Stiff person syndrome (SPS) complicated by respiratory failure: successful treatment with rituximab

An update on malignant tumor-related stiff person syndrome spectrum disorders: clinical mechanism, treatment, and outcomes

Stiff person syndrome (SPS) is a rare central nervous system disorder associated with malignancies. In this review, we retrieved information from PubMed, up until August 2023, using various search terms and their combinations, including SPS, stiff person syndrome spectrum disorders (SPSSDs), paraneoplastic, cancer, and malignant tumor. Data from peer-reviewed journals printed in English were organized to explain the possible relationships between different carcinomas and SPSSD subtypes, as well as related autoantigens. From literature searching, it was revealed that breast cancer was the most prevalent carcinoma linked to SPSSDs, followed by lung cancer and lymphoma. Furthermore, classic SPS was the most common SPSSD subtype, followed by stiff limb syndrome and progressive encephalomyelitis with rigidity and myoclonus. GAD65 was the most common autoantigen in patients with cancer and SPSSDs, followed by amphiphysin and GlyR. Patients with cancer subtypes might have multiple SPSSD subtypes, and conversely, patients with SPSSD subtypes might have multiple carcinoma subtypes. The first aim of this review was to highlight the complex nature of the relationships among cancers, autoantigens, and SPSSDs as new information in this field continues to be generated globally. The adoption of an open-minded approach to updating information on new cancer subtypes, autoantigens, and SPSSDs is recommended to renew our database. The second aim of this review was to discuss SPS animal models, which will help us to understand the mechanisms underlying the pathogenesis of SPS. In future, elucidating the relationship among cancers, autoantigens, and SPSSDs is critical for the early prediction of cancer and discovery of new therapeutic modalities.

Psychiatric Symptoms in Stiff-Person Syndrome: A Systematic Review and a Report of Two Cases

BACKGROUND

The clinical spectrum of stiff-person syndrome (SPS) encompasses a wide range of signs including psychiatric symptoms (PS).

OBJECTIVE

Our objective was to provide an overview of the spectrum of PS in SPS through a systematic literature search and 2 illustrative case reports.

METHODS

We reported 2 anti-glutamic acid decarboxylase-positive SPS cases that presented with phobic disorder, and we performed a systematic review by following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles published in PubMed, MEDLINE on Ovid, Embase, and via a manual search before October 20, 2020, were selected by 2 independent reviewers. Original studies, case reports, editorials, commentaries, and letters to the editor reporting cases of SPS with PS were all included. Conference abstracts, reviews and book chapters, unavailable articles, and those not reporting SPS cases or PS were excluded. Quantitative summary data were calculated.

RESULTS

In addition to our 2 cases, we identified 237 cases of SPS with PS from 74 additional included publications totaling 239 patients. Anxiety (56%) and depression (45%) were the most common PS in SPS. Mean diagnostic delay was 4.7 years. Among the 3 SPS phenotypes, the classic form was predominant (77%), followed by stiff-limb syndrome (13%) and progressive encephalomyelitis with rigidity and myoclonus (10%). The most frequent etiology of SPS with PS was autoimmune (90%), followed by cryptogenic (7%) and paraneoplastic forms (7%). These patients were mainly treated with immune-mediated therapies and GABAergic drugs.

CONCLUSIONS

Our review revealed that the most common PS of SPS are anxiety and depression occurring mostly in autoimmune and classic forms, allowing a clearer understanding of this entity, which may lead to earlier diagnosis and better outcome.

A Rare Case of Stiff Person Syndrome With Pulmonary Complications

Stiff person syndrome (SPS) is a specific neurological condition, as it's both rare and unique. SPS is distinguished by muscle rigidity that occurs in waves with simultaneous painful and debilitating muscular spasms. Tactile or auditory stimuli can induce spasms. On electromyographic study, the patient has continuous motor activity, very similar to tetanus. The syndrome can lead to difficulty doing essential daily tasks or even painful conditions like fractures. Apart from clinical signs, some patients have positive anti-glutamic acid decarboxylase (anti-GAD) antibodies, which can also be an excellent confirmatory test for diagnosing SPS. In this case report, we present a 36-year-old female with a long history of SPS, with positive anti-GAD antibodies, leading to her chronic dependence on a tracheostomy tube and the pulmonary complications that followed. The patient suffered from acute encephalopathy secondary to acute respiratory failure. She was placed on a mechanical ventilator due to her respiratory failure but later developed a case of ventilator-associated pneumonia. Respiratory complications have not been reported vividly with this syndrome, so this case sheds light on the same.

