Clinical features and natural history of multiple system atrophy. An analysis of 100 cases

An update on the cerebellar subtype of multiple system atrophy

Multiple system atrophy is a rare and fatal neurodegenerative disorder characterized by progressive autonomic failure, ataxia and parkinsonism in any combination. The clinical manifestations reflect central autonomic and striatonigral degeneration as well as olivopontocerebellar atrophy. Glial cytoplasmic inclusions, composed of α-synuclein and other proteins are considered the cellular hallmark lesion. The cerebellar variant of MSA (MSA-C) denotes a distinctive motor subtype characterized by progressive adult onset sporadic gait ataxia, scanning dysarthria, limb ataxia and cerebellar oculomotor dysfunction. In addition, there is autonomic failure and variable degrees of parkinsonism. A range of other disorders may present with MSA-C like features and therefore the differential diagnosis of MSA-C is not always straightforward. Here we review key aspects of MSA-C including pathology, pathogenesis, diagnosis, clinical features and treatment, paying special attention to differential diagnosis in late onset sporadic cerebellar ataxias.

Treatment of cerebellar ataxia

SUMMARY 

Symptoms of cerebellar degeneration include ataxia or wide-based gait, visual and speech dysfunction, dysmetria, and dyscoordination. The etiology of cerebellar degeneration is vast and often complex, and requires neuroimaging, lab assessments, and a thorough family history to delineate its cause. There is currently no accepted treatment of hereditary cerebellar degeneration, although several pharmaceutical agents have shown potential promise.

Mutation scanning of the COQ2 gene in ethnic Chinese patients with multiple-system atrophy

Multiple-system atrophy (MSA) is a fatal neurodegenerative disorder with unknown etiology. It is widely considered to be a nongenetic disorder, but accumulating evidence suggests that several genes are linked to MSA. Recently, functionally impaired variants in the coenzyme Q2 4-hydroxybenzoate polyprenyltransferase (COQ2) gene have been reported to increase the risk of MSA in familial and sporadic Japanese patients. In this study, we investigated the mutation spectrum of COQ2 and analyzed the association between the common variant Val393Ala in exon 7 of COQ2 and MSA in a Chinese population. This study included 312 sporadic MSA patients from the Department of Neurology, West China Hospital of Sichuan University. All 7 exons of COQ2 in all the patients and exon 7 in 598 healthy controls (HCs) were directly sequenced. Novel candidate mutations and variations were confirmed by direct sequencing in 300 HCs. Two novel nonsynonymous variants, including p.R173H and p.N386I, and a reported missense variant, p.L162F, were found in 4 patients (p.R173H in 2 patients). However, the Val393Ala variant was not detected in the above 4 patients. Thirteen MSA patients (4.17%) and 18 controls (3.01%) had the heterozygous variant (Val393Ala/NM) of COQ2. No significant differences existed in the genotype frequency and minor allele frequency of Val393Ala between patients and controls or between MSA characterized predominantly by cerebellar ataxia and by pakinsonism groups. The mutation frequency of COQ2 is 1.28% in a Chinese MSA population. The common variant Val393Ala in COQ2 does not appear to be associated with MSA in ethnic Chinese.

Behavioral and neurophysiological effects of transdermal rotigotine in atypical parkinsonism

Effective therapies for the so-called atypical parkinsonian syndrome (APS) such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome (CBS) are not available. Dopamine agonists (DA) are not often used in APS because of inefficacy and in a minority of case, their side effects, like dyskinesias, impairment of extrapyramidal symptoms or the appearance of psychosis, and REM sleep behavioral disorders (RBD). Transdermal rotigotine (RTG) is a non-ergot dopamine agonist indicated for use in early and advanced Parkinson’s disease with a good tolerability and safety. Moreover, its action on a wide range of dopamine receptors, D1, D2, D3, unlike other DA, could make it a good option in APS, where a massive dopamine cell loss is documented. In this pilot, observational open-label study we evaluate the efficacy and tolerability of RTG in patients affected by APS. Thirty-two subjects with diagnosis of APS were treated with transdermal RTG. APS diagnosis was: MSA parkinsonian type (MSA-P), MSA cerebellar type (MSA-C), PSP, and CBS. Patients were evaluated by UPDRS-III, neuropsychiatric inventory, mini mental state examination at baseline, and after 6, 12, and 18 months. The titration schedule was maintained very flexible, searching the major clinical effect and the minor possible adverse events (AEs) at each visit. AEs were recorded. APS patients treated with RTG show an overall decrease of UPDRS-III scores without increasing behavioral disturbances. Only three patients were dropped out of the study. Main AEs were hypotension, nausea, vomiting, drowsiness, and tachycardia. The electroencephalographic recording power spectra analysis shows a decrease of theta and an increase of low alpha power. In conclusion, transdermal RTG seems to be effective and well tolerated in APS patients.

Multiple system atrophy: prognostic indicators of survival

Neurological and autonomic presentation in multiple system atrophy (MSA) may predict early mortality. Quantification of early autonomic failure as a mortality predictor is lacking. Early neurological and autonomic clinical features were retrospectively reviewed in 49 MSA cases (median age at onset, 56.1 years; 16 women) confirmed by autopsy at Mayo Clinic. When available, the 10-point composite autonomic severity score derived from the autonomic reflex screen provided quantification of the degree of autonomic failure and thermoregulatory sweat test quantitated body surface anhidrosis. Symptoms at onset were autonomic in 50%, parkinsonian in 30%, and cerebellar in 20% of cases. Survival (median [95% confidence interval]) was 8.6 [6.7-10.2] years. Survival was shorter in patients with early laboratory evidence of generalized (composite autonomic severity score ≥ 6) autonomic failure (7.0 [3.9-9.8] vs. 9.8 [4.6-13.8] years; P = 0.036), and early requirement of bladder catheterization (7.3 [3.1-10.2] vs. 13.7 [8.5-14.9] years; P = 0.003) compared with those without these clinical features. On Cox proportional analysis, prognostic indicators of shorter survival were older age at onset (hazard ratio [95% confidence interval], 1.04 [1.01-1.08]; P = 0.03), early requirement of bladder catheterization (7.9 [1.88-38.63]; P = 0.004), and early generalized (composite autonomic severity score ≥ 6) autonomic failure (2.8 [1.01-9.26]; P = 0.047). Gender, phenotype, and early development of gait instability, aid-requiring ambulation, orthostatic symptoms, neurogenic bladder, or significant anhidrosis (thermoregulatory sweat test ≥ 40%) were not indicators of shorter survival. Our data suggest that early development of severe generalized autonomic failure more than triples the risk of shorter survival in patients with MSA.

