Movement disorders in paraneoplastic and autoimmune disease

Anti-Ri paraneoplastic neurological syndrome presenting with bilateral cranial nerve VI palsy and jaw dystonia-a distinctive syndrome within the anti-Ri spectrum? : Case report and literature review

OBJECTIVE

Paraneoplastic neurological syndromes (PNS) are rare disorders associated with various onconeuronal antibodies. Anti-Ri antibodies (ANNA-2) are typically found in patients with opsoclonus myoclonus syndrome (OMS) and ataxia.

CASE REPORT

We present an anti-Ri antibody-positive 77-year-old woman with subacute progressive bilateral cranial nerve VI palsy, gait disturbance and jaw dystonia. MRI of the brain showed hyperintense signals on T2 bitemporal without contrast enhancement. Cerebrospinal fluid (CSF) examination exhibited mild pleocytosis of 13 cells/µl and positive oligoclonal bands. CSF was overall inconspicuous for a malignant or inflammatory etiology. Immunofluorescence analysis revealed anti-Ri antibodies in both serum and CSF. Subsequent diagnostic work up resulted in a newly diagnosed ductal carcinoma of the right breast. PNS in this case partially responded to the anti-tumor therapy.

CONCLUSION

This case shows similarities with recently published anti-Ri syndromes, which might form a distinct triad within the anti-Ri spectrum.

Chorea: An unusual manifestation of endocrine diseases

Chorea is a movement disorder involving involuntary movements of muscles of the face, neck, and limbs, usually caused by basal ganglia lesions. As an important part of the presentation of many neurological diseases, chorea is also an unusual manifestation of endocrine diseases and can be challenging to diagnose. Although the most common etiology of chorea is genetic, it is vital to identify acquired or symptomatic chorea, as these are potentially treatable conditions. This review summarizes the latest developments in various endocrine disease-related chorea, which will help clinicians to correctly identify and accurately treat it.

Paraneoplastic syndrome in neuroophthalmology

Paraneoplastic syndrome is a group of clinical symptoms that occur in the state of systemic malignant tumors. Paraneoplastic syndrome of the nervous system can affect any part of the central and peripheral nervous system and may also affect the eyes. In neuroophthalmology, paraneoplastic syndrome has a variety of manifestations that can affect both the afferent and efferent visual systems. The afferent system may involve the optic nerve, retina and uvea; the efferent system may involve eye movement, neuromuscular joints or involuntary eye movements and pupil abnormalities and may also have other neurological symptoms outside the visual system. This article discusses the clinical manifestations, pathological mechanisms, detection methods and treatment methods of paraneoplastic syndrome in neuroophthalmology. The performance of paraneoplastic syndrome is diverse, the diagnosis is difficult, and the treatment should be considered systematically. Differential diagnosis, optimal evaluation and management of these manifestations is not only the key to treatment but also a challenge.

Diagnosis and Clinical Features in Autoimmune-Mediated Movement Disorders

Movement disorders are common manifestations in autoimmune-mediated encephalitis. This group of diseases is suspected to be triggered by infection or neoplasm. Certain phenotypes correlate with specific autoantibody-related neurological disorders, such as orofacial-lingual dyskinesia with N-methyl-D-aspartate receptor encephalitis and faciobrachial dystonic seizures with leucine-rich glioma-inactivated protein 1 encephalitis. Early diagnosis and treatment, especially for autoantibodies targeting neuronal surface antigens, can improve prognosis. In contrast, the presence of autoantibodies against intracellular neuronal agents warrants screening for underlying malignancy. However, early clinical diagnosis is challenging because these diseases can be misdiagnosed. In this article, we review the distinctive clinical phenotypes, magnetic resonance imaging findings, and current treatment options for autoimmune-mediated encephalitis.

Characteristics of Movement Disorders in Patients with Autoimmune GFAP Astrocytopathy

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy (GFAP-A) is a type of autoimmune corticosteroid-responsive meningoencephalitis that occurs with or without myelitis. Movement disorders have been reported in GFAP-A patients but have not been characterized. In this study, we examined the characteristics of movement disorders in GFAP-A patients. We retrospectively reviewed clinical data from 87 consecutive patients with GFAP-A attending Gifu University Hospital in Japan. We compared the demographics, clinical features, cerebrospinal fluid characteristics, and neuroimaging findings from patients with and without movement disorders. Seventy-four patients (85%) had movement disorders, including ataxia (49%), tremor (45%), myoclonus (37%), dyskinesia (2%), opsoclonus (2%), rigidity (2%), myokymia (1%), and choreoathetosis (1%). GFAP-A patients with movement disorders were significantly older than those without. Movement disorders are therefore common in GFAP-A patients, and the main types of movement disorders observed in this population were ataxia, tremor, and myoclonus. These abnormal movements can serve as clinical features that facilitate the early diagnosis of GFAP-A. Elderly GFAP-A patients are more likely to have movement disorder complications than younger patients.