Stiff-person syndrome: an atypical presentation and a review of the literature

Introduction: Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder associated with muscle rigidity and spasms. A number of antibodies have been associated with disorder, including anti-glutamic acid decarboxylase and anti-amphiphysin.Case report; In this report, we present a rare case of a 79-year-old woman who presented with bilateral lower extremity weakness who was ultimately diagnosed with stiff-limb syndrome, a rare variant of SPS. Extensive laboratory and CSF studies were unrevealing. Electromyography showed significant peroneal motor neuropathy and complex repetitive discharges in the left tibialis anterior muscle. Antibodies to glutamic acid decarboxylase were significantly elevated at 124 units/mL. She was subsequently started on oral diazepam with significant improvement in her symptoms.Conclusion: The presentation of SPS can vary based on epidemiologic factors, clinical symptoms, and associated disorders. These forms can have overlapping features which may make the categorization of patients into one of these forms challenging.

Stiff-Person Syndrome: A Treatment Update and New Directions

Stiff-person syndrome (SPS) is a rare and disabling central nervous system disorder with no satisfactory treatment. Muscle rigidity, sporadic muscle spasms, and chronic muscle pain characterize SPS. SPS is strongly correlated with autoimmune diseases, and it is usual to find high titers of antibodies against acid decarboxylase (GAD65). Due to its highly disabling nature and complicated treatment, we aim to create a treatment protocol through a narrative review of currently available treatments that show efficacy. We expect to facilitate management based on treatment responses ranging from first-line medication to refractory medication. We conducted a medical subject heading (MeSH) strategy. We used the term SPS with the subheading treatment: "Stiff-Person Syndrome/Therapy" [MeSH]. An initial data gathering of 270 papers came out with the initial research. After using the inclusion criteria, we had 159 articles. We excluded 31 papers for being either systematic reviews, literature reviews, or meta-analysis. From the 128 remaining articles, we excluded another 104 papers because the extraction of the data was not possible or the study outcome did not meet our demands. There are two main treatments for SPS: GABAergic (gamma-aminobutyric acid) therapy and immunotherapy. For treatment, we suggest starting with benzodiazepines as first-line treatment. We recommend adding levetiracetam or pregabalin if symptoms persist. As second-line therapy, we recommend oral baclofen over rituximab and tacrolimus. We also suggest rituximab over tacrolimus. For patients with refractory treatment, we can use intrathecal baclofen, intravenous immunoglobulin (IVIG), or plasmapheresis. We conclude that intrathecal baclofen and IVIG are more effective than plasmapheresis in patients with refractory symptoms. Propofol may be used as a bridge - temporary therapy before initiating a permanent treatment.

Improving Ambulation and Minimizing Disability with Therapeutic Plasma Exchange in a Stiff-person Syndrome Patient with Recurrent Falls

Stiff-person syndrome (SPS) is a rare, autoimmune, neuromuscular disorder that manifests with axial and proximal muscle stiffness, rigidity, and painful muscle spasms, often causing progressive disability due to limited movement. First-line therapies comprise symptomatic management with γ-aminobutyric acid-modulating drugs such as benzodiazepines and baclofen. Patients resistant to these treatments are often given intravenous immunoglobulin (IVIg). Severe disease refractory to first-line therapy and IVIg may be treated with therapeutic plasma exchange (TPE) or immunomodulatory agents such as rituximab. Current evidence derived from case reports and case series has shown that roughly half of SPS patients treated with TPE report benefits. Here, we report the case of a 68-year-old man with a 20-year history of severe SPS and recurrent falls who was admitted to the emergency department for a traumatic hip fracture. He had significant rigidity in the axial and extremity muscles with persistent spasms of the quadriceps femoris muscle. Postoperatively, he was unable to participate in physical therapy (PT) due to these symptoms. He previously failed treatment with diazepam, baclofen, and monthly IVIg. Under our care, he underwent seven TPE treatments. By the end of treatment, he reported significant improvement in mobility with a resolution of muscle spasms and was able to be discharged to inpatient rehabilitation. This suggests that TPE may offer an effective, safe treatment modality for patients with severe refractory SPS that may significantly improve mobility and disability associated with the disease.