Clinical outcomes of two main variants of progressive supranuclear palsy and multiple system atrophy: a prospective natural history study

Progressive supranuclear palsy (PSP) and parkinsonian subtype of multiple system atrophy (MSA-P) are, after Parkinson's disease (PD), the most common forms of neurodegenerative parkinsonism. Clinical heterogeneity of PSP includes two main variants, Richardson syndrome (PSP-RS) and PSP-parkinsonism (PSP-P). Clinical differentiation between them may be impossible at least during the first 2 years of the disease. Little is known about the differences in natural course of PSP-RS and PSP-P and, therefore, in this study we prospectively followed the clinical outcomes of consecutive, pathologically unconfirmed patients with the clinical diagnoses of PSP-RS (51 patients), PSP-P (21 patients) and MSA-P (49 patients). Estimated mean survival time was 11.2 years for PSP-P, 6.8 years for PSP-RS, and 7.9 years for MSA-P, where a 5-year survival probabilities were 90, 66 and 78 %, respectively. More disabling course of PSP-RS compared to PSP-P was also highlighted through the higher number of milestones reached in the first 3 years of the disease, as well as in the trend to reach all clinical milestones earlier. We found that PSP-P variant had a more favorable course with longer survival, not only when compared to PSP-RS, but also when compared to another form of atypical parkinsonism, MSA-P.

Clinical syndromes: Parkinsonian gait

Disturbances of gait manifest in almost all cases of Parkinson's disease (PD), often leading to loss of mobility and increased mortality. In this review a clinically oriented approach to gait disorders in different stages of PD is presented. In addition, interactions between motor behavior and mental processing will be discussed. Analyzing the clinical features of gait can be helpful to differentiate PD from atypical forms of parkinsonism. Bedside tests to distinguish parkinsonian gait disorders are reviewed. There is still an unmet need to effectively treat complex gait disturbances, which are frequently not responsive to dopamine replacement medication. We thus present current approaches for the management of dopa-refractory gait disorders.

Towards translational therapies for multiple system atrophy

Multiple system atrophy (MSA) is a fatal adult-onset neurodegenerative disorder of uncertain etiopathogenesis manifesting with autonomic failure, parkinsonism, and ataxia in any combination. The underlying neuropathology affects central autonomic, striatonigral and olivopontocerebellar pathways and it is associated with distinctive glial cytoplasmic inclusions (GCIs, Papp-Lantos bodies) that contain aggregates of α-synuclein. Current treatment options are very limited and mainly focused on symptomatic relief, whereas disease modifying options are lacking. Despite extensive testing, no neuroprotective drug treatment has been identified up to now; however, a neurorestorative approach utilizing autologous mesenchymal stem cells has shown remarkable beneficial effects in the cerebellar variant of MSA. Here, we review the progress made over the last decade in defining pathogenic targets in MSA and summarize insights gained from candidate disease-modifying interventions that have utilized a variety of well-established preclinical MSA models. We also discuss the current limitations that our field faces and suggest solutions for possible approaches in cause-directed therapies of MSA.

Multiple system atrophy of the cerebellar type: clinical state of the art

Multiple system atrophy (MSA) is a late-onset, sporadic neurodegenerative disorder clinically characterized by autonomic failure and either poorly levodopa-responsive parkinsonism or cerebellar ataxia. It is neuropathologically defined by widespread and abundant central nervous system α-synuclein-positive glial cytoplasmic inclusions and striatonigral and/or olivopontocerebellar neurodegeneration. There are two clinical subtypes of MSA distinguished by the predominant motor features: the parkinsonian variant (MSA-P) and the cerebellar variant (MSA-C). Despite recent progress in understanding the pathobiology of MSA, investigations into the symptomatology and natural history of the cerebellar variant of the disease have been limited. MSA-C presents a unique challenge to both clinicians and researchers alike. A key question is how to distinguish early in the disease course between MSA-C and other causes of adult-onset cerebellar ataxia. This is a particularly difficult question, because the clinical framework for conceptualizing and studying sporadic adult-onset ataxias continues to undergo flux. To date, several investigations have attempted to identify clinical features, imaging, and other biomarkers that may be predictive of MSA-C. This review presents a clinically oriented overview of our current understanding of MSA-C with a focus on evidence for distinguishing MSA-C from other sporadic, adult-onset ataxias.

Lipid dysfunction and pathogenesis of multiple system atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by the accumulation of α-synuclein protein in the cytoplasm of oligodendrocytes, the myelin-producing support cells of the central nervous system (CNS). The brain is the most lipid-rich organ in the body and disordered metabolism of various lipid constituents is increasingly recognized as an important factor in the pathogenesis of several neurodegenerative diseases. α-Synuclein is a 17 kDa protein with a close association to lipid membranes and biosynthetic processes in the CNS, yet its precise function is a matter of speculation, particularly in oligodendrocytes. α-Synuclein aggregation in neurons is a well-characterized feature of Parkinson’s disease and dementia with Lewy bodies. Epidemiological evidence and in vitro studies of α-synuclein molecular dynamics suggest that disordered lipid homeostasis may play a role in the pathogenesis of α-synuclein aggregation. However, MSA is distinct from other α-synucleinopathies in a number of respects, not least the disparate cellular focus of α-synuclein pathology. The recent identification of causal mutations and polymorphisms in COQ2, a gene encoding a biosynthetic enzyme for the production of the lipid-soluble electron carrier coenzyme Q₁₀ (ubiquinone), puts membrane transporters as central to MSA pathogenesis, although how such transporters are involved in the early myelin degeneration observed in MSA remains unclear. The purpose of this review is to bring together available evidence to explore the potential role of membrane transporters and lipid dyshomeostasis in the pathogenesis of α-synuclein aggregation in MSA. We hypothesize that dysregulation of the specialized lipid metabolism involved in myelin synthesis and maintenance by oligodendrocytes underlies the unique neuropathology of MSA.

