction being associated with decreased life expectancy and quality of life, systematic assessments of laryngeal dysfunction in large cohorts are missing.

Objectives

The objective of this study was to systematically assess laryngeal dysfunction in MSA and PD and identify laryngeal symptoms that allow for differentiating MSA from PD.

Methods

Patients with probable or possible MSA underwent flexible endoscopic evaluation of swallowing performing a systematic task protocol. Findings were compared with an age‐matched PD cohort.

Results

A total of 57 patients with MSA (64 [59–71] years; 35 women) were included, and task assessments during endoscopic examination compared with 57 patients with PD (67 [60–73]; 28 women). Patients with MSA had a shorter disease duration (4 [3–5] years vs 7 [5–10]; P < 0.0001) and higher disease severity (Hoehn & Yahr stage 4 [3–4] vs 3 [2–4]; P < 0.0001). Of the patients with MSA, 43.9% showed clinically overt laryngeal dysfunction with inspiratory stridor. During endoscopic task assessment, however, 93% of patients with MSA demonstrated laryngeal dysfunction in contrast with only 1.8% of patients with PD (P < 0.0001). Irregular arytenoid cartilages movements were present in 91.2% of patients with MSA, but in no patients with PD (P < 0.0001). Further findings included vocal fold motion impairment (75.4%), paradoxical vocal fold motion (33.3%), and vocal fold fixation (19.3%). One patient with PD showed vocal fold motion impairment.

Conclusion

Laryngeal movement disorders are highly prevalent in patients with MSA when assessed by a specific task protocol despite the lack of overt clinical symptoms. Our data suggest that irregular arytenoid cartilage movements could be used as a clinical marker to delineate MSA from PD with a specificity of 1.0 and sensitivity 0.9. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Induced pluripotent stem cells in multiple system atrophy: recent developments and scientific challenges

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disease, with no known genetic cause to date. Oligodendroglial α-synuclein accumulation, neuroinflammation, and early myelin dysfunction are hallmark features of the disease and have been modeled in part in various preclinical models of MSA, yet the pathophysiology of MSA remains elusive. Here, we review the role and scientific challenges of induced pluripotent stem cells in the detection of novel biomarkers and druggable targets in MSA.

Clinical and Imaging Features of Multiple System Atrophy: Challenges for an Early and Clinically Definitive Diagnosis

Multiple system atrophy (MSA) is an adult-onset, progressive neurodegenerative disorder. Patients with MSA show various phenotypes during the course of their illness, including parkinsonism, cerebellar ataxia, autonomic failure, and pyramidal signs. Patients with MSA sometimes present with isolated autonomic failure or motor symptoms/ signs. The median duration from onset to the concomitant appearance of motor and autonomic symptoms is approximately 2 years but can range up to 14 years. As the presence of both 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. In contrast, patients with MSA may show severe autonomic failure and die before the presentation of motor symptoms/signs, which are currently required for the diagnosis of MSA. Recent studies have also revealed that patients with MSA may show nonsupporting features of MSA such as dementia, hallucinations, and vertical gaze palsy. To establish early diagnostic criteria and clinically definitive categorization for the successful development of disease-modifying therapy or symptomatic interventions for MSA, research should focus on the isolated phase and atypical symptoms to develop specific clinical, imaging, and fluid biomarkers that satisfy the requirements for objectivity, for semi- or quantitative measurements, and for uncomplicated, worldwide availability. Several novel techniques, such as automated compartmentalization of the brain into multiple parcels for the quantification of gray and white matter volumes on an individual basis and the visualization of α-synuclein and other candidate serum and cerebrospinal fluid biomarkers, may be promising for the early and clinically definitive diagnosis of MSA.

Rapid eye movement sleep behavior disorder and the link to alpha-synucleinopathies

Rapid eye movement (REM) sleep behavior disorder (RBD) involves REM sleep without atonia in conjunction with a recurrent nocturnal dream enactment behavior, with vocalizations such as shouting and screaming, and motor behaviors such as punching and kicking. Secondary RBD is well described in association with neurological disorders including Parkinson's disease (PD), multiple system atrophy (MSA), and other conditions involving brainstem structures such as tumors. However, RBD alone is now considered to be a potential harbinger of later development of neurodegenerative disorders, in particular PD, MSA, dementia with Lewy bodies (DLB), and pure autonomic failure. These conditions are linked by their underpinning pathology of alpha-synuclein protein aggregation. In RBD, it is therefore important to recognize the potential risk for later development of an alpha-synucleinopathy, and to investigate for other potential causes such as medications. Other signs and symptoms have been described in RBD, such as orthostatic hypotension, or depression. While it is important to recognize these features to improve patient management, they may ultimately provide clinical clues that will lead to risk stratification for phenoconversion. A critical need is to improve our ability to counsel patients, particularly with regard to prognosis. The ability to identify who, of those with RBD, is at high risk for later neurodegenerative disorders will be paramount, and would in addition advance our understanding of the prodromal stages of the alpha-synucleinopathies. Moreover, recognition of at-risk individuals for neurodegenerative disorders may ultimately provide a platform for the testing of possible neuroprotective agents for these neurodegenerative disorders.