Autoimmune and Paraneoplastic Chorea: A Review of the Literature

Autoimmune chorea syndromes represent a vast array of paraneoplastic, parainfectious and idiopathic disorders. It is increasingly apparent that familiarity with these disorders is critically important, as they may be treatable or may be part of a syndrome requiring further work-up and monitoring. These disorders are mediated by an aberrant immunologic attack with resultant neuronal dysfunction, manifesting as chorea. These conditions are typically accompanied by other neurologic or systemic manifestations. In this review we outline the clinical features, epidemiologic factors, and delineate the specific antibodies associated with each of these autoimmune mediated disorders. We highlight up to date information regarding this heterogeneous group of disorders, including a discussion of parainfectious Sydenham's chorea; paraneoplastic syndromes associated with CRMP-5 (collapsin response mediated protein-5/CV2) and ANNA-1 (antineuronal nuclear antibody / Hu) antibodies, in addition to neuronal antibody-associated disorders including anti-NMDAR, LGI1 (leucine-rich glioma inactivated-1) and CASPR2 (contactin associated protein-2). We discuss the more recently described entities of IgLON5, which has evidence of both immunologic and degenerative pathophysiology, in addition to PDE-10A antibody-associated chorea. We also outline chorea secondary to systemic diseases including Systemic Lupus Erythematosus (SLE) and Primary Antiphospholipid Syndrome (PAPS). We provide a framework for diagnosis and treatment.

Seventeen-Year-Old Female With History of Depression Presented With Mania and Enuresis

A 17-year-old girl with a history of depression was referred by her psychologist to the emergency department (ED) because of concerning behavioral changes for the past 2 weeks. She was engaging in erratic behaviors, including excessive baking, handling broken glass, mixing chemicals, and swimming alone while clothed. She denied any intention to harm herself or others. She was feeling energized in the morning despite only sleeping a few hours at night. She also urinated on herself the day before her ED visit. Her examination and preliminary testing findings in the ED were largely normal. Her initial presentation was concerning for a psychiatric etiology, such as new-onset bipolar disorder given previous history of depression and recent impulsive symptoms suggestive of mania. As her clinical course evolved and urinary incontinence continued, her definitive diagnosis was made by an interdisciplinary team that included child psychiatry and pediatric neurology.

Pediatric acute disseminated encephalomyelitis associated with myelin oligodendrocyte glycoprotein antibodies

Introduction. Myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are immune-mediated inflammatory conditions of the central nervous system (CNS) with a wide clinical phenotypic variability. In order to further understand the possible phenotype of MOGAD here we report a pediatric case of acute disseminated encephalomyelitis (ADEM) associated with MOG antibodies. Case outline. A previously healthy four-month-old infant presented due to a 1-day history of fever up to 39?C and vomiting. On admission, she was encephalopathic. Repetitive and frequent stereotyped dystonic movements were observed. Cerebrospinal fluid (CSF) examination showed pleocytosis (lymphocytes were predominant) and proteinorachy. CSF culture and virology results were negative. Serum MOG antibodies were positive. A prolonged electroencephalography (EEG) showed continuous high-amplitude slow rhythmic activity with captured stereotyped movement. Epileptic discharges were not seen. Although magnetic resonance imaging showed signs of acute demyelinating encephalomyelitis, our patient did not have seizures, despite neuroimaging findings of cortical lesions. Acute treatment with the corticosteroids led to excellent response with full recovery. Conclusion. This case emphasizes the inclusion of the MOG antibodies testing in the initial work-up in children presenting with acute encephalopathy associated with demyelinating or encephalitic abnormalities on brain and/or spinal magnetic resonance imaging even when the clinical phenotype is unusual. The prompt diagnosis of MOGAD is relevant for accurate disease monitoring and treatment strategies.

DOPA-Responsive Tremor Associated With Gammopathy: A Case Report and Literature Review

Tremors have been well-described in association with monoclonal gammopathy. We report a case of a patient with asymmetric hands tremor who responded well to levodopa-carbidopa treatment. Further workup showed an underlying gammopathy. To our knowledge, this is one of the rarest case reports of successful treatment of gammopathy-related tremors with levodopa-carbidopa. The patient was a 75-year-old male who presented to the neurology clinic for a one-year history of worsening tremors in bilateral upper extremities. A review of systems was only remarkable for mild numbness and tingling in his feet. His neurological examination was remarkable for asymmetric right more than left (R > L) resting and kinetic tremor in both upper extremities associated with mild rigidity and bradykinesia in right upper extremity and decreased bilateral ankle jerks. With the primary diagnosis of Parkinson’s disease, he was started on levodopa-carbidopa and a neuropathy workup was requested. His follow-up visit after three months was remarkable for significant improvement of his tremors with carbidopa-levodopa. However, his blood work was consistent with a significant increase in lambda light chain levels and the presence of an M spike in serum protein electrophoresis. Based on the presentation and clinical workup, he was finally found to have both multiple myeloma and ​Waldenstrom’s macroglobulinemia. Underlying malignancy was treated with chemotherapy and immunotherapy. Levodopa-carbidopa was discontinued after three months of chemotherapy and his tremor did not recur in one year of follow-up. Gammopathy is one of the well-known causes of tremors in the adult population. It can cause both resting and kinetic tremors in the upper extremities. It is supposed that peripheral neuropathy associated with gammopathy is the main underlying cause of tremors in these groups of patients. However, central causes are also suggested. In this case, we are led to conclude that our patient’s tremor was centrally mediated since it responded well to dopamine replacement therapy. However, further study is needed to elucidate the role of dopamine depletion in the pathogenesis of tremors associated with gammopathies.

N-methyl-D-aspartate receptor antibody and the choroid plexus in schizophrenia patients with tardive dyskinesia

BACKGROUND

Immune disturbance has been postulated to be one of the mechanisms underlying the pathogenesis of tardive dyskinesia (TD). Recently, the role of autoimmune abnormality in TD has been increasingly recognized. Autoantibodies against neuronal N-methyl-D-aspartate receptor (NMDAR) may be cross-reactive in the brain in neuropsychiatric disorders, and the choroid plexus (CP) is a crucial immune barrier in the central nervous system (CNS). We supposed that NMDAR antibodies might underlie the pathophysiological process of TD through the mediation of CP.

