Stiff-person syndrome: an autoimmune disease

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.

Quantitative Assessment of Response to Long-Term Treatment with Intravenous Immunoglobulin in Patients with Stiff Person Syndrome

Background

Stiff person syndrome (SPS) is an autoimmune condition involving antibodies against several components of the inhibitory synapse in the spinal cord, with glutamic acid decarboxylase antibodies being the predominant immune marker. SPS affects approximately 1 patient per million population per year. The effect of intravenous immunoglobulin (IVIG) has been established, but studies on the long-term efficacy of regular IVIG are limited.

Objectives

To review clinical details and long-term treatment response using a patient-reported questionnaire in SPS and related syndromes.

Methods

Patients were identified from a tertiary neuroimmunology clinic based on classical clinical symptoms, autoimmune profiles, and neurophysiological changes (Dalakas criteria). They were followed up after treatment to assess the response to IVIG.

Results

A total of 23 patients fulfilled the selection criteria. Patients' demographic profiles and clinical presentations were akin to that reported in literature. There was significant improvement in the functional ability (assessed by the modified Rankin scale [mRS]) and quality of life (QoL) following treatment with IVIG within 4 to 10 weeks (pre-mRS vs. post-mRS, P < 0.0001; pre-QoL vs. post-QoL, P = 0.0003) and sustained after 5 years of treatment (pre-mRS vs. present mRS, P = 0.0003; pre-QoL vs. present QoL, P = 0.0002).

Conclusions

This article describes one of the largest single-center experiences of 23 patients with SPS and related syndromes and is the first to establish the long-term efficacy of regular IVIG using a patient-reported scoring system (Birmingham Response to Immunomodulatory Therapy [BRIT]). Consistent improvement in QoL and functional scores were seen over nearly 5 years after regular use of IVIG. It is recommended to use BRIT scores to assess the initial response as well as to monitor continued improvement to immunomodulation in SPS.

Serum glutamate decarboxylase antibodies and neurological disorders: when to suspect their association?

OBJECTIVES

To explore different neurological manifestations with suspicion of being associated to serum glutamate decarboxylase antibodies (GAD-Abs) in order to better characterize anti-GAD neurological syndromes.

METHODS

Observational retrospective study including all patients for whom GAD65-Abs titers in serum were requested by the Neurology Department at La Paz University Hospital between 2015 and 2019. GAD-Abs were measured by ELISA. Demographic data, neurological symptoms, comorbidity with diabetes mellitus (DM) or with another autoimmune disease, and GAD-Abs titers were studied. Stiff-person syndrome, ataxia, encephalitis, and epilepsy were considered typical anti-GAD neurological syndromes and were compared to other atypical manifestations.

RESULTS

A total of 173 patients (51.7% men, mean age 51.62) were included. A progressive increase in requests of serum GAD-Abs has occurred over the last 5 years, especially in patients with atypical neurological manifestations. GAD-Abs were found in the serum of 22 patients (12.7%); of those, 15 (68.18%) suffered a typical anti-GAD syndrome. Presence of DM or another organ-specific autoimmune disease was predictive of GAD-AB seropositivity (p < 0.001). 6.6% of requested patients with an atypical syndrome had GAD-Abs, but serum levels were significantly lower than those found in patients with a typical syndrome (706.67 vs 1430.23 UI/mL; Mann-Whitney U, p = 0.034), and were finally diagnosed with another neurological disease.

CONCLUSION

Serum GAD-Abs were infrequently found in patients with clinical phenotypes other than those classically described as anti-GAD disorders, and with very low titers. In typical anti-GAD syndromes, there is a high comorbidity with DM and with other autoimmune diseases, and high serum GAD-Abs levels are usually present.