Cerebellar ataxia and epilepsy with anti-GAD antibodies: treatment with IVIG and plasmapheresis

Glutamic acid decarboxylase autoantibody (GAD-65) catalyses glutamate conversion into γ-aminobutyric acid (GABA) in the central nervous system and in the pancreatic β cells. Antibodies targeting GAD-65 are of uncertain pathogenic significance and occur in stiff person syndrome, cerebellar ataxia, epilepsy, limbic encephalitis and combinations thereof and diabetes mellitus. A 45-year-old man with a cerebellar gait ataxia, dysmetria, nystagmus and mild cerebellar dysarthria was diagnosed with insulin-dependent diabetes mellitus a year after the onset of neurological symptoms. He also developed complex and tonic-clonic seizures, resistant to anticonvulsant medication and deteriorated cognitively. Blood and cerebrospinal fluid serology, and imaging supported the diagnosis of GAD-65 cerebellar ataxia and epilepsy. He was treated with intravenous immunoglobulin and subsequently plasmapheresis. We report the outcome of 3 years of treatment, which resulted in the improvement of cerebellar signs (particularly gait), with some ultimate decline of efficacy.

Opsoclonus-myoclonus syndrome associated with multiple system atrophy

Opsoclonus-myoclonus syndrome (OMS) is well known as a paraneoplastic syndrome or as a parainfectious neurologic complication. However, OMS associated with a neurodegenerative disorder has not been described previously. A 48-year-old woman had been diagnosed as multiple system atrophy-parkinsonian type (MSA-P) based on the findings of dopamine non-responsive parkinsonism with autonomic failure and typical findings on magnetic resonance imaging 5 years ago. She exhibited recurrent asynchronous and arrhythmic myoclonic movements of the upper limbs and abdomen with a very short duration, and involuntary eye movements, which were repetitive, rapid, random, multidirectional, conjugate saccades of irregular amplitude and frequency at rest. Based on hematological and radiological findings, the diagnosis was advanced MSA-P associated with OMS. As far as we are aware, there have not been any previous reports of such a case.

Neuroprotective function of 14-3-3 proteins in neurodegeneration

14-3-3 proteins are abundantly expressed adaptor proteins that interact with a vast number of binding partners to regulate their cellular localization and function. They regulate substrate function in a number of ways including protection from dephosphorylation, regulation of enzyme activity, formation of ternary complexes and sequestration. The diversity of 14-3-3 interacting partners thus enables 14-3-3 proteins to impact a wide variety of cellular and physiological processes. 14-3-3 proteins are broadly expressed in the brain, and clinical and experimental studies have implicated 14-3-3 proteins in neurodegenerative disease. A recurring theme is that 14-3-3 proteins play important roles in pathogenesis through regulating the subcellular localization of target proteins. Here, we review the evidence that 14-3-3 proteins regulate aspects of neurodegenerative disease with a focus on their protective roles against neurodegeneration.

Tremor in Multiple System Atrophy - a review

BACKGROUND

Multiple system atrophy (MSA) is a rare neurodegenerative movement disorder characterized by a rapidly progressive course. The clinical presentation can include autonomic failure, parkinsonism, and cerebellar signs. Differentiation from Parkinson's disease (PD) is difficult if there is levodopa-responsive parkinsonism, rest tremor, lack of cerebellar ataxia, or mild/delayed autonomic failure. Little is known about tremor prevalence and features in MSA.

METHODS

We performed a PubMed search to collect the literature on tremor in MSA and considered reports published between 1900 and 2013.

RESULTS

Tremor is a common feature among MSA patients. Up to 80% of MSA patients show tremor, and patients with the parkinsonian variant of MSA are more commonly affected. Postural tremor has been documented in about half of the MSA population and is frequently referred to as jerky postural tremor with evidence of minipolymyoclonus on neurophysiological examination. Resting tremor has been reported in about one-third of patients but, in contrast to PD, only 10% show typical parkinsonian "pill-rolling" rest tremor. Some patients exhibit intention tremor associated with cerebellar dysmetria. In general, MSA patients can have more than one tremor type owing to a complex neuropathology that includes both the basal ganglia and pontocerebellar circuits.

DISCUSSION

Tremor is not rare in MSA and might be underrecognized. Rest, postural, action and intention tremor can all be present, with jerky tremulous movements of the outstretched hands being the most characteristic. However, reviewing the data on tremor in MSA suggests that not every shaky movement satisfies tremor criteria; therefore, further studies are needed.

Surgical management of airway dysfunction in Parkinson's disease compared with Parkinson-plus syndromes

OBJECTIVES

We sought to compare the laryngeal symptoms of Parkinson's disease (PD) with those of multiple system atrophy (MSA), a Parkinson-plus syndrome; to review the differences in surgical management of upper airway dysfunction between patients with PD and those with MSA; and to present a treatment algorithm for management of upper airway disorders in patients with PD and MSA.

METHODS

We analyzed the airway manifestations of each disease, including clinical and physiological test results and management outcomes, in a case series of 30 patients (24 with PD and 6 with MSA).

RESULTS

Vocal fold atrophy causing bowing with a midfold glottic gap was common in patients with PD. One third of patients with PD underwent vocal fold augmentation with noticeable improvement in vocal volume and phonation time. Tracheostomy was required for life-threatening sleep apnea in 50% of the patients with MSA. Systemic medications and speech therapy were integral components of the management regimen.

CONCLUSIONS

Surgical management of laryngeal disorders in patients with PD should focus on restoring bulk to atrophic vocal folds to minimize glottic gaps, thus improving vocalization efficiency even in the presence of impaired respiratory effort. Conversely, the autonomic dysfunction that characterizes MSA results in upper airway obstruction, and thus surgical management focuses primarily on maintaining an adequate airway, which frequently necessitates tracheostomy.

Update on diffusion MRI in Parkinson's disease and atypical parkinsonism

Differentiating Parkinson's disease (PD) from other types of neurodegenerative atypical parkinsonism (AP) can be challenging, especially in early disease stages. Routine brain magnetic resonance imaging (MRI) can show atrophy or signal changes in several parts of the brain with fairly high specificity for particular forms of AP, but the overall diagnostic value of routine brain MRI is limited. In recent years, various advanced MRI sequences have become available, including diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI). Here, we review available literature on the value of diffusion MRI for identifying and quantifying different patterns of neurodegeneration in PD and AP, in relation to what is known of underlying histopathologic changes and clinical presentation of these diseases. Next, we evaluate the value of diffusion MRI to differentiate between PD and AP and the potential value of serial diffusion MRI to monitor disease progression. We conclude that diffusion MRI may quantify patterns of neurodegeneration which could be of additional value in clinical use. Future prospective clinical cohort studies are warranted to assess the added diagnostic value of diffusion MRI.