First symptoms in multiple system atrophy

Purpose

The initial symptoms of multiple system atrophy (MSA) and, in particular, early autonomic symptoms, have received less attention than motor symptoms. Whereas pathognomonic motor signs are essential to diagnostic specificity, early symptoms important to recognition of a neurodegenerative disorder may be less apparent or diagnostically ambiguous. This observational study sought to identify the very earliest symptoms in the natural history of MSA.

Methods

Detailed clinical histories focusing on early symptoms were obtained from 30 subjects recently diagnosed with MSA. Historical data were correlated with neurological examinations and laboratory autonomic testing.

Results

Subjects’ mean age was 63.9 years. Ten were classified as having MSA-P and 20 MSA-C. The evaluations occurred 2.9 ± 0.4 months after diagnosis. The first symptom of MSA was autonomic in 22 (73%) and motor in 3 (10%) subjects (p < 0.0001). The most frequent first symptom was erectile failure, which occurred in all men beginning 4.2 ± 2.6 years prior to diagnosis. After erectile failure, postural lightheadness or fatigue following exercise, urinary urgency or hesitancy, and violent dream enactment behavior consistent with REM behavioral sleep disorder were the most frequent initial symptoms. Neither the order of symptom progression, which was highly variable, nor autonomic severity scores differentiated between MSA-P and MSA-C.

Conclusions

The first symptoms of MSA are frequently autonomic and may predate recognition of motor manifestations. Orthostatic hypotension and, in men, erectile failure are among the first symptoms that, when evaluated in the context of associated clinical findings, may facilitate accurate and earlier diagnosis.

Multiple System Atrophy: An Oligodendroglioneural Synucleinopathy1

Multiple system atrophy (MSA) is an orphan, fatal, adult-onset neurodegenerative disorder of uncertain etiology that is clinically characterized by various combinations of parkinsonism, cerebellar, autonomic, and motor dysfunction. MSA is an α-synucleinopathy with specific glioneuronal degeneration involving striatonigral, olivopontocerebellar, and autonomic nervous systems but also other parts of the central and peripheral nervous systems. The major clinical variants correlate with the morphologic phenotypes of striatonigral degeneration (MSA-P) and olivopontocerebellar atrophy (MSA-C). While our knowledge of the molecular pathogenesis of this devastating disease is still incomplete, updated consensus criteria and combined fluid and imaging biomarkers have increased its diagnostic accuracy. The neuropathologic hallmark of this unique proteinopathy is the deposition of aberrant α-synuclein in both glia (mainly oligodendroglia) and neurons forming glial and neuronal cytoplasmic inclusions that cause cell dysfunction and demise. In addition, there is widespread demyelination, the pathogenesis of which is not fully understood. The pathogenesis of MSA is characterized by propagation of misfolded α-synuclein from neurons to oligodendroglia and cell-to-cell spreading in a "prion-like" manner, oxidative stress, proteasomal and mitochondrial dysfunction, dysregulation of myelin lipids, decreased neurotrophic factors, neuroinflammation, and energy failure. The combination of these mechanisms finally results in a system-specific pattern of neurodegeneration and a multisystem involvement that are specific for MSA. Despite several pharmacological approaches in MSA models, addressing these pathogenic mechanisms, no effective neuroprotective nor disease-modifying therapeutic strategies are currently available. Multidisciplinary research to elucidate the genetic and molecular background of the deleterious cycle of noxious processes, to develop reliable biomarkers and targets for effective treatment of this hitherto incurable disorder is urgently needed.

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.