Paraneoplastic neurological syndrome: an evolving story

Paraneoplastic neurological syndrome (PNS) comprises a group of neurological disorders that result from a misguided immune response to the nervous system triggered by a distant tumor. These disorders frequently manifest before the diagnosis of the underlying neoplasm. Since the first reported case in 1888 by Oppenheim, the knowledge in this area has evolved rapidly. Several classic PNS have been described, such as limbic encephalitis, paraneoplastic cerebellar degeneration, encephalomyelitis, opsoclonus-myoclonus, sensory neuronopathy, Lambert-Eaton Myasthenic syndrome, and chronic gastrointestinal dysmotility. It is now recognized that PNS can have varied nonclassical manifestations that extend beyond the traditional syndromic descriptions. Multiple onconeural antibodies with high specificity for certain tumor types and neurological phenotypes have been discovered over the past 3 decades. Increasing use of immune checkpoint inhibitors (ICIs) has led to increased recognition of neurologic ICI-related adverse events. Some of these resemble PNS. In this article, we review the clinical, oncologic, and immunopathogenic associations of PNS.

Antibodies From Children With PANDAS Bind Specifically to Striatal Cholinergic Interneurons and Alter Their Activity

OBJECTIVE

Pediatric obsessive-compulsive disorder (OCD) sometimes appears rapidly, even overnight, often after an infection. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS, describes such a situation after infection with Streptococcus pyogenes. PANDAS may result from induced autoimmunity against brain antigens, although this remains unproven. Pilot work suggests that IgG antibodies from children with PANDAS bind to cholinergic interneurons (CINs) in the striatum. CIN deficiency has been independently associated with tics in humans and with repetitive behavioral pathology in mice, making it a plausible locus of pathology. The authors sought to replicate and extend earlier work and to investigate the cellular effects of PANDAS antibodies on cholinergic interneurons.

METHODS

Binding of IgG to specific neurons in human and mouse brain slices was evaluated ex vivo after incubation with serum from 27 children with rigorously characterized PANDAS, both at baseline and after intravenous immunoglobulin (IVIG) treatment, and 23 matched control subjects. Binding was correlated with symptom measures. Neural activity after serum incubation was assessed in mouse slices using molecular markers and electrophysiological recording.

RESULTS

IgG from children with PANDAS bound to CINs, but not to several other neuron types, more than IgG from control subjects, in three independent cohorts of patients. Post-IVIG serum had reduced IgG binding to CINs, and this reduction correlated with symptom improvement. Baseline PANDAS sera decreased activity of striatal CINs, but not of parvalbumin-expressing GABAergic interneurons, and altered their electrophysiological responses, in acute mouse brain slices. Post-IVIG PANDAS sera and IgG-depleted baseline sera did not alter the activity of striatal CINs.

CONCLUSIONS

These findings provide strong evidence for striatal CINs as a critical cellular target that may contribute to pathophysiology in children with rapid-onset OCD symptoms, and perhaps in other conditions.

Sex differences in movement disorders

A number of studies reported the possible differences between men and women in movement disorders. Evidence shows that estrogens may have a neuroprotective effect and may modulate the neurodevelopment of the different brain structures. Movement disorders including Parkinson's disease, dementia with Lewy body, Huntington's disease, Tourette's syndrome, and dystonia among others display significant clinical differences between sexes, with structural differences in the dopaminergic pathways between men and women. Here we summarize the most relevant clinical aspects of some of the most common movement disorders, highlighting the differences in disease onset, clinical presentation, therapy, and outcomes. Increased recognition of these differences may help physicians better understand the pathophysiology of these conditions and provide a tailored therapeutic approach.

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.

Phosphorylation of pyridoxal 5'-phosphate enzymes: an intriguing and neglected topic

Pyridoxal 5'-phosphate (PLP)-dependent enzymes catalyze a wide range of reactions of amino acids and amines, with the exception of glycogen phosphorylase which exhibits peculiar both substrate preference and chemical mechanism. They represent about 4% of the gene products in eukaryotic cells. Although structure-function investigations regarding these enzymes are copious, their regulation by post-translational modifications is largely unknown. Protein phosphorylation is the most common post-translational modification fundamental in mediating diverse cellular functions. This review aims at summarizing the current knowledge on regulation of PLP enzymes by phosphorylation. Starting from the paradigmatic PLP-dependent glycogen phosphorylase, the first phosphoprotein discovered, we collect data in literature regarding functional phosphorylation events of eleven PLP enzymes belonging to different fold types and discuss the impact of the modification in affecting their activity and localization as well as the implications on the pathogenesis of diseases in which many of these enzymes are involved. The pivotal question is to correlate the structural consequences of phosphorylation among PLP enzymes of different folds with the functional modifications exerted in terms of activity or conformational changes or others. Although the literature shows that the phosphorylation of PLP enzymes plays important roles in mediating diverse cellular functions, our recapitulation of clue findings in the field makes clear that there is still much to be learnt. Besides mass spectrometry-based proteomic analyses, further biochemical and structural studies on purified native proteins are imperative to fully understand and predict how phosphorylation regulates PLP enzymes and to find the relationship between addition of a phosphate moiety and physiological response.