Differentiation of progressive supranuclear palsy: clinical, imaging and laboratory tools

Progressive supranuclear palsy (PSP) is the most common atypical parkinsonian syndrome comprising two main clinical subtypes: Richardson's syndrome (RS), characterized by prominent postural instability, supranuclear vertical gaze palsy and frontal dysfunction; and PSP-parkinsonism (PSP-P) which is characterized by an asymmetric onset, tremor and moderate initial therapeutic response to levodopa. The early clinical features of PSP-P are often difficult to discern from idiopathic Parkinson's disease (PD), and other atypical parkinsonian disorders, including multiple system atrophy (MSA) and corticobasal syndrome (CBS). In addition, rare PSP subtypes may be overlooked or misdiagnosed if there are atypical features present. The differentiation between atypical parkinsonian disorders and PD is important because the prognoses are different, and there are different responses to therapy. Structural and functional imaging, although currently of limited diagnostic value for individual use in early disease, may contribute valuable information in the differential diagnosis of PSP. A growing body of evidence shows the importance of CSF biomarkers in distinguishing between atypical parkinsonian disorders particularly early in their course when disease-modifying therapies are becoming available. However, specific diagnostic CSF biomarkers have yet to be identified. In the absence of reliable disease-specific markers, we provide an update of the recent literature on the assessment of clinical symptoms, pathology, neuroimaging and biofluid markers that might help to distinguish between these overlapping conditions early in the course of the disease.

Immunohistochemical localization of aggresomal proteins in glial cytoplasmic inclusions in multiple system atrophy

AIMS

Multiple system atrophy (MSA) is pathologically characterized by the formation of α-synuclein-containing glial cytoplasmic inclusions (GCIs) in oligodendrocytes. However, the mechanisms of GCI formation are not fully understood. Cellular machinery for the formation of aggresomes has been linked to the biogenesis of the Lewy body, a characteristic α-synuclein-containing inclusion of Parkinson's disease and dementia with Lewy bodies. Here, we examined whether GCIs contain the components of aggresomes by immunohistochemistry.

METHODS

Sections from five patients with MSA were stained immunohistochemically with antibodies against aggresome-related proteins and analysed in comparison with sections from five patients with no neurological disease. We evaluated the presence or absence of aggresome-related proteins in GCIs by double immunofluorescence and immunoelectron microscopy.

RESULTS

GCIs were clearly immunolabelled with antibodies against aggresome-related proteins, such as γ-tubulin, histone deacetylase 6 (HDAC6) and 20S proteasome subunits. Neuronal cytoplasmic inclusions (NCIs) were also immunopositive for these aggresome-related proteins. Double immunofluorescence staining and quantitative analysis demonstrated that the majority of GCIs contained these proteins, as well as other aggresome-related proteins, such as Hsp70, Hsp90 and 62-kDa protein/sequestosome 1 (p62/SQSTM1). Immunoelectron microscopy demonstrated immunoreactivities for γ-tubulin and HDAC6 along the fibrils comprising GCIs.

CONCLUSIONS

Our results indicate that GCIs, and probably NCIs, share at least some characteristics with aggresomes in terms of their protein components. Therefore, GCIs and NCIs may be another manifestation of aggresome-related inclusion bodies observed in neurodegenerative diseases.

The natural history of multiple system atrophy: a prospective European cohort study

BACKGROUND

Multiple system atrophy (MSA) is a fatal and still poorly understood degenerative movement disorder that is characterised by autonomic failure, cerebellar ataxia, and parkinsonism in various combinations. Here we present the final analysis of a prospective multicentre study by the European MSA Study Group to investigate the natural history of MSA.

METHODS

Patients with a clinical diagnosis of MSA were recruited and followed up clinically for 2 years. Vital status was ascertained 2 years after study completion. Disease progression was assessed using the unified MSA rating scale (UMSARS), a disease-specific questionnaire that enables the semiquantitative rating of autonomic and motor impairment in patients with MSA. Additional rating methods were applied to grade global disease severity, autonomic symptoms, and quality of life. Survival was calculated using a Kaplan-Meier analysis and predictors were identified in a Cox regression model. Group differences were analysed by parametric tests and non-parametric tests as appropriate. Sample size estimates were calculated using a paired two-group t test.

FINDINGS

141 patients with moderately severe disease fulfilled the consensus criteria for MSA. Mean age at symptom onset was 56·2 (SD 8·4) years. Median survival from symptom onset as determined by Kaplan-Meier analysis was 9·8 years (95% CI 8·1-11·4). The parkinsonian variant of MSA (hazard ratio [HR] 2·08, 95% CI 1·09-3·97; p=0·026) and incomplete bladder emptying (HR 2·10, 1·02-4·30; p=0·044) predicted shorter survival. 24-month progression rates of UMSARS activities of daily living, motor examination, and total scores were 49% (9·4 [SD 5·9]), 74% (12·9 [8·5]), and 57% (21·9 [11·9]), respectively, relative to baseline scores. Autonomic symptom scores progressed throughout the follow-up. Shorter symptom duration at baseline (OR 0·68, 0·5-0·9; p=0·006) and absent levodopa response (OR 3·4, 1·1-10·2; p=0·03) predicted rapid UMSARS progression. Sample size estimation showed that an interventional trial with 258 patients (129 per group) would be able to detect a 30% effect size in 1-year UMSARS motor examination decline rates at 80% power.

INTERPRETATION

Our prospective dataset provides new insights into the evolution of MSA based on a follow-up period that exceeds that of previous studies. It also represents a useful resource for patient counselling and planning of multicentre trials.

Treatment outcomes in REM sleep behavior disorder

OBJECTIVE

REM sleep behavior disorder (RBD) is usually characterized by potentially injurious dream enactment behaviors (DEB). RBD treatment aims to reduce DEBs and prevent injury, but outcomes require further elucidation. We surveyed RBD patients to describe longitudinal treatment outcomes with melatonin and clonazepam.

