Paraneoplastic movement disorders

The Clinical Spectrum of Autoimmune-Mediated Neurological Diseases in Paediatric Population

Neurological autoimmune diseases have various origins and pathogeneses. Specific antibodies are associated with paraneoplastic syndromes, other infectious agents, or inherited disorders. We aim to evaluate the relation between the autoantibodies, the chosen symptoms, demographic characteristics, and infection history. We retrospectively analysed 508 children during neurological diagnostics. We investigated serum antineuronal, IgG, IgM anti-ganglioside, and anti-aquaporin-4 in both the serum and cerebrospinal fluid (CSF) anti-cell surface and anti-synaptic protein antibodies in 463, 99, 44, 343, and 119 patients, respectively. The CSF polymerase chain reaction detection of Herpesviridae, enterovirus, B19 parvovirus, adenovirus, and parechovirus involved 261 patients. We included available clinical information and electroencephalographic, radiologic, and microbiological results. The IgM anti-ganglioside antibodies increased the risk of tics and positive symptoms (p = 0.0345, p = 0.0263, respectively), the anti-glutamic acid decarboxylase particle of paresis (p = 0.0074), and anti-neuroendothelium of mutism (p = 0.0361). Anti-neuroendothelium, IgM anti-ganglioside, and CSF anti-N-methyl-D-aspartate antibodies were more often associated with consciousness loss (p = 0.0496, p = 0.0044, p = 0.0463, respectively). Anti-myelin antibodies co-occured with Herpes simplex virus (HSV)-2 IgG (p = 0.0415), anti-CV2 with HSV-1 IgM (p = 0.0394), whereas anti-glial fibrillary acidic protein was linked with past Epstein-Barr virus infection. The anti-ganglioside IgM and anti-myelin particles were bilaterally correlated (p = 0.0472). The clinical pictures may overlap, requiring specialistic diagnostics. We noticed the links between the infection aetiology and the specific autoantibody’s positivity.

Paraneoplastic movement disorders: phenomenology, diagnosis, and treatment

Paraneoplastic syndromes include, by definition, any symptomatic and non-metastatic condition associated with a neoplasm. Paraneoplastic movement disorders are a heterogeneous group of syndromes encompassing both hyperkinetic and hypokinetic conditions, characterized by acute/sub-acute onset, rapidly progressive evolution, and multifocal localizations with several overlapping features. These movement disorders are immune-mediated, as shown by the rapid onset and by the presence of antineuronal antibodies in biological samples of patients, fundamental for the diagnosis. Antineuronal antibodies could be targeted against intracellular or neuronal surface antigens. Paraneoplastic movement disorders associated with anti-neuronal surface antigens antibodies respond more frequently to immunotherapy. The underlying tumors may be different, according to the clinical presentation, age, and gender of patients. Our search considered articles involving human subjects indexed in PubMed. Abstracts were independently reviewed for eligibility criteria by one author and validated by at least one additional author. In this review, we sought to critically reappraise the clinical features and the pathophysiological mechanisms of paraneoplastic movement disorders, focusing on diagnostic and therapeutic strategies. Our main aim is to make clinicians aware of paraneoplastic movement disorders, and to provide assistance in the early diagnosis and management of these rare but life-threatening conditions.

Neuronal Antibodies and Associated Syndromes

INTRODUCTION

Multiple well-recognized conditions, such as Lambert-Eaton myasthenic syndrome (LEMS) and myasthenia gravis (MG), have been associated with neuronal antibodies.

MATERIALS AND METHODS

A search was performed using Embase, PubMed, and CINAHL. An initial search of each database was conducted using keywords and terms related to the aim of the current review. Additional articles were obtained by examining the reference lists and citations in the selected records.

RESULTS

The studies identified through the search process used different designs and methods to explore neuronal antibodies and associated syndromes. Previous studies have shown that neurological and psychiatric disorders can be mediated and influenced by various antibodies. The identification of autoantibodies can help with the accurate diagnosis of conditions and commencement of early treatment.

DISCUSSION

A review of selected studies identified in the literature implicated that classic anti-neuronal antibodies, such as anti-Ri and anti-Hu, play a role in the development of neurological diseases. More recent studies have indicated that other novel antibodies act on neuronal cell surface antigens to contribute to the development of neurological disorders.

CONCLUSION

Existing research provides evidence revealing a spectrum of antibodies linked to the development and progression of neurological diseases. However, further antibody testing and studies should be performed to validate the relationship between conditions and antibodies.

Neuropathology and pathogenesis of extrapyramidal movement disorders: a critical update-I. Hypokinetic-rigid movement disorders