A case of stiff dog syndrome associated with anti-glutamic acid decarboxylase antibodies

BACKGROUND

The stiff person syndrome (SPS) is a rare and debilitating autoimmune disorder with an unknown pathogenesis and variable clinical presentation that can present a diagnostic challenge. Although entities that clinically mimic stiff-person spectrum disorders (SPSD) have manifested in horses, they have not been reported in dogs.

CASE PRESENTATION

We describe a 2-year-old beagle dog presented for progressive attacks of muscular rigidity and lordosis with superimposed spasms of the appendicular muscles triggered by tactile stimulation which resulted in marked gait impairment. Resting electromyography revealed continuous motor unit activity in the axial musculature. Compared to age-matched healthy beagle dogs, this patient had elevated glutamic acid decarboxylase antibody concentrations in serum and cerebrospinal fluid.

CONCLUSION

This dog presented with phenotypic, electrodiagnostic, and immunologic criterion consistent with an SPSD, including elevated anti-GAD antibody titers, which we have termed the "stiff dog syndrome (SDS)". Durable clinical improvement was achieved with symptomatic and immunosuppressive treatments including baclofen, gabapentin, prednisone, and intravenous immunoglobulin.

Stiff-Person Syndrome and Graves' Disease: A Pediatric Case Report

A 9-year-old female child presented with a history of falls, weight loss, diffuse leg pain, and progressive gait disorder, following 1 previous event described as a tonic-clonic seizure. She had increased thyroid volume, brisk symmetric reflexes, abnormal gait, and painful spasms of the paraspinal musculature. Thyroid function tests indicated biochemical hyperthyroidism, and thyrotropin receptor antibodies were positive. Her electromyography showed continuous activation of normal motor units of the paraspinal and proximal lower extremity muscles. The patient had a diagnosis of Graves' disease with associated stiff-person syndrome, with elevated anti-glutamic acid decarboxylase antibody levels. After intravenous immunoglobulin therapy, her ambulation was substantially improved and the symptoms of stiff-person syndrome decreased dramatically.

Stiff-Man Syndrome: GABA, GAD, and Mechanisms of Disease

Stiff-man syndrome (SMS) is a rare disease of progressive muscle stiffness, most common in middle age, often associated with autoimmunity to glutamic acid decarboxylase (GAD) and responsive to treatment with GABA agonists. Diagnosis is established by clinical characteristics and confirmed by EMG or antibody testing. Anti-GAD antibodies are present in 60% of those with SMS and antiamphiphysin antibodies are found in fewer than 10%. The production of antibodies has an unclear relationship to the pathological processes of the disease. GABA receptors and GABA receptor mRNAs are found in high density in the spinal cord laminae and identify possible sites of dys-function in SMS. At some spinal cord synapses, GABA co-localizes with glycine, a neurotransmitter implicated in hyperekplexia. Failure of spinal cord reflexes explains the symptoms of SMS, but electrophysiological studies have not yet identified a single locus of inhibitory failure. Immunomodulation may alter the disease course, but consistently effective treatments for SMS await development.

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.

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.