METHODS

We surveyed and reviewed records of consecutive RBD patients seen at Mayo Clinic between 2008-2010 to describe RBD-related injury frequency-severity as well as RBD visual analog scale (VAS) ratings, medication dosage, and side effects. Statistical analyses were performed with appropriate non-parametric matched pairs tests before and after treatment, and with comparative group analyses for continuous and categorical variables between treatment groups. The primary outcome variables were RBD VAS ratings and injury frequency.

RESULTS

Forty-five (84.9%) of 53 respondent surveys were analyzed. Mean age was 65.8 years and 35 (77.8%) patients were men. Neurodegenerative disorders were seen in 24 (53%) patients and 25 (56%) received antidepressants. Twenty-five patients received melatonin, 18 received clonazepam, and two received both as initial treatment. Before treatment, 27 patients (60%) reported an RBD associated injury. Median dosages were melatonin 6 mg and clonazepam 0.5 mg. RBD VAS ratings were significantly improved following both treatments (p(m) = 0.0001, p(c) = 0.0005). Melatonin-treated patients reported significantly reduced injuries (p(m) = 0.001, p(c) = 0.06) and fewer adverse effects (p = 0.07). Mean durations of treatment were no different between groups (for clonazepam 53.9 ± 29.5 months, and for melatonin 27.4 ± 24 months, p = 0.13) and there were no differences in treatment retention, with 28% of melatonin and 22% of clonazepam-treated patients discontinuing treatment (p = 0.43).

CONCLUSIONS

Melatonin and clonazepam were each reported to reduce RBD behaviors and injuries and appeared comparably effective in our naturalistic practice experience. Melatonin-treated patients reported less frequent adverse effects than those treated with clonazepam. More effective treatments that would eliminate injury potential and evidence-based treatment outcomes from prospective clinical trials for RBD are needed.

Therapeutic response to pramipexole in a patient with multiple system atrophy with predominant parkinsonism: positron emission tomography and pharmacokinetic assessments

Multiple system atrophy with predominant parkinsonism (MSA-P) usually shows poor responsiveness to dopaminergic medications. We herein describe a patient with MSA-P who exhibited a good response to pramipexole but not to an ordinary dose of L-dopa. Positron emission tomography (PET) displayed severely impaired presynaptic dopaminergic availability and relatively preserved postsynaptic D2 receptor binding capacity. The pharmacokinetic analyses demonstrated relatively low bioavailability for L-dopa and adequate plasma levels of pramipexole, even at baseline, on a stable daily dose. The PET features and pharmacokinetic differences between L-dopa and pramipexole indicate the presence of unique therapeutic responses to dopaminergic medications in the patient.

Models of multiple system atrophy

Multiple system atrophy (MSA) is a predominantly sporadic, adult-onset, fatal neurodegenerative disease of unknown etiology. MSA is characterized by autonomic failure, levodopa-unresponsive parkinsonism, cerebellar ataxia and pyramidal signs in any combination. MSA belongs to a group of neurodegenerative disorders termed α-synucleinopathies, which also include Parkinson's disease and dementia with Lewy bodies. Their common pathological feature is the occurrence of abnormal α-synuclein positive inclusions in neurons or glial cells. In MSA, the main cell type presenting aggregates composed of α-synuclein are oligodendroglial cells . This pathological hallmark, also called glial cytoplasmic inclusions (GCIs) , is associated with progressive and profound neuronal loss in various regions of the brain. The development of animal models of MSA is justified by the limited understanding of the mechanisms of neurodegeneration and GCIs formation, which is paralleled by a lack of therapeutic strategies. Two main types of rodent models have been generated to replicate different features of MSA neuropathology. On one hand, neurotoxin-based models have been produced to reproduce neuronal loss in substantia nigra pars compacta and striatum. On the other hand, transgenic mouse models with overexpression of α-synuclein in oligodendroglia have been used to reproduce GCIs-related pathology. This chapter gives an overview of the atypical Parkinson's syndrome MSA and summarizes the currently available MSA animal models and their relevance for pre-clinical testing of disease-modifying therapies.

Topographical differences of brain iron deposition between progressive supranuclear palsy and parkinsonian variant multiple system atrophy

OBJECTIVE

There have been various studies showing increased iron levels in parkinsonian disorders. The purpose of this study was to demonstrate topographical differences of brain iron deposition between progressive supranuclear palsy (PSP) and the parkinsonian variant of multiple system atrophy (MSA-p) with SWI images.

METHODS

A total of 11 patients with PSP, 12 with MSA-p, 15 with Parkinson's disease (PD), and 20 age-matched healthy controls underwent SWI of the brain. Mean phase shift values of the red nucleus (RN), substantia nigra (SN), head of the caudate nucleus (CN), globus pallidus (GP), putamen (PUT), and thalamus (TH) were calculated and compared between groups. A voxel-based analysis of the processed SWI was performed to determine topographical differences of iron-related hypointense signals in PUT, GP, and TH.

RESULTS

Patients with PSP and MSA-p had significantly higher levels of iron deposition than control and PD groups. Comparing patients with PSP and MSA-p, differences were found in iron concentrations of the RN, SN, GP, and TH, which were higher in the PSP group. However, iron levels in the PUT were higher in the MSA group (p<0.05). The area under curve (AUC) indicated that the PUT was the most valuable nucleus in differentiating MSA-p from PSP and PD according to phase shift values (AUC=0.836). Meanwhile the GP (AUC=0.869) and TH (AUC=0.884) were the two most valuable nuclei in differentiating PSP from MSA-p and PD. Voxel-based analysis showed subregional differences in iron-related hypointense signals in the PUT, GP, and TH between MSA-p and PSP groups. Patients with MSA-p had significant increases of iron-related hypointense signals in the posterolateral PUT and adjacent lateral aspect of the GP, whereas the PSP group had increased hypodense signals in the anterior and medial aspects of the GP and TH.

CONCLUSION

Our data demonstrate that pathological iron accumulations are more prevalent and severe in PSP compared to MSA-p. The distribution of high-iron-content regions in this study reflects pathoanatomically relevant sites. This finding allows for the use of MRI-based brain iron mapping as a technique to indirectly identify pathological changes.

Does a prion-like mechanism play a major role in the apparent spread of α-synuclein pathology?