Rituximab improves not only back stiffness but also "stiff eyes" in stiff person syndrome: Implications for immune-mediated treatment

OBJECTIVE

Stiff person syndrome (SPS) is usually characterized by truncal muscle rigidity and episodic painful spasms, but it sometimes appears with ocular symptoms called "stiff eyes". We recorded saccade movements in an SPS patient manifesting with "stiff eyes" conditions with slow saccade velocity and evaluated the effect of immunotherapy including rituximab on saccade parameters.

METHODS

We repeatedly conducted saccade eye recordings using video-based eye tracking system on a 42-year-old male SPS patient with slow saccade. The velocity and onset latency of visual guided saccades (VGS) were measured at each recording. Because VGS velocity is affected by saccade amplitude, estimated peak velocity (Vmax) was also calculated by taking the relationship between the velocity and the amplitude of saccade into account.

RESULTS

The mean VGS velocity improved significantly after two courses of rituximab administration compared with its lowest value. The estimated Vmax decreased as the clinical manifestations worsened, but it increased after rituximab administration. Other neurological symptoms in this patient such as muscle rigidity and gait instability also improved after the treatment.

CONCLUSION

Slow saccade in a "stiff eyes" patient improved after rituximab administration. Our study also indicated that the saccade eye recording is useful for evaluating the clinical condition of SPS when it is complicated with ocular symptoms.

Dyspnea in Patients with Stiff-Person Syndrome

BACKGROUND

Stiff-person syndrome (SPS) is a rare autoimmune disorder that leads to progressively worsening stiffness and spasm of thoracic and proximal-limb musculature. Dyspnea has been reported but not analyzed in patients with SPS.

MATERIALS AND METHODS

For this prospective study, 17 patients were recruited from a university-based neurology clinic. History and exam were performed, demographic information collected and available imaging reviewed. Dyspnea was assessed using vertical visual analog scales (VAS), the University of California San Diego Shortness of Breath Questionnaire (UCSD-SOBQ) and dyspnea "descriptors". Standardized assessments of SPS severity were performed by an experienced neurologist. Forced vital capacity (FVC) spirometric analysis was performed on all patients.

RESULTS

Fifteen of 17 patients complained of dyspnea, including dyspnea at rest, with exertion, and disturbing sleep. A restrictive pattern was the most common abnormality noted on spirometry. FVC (r = -0.67; P < 0.01) and forced expiratory volume in 1-second (FEV1) (r = -0.76; P < 0.01) percent predicted correlated with dyspnea measured by VAS over the preceding 2 weeks. Pulmonary function did not correlate with UCSB-SOBQ or standardized measures of SPS severity.

CONCLUSIONS

Dyspnea in SPS is common and occurs at rest with exertion and disturbs sleep. The finding of restrictive physiology and correlation between pulmonary function variables and dyspnea support the hypothesis that thoracic cage constriction by rigidity and/or spasm of the muscles of the trunk causes or contributes to the sensation of dyspnea. The possibility of diaphragmatic involvement requires further study.

SPS: Understanding the complexity

INTRODUCTION

Stiff-person syndrome (SPS), first described in 1956 by Moersch and Woltman, is a progressive autoimmune disorder with core features of chronic fluctuating progressive truncal and limb rigidity and painful muscle spasms leading to gait difficulties, falls and an appearance that resembles tin soldiers. The syndrome is a rare, highly disabling disorder of the central nervous and frequently results in significant disability. Understanding of the etiology, clinical spectrum, diagnostic workup and therapeutic modalities for this painful and disabling disorder has vastly evolved over the past few years with more confidence in classifying and treating the patients. The purpose of this review is to increase the awareness, early detection, and treatment of this disabling disease.