Stiff-Person Syndrome

The stiff-person syndrome is a disorder of persistent, painful muscle contractions predominately affecting the axial musculature. We describe a patient with this disorder and review its pathophysiology. Molecular biologic and immunologic techniques have recently added to the understanding of the mechanism of this disorder. Association with diseases such as diabetes, vitiligo and hypothyroidism have strengthened the auto-immune nature of this syndrome. Auto-antibodies against glutamic acid decarboxylase (GAD), an intraneuronal enzyme, have been implicated in the etiology of this unique disease. Therapeutic intervention with agents such as benzodiazepines that modify central GABAergic activity have demonstrated significant benefit in patients with stiff-person syndrome.

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.

Stiff-person syndrome: case series

Stiff-person syndrome (SPS) is a rare disorder, characterized by progressive fluctuating muscular rigidity and spasms. Glutamic acid decarboxylase (GAD) antibody is primarily involved in the pathogenesis of SPS and SPS is strongly associated with other autoimmune disease. Here we report three cases of patients with classical SPS finally confirmed by high serum level of GAD antibodies. All of our patients respond favorably to gamma amino butyric acid-enhancing drugs and immunotherapies.

Rediscovering catatonia: the biography of a treatable syndrome

OBJECTIVE

Catatonia, a disorder of movement and mood, was described and named in 1874. Other observers quickly made the same recognition. By the turn of the century, however, catatonia was incorporated as a type within a conjured syndrome of schizophrenia. There, catatonia has lain in the psychiatric classification for more than a century.

METHOD

We review the history of catatonia and its present status. In the 1970s, the tie was questioned when catatonia was recognized among those with mood disorders. The recognition of catatonia within the neuroleptic malignant syndrome offered effective treatments of high doses of benzodiazepines and electroconvulsive therapy (ECT), again questioning the tie. A verifying test for catatonia (the lorazepam sedation test) was developed. Soon the syndromes of delirious mania, toxic serotonin syndrome, and the repetitive behaviors in adolescents with autism were recognized as treatable variations of catatonia.

RESULTS

Ongoing studies now recognize catatonia among patients labeled as suffering from the Gilles de la Tourette's syndrome, anti-NMDAR encephalitis, obsessive-compulsive disease, and various mutisms.

CONCLUSION

Applying the treatments for catatonia to patients with these syndromes offers opportunities for clinical relief. Catatonia is a recognizable and effectively treatable neuropsychiatric syndrome. It has many faces. It warrants recognition outside schizophrenia in the psychiatric disease classification.

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.

Stiff-person syndrome (SPS) and anti-GAD-related CNS degenerations: protean additions to the autoimmune central neuropathies

Stiff Person Syndrome (SPS) is a rare autoimmune neurological disease attributable to autoantibodies to glutamic acid decarboxylase (anti-GAD) more usually associated with the islet beta cell destruction of autoimmune type 1 diabetes (T1D). SPS is characterized by interference in neurons with the synthesis/activity of the inhibitory neurotransmitter gamma amino butyric acid (GABA) resulting in the prototypic progressive spasmodic muscular rigidity of SPS, or diverse neurological syndromes, cerebellar ataxia, intractable epilepsy, myoclonus and several others. Remarkably, a single autoantibody, anti-GAD, can be common to widely different disease expressions, i.e. T1D and SPS. One explanation for these data is the differences in epitope engagement between the anti-GAD reactivity in SPS and T1D: in both diseases, anti-GAD antibody reactivity is predominantly to a conformational epitope region in the PLP- and C-terminal domains of the 65 kDa isoform but, additionally in SPS, there is reactivity to conformational epitope(s) on GAD67, and short linear epitopes in the C-terminal region and at the N-terminus of GAD65. Another explanation for disease expressions in SPS includes ready access of anti-GAD to antigen sites due to immune responsiveness within the CNS itself according to intrathecal anti-GAD-specific B cells and autoantibody. Closer study of the mysterious stiff-person syndrome should enhance the understanding of this disease itself, and autoimmunity in general.

Stiff person syndrome: presentation of a case with repetitive complex discharges in electromiograms

INTRODUCTION

Stiff person syndrome is characterized by rigidity of axial and proximal limb muscles, associated with muscle spasms, triggered by unexpected acoustic or somesthetic stimuli. It usually has an autoimmune basis, in which the blood contains antiglutamate decarboxylase antibodies, and is associated with different types of autoimmune diseases. The electromyogram provides evidences of continuous muscular activity.