Parkinson's disease, the most common movement disorder, results in an insidious reduction for patients in quality of life and ability to function. A hallmark of Parkinson's disease is the brain accumulation of neuronal cytoplasmic inclusions comprised of the protein α-synuclein. The presence of α-synuclein brain aggregates is observed in several neurodegenerative diseases, including dementia with Lewy bodies and Lewy body variant of Alzheimer's disease. These disorders, as a group, are termed synucleinopathies. Mounting evidence indicates that α-synuclein amyloid pathology may spread during disease progression by a prion-like (self-templating alteration in protein conformation) mechanism. Clear in vitro and cell culture data demonstrate that amyloidogenic α-synuclein can readily induce the conversion of other α-synuclein molecules into this conformation. Some data from experimental mouse studies and autopsied brain analyses also are consistent with the notion that a self-promoting process of α-synuclein amyloid inclusion formation may lead to a progressive spread of disease in vivo. However, as pointed out in this review, there are alternative explanations and interpretations for these findings. Therefore, from a therapeutic perspective, it is critical to determine the relative importance and contribution of α-synuclein prionlike spread in disease before embarking on elaborate efforts to target this putative pathogenic mechanism.

Orthostatic hypotension is differentially associated with the cerebellar versus the parkinsonian variant of multiple system atrophy: a comparative study

Orthostatic hypotension (OH) is a cardinal feature of autonomic failure in multiple system atrophy (MSA); however, there are few comparative data on OH in the motor subtypes of MSA. In the present retrospective study, postural blood pressure drop after 3 min of standing was determined in 16 patients with the cerebellar variant of MSA (MSA-C) and in 17 patients with the Parkinson variant (MSA-P). Twenty idiopathic Parkinson's disease (IPD) patients matched for age, sex, disease duration and dopaminergic therapy served as control group. OH frequency and severity were more pronounced in MSA-C followed by MSA-P and IPD. Differences in brainstem pathology are likely to account for the tight association of MSA-C and OH. A simple standing test should be obligatory in the work-up of patients with sporadic late-onset ataxias.

Clinical features and disability milestones in multiple system atrophy and progressive supranuclear palsy

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are an adult-onset progressive neurodegenerative disorder that are known to display diverse clinical features and disease progression. We aim to characterize the clinical features and disease progression in patients with MSA and PSP by using a number of relevant disability milestones in Koreans. Forty-one patients with MSA and 14 patients with PSP had been enrolled. The mean age at onset of MSA-C, MSA-P and PSP was 56.7 ± 7.8, 62.5 ± 8.0, 68.9 ± 6.1 years respectively. The most commonly reported symptom at disease onset is disequilibrium/dizziness in MSA-C, tremor in MSA-P and frequent falling in PSP. The mean duration of reaching milestones after disease onset in MSA-C were as followings: 20.8 (urinary incontinence), 22.9 (frequent falling), 27.8 (wheelchair bound), 31.8 (dysarthria) and 35.8 months (diagnosis). The mean duration of reaching milestones after disease onset were 22.0 (urinary incontinence), 32.6 (frequent falling and diagnosis), 41.2 (dysarthria), 61.4 months (wheelchair bound) in MSA-P and 16.8 (dysarthria), 21.6 (diagnosis), 21.7 (frequent falling), 24.0 months (wheel chair bound) in PSP. In the case of MSA, dizziness may occur for the first time. Thus, when the patient complains of non-specific dizziness, a follow-up examination to distinguish it from MSA can be helpful. There was a trend for patients with MSA-C to reach more disability milestones than in MSA-P and PSP before diagnosis. It may explain why patients with MSA-C are required more detail history taking and neurologic examination at an earlier stage.

Amantadine effectiveness in multiple system atrophy and progressive supranuclear palsy

Progressive Supranuclear palsy (PSP) and multiple system atrophy (MSA) each respond poorly to most anti-parkinsonian drugs. We assessed PSP and MSA cases seen between 1970 and 1996 for response to amantadine (Amd) 100 mg twice daily. Of 13 MSA cases (six females, seven males), eight (61.5%) improved, four (30.8%) did not benefit and one had insufficient documentation. Adverse effects were observed in three (23.1%) cases. Of 14 PSP (three females, 11 males), six (42.9%) had some improvement, five (35.7%) had no benefit, and three (21.4%) had inadequate documentation. Adverse effects were noted in three (28.6%) cases. Improvement is likely related to NMDA antagonist properties of Amd. We recommend consideration of Amd in the management of both PSP and MSA.

Multiple system atrophy-parkinsonism with slow progression and prolonged survival: a diagnostic catch

BACKGROUND

Multiple system atrophy (MSA) is a neurodegenerative disease leading to severe physical impairment, with a disease duration from onset to death of 6-9 years.

METHODS

The clinical and neuropathological features of 4 MSA cases with disease duration of 15 years or more were analyzed.

RESULTS

All patients presented with parkinsonism and had a mean latency of 11 years before the development of dysautonomia. Mean duration from onset of first symptoms to anterocollis, inspiratory stridor, and dysphagia was 9 years. Despite the limited levodopa response, all patients developed levodopa-induced dyskinesia.

CONCLUSIONS

Late appearance of dysautonomia is a favorable prognostic factor in MSA-P. Greater awareness of this uncommon "benign" subgroup of MSA will improve diagnostic accuracy and help to more accurately inform treatment options.

Profile of multiple system atrophy in Moroccan patients attending a movement disorders outpatient clinic in Rabat university hospital

INTRODUCTION

Multiple system atrophy (MSA) is a sporadic and rapidly progressive neurodegenerative disorder of poor prognosis, characterised clinically by any combination of parkinsonian, autonomic, cerebellar, or pyramidal signs. We report our experience in movement disorders consultation concerning the clinical presentation and the course of MSA in Moroccan patients.

METHODS

A retrospective review of the medical records of 17 patients with diagnosis of MSA seen in our outpatient clinic from January 2007 to December 2010.

RESULTS

In our 17 patients, 76.5% were men and the mean age of onset was 52±9 years. MSA-P was the major clinical phenotype (82.4%). Eleven patients (64.7%) were classified as having probable MSA and six patients (35.3%) as possible MSA. Dysautonomic features were detected in all patients; urinary symptoms were found in 76.5% of cases and orthostatic hypotension in 64.7%. Treatment regimen included l-Dopa with a mean daily dose of 621.4±346.8mg/day and symptomatic treatment of dysautonomia. The mean duration of disease evolution was of 4.7±1.9 years.