METHOD

PubMed was searched, all date inclusive, using the following phrases: stiff person syndrome,anti-Glutamic acid decarboxylase (Anti-GAD) antibody syndrome, Progressive encephalomyelitis with rigidity and myoclonus (PERM), and Paraneoplastic Stiff Person syndrome. No filters or restrictions were used. A total of 888 articles were identified.

RESULTS

The results were narrowed to 190 citations after excluding non-English and duplicate reports. Clinical presentation, laboratory testing, treatment, and prognosis were categorized and summarized.

DISCUSSION

In this article we will discuss the epidemiology, presentation and classification. Explain the pathophysiology of SPS and the autoimmune mechanisms involved. Discuss the diagnostic approach and treatments available, as well as, the prognosis and outcome.

Stiff-person Syndrome with Waldenström Macroglobulinemia

We herein report the case of stiff-person syndrome in a 73-year-old woman. She experienced episodes of painful muscle spasms and was admitted to another hospital. She was diagnosed with Waldenström macroglobulinemia. She showed improvement in muscle spasms post-chemotherapy, which was discontinued due to pancytopenia. Six months later, she was admitted to our hospital for repeated whole-body muscle spasms, at which point she was diagnosed with stiff-person syndrome. An anti-glutamic acid decarboxylase antibody text was negative. Her muscle spasms disappeared after the administration of corticosteroids and rituximab. Stiff-person syndrome may develop with Waldenström macroglobulinemia. In the present case, corticosteroids and rituximab provided effective treatment.

A double-blind, placebo-controlled study of rituximab in patients with stiff person syndrome

OBJECTIVE

In stiff person syndrome (SPS), an antibody-mediated impaired γ-aminobutyric acidergic (GABAergic) neurotransmission is believed to cause muscle stiffness and spasms. Most patients improve with GABA-enhancing drugs and intravenous immunoglobulin, but some respond poorly and remain disabled. The need for more effective therapy prompted a trial with the anti-CD20 monoclonal antibody rituximab.

METHODS

This was a placebo-controlled randomized trial of rituximab (2 biweekly infusions of 1g each). The primary outcome was a change in stiffness scores at 6 months. Secondary outcomes were changes in heightened-sensitivity and quality of life scores. Enrolling 24 patients was calculated to detect 50% change in stiffness scores.

RESULTS

Randomization was balanced for age, sex, disease duration, and glutamic acid decarboxylase autoantibody titers. No significant changes were noted at 6 months after treatment in all outcomes. Specifically, no differences were noted in the stiffness index, the primary outcome, or sensitivity scores, the secondary outcome, at 3 or 6 months. Quality of life scores improved significantly (p < 0.01) at 3 months in both groups, but not at 6 months, denoting an early placebo effect. Blinded self-assessment rating of the overall stiffness for individual patients revealed improvement in 4 patients in each group. At 6 months, improvement persisted in 1 patient in the placebo group versus 3 of 4 in the rituximab group, where these meaningful improvements were also captured by video recordings.

INTERPRETATION

This is the largest controlled trial conducted in SPS patients and demonstrates no statistically significant difference in the efficacy measures between rituximab and placebo. Rituximab's lack of efficacy could be due to a considerable placebo effect; insensitivity of scales to quantify stiffness, especially in the less severely affected patients; or drug effectiveness in only a small patient subset. Ann Neurol 2017;82:271-277.

Evaluation of Treatment Outcomes in Patients with Stiff Person Syndrome with Rituximab vs. Standard of Care

Stiff Person Syndrome (SPS) is a rare neurological disorder that primarily affects the ability to relax musculature. This results in affected muscle groups remaining in constant contracture, leading to painful spasms that have significant morbidity and impact the patient's quality of life. Disease prevalence is one to two persons in a million, and as a result, very few randomized controlled studies have examined the efficacy of various treatment regimens. One notable study examined intravenous immunoglobulin (IVIG) and its efficacy in the treatment of SPS. This study found that using IVIG was of significant benefit in improving stiffness in SPS. However, beyond this, immune modulating therapy is limited by lack of peer-reviewed evidence. The use of rituximab has been reported in cases of SPS that are refractory to treatment with IVIG and has had mixed outcomes. Our search of the literature involved examining case reports of patients with diagnosed SPS, who had been initially treated with the standard of care and were then placed on treatment with rituximab. Our review of the available case reports demonstrates an increase in SPS remission correlating with the frequency of dose. However, the limited number of case reports available limits conclusions related to the treatment of SPS. More studies are needed to assist in guiding therapy for SPS.