CASE REPORT

A 41-year-old woman with a history of diabetes mellitus type I, Hashimoto thyroiditis, vitiligo, and pernicious anemia developed symptoms compatible with stiff person syndrome. In the electromyogram, in addition to continuous muscular activity, there was evidence of complex repetitive activity in the form of doublets and triplets.

CONCLUSIONS

Given the absence of clinical or electrophysiological neuropathic affectation, the presence of doublets and triplets in our patient could be due to a subclinical functional alteration of alpha motoneurons. They could produce the complex repetitive discharges when released from the inhibition mediated by GABAergic neurons.

Rigidity and spasms from autoimmune encephalomyelopathies: stiff-person syndrome

Stiff-person syndrome (SPS) is a disorder characterized by progressive muscle rigidity with superimposed painful muscle spasms and gait impairment due to continuous motor activity. Evidence has accumulated in favor of SPS representing an autoimmune, predominantly encephalomyelopathic disorder resulting from B-cell-mediated clonal production of autoantibodies against presynaptic inhibitory epitopes on the enzyme glutamic acid decarboxylase (GAD) and the synaptic membrane protein amphiphysin. Recognition of the clinical spectrum of SPS is important, particularly the upper-limb, cervical, and cranial nerve involvement that occurs in paraneoplastic variants. The correlation between antibody levels and severity of disease offers evidence for a pathogenic role for the anti-GAD and anti-amphiphysin autoantibodies. The scarcity of neuropathological correlates stand in sharp contrast with the severity of the disability in affected individuals and suggests that functional impairment of inhibitory circuits without structural damage is sufficient to develop the full clinical spectrum of SPS. The rarity of this condition limits the feasibility of controlled clinical trials in the treatment of SPS, but the available evidence suggest that drugs that increase cortical and spinal inhibition such as benzodiazepines and drugs that provide immune modulation such as intravenous immunoglobulin, plasmapheresis, and prednisone are effective treatments.

Graves’ Disease and Stiff-Person (Stiff-Man) Syndrome: Case Report and Literature Review

OBJECTIVE

To report an association between two autoimmune conditions, Graves' disease and stiff-person (stiff-man) syndrome, and discuss the relevant literature.

METHODS

We present a case of a 52-year-old white woman with stiff-person syndrome who also had Graves' disease, discuss her management, and review the related literature. Pertinent published reports from 1950 through 2004 were researched with use of MEDLINE and PubMed, and cross-references to other articles were reviewed.

RESULTS

A 52-year-old white woman presented with symptoms of hyperthyroidism due to Graves' disease. Laboratory data were as follows: thyrotropin <0.005 m IU/mL, thyroxine 11.1 microg/dL, free thyroxine index (FTI) 10.7, and triiodothyronine 170 ng/dL. Thyroid-stimulating immunoglobulins (TSI) and thyrotropin-binding inhibitory immunoglobulins (TBII) were positive at 1,986% and 82.5 U/L, respectively. The hyperthyroidism was treated with propranolol. She had a long-standing history of musculoskeletal complaints and was ultimately diagnosed with stiff-person syndrome. During her thyroid evaluation, she had severe neurologic deterioration that necessitated hospitalization and treatment with clonazepam, baclofen, intravenous immunoglobulin, and subsequently prednisone and azathioprine for appreciable symptomatic relief. The aggressive immunosuppression had a profound effect on her symptoms of hyperthyroidism, results of thyroid function tests, and thyrotropin receptor antibodies (TRABs). Thyrotropin was 0.52 microIU/mL, thyroxine was 6.9 microg/dL, and FTI was 5.7. The TSI decreased from 1,986% to 248%, and her TBII normalized from 82.5 U/L to <5 U/L. She was clinically and biochemically euthyroid at last follow-up in May 2004.

CONCLUSION

This case illustrates the association between TRAB-positive Graves' disease and stiff-person syndrome and the improvement of Graves' disease with immunosuppressive therapy.