Idiopathic rapid eye movement sleep behaviour disorder: diagnosis, management, and the need for neuroprotective interventions

Idiopathic rapid eye movement (REM) sleep behaviour disorder (IRBD) manifests as unpleasant dreams and vigorous behaviours during REM sleep that can result in injuries. Patients with IRBD have no known neurological diseases or motor or cognitive complaints; however, this sleep disorder is not harmless. In most cases, IRBD is the prelude of the synucleinopathies Parkinson's disease, dementia with Lewy bodies, or, less frequently, multiple system atrophy. Patients can show abnormalities that are characteristic of the synucleinopathies, and longitudinal follow-up shows that most patients develop parkinsonism and cognitive impairments with time. Thus, diagnosis of IRBD needs to be accurate and involves informing the patient of the risk of developing a neurodegenerative disease. It is extraordinary for a sleep disorder to precede the full expression of a neurodegenerative disease, which renders IRBD of particular interest in studies of the prodromal stage of the synucleinopathies, and in the development of neuroprotective interventions to stop or slow neurodegenerative deterioration before motor and cognitive symptomatology emerges. Such therapeutics do not currently exist, and thus represent an unmet need in IRBD.

The Clinical Phenotype of Idiopathic Rapid Eye Movement Sleep Behavior Disorder at Presentation: A Study in 203 Consecutive Patients

OBJECTIVE

To describe the clinical phenotype of idiopathic rapid eye movement (REM) sleep behavior disorder (IRBD) at presentation in a sleep center.

METHODS

Clinical history review of 203 consecutive patients with IRBD identified between 1990 and 2014. IRBD was diagnosed by clinical history plus video-polysomnographic demonstration of REM sleep with increased electromyographic activity linked to abnormal behaviors.

RESULTS

Patients were 80% men with median age at IRBD diagnosis of 68 y (range, 50-85 y). In addition to the already known clinical picture of IRBD, other important features were apparent: 44% of the patients were not aware of their dream-enactment behaviors and 70% reported good sleep quality. In most of these cases bed partners were essential to convince patients to seek medical help. In 11% IRBD was elicited only after specific questioning when patients consulted for other reasons. Seven percent did not recall unpleasant dreams. Leaving the bed occurred occasionally in 24% of subjects in whom dementia with Lewy bodies often developed eventually. For the correct diagnosis of IRBD, video-polysomnography had to be repeated in 16% because of insufficient REM sleep or electromyographic artifacts from coexistent apneas. Some subjects with comorbid obstructive sleep apnea reported partial improvement of RBD symptoms following continuous positive airway pressure therapy. Lack of therapy with clonazepam resulted in an increased risk of sleep related injuries. Synucleinopathy was frequently diagnosed, even in patients with mild severity or uncommon IRBD presentations (e.g., patients who reported sleeping well, onset triggered by a life event, nocturnal ambulation) indicating that the development of a neurodegenerative disease is independent of the clinical presentation of IRBD.

CONCLUSIONS

We report the largest IRBD cohort observed in a single center to date and highlight frequent features that were not reported or not sufficiently emphasized in previous publications. Physicians should be aware of the full clinical expression of IRBD, a sleep disturbance that represents a neurodegenerative disease.

COMMENTARY

A commentary on this article appears in this issue on page 7.

Diagnosis and differential diagnosis of MSA: boundary issues

Because the progression of multiple system atrophy (MSA) is usually rapid and there still is no effective cause-related therapy, early and accurate diagnosis is important for the proper management of patients as well as the development of neuroprotective agents. However, despite the progression in the field of MSA research in the past few years, the diagnosis of MSA in clinical practice still relies largely on clinical features and there are limitations in terms of sensitivity and specificity, especially in the early course of the disease. Furthermore, recent pathological, clinical, and neuroimaging studies have shown that (1) MSA can present with a wider range of clinical and pathological features than previously thought, including features considered atypical for MSA; thus, MSA can be misdiagnosed as other diseases, and conversely, disorders with other etiologies and pathologies can be clinically misdiagnosed as MSA; and (2) several investigations may help to improve the diagnosis of MSA in clinical practice. These aspects should be taken into consideration when revising the current diagnostic criteria. This is especially true given that disease-modifying treatments for MSA are under investigation.

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.

Clinicopathologic correlations in 172 cases of rapid eye movement sleep behavior disorder with or without a coexisting neurologic disorder

OBJECTIVE

To determine the pathologic substrates in patients with rapid eye movement (REM) sleep behavior disorder (RBD) with or without a coexisting neurologic disorder.

METHODS

The clinical and neuropathologic findings were analyzed on all autopsied cases from one of the collaborating sites in North America and Europe, were evaluated from January 1990 to March 2012, and were diagnosed with polysomnogram (PSG)-proven or probable RBD with or without a coexisting neurologic disorder. The clinical and neuropathologic diagnoses were based on published criteria.