METHODS

Serum NMDAR antibody levels were assessed by enzyme-linked immunosorbent assay, CP and ventricle volumes were assessed by magnetic resonance imaging in schizophrenia patients with TD (n = 61), without TD (NTD, n = 61), and in healthy controls (n = 74). Psychopathology and TD severity were assessed by the Positive and Negative Syndrome Scale and Abnormal Involuntary Movement Scale (AIMS).

RESULTS

NMDAR antibody levels were significantly higher, CP volumes were larger in the TD group than in the NTD group (p = 0.022; p = 0.019, respectively). In the TD group, higher NMDAR antibody level was correlated with larger CP volume (β = 0.406, p = 0.002). An elevated NMDAR antibody level and enlarged CP volume were correlated with orofacial AIMS score (β = 0.331, p = 0.011; β = 0.459, p = 3.34 × 10^-4, respectively). In a mediation model, the effect of NMDAR antibody level on the orofacial AIMS score was mediated by the CP volume (indirect effect: β = 0.08, 95% confidence interval = 0.002-0.225; direct effect: β = 0.14, p = 0.154).

CONCLUSIONS

Our findings highlight a potential NMDAR antibody-associated mechanism in orofacial TD, which may be mediated by increased CP volume.

Update in Autoimmune Movement Disorders: Newly Described Antigen Targets in Autoimmune and Paraneoplastic Cerebellar Ataxia

Movement disorders are a common feature of many antibody-associated neurological disorders. In fact, cerebellar ataxia is one of the most common manifestations of autoimmune neurological diseases. Some of the first autoantibodies identified against antigen targets include anti-neuronal nuclear antibody type 1 (ANNA-1 or anti-Hu) and Purkinje cell cytoplasmic antibody (PCA-1) also known as anti-Yo have been identified in paraneoplastic cerebellar degeneration. Historically these antibodies have been associated with an underlying malignancy; however, recently discovered antibodies can occur in the absence of cancer as well, resulting in the clinical syndrome of autoimmune cerebellar ataxia. The pace of discovery of new antibodies associated with autoimmune or paraneoplastic cerebellar ataxia has increased rapidly over the last few years, and pathogenesis and potential treatment options remains to be explored. Here we will review the literature on recently discovered antibodies associated with autoimmune and paraneoplastic cerebellar ataxia including adaptor protein-3B2 (AP3B2); inositol 1,4,5-trisphophate receptor type 1 (ITPR1); tripartite motif-containing (TRIM) proteins 9, 67, and 46; neurochondrin; neuronal intermediate filament light chain (NIF); septin 5; metabotropic glutamate receptor 2 (mGluR2); seizure-related 6 homolog like 2 (SEZ6L2) and homer-3 antibodies. We will review their clinical characteristics, imaging and CSF findings and treatment response. In addition, we will discuss two clinical case examples of autoimmune cerebellar ataxia.

Opsoclonus-myoclonus syndrome with severe clinical course and beneficial outcome: A case report

RATIONALE

Opsoclonus-myoclonus syndrome (OMS) is a rare immune-mediated movement disorder, mostly of paraneoplastic or idiopathic origin. The disease usually has an acute onset, serious course and leads rapidly to disability in adult patients. To the best of our knowledge, this is the fourth presented case of OMS with a severe course and complete reversibility of neurological symptoms in a pregnant woman. This report includes videos and a literature review.

PATIENT CONCERNS

A 30-year-old woman in the 12th week of pregnancy developed severe nausea and vomiting, after several days balance and gait disorders appeared. On admission to hospital, neurological examination revealed opsoclonus, dysarthria, myoclonic jerks with ataxia of the trunk and limbs with inability to sit, stand or walk.

DIAGNOSIS

Well-known causes of OMS were excluded. Although in our patient the idiopathic origin of the disorder was taken under consideration, diagnosis of opsoclonus-myoclonus related to the pregnancy was highly likely.

INTERVENTIONS

After administration of steroids and benzodiazepines the patient improved.

OUTCOMES

In the 6th month of pregnancy, after termination of immunotherapy, she recovered completely and was able to sit, stand and walk independently. In the 39th week of pregnancy, she delivered a healthy child.

LESSONS

We confirm that understanding of clinical symptoms and rare causes of OMS contributes to early diagnosis and therapy, which ensures an optimal outcome. One probable cause of OMS could be a physiological change to immune system regulation during pregnancy. The relationship between OMS and pregnancy remains uncertain and needs further investigation.

Opsoclonus-myoclonus syndrome associated with anti Kelch-like protein-11 antibodies in a young female patient without cancer

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder. The pathogenesis is thought to be immune-mediated. In adults, it may be idiopathic or paraneoplastic in origin. However, most cases of paraneoplastic OMS in adults are not associated with well-characterized antibodies, except for a small subgroup who have anti-Ri antibodies. Herein, we provide the first detailed description of a case of OMS associated with a Kelch-like protein-11 antibody, a newly discovered biomarker for paraneoplastic neurological syndromes associated with germ-cell tumors. This was a young female patient in whom no tumor was ever detected and who had an excellent response to rituximab.