Extrapyramidal movement disorders include hypokinetic rigid and hyperkinetic or mixed forms, most of them originating from dysfunction of the basal ganglia (BG) and their information circuits. The functional anatomy of the BG, the cortico-BG-thalamocortical, and BG-cerebellar circuit connections are briefly reviewed. Pathophysiologic classification of extrapyramidal movement disorder mechanisms distinguish (1) parkinsonian syndromes, (2) chorea and related syndromes, (3) dystonias, (4) myoclonic syndromes, (5) ballism, (6) tics, and (7) tremor syndromes. Recent genetic and molecular-biologic classifications distinguish (1) synucleinopathies (Parkinson's disease, dementia with Lewy bodies, Parkinson's disease-dementia, and multiple system atrophy); (2) tauopathies (progressive supranuclear palsy, corticobasal degeneration, FTLD-17; Guamian Parkinson-dementia; Pick's disease, and others); (3) polyglutamine disorders (Huntington's disease and related disorders); (4) pantothenate kinase-associated neurodegeneration; (5) Wilson's disease; and (6) other hereditary neurodegenerations without hitherto detected genetic or specific markers. The diversity of phenotypes is related to the deposition of pathologic proteins in distinct cell populations, causing neurodegeneration due to genetic and environmental factors, but there is frequent overlap between various disorders. Their etiopathogenesis is still poorly understood, but is suggested to result from an interaction between genetic and environmental factors. Multiple etiologies and noxious factors (protein mishandling, mitochondrial dysfunction, oxidative stress, excitotoxicity, energy failure, and chronic neuroinflammation) are more likely than a single factor. Current clinical consensus criteria have increased the diagnostic accuracy of most neurodegenerative movement disorders, but for their definite diagnosis, histopathological confirmation is required. We present a timely overview of the neuropathology and pathogenesis of the major extrapyramidal movement disorders in two parts, the first one dedicated to hypokinetic-rigid forms and the second to hyperkinetic disorders.

Movement disorders in systemic diseases

Movement disorders, classically involving dysfunction of the basal ganglia commonly occur in neurodegenerative and structural brain disorders. At times, however, movement disorders can be the initial manifestation of a systemic disease. In this article we discuss the most common movement disorders which may present in infectious, autoimmune, paraneoplastic, metabolic and endocrine diseases. Management often has to be multidisciplinary involving primary care physicians, neurologists, allied health professionals including nurses, occupational therapists and less frequently neurosurgeons. Recognizing and treating the underlying systemic disease is important in order to improve the neurological symptoms.

Reversible cerebellar ataxia due to ovarian teratoma

Cerebellar dysfunction is a classic paraneoplastic syndrome associated with various types of cancer, including gynecological and breast tumors, small-cell lung cancer, thymoma, and Hodgkin's lymphoma. We present a 22-year-old woman with acute cerebellar ataxia that subsided upon removal of an ovarian teratoma. This patient may represent a new category of immune-mediated cerebellar ataxia that is reversible with removal of an underlying tumor.

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.

Movement disorders in autoimmune diseases

Movement disorders have been known to be associated with a variety of autoimmune diseases, including Sydenham's chorea, pediatric autoimmune neuropsychiatric disorders associated with streptococcus, systemic lupus erythematosus, antiphospholipid syndrome, gluten sensitivity, paraneoplastic and autoimmune encephalopathies. Tremors, dystonia, chorea, ballism, myoclonus, parkinsonism, and ataxia may be the initial and even the only presentation of these autoimmune diseases. Although antibodies directed against various cellular components of the central nervous system have been implicated, the pathogenic mechanisms of these autoimmune movement disorders have not yet been fully elucidated. Clinical recognition of these autoimmune movement disorders is critically important as many improve with immunotherapy or dietary modifications, particularly when diagnosed early. We discuss here the clinical features, pathogenic mechanisms, and treatments of movement disorders associated with autoimmune diseases, based on our own experience and on a systematic review of the literature.

Movement disorders in paraneoplastic and autoimmune disease

PURPOSE OF REVIEW

The most relevant advances in immune-mediated movement disorders are described, with emphasis on the clinical--immunological associations, novel antigens, and treatment.

RECENT FINDINGS

Many movement disorders previously considered idiopathic or degenerative are now recognized as immune-mediated. Some disorders are paraneoplastic, such as anti-CRMP5-associated chorea, anti-Ma2 hypokinesis and rigidity, anti-Yo cerebellar ataxia and tremor, and anti-Hu ataxia and pesudoathetosis. Other disorders such as Sydenham's chorea, or chorea related to systemic lupus erythematosus and antiphospholipid syndrome occur in association with multiple antibodies, are not paraneoplastic, and are triggered by molecular mimicry or unknown mechanisms. Recent studies have revealed a new category of disorders that can be paraneoplastic or not, and associate with antibodies against cell-surface or synaptic proteins. They include anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, which may cause dyskinesias, chorea, ballismus or dystonia (NMDAR antibodies), the spectrum of Stiff-person syndrome/muscle rigidity (glutamic acid decarboxylase, amphiphysin, GABA(A)-receptor-associated protein, or glycine receptor antibodies), neuromyotonia (Caspr2 antibodies), and opsoclonus--myoclonus--ataxia (unknown antigens).

SUMMARY

Neurologists should be aware that many movement disorders are immune-mediated. Recognition of these disorders is important because it may lead to the diagnosis of an occult cancer, and a substantial number of patients, mainly those with antibodies to cell-surface or synaptic proteins, respond to immunotherapy.

Late-onset asymmetric myoclonus: an emerging syndrome

BACKGROUND

Asymmetric cortical myoclonus is typically thought to be associated with either contralateral cortical structural lesions or degenerative disorders such as corticobasal degeneration when onset is in middle-aged or aged adults. This view has been challenged after a recent case series brought to light a syndrome of senile-onset, asymmetric cortical myoclonus not associated with any such identifiable disorders, thus, named "primary progressive myoclonus of aging." This is rare and no other reports have been published; hence, further such cases need to be highlighted.

CASE REPORTS

Here, we describe 3 patients with some similarities, namely, adult-onset, asymmetric myoclonus that is most likely to be cortical, with an unremarkable thorough diagnostic workup, but with younger age at onset and longer follow-up time.

CONCLUSIONS

This report expands on previous phenotypical descriptions attempting to further develop and refine this possible diagnostic entity.