RESULTS

172 cases were identified, of whom 143 (83%) were men. The mean±SD age of onset in years for the core features were as follows - RBD, 62±14 (range, 20-93), cognitive impairment (n=147); 69±10 (range, 22-90), parkinsonism (n=151); 68±9 (range, 20-92), and autonomic dysfunction (n=42); 62±12 (range, 23-81). Death age was 75±9 years (range, 24-96). Eighty-two (48%) had RBD confirmed by PSG, 64 (37%) had a classic history of recurrent dream enactment behavior, and 26 (15%) screened positive for RBD by questionnaire. RBD preceded the onset of cognitive impairment, parkinsonism, or autonomic dysfunction in 87 (51%) patients by 10±12 (range, 1-61) years. The primary clinical diagnoses among those with a coexisting neurologic disorder were dementia with Lewy bodies (n=97), Parkinson's disease with or without mild cognitive impairment or dementia (n=32), multiple system atrophy (MSA) (n=19), Alzheimer's disease (AD)(n=9) and other various disorders including secondary narcolepsy (n=2) and neurodegeneration with brain iron accumulation-type 1 (NBAI-1) (n=1). The neuropathologic diagnoses were Lewy body disease (LBD)(n=77, including 1 case with a duplication in the gene encoding α-synuclein), combined LBD and AD (n=59), MSA (n=19), AD (n=6), progressive supranulear palsy (PSP) (n=2), other mixed neurodegenerative pathologies (n=6), NBIA-1/LBD/tauopathy (n=1), and hypothalamic structural lesions (n=2). Among the neurodegenerative disorders associated with RBD (n=170), 160 (94%) were synucleinopathies. The RBD-synucleinopathy association was particularly high when RBD preceded the onset of other neurodegenerative syndrome features.

CONCLUSIONS

In this large series of PSG-confirmed and probable RBD cases that underwent autopsy, the strong association of RBD with the synucleinopathies was further substantiated and a wider spectrum of disorders which can underlie RBD now are more apparent.

Curcumin inhibition of JNKs prevents dopaminergic neuronal loss in a mouse model of Parkinson's disease through suppressing mitochondria dysfunction

Curcumin,a natural polyphenol obtained from turmeric,has been implicated to be neuroprotective in a variety of neurodegenerative disorders although the mechanism remains poorly understood. The results of our recent experiments indicated that curcumin could protect dopaminergic neurons from apoptosis in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson’s disease (PD). The death of dopaminergic neurons and the loss of dopaminergic axon in the striatum were significantly suppressed by curcumin in MPTP mouse model. Further studies showed that curcumin inhibited JNKs hyperphosphorylation induced by MPTP treatment. JNKs phosphorylation can cause translocation of Bax to mitochondria and the release of cytochrome c which both ultimately contribute to mitochondria-mediated apoptosis. These pro-apoptosis effect can be diminished by curcumin. Our experiments demonstrated that curcumin can prevent nigrostriatal degeneration by inhibiting the dysfunction of mitochondrial through suppressing hyperphosphorylation of JNKs induced by MPTP. Our results suggested that JNKs/mitochondria pathway may be a novel target in the treatment of PD patients.

Premotor signs and symptoms of multiple system atrophy

Diagnostic criteria for multiple system atrophy are focused on motor manifestations of the disease, in particular ataxia and parkinsonism, but these criteria often cannot detect the early stages. Non-motor symptoms and signs of multiple system atrophy often precede the onset of classic motor manifestations, and this prodromal phase is estimated to last from several months to years. Autonomic failure, sleep problems, and respiratory disturbances are well known symptoms of established multiple system atrophy and, when presenting early and preceding ataxia or parkinsonism, should be regarded as evidence of premotor multiple system atrophy. An early and accurate diagnosis is becoming increasingly important as new neuroprotective agents are developed.

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.

Targeted overexpression of human alpha-synuclein in oligodendroglia induces lesions linked to MSA-like progressive autonomic failure

Multiple system atrophy (MSA) is a rare neurodegenerative disease of undetermined cause manifesting with progressive autonomic failure (AF), cerebellar ataxia and parkinsonism due to neuronal loss in multiple brain areas associated with (oligodendro)glial cytoplasmic α-synuclein (αSYN) inclusions (GCIs). Using proteolipid protein (PLP)-α-synuclein (αSYN) transgenic mice we have previously reported parkinsonian motor deficits triggered by MSA-like αSYN inclusions. We now extend these observations by demonstrating degeneration of brain areas that are closely linked to progressive AF and other non-motor symptoms in MSA, in (PLP)-αSYN transgenic mice as compared to age-matched non-transgenic controls. We show delayed loss of cholinergic neurons in nucleus ambiguus at 12 months of age as well as early neuronal loss in laterodorsal tegmental nucleus, pedunculopontine tegmental nucleus and Onuf's nucleus at 2 months of age associated with αSYN oligodendroglial overexpression. We also report that neuronal loss triggered by MSA-like αSYN inclusions is absent up to 12 months of age in the thoracic intermediolateral cell column suggesting a differential dynamic modulation of αSYN toxicity within the murine autonomic nervous system. Although the spatial and temporal evolution of central autonomic pathology in MSA is unknown our findings corroborate the utility of the (PLP)-αSYN transgenic mouse model as a testbed for the study of oligodendroglial αSYN mediated neurodegeneration replicating both motor and non-motor aspects of MSA.