Neuropsychiatric involvement in systemic lupus erythematosus: A review

The neuropsychiatric involvement in systemic lupus erythematosus (NPSLE) is a challenge for clinicians, both at a diagnostic and therapeutic level. Although in 1999 the American College of Rheumatology (ACR) proposed a set of definitions for 19 NPSLE syndromes, with the intention of homogenizing the terminology for research purposes and clinical practice, the prevalence of NPSLE varies widely according to different series and is estimated to be between 37 and 95%. This is due to multiple factors such as the unalike definitions used, the diverse design of the studies, type of population, race, type and severity of symptoms, and follow-up of the different cohorts of patients with SLE. In recent years, some authors have tried excluding minor neuropsychiatric manifestations in order to try to reduce this wide variation in the prevalence of NPSLE since they are very prevalent in the general population; others authors have developed various models for the attribution of neuropsychiatric events to SLE that can assist clinicians in this diagnostic process, and finally, some authors developed and validated in 2014 a new algorithm based on the definitions of the ACR that includes the evaluation of the patient's lupus activity together with imaging techniques and the analysis of cerebrospinal fluid (CSF), with the aim of trying to differentiate the true neuropsychiatric manifestations attributable to SLE. In 2010, the European League Against Rheumatism (EULAR) developed recommendations for the management of NPSLE. We found abundant literature published later where, in addition to the recommendations for the management of the 19 NPSLE syndromes defined by the ACR, additional recommendations are given for other neurological and/or psychiatric syndromes, conditions, and complications that have been associated to SLE in recent years. We review below the diagnostic and therapeutic management of the different entities.

Clinical manifestations in patients with antiphospholipid antibodies: Beyond thrombosis and pregnancy loss

The clinical spectrum of the antiphospholipid syndrome (APS) encompasses additional manifestations other than thrombosis and pregnancy morbidity, which may potentially affect every organ and system. The pathophysiology of APS indeed cannot be explained exclusively by a prothrombotic state and the "extra-criteria" manifestations of the syndrome should be attributed to other mechanisms, such as inflammation, complement and platelet activation. In this case-series, we report patients with uncommon clinical APS presentations, to highlight relevant peculiarities of the syndrome, potentially paving the way for a further update of clinical as well as laboratory manifestations of this complex immunological condition.

Paraneoplastic Disorders of the Nervous System

PURPOSE OF REVIEW

This article reviews paraneoplastic neurologic disorders and includes an overview of the diagnostic approach, the role of autoantibody testing, the pathophysiology of these disorders, and treatment approaches. This article also provides an overview of the emerging clinical scenarios in which paraneoplastic and autoimmune neurologic disorders may occur.

RECENT FINDINGS

The number of autoantibodies associated with paraneoplastic neurologic disorders has rapidly expanded over the past 2 decades. These discoveries have improved our ability to diagnose patients with these disorders and have provided insight into their pathogenesis. It is now recognized that these antibodies can be broadly divided into two major categories based on the location of the target antigen: intracellular and cell surface/synaptic. Antibodies to intracellular antigens are almost always accompanied by cancer, respond less well to immunotherapy, and have an unfavorable outcome. In contrast, antibodies to cell surface or synaptic targets are less often accompanied by cancer, generally respond well to immunotherapy, and have a good prognosis. Paraneoplastic and autoimmune neurologic disorders are now being recognized in novel settings, including their occurrence as an immune-related adverse effect of immune checkpoint inhibitor treatment for cancer.

SUMMARY

This article discusses when to suspect a paraneoplastic neurologic syndrome, the diagnostic utility and pitfalls of neural autoantibody testing, how to best detect the underlying tumor, and the treatment approach that involves combinations of antineoplastic treatments, immunosuppressants, and supportive/symptomatic treatments.

Anti-Ma-associated paraneoplastic cerebellar degeneration in a patient with nodular lymphocyte-predominant Hodgkin lymphoma: a case report

BACKGROUND

Paraneoplastic cerebellar degeneration (PCD) is a devastating paraneoplastic syndrome that occasionally occurs in patients with Hodgkin lymphoma (HL). Anti-Ma2 is a well-characterized onconeuronal antibody and one of the causes of PCD. There has been only one previous report of anti-Ma2-associated paraneoplastic syndrome as a complication of HL. Here we present a rare case of anti-Ma2-associated PCD in a patient with nodular lymphocyte-predominant HL (NLPHL).

CASE PRESENTATION

A 77-year-old man with a 3-month history of gait instability and a 2-month history of oscillopsia was referred to our hospital for further investigation. On examination, his cognition was normal. He had nystagmus in all directions of gaze; specifically, he had horizontal and rotatory nystagmus in the primary position, downbeat nystagmus after right, left, and up gaze, and upbeat nystagmus after down gaze. Although his limb ataxia was mild, his trunk ataxia was so pronounced that he was unable to walk without support. We strongly suspected paraneoplastic syndrome and tested for neuronal autoantibodies. The anti-Ma2 antibody was strongly positive in the blood and cerebrospinal fluid but other antineuronal autoantibodies were negative. Computed tomography showed an enlarged lymph node in the right axilla but no masses. Biopsy confirmed a diagnosis of NLPHL. The NLPHL cells stained with anti-Ma-2 antibody in the cytoplasm, suggesting these abnormal cells contained protein that was cross-reactive with Ma-2.

CONCLUSIONS

To the best of our knowledge, this is the first case of anti-Ma2-associated PCD in a patient with NLPHL that was confirmed using immunostaining of the lymph node tissue with anti-Ma2 antibody. Our case confirms an association between anti-Ma2-associated PCD and NLPHL.