DISCUSSION

Our results show a male predominance and an early age of disease onset. MSA-P was the predominant subtype. Our results are similar to the European MSA series.

CONCLUSION

Multicentre studies are needed to better characterise MSA in Morocco given the rarity of this disease.

Autopsy confirmed multiple system atrophy cases: Mayo experience and role of autonomic function tests

BACKGROUND

Multiple system atrophy (MSA) is a sporadic progressive neurodegenerative disorder characterised by autonomic failure, manifested as orthostatic hypotension or urogenital dysfunction, with combinations of parkinsonism that is poorly responsive to levodopa, cerebellar ataxia and corticospinal dysfunction. Published autopsy confirmed cases have provided reasonable neurological characterisation but have lacked adequate autonomic function testing.

OBJECTIVES

To retrospectively evaluate if the autonomic characterisation of MSA is accurate in autopsy confirmed MSA and if consensus criteria are validated by autopsy confirmation.

METHODS

29 autopsy confirmed cases of MSA evaluated at the Mayo Clinic who had undergone formalised autonomic testing, including adrenergic, sudomotor and cardiovagal functions and Thermoregulatory Sweat Test (TST), from which the Composite Autonomic Severity Score (CASS) was derived, were included in the study.

PATIENT CHARACTERISTICS

17 men, 12 women; age of onset 57±8.1 years; disease duration to death 6.5±3.3 years; first symptom autonomic in 18, parkinsonism in seven and cerebellar in two. Clinical phenotype at first visit was MSA-P (predominant parkinsonism) in 18, MSA-C (predominant cerebellar involvement) in eight, pure autonomic failure in two and Parkinson's disease in one. Clinical diagnosis at last visit was MSA for 28 cases. Autonomic failure was severe: CASS was 7.2±2.3 (maximum 10). TST% was 65.6±33.9% and exceeded 30% in 82% of patients. The most common pattern was global anhidrosis. Norepinephrine was normal supine (203.6±112.7) but orthostatic increment of 33.5±23.2% was reduced. Four clinical features (rapid progression, early postural instability, poor levodopa responsiveness and symmetric involvement) were common.

CONCLUSION

The pattern of severe and progressive generalised autonomic failure with severe adrenergic and sudomotor failure combined with the clinical phenotype is highly predictive of MSA.

Circadian rhythms and cardiovascular health

The functional organization of the cardiovascular system shows clear circadian rhythmicity. These and other circadian rhythms at all levels of organization are orchestrated by a central biological clock, the suprachiasmatic nuclei of the hypothalamus. Preservation of the normal circadian time structure from the level of the cardiomyocyte to the organ system appears to be essential for cardiovascular health and cardiovascular disease prevention. Myocardial ischemia, acute myocardial infarct, and sudden cardiac death are much greater in incidence than expected in the morning. Moreover, supraventricular and ventricular cardiac arrhythmias of various types show specific day-night patterns, with atrial arrhythmias--premature beats, tachycardias, atrial fibrillation, and flutter - generally being of higher frequency during the day than night--and ventricular fibrillation and ventricular premature beats more common, respectively, in the morning and during the daytime activity than sleep span. Furthermore, different circadian patterns of blood pressure are found in arterial hypertension, in relation to different cardiovascular morbidity and mortality risk. Such temporal patterns result from circadian periodicity in pathophysiological mechanisms that give rise to predictable-in-time differences in susceptibility-resistance to cyclic environmental stressors that trigger these clinical events. Circadian rhythms also may affect the pharmacokinetics and pharmacodynamics of cardiovascular and other medications. Knowledge of 24-h patterns in the risk of cardiac arrhythmias and cardiovascular disease morbidity and mortality plus circadian rhythm-dependencies of underlying pathophysiologic mechanisms suggests the requirement for preventive and therapeutic interventions is not the same throughout the day and night, and should be tailored accordingly to improve outcomes.

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.

Brain monoamine systems in multiple system atrophy: a positron emission tomography study

Post-mortem studies of multiple system atrophy (MSA) patients have shown widespread subcortical neurodegeneration. In this study, we have used 18F-dopa PET, a marker of monoaminergic nerve terminal function, to explore in vivo changes in striatal and extrastriatal dopamine, noradrenaline, and serotonin transmission for a cohort of patients with MSA with predominant parkinsonism. Fourteen patients with MSA, ten patients with idiopathic Parkinson's disease (PD) matched for disease duration, and ten healthy controls were studied with 18F-dopa PET. Regions of interest (ROIs) were placed to sample 18F-dopa uptake in thirteen structures and mean activity was compared between groups. The MSA patients showed significantly decreased 18F-dopa uptake in putamen, caudate nucleus, ventral striatum, globus pallidus externa and red nucleus compared to controls, whereas PD patients only had decreased 18F-dopa uptake in putamen, caudate nucleus, and ventral striatum. MSA cases with orthostatic hypotension had lower 18F-dopa uptake in the locus coeruleus than patients without this symptom. In conclusion, 18F-dopa PET showed more widespread basal ganglia dysfunction in MSA than in PD with similar disease duration, and extrastriatal loss of monoaminergic innervation could be detected in the red nucleus and locus coeruleus. In contrast to PD, there was no evidence of early compensatory increases in regional 18F-dopa uptake.

Sporadic adult-onset ataxia of unknown etiology

Sporadic adult-onset ataxia of unknown etiology (SAOA) denotes the non-hereditary degenerative adult-onset ataxia disorders that are distinct from multiple system atrophy (MSA). Rather than being a defined disease entity, SAOA has to be regarded as a group of disorders of unknown etiology that are defined by a common clinical syndrome and the exclusion of known disease causes. Epidemiological studies have revealed prevalence rates ranging from 2.2 to 8.4 per 100000, which are higher than those of hereditary ataxias. Clinically, SAOA is characterized by a slowly progressive cerebellar syndrome starting around the age of 50 years. About one-third of SAOA patients have either polyneuropathy or pyramidal tract involvement accompanying cerebellar ataxia. Cognitive impairment is not the rule, and, if present, is only mild. More than half of SAOA patients have signs of mild autonomic dysfunction that do not meet the criteria of severe autonomic failure required for a diagnosis of MSA. Neuropathological and imaging studies show an isolated cerebellar cortical degeneration with no or only mild brainstem involvement. There is no established therapy for SAOA.