Stiff-Person Syndrome

BACKGROUND

Stiff-person syndrome (SPS) is a rare neurologic disorder with autoimmune features. It is characterized by progressive, severe muscle rigidity or stiffness most prominently affecting the spine and lower extremities.

REVIEW SUMMARY

Superimposed muscle spasms result in simultaneous contraction of agonist and antagonist muscles which are detectable by electromyography (EMG) and relieved by administration of benzodiazepines. The exacerbation of SPS by emotional stressors often results in the referral of these patients for psychiatric assessment although this was more common before the discovery of an association with antibodies to glutamic acid decarboxylase (GAD antibodies). Formerly known as stiff-man syndrome, the female to male ratio is 2:1 and the principle paraneoplastic variant is associated with breast cancer. Although rare, this is a disease of middle age that severely curtails the functional capacity of those it strikes. It is frequently associated with diabetes and other autoimmune diseases. IVIg is recently demonstrated to be effective in the treatment of SPS; diazepam remains useful in managing the symptoms.

CONCLUSIONS

This article summarizes the history of SPS, describes important clinical features, discusses management, touches upon areas of uncertainty, and postulates some avenues for research.

Pregnancy in stiff-limb syndrome

To our knowledge, pregnancy in a patient with stiff-limb-syndrome (SLS) has not been reported. We present the case of a woman with SLS who improved during pregnancy, delivered a normal healthy baby by forceps-assisted vaginal delivery, and suffered a mild postpartum "relapse."

Stiff-man syndrome: identification of 17 beta-hydroxysteroid dehydrogenase type 4 as a novel 80-kDa antineuronal antigen

Stiff-man syndrome (SMS) is a rare autoimmune disorder of the central nervous system associated with autoantibodies to glutamate decarboxylase (GAD). We isolated five brain-reactive human monoclonal antibodies, with reactivity distinct from GAD, from peripheral blood of a patient newly diagnosed with SMS. Two antibodies reacted with both Purkinje cells and ependymal cells, and precipitated an 80-kDa protein from rat neuronal primary cultures, which was also recognized by 12% (3/25) of SMS sera and 13% (2/15) of SMS cerebrospinal fluid (CSF) samples. The corresponding antigen was identified as 17 beta-hydroxysteroid dehydrogenase type 4 and may represent a possible novel target of autoimmunity in SMS.

Quality of life in stiff-person syndrome

Stiff person syndrome (SPS) is a rare, chronic disorder characterized by painful spasm and stiffness. We investigated the quality of life (QoL) in SPS patients, and identified factors associated with impairment in patients' QoL. Twenty-four SPS patients (10 men, 14 women; mean age +/- S.D., 52.6 +/- 9.5 years) completed the medical outcomes study Short Form health survey (SF-36), the Beck Depression Inventory (BDI), and a questionnaire asking for sociodemographic and clinical details. Extent of the disease was assessed using a distribution of stiffness score. SPS patients showed markedly reduced mean scores for all dimensions of the SF-36 when compared to norms from the general population of the United Kingdom. QoL scores showed a strong correlation with the extent of the disease. Depression was a common finding; 14 of 24 patients had depressive symptoms as evidenced by the BDI. There was a significant and strong correlation between the BDI score and several SF-36 subscores. This is the first study to address QoL in patients with SPS. We have shown that SPS has a significant impact on patients' reported QoL. The association between depression and QoL highlights the importance of recognizing and treating depression in SPS.

Stiffness, spasticity, or both: a case report of stiff-person syndrome

Stiffness and spasticity are common neurologic symptoms that affect limb movements. We describe a patient who presented with ill-defined stiffness and an exaggerated startle response, who on serial examinations had variable degrees of stiffness and marked hyperreflexia but with plantar flexor signs. Stiff-person syndrome (SPS) was considered when axial stiffness became evident and was confirmed with highly elevated anti-GAD antibody titers. A favorable response to a short course of intravenous immunoglobulin treatment was sustained for more than 10 months, an unusual feature to the disease. We review the clinical features, pathologic mechanism, and treatment of this disorder.