Neuroinflammation

Neuroinflammation is implicated in contributing to a variety of neurologic and somatic illnesses including Alzheimer's disease (AD), Parkinson's disease (PD), and depression. In this chapter, we focus on the role of neuroinflammation in mediating these three illnesses and portray interactions between the immune response and the central nervous system in the context of sex differences in disease progression. The majority of this chapter is supported by clinical findings; however, we occasionally utilize preclinical models where human studies are currently lacking. We begin by detailing the pathology of neuroinflammation, distinguishing between acute and chronic inflammation, and examining contributions from the innate and adaptive immune systems. Next, we summarize potential mechanisms of immune cell mediators including interleukin-1 beta (IL-1β), tumor necrosis factor α, and IL-6 in AD, PD, and depression development. Given the strong sex bias seen in these illnesses, we additionally examine the role of sex hormones, e.g., estrogen and testosterone in mediating neuroinflammation at the cellular level. Systematically, we detail how sex hormones may contribute to distinct behavioral and clinical symptoms and prognosis between males and females with AD, PD, or depression. Finally, we highlight the possible role of exercise in alleviating neuroinflammation, as well as evidence that antiinflammatory drug therapies improve cognitive symptoms observed in brain-related diseases.

Neurological Complications in Patients with Systemic Lupus Erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is commonly associated with neurological manifestations. Rapid recognition and treatment of these complications may improve outcomes. In this article, we review the neurological conditions associated with SLE, their diagnosis and management strategies.

RECENT FINDINGS

Recent meta-analysis showed that patients with neuropsychiatric manifestations of SLE were more likely to have positive antiphospholipid, antiribosomal P, and antineuronal antibodies. Another meta-analysis showed an association between SLE and antiphospholipid antibodies with cognitive impairment. Two large retrospective studies have shown that the peripheral nervous system is commonly involved in SLE frequently alongside the central nervous system. Neurological manifestations occur in most of SLE patients. Antiphospholipid antibodies are common in patients with SLE and increase the odds of neurological complications. Management typically involved a combination of treatments directed toward the neurological complication and therapies directed toward SLE itself. The efficacy of these treatment protocols, however, has not been rigorously studied and deserves further investigation.

The use, misuse and abuse of paraneoplastic panels in neurological disorders. A retrospective study

OBJECTIVES

The field of paraneoplastic neurological syndromes PNS has grown exponentially with the increased identification of associated antibodies. Testing for these antibodies is commonly done in "panels" to increase sensitivity, and these panels have become a routine test on CSF samples obtained for a variety of clinical indications. Excessive testing has raised concerns about the correct utilization of these panels. Our study investigates the appropriateness of use of paraneoplastic panel in an academic, tertiary-care medical center.

PATIENTS AND METHODS

We retrospectively reviewed charts of all patients who had autoimmune paraneoplastic panel testing in one year period. We collected date on demographics, clinical presentations and ancillary testings on all reviewed charts. Then, we devised an algorithm based on available data to define cases where testing had been unnecessary or likely unnecessary.

RESULTS

We collected 60 cases that had undergone autoimmune paraneoplastic testing serum and/or CSF. Testing was unnecessary in 10 cases (16%), in which presentations had a definitive confirmatory tests. Testing was unlikely necessary in 11 cases (18%), in which all ancillary testing was normal in 6 cases, and presentation was not compatible with any known syndrome in 5 cases. Collectively, paraneoplastic panel testing was of extremely low yield on more than one third of the cases where where w testing was done.

CONCLUSION

Our results adds to the growing concerns about the utilization of paraneoplastic panels, and the urgent need for enhanced screening and establishing a framework that can guide neurologists on when testing can have a sufficient yield to warrant it. Such framework should be built using diagnostic algorithms based on risk, clinical manifestations, characterization of autoantibodies and their associations.

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.

The role of 18F-FDG PET/CT in management of paraneoplastic limbic encephalitis combined with small cell lung cancer: A case report

RATIONALE

Limbic encephalitis is one of the most common paraneoplastic neurological disorders (PND). The role of brain Fluorine-18-fluorodeoxyglucose position emission tomography/computed tomography (CT) in paraneoplastic limbic encephalitis (PLE) and of the whole body 18F-FDG PET/CT in this setting, remains still not well defined.

PATIENT CONCERNS

We report a case of a patient with chronic inflammatory rheumatism, psoriasis and Hashimoto thyroiditis and subsequent appearance of static and dynamic ataxia and episodic memory deficit who was diagnosed as PLE combined with small cell lung cancer (SCLC).

DIAGNOSES

The diagnosis of SCLC was made with EBUS-TBNA of a mediastinal lymph node.

INTERVENTIONS

Whole-body 18F-FDG PET/CT was performed for the initial staging of SCLC, in the planning of radiotherapy treatment, to evaluate therapeutic response and in the follow-up. A dedicated brain scan was included to the same PET session. Whole-body contrast enhanced computed tomography (CT) and contrast enhanced whole-brain MRI were also performed.

OUTCOMES

She was administered neoadjuvant chemioterapy with Cisplatin and Etoposide with concomitant radiotherapy treatment. Whole body 18F-FDG PET/CT showed a complete metabolic response already after 3 cycles of chemioterapy. Brain functional study showed a metabolic pattern characterized by the migration of hypermetabolism in the bilateral hippocampal areas during the therapeutic treatment, which correlated with the persistence of clinical symptoms.