Sleep disturbances and brain MRI morphometry in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy - a comparative study

Despite common reports in Parkinson's disease (PD), in other parkinsonian syndromes, sleep disturbances have been less frequently described. This study evaluated and compared sleep disturbances in patients with PD, multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) and analyzed associations with brain magnetic resonance imaging (MRI) morphometry. This was a cross-sectional study of 16 PD cases, 13 MSA, 14 PSP and 12 control. Sleep disturbances were evaluated by Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI), Restless Legs Scale and Berlin questionnaire. Pons area, midbrain area, medial cerebellar peduncle (MCP) width, and superior cerebellar peduncle width were measured using MRI. Poor quality sleep, risk of obstructive sleep apnea (OSA) and restless legs syndrome (RLS) were detected in all groups. Patients with MSA showed higher risk of OSA and less frequent RLS. In MSA, a correlation between PSQI scores and Hoehn and Yahr stage was observed (p<0.05). In PSP, RLS was frequent (57%) and related with reduced sleep duration and efficiency. In PD, excessive daytime sleepiness was related to atrophy of the MCP (p=0.01). RLS was more frequent in PD and PSP, and in PSP, was associated with reduced sleep efficiency and sleep duration. Brain morphometry abnormalities were found in connection with excessive daytime sleepiness and risk of OSA in PD and PSP suggesting widespread degeneration of brainstem sleep structures on the basis of sleep abnormalities in these patients.

REM sleep behavior disorder: Updated review of the core features, the REM sleep behavior disorder-neurodegenerative disease association, evolving concepts, controversies, and future directions

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia manifested by vivid, often frightening dreams associated with simple or complex motor behavior during REM sleep. The polysomnographic features of RBD include increased electromyographic tone +/- dream enactment behavior during REM sleep. Management with counseling and pharmacologic measures is usually straightforward and effective. In this review, the terminology, clinical and polysomnographic features, demographic and epidemiologic features, diagnostic criteria, differential diagnosis, and management strategies are discussed. Recent data on the suspected pathophysiologic mechanisms of RBD are also reviewed. The literature and our institutional experience on RBD are next discussed, with an emphasis on the RBD-neurodegenerative disease association and particularly the RBD-synucleinopathy association. Several issues relating to evolving concepts, controversies, and future directions are then reviewed, with an emphasis on idiopathic RBD representing an early feature of a neurodegenerative disease and particularly an evolving synucleinopathy. Planning for future therapies that impact patients with idiopathic RBD is reviewed in detail.

The clinical and pathophysiological relevance of REM sleep behavior disorder in neurodegenerative diseases

REM sleep behavior disorder (RBD) is characterized by vigorous movements associated with unpleasant dreams and increased electromyographic activity during REM sleep. Polysomnography with audiovisual recording is needed to confirm the diagnosis of RBD and to exclude other sleep disorders that can mimic its symptoms including obstructive sleep apnea, nocturnal hallucinations and confusional awakenings. RBD may be idiopathic or related to neurodegenerative diseases, particularly multiple system atrophy, Parkinson's disease and dementia with Lewy bodies. RBD may be the first manifestation of these disorders, antedating the onset of parkinsonism, cerebellar syndrome, dysautonomia, and dementia by several years. RBD should thus be considered an integral part of the disease process. When effective, neuroprotective strategies should be considered in subjects with idiopathic RBD. Patients with other neurodegenerative diseases, though, such as spinocerebellar ataxias, may also present with RBD. When clinically required, clonazepam at bedtime is effective in decreasing the intensity of dream-enacting behaviors and unpleasant dreams in both the idiopathic and secondary forms. When part of a neurodegenerative disorder the development of RBD is thought to reflect the location and extent of the underlying lesions involving the REM sleep centers of the brain (e.g., locus subceruleus, amygdala, etc.), leading to a complex multiple neurotransmitter dysfunction that involves GABAergic, glutamatergic and monoaminergic systems. RBD is mediated neither by direct abnormal alpha-synuclein inclusions nor by striatonigral dopaminergic deficiency alone.