Spinocerebellar ataxia type 12

SCA12 is a late-onset, autosomal dominant, slowly progressive disorder. Action tremor is the usual presenting sign. Subsequent development of ataxia and hyperreflexia suggests spinocerebellar ataxia. In the index SCA12 kindred, which resides in North America and is of German ancestry, parkinsonism, anxiety, depression, and cognitive dysfunction are not uncommon. SCA12 is linked to a CAG repeat expansion mutation in exon 7 of PPP2R2B, a gene that encodes Bβ, a regulatory subunit of protein phosphatase 2A (PP2A). CAG repeats number 7-28 in normal individuals and 55-78 in SCA12 patients. The mechanism by which this mutation leads to SCA12 has not been determined. The CAG expansion in PPP2R2B has promoter function in vitro. CAG length correlates with increased Bβ expression. There is no evidence that this CAG expansion results in polyglutamine production. In addition to the North. American SCA12 kindred, multiple SCA12 families have been found in Northern India that are not related to the index SCA12 kindred. SCA12 has been reported, rarely, in Singapore and China. Action tremor, anxiety, and depression in SCA12 have responded to usual treatments for these disorders. SCA12 may be considered in patients who present with action tremor and later develop signs of cerebellar and cortical dysfunction.

Dopamine transporter imaging in autopsy-confirmed Parkinson's disease and multiple system atrophy

Dopamine transporter single-photon emission computerized tomography can visualize dopaminergic degeneration in Parkinson's disease and multiple system atrophy. Some studies have suggested that dopamine transporter imaging can distinguish these disorders based on a more diffuse and symmetric striatal dopamine transporter binding loss in multiple system atrophy. The present study compared patterns of striatal dopamine transporter distribution in postmortem-confirmed Parkinson's disease and multiple system atrophy. Patients with a postmortem diagnosis of multiple system atrophy (n = 6) or Parkinson's disease (n = 8) who had undergone dopamine transporter imaging were included. Imaging had been performed after a mean disease duration of 3.6 and 4.1 years in multiple system atrophy and Parkinson's disease, respectively. Visual analysis showed bilaterally reduced binding in all patients. Mean overall striatal binding was reduced by 53% in multiple system atrophy and 52% in Parkinson's disease. There was a trend for greater asymmetry of striatal binding in multiple system atrophy compared with Parkinson's disease (23% ± 15% vs 10.5% ± 7%, respectively; P = .071), with 3 multiple system atrophy patients showing more asymmetry of striatal binding than any Parkinson's disease patient. Putamen/caudate binding ratios did not differ between the groups. This is the first study comparing dopamine transporter imaging in autopsy-confirmed multiple system atrophy and Parkinson's disease. Unexpectedly, we found a tendency for greater asymmetry of striatal binding in multiple system atrophy than in Parkinson's disease. Our findings demonstrate that these conditions cannot be differentiated by subregional analysis of striatal dopamine transporter binding.

Laryngeal dystonia in the course of multiple system atrophy: a cause of postoperative respiratory insufficiency

Multiple system atrophy (MSA) is an adult onset, incurable neurodegenerative disease, characterized by symptoms of nervous system failure. Occurrence of laryngeal dystonia indicates increased risk of sudden death caused by airway occlusion. We present the case report of 63-year-old patient with history of orthostatic hypotension, parkinsonism, progressive adynamia, and stridor. The patient was admitted to the hospital for diagnosis of orthostatic hypotension. A diagnosis of possible MSA was made. Because of patient's complaints, an X-ray of the hip joint was taken. It revealed femoral neck fracture. Endoprosthesis insertion under general anesthesia was performed. Two days later the patient presented progressive adynamy and respiratory insufficiency. Endotracheal intubation and respiratory support were required followed by extubation and one more intubation. After second extubation, stridor and acute respiratory insufficiency occurred. Urgent tracheostomy was performed. After 13 days in ICU, the patient was discharged to the rehabilitation center.

Putaminal hypointensity in the parkinsonian variant of multiple system atrophy: simple visual assessment using susceptibility-weighted imaging

Background and Purpose

Susceptibility-weighted imaging (SWI) has been shown to be superior in its ability to demonstrate brain mineralization than other conventional MR imaging. The goal of our study was therefore to assess the frequency and extent of putaminal hypointensity in parkinsonian variant MSA using SWI.

Methods

11 patients with multiple system atrophy-parkinsonian type (MSA-p), 30 patients with Parkinson’s disease (PD), and age matched 30 controls were investigated using 3 Tesla MRI. The pattern of putaminal hypointensity was measured using a visual grading scale and scored from 0 to 3.

Results

Hemi- or bilateral putaminal hypointensity (a score of ≥ 2) and hyperintense rim were recognized in 81.8% and 54.5% of 11 MSA-p, respectively. The scores of putaminal hypointensity of MSA-p were significantly higher than other groups (p < 0.001), a score of ≥ 2 differentiated MSA-p from other groups. And all five patients with early disease stage also showed these characteristic findings.

Conclusions

SWI appears to be useful for depicting putaminal hypointensity even in early stage of MSA-p. This finding suggests that iron deposition associated putaminal degeneration can occur early in the disease process.

A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability

AIM

To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study.

METHODS

The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP = 362, MSA = 398), 627 had per protocol images (PSP = 297, MSA = 330). Intra-rater (n = 60) and inter-rater (n = 555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n = 441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis.

RESULTS

Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (≥ 0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75-0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1-F2; MSA: F2-F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity.

CONCLUSIONS

The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA. Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224.

Asymmetry in parkinsonism, spreading pathogens and the nose

Parkinson's disease, as well as many other parkinsonisms, including most toxic, neurodegenerative and familial types are typically asymmetric. No explanation for this phenomenon exists. A summary of the frequency of asymmetry in a spectrum of parkinsonian disorders is provided. Evidence against asymmetry being the result of normal asymmetries of the substantia nigrais reviewed. Asymmetry either results from a greater susceptibility on one side or a spreading pathology entering or starting on one side of the CNS. With the increasing evidence for spreading pathologies (toxins, viruses, α-synuclein), knowledge of neuroanatomical connections, and literature implicating spreading pathogens from the enteric and olfactory nerves, potential explanations can be theorized and explored, including the possibility of a pathogen preferentially entering or originating in the olfactory bulb on one side, with subsequent involvement of the other side.