LESSONS

In the era of personalized medicine and targeted therapy, this case highlights the importance of the 18F-FDG PET/CT study as an accurate tool to identify PLE and to guide the diagnostic work-up of the underlying tumor. Considering that most of these are 18F-FDG avid tumors and that the 18F-FDG PET/CT scan is often added to the diagnostic work-up when screening patients for malignancy, this functional imaging can play a decisive role.

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.

Delayed onset of severe chronic pain in CASPR2 autoantibody-associated Morvan syndrome in a former UK swine abattoir worker

Introduction

Autoantibody-mediated autoimmunity directed against targets within the voltage-gated potassium channel complex (VGKCC autoantibodies) has been implicated in causing neuropathic pain.

Methods

We report the case of a 76-year-old, United Kingdom male who was diagnosed with contactin-associated protein 2 (CASPR2) autoantibody-associated Morvan syndrome, a rare neurological condition.

Results

He had previously worked in a swine abattoir; exposure to aerosol within swine abattoirs has been reported to elicit an immune response resulting in the production of these autoantibodies; however, unusually, his manifestations emerged with several years' latency. Although this patient's Morvan syndrome-associated seizures were well-controlled with antiepileptic drugs, his neuropathic pain and painful muscle fasciculations did not respond to pharmacological interventions. He refused pain management program treatment, but high-dose immunoglobulin treatment or treatment with rituximab, reported to be sometimes effective in this group, was not initiated because of concerns regarding his general frailty.

Discussion and Conclusion

This case highlights issues around the identification and treatment of rare patients with chronic pain who have voltage-gated potassium channel complex autoantibodies; it also emphasizes the possibility that former swine abattoir workers might be at risk of developing neuropathic pain even years after their vocational exposure.

Paediatric MOG antibody-associated ADEM with complex movement disorder: A case report

Myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) are a well-recognized cause of acquired demyelinating syndromes in both adult and children. Despite basal ganglia involvement on imaging, movement disorder is not a cardinal feature. We describe a 2-year-9-month-old girl who presented with severe encephalopathy with aphasia, seizures and a complex movement disorder with dystonic posturing and tonic eye deviation. Neuroimaging revealed subtle asymmetrical predominantly white matter signal changes. MOG-Abs were positive in the serum. Other known pathogenic autoantibodies including N-methyl-D-aspartate receptor antibodies (NMDAR-Abs) were negative. The patient made a complete recovery following 2-week corticosteroid treatment. This case highlights the need for MOG-Ab testing in children with suspected autoimmune encephalopathies.

Autoimmune Movement Disorders in Children

Over the last decade, there have been significant advances in the identification, characterization, and treatment of autoimmune neurologic disorders in children. Many of these diseases include a typical movement disorder that can be a powerful aid to diagnosis. Frequently, movement disorders in autoimmune conditions are the sole or among a few presenting symptoms, allowing for earlier diagnosis of an underlying malignancy or systemic autoimmune disease. Given that early detection and treatment with immunotherapy may confer improved outcomes, recognizing these patterns of abnormal movements is essential for child neurologists. The purpose of this review is to summarize the clinical characteristics, diagnosis, and treatment of movement disorders that occur in pediatric autoimmune disorders.

Peripheral complement interactions with amyloid β peptide in Alzheimer's disease: 2. Relationship to amyloid β immunotherapy

INTRODUCTION

Our previous studies have shown that amyloid β peptide (Aβ) is subject to complement-mediated clearance from the peripheral circulation, and that this mechanism is deficient in Alzheimer's disease. The mechanism should be enhanced by Aβ antibodies that form immune complexes (ICs) with Aβ, and therefore may be relevant to current Aβ immunotherapy approaches.

METHODS

Multidisciplinary methods were employed to demonstrate enhanced complement-mediated capture of Aβ antibody immune complexes compared with Aβ alone in both erythrocytes and THP1-derived macrophages.

RESULTS

Aβ antibodies dramatically increased complement activation and opsonization of Aβ, followed by commensurately enhanced Aβ capture by human erythrocytes and macrophages. These in vitro findings were consistent with enhanced peripheral clearance of intravenously administered Aβ antibody immune complexes in nonhuman primates.

DISCUSSION

Together with our previous results, showing significant Alzheimer's disease deficits in peripheral Aβ clearance, the present findings strongly suggest that peripheral mechanisms should not be ignored as contributors to the effects of Aβ immunotherapy.

Autoantibody-Associated Movement Disorders in Children: Proven and Proposed

Movement disorders secondary to autoantibodies in children represent a rapidly expanding group of conditions. Once considered to be limited to poststreptococcal Sydenham's chorea or rare cases of childhood systemic lupus erythematosus, a variety of antibody-related movement abnormalities are now seen as part of noninfectious autoimmune encephalitis or within an expanding list of postinfectious disorders. In this article, several proposed autoantibody-mediated movement disorders in children are reviewed. In each one, there is a hypothesized antibody biomarker that is believed to be pathogenic and cause the clinical symptoms. As will be discussed, in some, such as anti-NMDA receptor encephalitis, the strength of supporting evidence is strong. In others, antibodies have been identified, but their role as the pathophysiological mechanism remains undetermined. Lastly, there are proposed disorders, such as PANDAS, that are controversial on both a clinical and autoimmune basis.

Anti-Yo, chorea and hemiballismus: A case report

68-year-old female presented with involuntary movements. MRI was normal. Cerebrospinal fluid analysis was normal. whole body CT and biopsy confirmed diagnosis of metastatic adenocarnimoa. The autoimmune panel was positive for anti-Yo antibodies.

Unilateral predominance of abnormal movements: A characteristic feature of the pediatric anti-NMDA receptor encephalitis?