GAD65 neurological autoimmunity

The glutamic acid decarboxylase 65-kilodalton isoform (GAD65) antibody is a biomarker of autoimmune central nervous system (CNS) disorders and, more commonly, nonneurological autoimmune diseases. Type 1 diabetes, autoimmune thyroid disease, and pernicious anemia are the most frequent GAD65 autoimmune associations. One or more of these disorders coexists in approximately 70% of patients with GAD65 neurological autoimmunity. Neurological phenotypes have CNS localization and include limbic encephalitis, epilepsy, cerebellar ataxia, and stiff-person syndrome (SPS), among others. Classic SPS is a disorder on the spectrum of CNS hyperexcitability which also includes phenotypes that are either more restricted (stiff-limb syndrome) or more widespread (progressive encephalomyelitis with rigidity and myoclonus). GAD65 antibody is not highly predictive of a paraneoplastic cause for neurological disorders, but diverse cancer types have been occasionally reported. For all phenotypes, responses to immunotherapy are variable (approximately 50% improve). GAD65 autoimmunity is important to recognize for both coexisting nonneurological autoimmune associations and potential immunotherapy-response. Muscle Nerve 56: 15-27, 2017.

Gastrointestinal and Urologic Sphincter Dysfunction in Stiff Person Syndrome

OBJECTIVES

Stiff person syndrome is a neurologic disorder characterized by axial rigidity leading to progressive disability, with broad clinical spectrum.

METHODS

We report 2 cases with unique clinical presentation.

RESULTS

Two young men suffered progressive urinary retention requiring bladder catheterization, anorectal spasms and constipation, complicated subsequently with lower extremity trigger-induced spasms, and gait instability. Associated symptoms revealed brainstem involvement (vertigo, diplopia, and cranial neuropathies) and dysautonomia (abnormal sweating and orthostatic hypotension). Anal manometry demonstrated incomplete relaxation of the anal sphincter. The first case was associated with diabetes mellitus type I, did not respond to classical therapies, but was responsive to rituximab. The second case responded to intravenous immunoglobulin infusions. Paraneoplastic profiles were negative, and anti-GAD65 antibody titers remained elevated despite successful therapeutic responses.

CONCLUSIONS

We want to raise awareness that stiff person syndrome can present with esophageal, anorectal, and urethral sphincter disturbance. Rituximab is a good therapeutic option in intractable cases.

Clinical Spectrum of Stiff Person Syndrome: A Review of Recent Reports

Background

“Classic” stiff person syndrome (SPS) features stiffness, anti-glutamic acid decarboxylase (anti-GAD) antibodies, and other findings. Anti-GAD antibodies are also detected in some neurological syndromes (such as ataxia) in which stiffness is inconsistently present. Patients with otherwise “classic” SPS may either lack anti-GAD antibodies or be seropositive for others. Hence, SPS cases appear to fall within a clinical spectrum that includes conditions such as progressive encephalomyelitis with rigidity and myoclonus (PERM), which exhibits brainstem and autonomic features. We have compiled herein SPS-spectrum cases reported since 2010, and have segregated them on the basis of likely disease mechanism (autoimmune, paraneoplastic, or cryptogenic) for analysis.

Methods

The phrases “stiff person syndrome”, “PERM”, “anti-GAD antibody syndrome”, and “glycine receptor antibody neurological disorders” were searched for in PubMed in January 2015. The results were narrowed to 72 citations after excluding non-English and duplicate reports. Clinical descriptions, laboratory data, management, and outcomes were categorized, tabulated, and analyzed.

Results

Sixty-nine autoimmune, 19 paraneoplastic, and 13 cryptogenic SPS-spectrum cases were identified. SPS was the predominant diagnosis among the groups. Roughly two-thirds of autoimmune and paraneoplastic cases were female. Anti-GAD antibodies were most frequently identified, followed by anti-amphiphysin among paraneoplastic cases and by anti-glycine receptor antibodies among autoimmune cases. Benzodiazepines were the most commonly used medications. Prognosis seemed best for cryptogenic cases; malignancy worsened that of paraneoplastic cases.

Discussion

Grouping SPS-spectrum cases by pathophysiology provided insights into work-up, treatment, and prognosis. Ample phenotypic and serologic variations are present within the categories. Ruling out malignancy and autoimmunity is appropriate for suspected SPS-spectrum cases.

Anti-B-Cell Therapies in Autoimmune Neurological Diseases: Rationale and Efficacy Trials

B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antibody-producing cells and, most importantly, as sensors, coordinators, and regulators of the immune response. B cells, among other functions, regulate the T-cell activation process through their participation in antigen presentation and production of cytokines. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules or B-cell trophic factors bestows a rational approach for treating autoimmune neurological disorders, even when T cells are the main effector cells. This review summarizes basic aspects of B-cell biology, discusses the role(s) of B cells in neurological autoimmunity, and presents anti-B-cell drugs that are either currently on the market or are expected to be available in the near future for treating neurological autoimmune disorders.

Stiff-person syndrome: insights into a complex autoimmune disorder

Stiff-person syndrome (SPS) is characterised by progressive rigidity and muscle spasms affecting the axial and limb muscles. Since its initial description in 1956, marked progress has been made in the clinical characterisation, understanding of pathogenesis and therapy of this disorder. SPS can be classified according to the clinical presentation into classic SPS and SPS variants: focal or segmental-SPS, jerking-SPS and progressive encephalomyelitis with rigidity and myoclonus. Most patients with SPS have antibodies directed against the glutamic acid decarboxylase, the rate-limiting enzyme for the production of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Antibodies directed against GABA(A) receptor-associated protein, and the glycine-α1 receptor can also be observed. Paraneoplastic SPS is commonly associated with antiamphiphysin antibodies and breast cancer. Treatment of SPS with drugs that increase the GABAergic tone combined with immunotherapy can improve the neurological manifestations of these patients. The prognosis, however, is unpredictable and spontaneous remissions are unlikely.

Experience with low-dose rituximab in off-label indications at two tertiary hospitals

BACKGROUND

Rituximab is a monoclonal antibody directed against B cells and is increasingly used to treat a variety of autoimmune conditions. Most published evidence reporting the successful use of rituximab in off-label indications has empirically used a high-dose regimen (either 375 mg/m(2) weekly for 4 weeks, or 1000 mg × 2), which is the approved course of treatment for lymphoma and rheumatoid arthritis patients.

AIMS

The aims of this report are to review the indications, outcomes and adverse events of low-dose (500 mg twice, given 1-2 weeks apart), off-label use of rituximab in our institutions, and to review the available evidence.

METHODS

We performed a retrospective audit of the off-label use of low-dose rituximab at two university teaching, tertiary referral hospitals, from mid-2008 until the end of 2011.

RESULTS

Off-label rituximab was given to 52 patients (53 indications) across a heterogeneous group of autoimmune conditions. Outcomes were known for 46 conditions (affecting 45 patients), and of these, complete responses were observed in 16 (35%) conditions and a further 19 (41%) had a partial response. There was no response to rituximab in 11 (24%) patients. There were eight significant adverse events, mostly related to infectious complications.

CONCLUSION

This case series suggests that low-dose courses of rituximab can be used off-label to treat several severe and/or refractory immunological disorders with a reasonable safety profile; however, further trials are required in many off-label indications.

Childhood stiff-person syndrome improved with rituximab

Introduction

Stiff-person syndrome (SPS) is manifested by fluctuating rigidity of axial musculature with painful episodic spasms due to simultaneous co-contraction of agonist and antagonist muscles. We present a case report and video illustrating response to treatment with rituximab.

Materials and Methods

Case description and video are provided. A literature search for other reports of treatment with rituximab was performed.

Results

Nine cases in addition to our case were described. Substantial clinical benefit was reported in 7/9 (78%) cases. Four out of 9 (44%) cases displayed persistent anti-glutamic acid decarboxylase (GAD) antibody positivity.

Conclusion

Rituximab is an important treatment strategy in SPS. The persistence of anti-GAD antibody positivity even with clinical remission remains to be elucidated.

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.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.