Anti-NMDA receptor encephalitis is a treatable autoimmune disease characterized by cognitive, motor and psychiatric features that primarily affects young adults and children. We present a case of a 7-year-old boy with asymmetrical (mainly right hemibody) and abnormal polymorphic movements without concomitant scalpictal EEG changes but had background slowing predominating over the left hemisphere. This report illustrates previous descriptions of asymmetric presentation of abnormal movements in pediatric anti-NMDA receptor encephalitis and emphasizes the importance of video-EEG interpreted within the overall clinical context, to differentiate epileptic from non-epileptic abnormal movements in patients with autoimmune encephalitis.

Paraneoplastic autoantibody panels: sensitivity and specificity, a retrospective cohort

BACKGROUND

Experts in the autoimmune paraneoplastic field recommend autoantibody testing as "panels" to improve the poor sensitivity of individual autoantibodies in detecting paraneoplastic neurological syndromes (PNS). The sensitivity of those panels was not reported to date in a fashion devoid of incorporation bias. We aimed to assess the collective sensitivity and specificity of one of the commonly used panels in detecting PNS.

METHODS

A single-centered retrospective cohort of all patients tested for paraneoplastic evaluation panel (PAVAL; test ID: 83380) over one year for the suspicion of PNS. Case adjudication was based on newly proposed diagnostic criteria in line with previously published literature, but modified to exclude serological status to avoid incorporation bias. Measures of diagnostic accuracy were subsequently calculated. Cases that failed to show association with malignancy within the follow-up time studied, reflecting a possibly pure autoimmune process was considered paraneoplastic-like syndromes.

RESULTS

Out of 321 patients tested, 51 patients tested positive. Thirty-two patients met diagnostic criteria for paraneoplastic/paraneoplastic-like syndromes. The calculated collective sensitivity was 34% (95% CI: 17-53), specificity was 86% (95% CI: 81-90), Youden's index 0.2 and a positive clinical utility index 0.07 suggesting poor utility for case-detection.

CONCLUSION

This is the first reported diagnostic accuracy measures of paraneoplastic panels without incorporation bias. Despite recommended panel testing to improve detection of PNS, sensitivity remains low with poor utility for case-detection. The high-calculated specificity suggests a possible role in confirming the condition in difficult cases suspicious for PNS, when enough supportive evidence is lacking on ancillary testing.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis in Children and Adolescents

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease that is becoming increasingly recognized in the pediatric population. It may be the most common cause of treatable autoimmune encephalitis. The majority of cases of anti-NMDAR encephalitis are idiopathic in etiology, but a significant minority can be attributed to a paraneoplastic origin. Children with anti-NMDAR encephalitis initially present with a prodrome of neuropsychiatric symptoms, often with orofacial dyskinesias followed by progressively worsening seizures, agitation, and spasticity, which may result in severe neurologic deficits and even death. Definitive diagnosis requires detection of NMDAR antibodies in the cerebrospinal fluid. Optimal outcomes are associated with prompt removal of the tumor in paraneoplastic cases, as well as aggressive immunosuppressive therapy. Early detection is essential for increasing the chances for a good outcome. Close follow-up is required to screen for relapse and later onset tumor presentation. The nurse practitioner plays a major role in the research, screening, diagnosis, treatment, follow-up, and rehabilitation of a child or adolescent with anti-NMDAR encephalitis.

Acute movement disorders in the medical setting

Objective Psychosomatic medicine psychiatrists are often tasked with the evaluation and treatment of complex neuropsychiatric states which may be motoric in phenotype. Little energy has been dedicated to understanding acute movement disorders in the hospital environment. Method Recognizing the importance of frontal-subcortical (corticostriatothalamocortical) circuitry and basal ganglia structures, we present a case series of acute movement disorder phenotypes resulting from underlying medical conditions, commonly-administered medications, or the interaction of both. We organize these scenarios into neurodegenerative disorders, primary psychiatric disorders, neuroinflammation, and polypharmacy, demonstrating a clinical example of each followed by background references on a variety of clinical states and medications contributing to acute movement disorders. In addition, we offer visual illustration of implicated neurocircuitry as well as proposed neurotransmitter imbalances involving glutamate, gamma aminobutyric acid, and dopamine. Furthermore, we review the various clinical syndromes and medications involved in the development of acute movement disorders. Results Acute movement disorder's involve complex interactions between frontal-subcortical circuits and acute events. Given the complexity of interactions, psychopharmacological considerations become critical, as some treatments may alleviate acute movement disorders while others will exacerbate them. Conclusion Integrating underlying medical conditions and acutely administered (or discontinued) pharmacological agents offers an interactional, neuromedical approach to acute movement disorders that is critical to the work of psychosomatic medicine.

Diminution of falsely elevated tumour markers following immunosuppression for systemic lupus erythematosus with neurological involvement

We describe the case of a patient with a long history of undifferentiated connective tissue disease who developed headache, ataxia and orofacial dyskinesia attributed to a diagnosis of systemic lupus erythematosus (SLE). Gross elevation of the concentration of several plasma tumour markers (CEA, CA-125, CA19-9, CA15-3) was detected in the absence of malignancy. These markers fell significantly within a month of starting immunosuppressive therapy alongside clinical improvement. Caution should be taken in the interpretation of plasma tumour markers in patients with connective tissue disease.

Spinal-generated movement disorders: a clinical review

Spinal-generated movement disorders (SGMDs) include spinal segmental myoclonus, propriospinal myoclonus, orthostatic tremor, secondary paroxysmal dyskinesias, stiff person syndrome and its variants, movements in brain death, and painful legs-moving toes syndrome. In this paper, we review the relevant anatomy and physiology of SGMDs, characterize and demonstrate their clinical features, and present a practical approach to the diagnosis and management of these unusual disorders.

Antibodies to dendritic neuronal surface antigens in opsoclonus myoclonus ataxia syndrome

Opsoclonus myoclonus ataxia syndrome (OMAS) is an autoimmune disorder characterized by rapid, random, conjugate eye movements (opsoclonus), myoclonus, and ataxia. Given these symptoms, autoantibodies targeting the cerebellum or brainstem could mediate the disease or be markers of autoimmunity. In a subset of patients with OMAS, we identified such autoantibodies, which bind to non-synaptic puncta on the surface of live cultured cerebellar and brainstem neuronal dendrites. These findings implicate autoimmunity to a neuronal surface antigen in the pathophysiology of OMAS. Identification of the targeted antigen(s) could elucidate the mechanisms underlying OMAS and provide a biomarker for diagnosis and response to therapy.

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.

Human-derived natural antibodies: biomarkers and potential therapeutics

The immune system generates antibodies and antigen-specific T-cells as basic elements of the immune networks that differentiate self from non-self in a finely tuned manner. The antigen-specific nature of immune responses ensures that normal immune activation contains non-self when tolerating self. Here we review the B-1 subset of lymphocytes which produce self-reactive antibodies. By analyzing the IgM class of natural antibodies that recognize antigens from the nervous system, we emphasize that natural antibodies are biomarkers of how the immune system monitors the host. The immune response activated against self can be detrimental when triggered in an autoimmune genetic background. In contrast, tuning immune activity with natural antibodies is a potential therapeutic strategy.

Aggressive course in encephalitis with opsoclonus, ataxia, chorea, and seizures: the first pediatric case of γ-aminobutyric acid type B receptor autoimmunity

IMPORTANCE

Autoantibodies to the γ-aminobutyric acid type B (GABAB) receptor have recently been identified as a cause of autoimmune encephalitis. Most patients with GABAB encephalitis have presented with limbic encephalitis. About half of the cases reported have been paraneoplastic in origin, with the majority of tumors representing small cell lung cancer.

OBSERVATIONS

We describe a 3-year-old boy who presented with a mixed movement disorder (opsoclonus, ataxia, and chorea) as well as seizures refractory to treatment. His seizures required continuous pentobarbital sodium infusion to be controlled. Despite treatment with intravenous corticosteroids and immunoglobulins, the patient ultimately died of overwhelming sepsis.

CONCLUSIONS AND RELEVANCE

To our knowledge, this report represents the first pediatric case of GABAB-associated encephalitis. Our patient presented with encephalopathy, refractory seizures, and a mixed movement disorder rather than limbic encephalitis. γ-Aminobutyric acid type B receptor autoimmunity deserves consideration in pediatric patients presenting with encephalitis. Immune-mediated encephalitis with autoantibodies directed against synaptic proteins has become an important component of the differential diagnosis of patients with encephalitis. Current estimates suggest that a substantial proportion of patients once suspected to have viral encephalitis in fact have an autoimmune etiology for their symptoms.1 Additional autoantigen targets continue to be identified, and the phenotypic spectrum associated with autoimmune encephalitis continues to expand. We describe a 3-year-old patient who presented with acute-onset confusion, opsoclonus, chorea, and intractable seizures. Neuroimaging disclosed involvement of the brainstem, basal ganglia, and hippocampi. γ-Aminobutyric acid type B (GABAB) receptor autoantibodies were identified in the serum and cerebrospinal fluid (CSF). Despite immunomodulating therapy, the patient died of overwhelming sepsis. To our knowledge, this is the first description of a pediatric patient with GABAB receptor autoantibodies. The presence of opsoclonus, ataxia, and chorea expands the clinical phenotype and indicates that GABAB receptor autoimmunity should be considered in cases of pediatric encephalitis

Reply to: Hemichorea Associated with CASPR2 Antibody

This letter was written in reply to this letter to the editor: Vynogradova I, Savitski V, Heckmann JG. Hemichorea associated with CASPR2 antibody. Tremor Other Hyperkinet Mov. 2014; 4. doi: 10.7916/D8VM49C5. The above letter to the editor was written in response to this article: Ramdhani RA, Frucht SJ. Isolated Chorea Associated with LGI1 Antibody. Tremor Other Hyperkinet Mov. 2014; 4. doi: 10.7916/D8MG7MFC.

Hemichorea Associated with CASPR2 Antibody

This letter was written in response to: Ramdhani RA, Frucht SJ. Isolated chorea associated with LGI1 antibody. Tremor Other Hyperkinet Mov. 2014; 4. doi: 10.7916/D8MG7MFC.

Paraneoplastic neurological syndromes

Paraneoplastic neurological syndromes are immune-mediated erroneous attacks on the central or peripheral nervous systems, or both, directed originally against the tumour itself. They have been known for more than 40 years, but recently the discovery of new subgroups of paraneoplastic encephalitis syndromes with a remarkably good response to immune therapy has ignited new clinical and scientific interest. Knowledge of these subgroups and their associated autoantibodies is important in therapeutic decision-making. However, the abundance of new autoantibodies and syndromes can be confusing. This review paper summarizes current knowledge and new developments in the field of paraneoplastic neurological syndromes, their classification, pathophysiology and treatment.