Effect of treatment with intravenous immunoglobulin on quality of life in patients with stiff-person syndrome

The therapeutic effects of intravenous immunoglobulin (IVIG) on the stiff-person syndrome (SPS) have been described exclusively in case reports or open-label studies in terms of clinical outcomes. We investigate whether IVIG improves quality of life (QoL) in the SPS. Six patients with the classic form of SPS completed a generic QoL instrument, the SF-36, and a Visual Analogue Scale (VAS) before treatment as well as 2 weeks after completion of a course of IVIG. There was significant improvement in the SF-36 subscores for pain, social functioning, general mental health, and energy-vitality with treatment. The VAS also improved significantly. We conclude that treatment with IVIG improves QoL in the SPS.

Stiff-person syndrome: autoimmunity and the central nervous system

Stiff-person syndrome (SPS) is a rare disease of severe progressive muscle stiffness in the spine and lower extremities with superimposed muscle spasms triggered by external stimuli. Patients with SPS are often referred for psychiatric evaluation and the psychiatrist may be the first to diagnosis SPS. Psychosocial stressors often precede the first manifestations of the disease; depression, anxiety, and alcohol abuse are comorbid illnesses. The identification of an association with antibodies to glutamic acid decarboxylase (GAD) was invaluable for definitively establishing a pathological basis for the disease; antibodies to amphiphysin and gephyrin are also found in cases of SPS but at much lower frequencies. Whether the antibodies inhibit GAD activity in vivo, target GAD-expressing neurons for immune-mediated destruction, are part of a wider immune process, or are merely a marker for destruction of GAD-expressing neurons by an independent neurodegenerative process is not yet clear. Both electromyography and the detection of GAD antibodies are useful in establishing a diagnosis of SPS. Treatment of SPS includes the use of immunomodulating therapies (plasmapheresis and intravenous immunoglobulins) and symptomatic treatment with benzodiazepines and baclofen. The use of tricyclic antidepressants and rapid withdrawal from therapy should be avoided.

Autoimmunity to gephyrin in Stiff-Man syndrome

Stiff-Man syndrome (SMS) is a rare disease of the central nervous system (CNS) characterized by chronic rigidity, spasms, and autoimmunity directed against synaptic antigens, most often the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD). In a subset of cases, SMS has an autoimmune paraneoplastic origin. We report here the identification of high-titer autoantibodies directed against gephyrin in a patient with clinical features of SMS and mediastinal cancer. Gephyrin is a cytosolic protein selectively concentrated at the postsynaptic membrane of inhibitory synapses, where it is associated with GABA(A) and glycine receptors. Our findings provide new evidence for a close link between autoimmunity directed against components of inhibitory synapses and neurological conditions characterized by chronic rigidity and spasms.

Amiodarone-induced cornea verticillata

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Stiff-man syndrome

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Botulinum toxin A improves muscle spasms and rigidity in stiff-person syndrome

We studied the effect of botulinum toxin A (BTA) on painful muscular spasms and rigidity in two bedridden patients with clinical, electrophysiologic, and immunologic evidence of stiff-person syndrome. We injected BTA or saline solution into several limb muscles with both the rater and patient blinded to the order of the injections. A physician, unaware of the treatment order, used an objective rating scale for rigidity and spasm frequency scale and independently assessed the treatment results. BTA administration significantly reduced rigidity and stopped the spasms in all limbs. Following BTA injection on one side, the spasm frequency decreased bilaterally possibly because of the spread of hematogenous toxin.

Gastrointestinal involvement in neurologic disorders: Stiff-man and Charcot-Marie-Tooth syndromes

Many neurologic conditions can affect the striated muscle of the gastrointestinal tract, resulting in dysphagia. In this article, two patients with rare neurologic disorders are reported (Stiff-man syndrome and Charcot-Marie-Tooth syndrome). Both patients had pharyngeal dysphagia. In addition, there was evidence of smooth muscle involvement in other areas of the gastrointestinal tract, specifically abnormal esophageal motility and delayed gastric emptying. In the English literature, there are only two reports of Stiff-man syndrome and dysphagia, and there are no reports of Charcot-Marie-Tooth syndrome. These represent the first accounts of smooth muscle dysfunction in those uncommon neurologic disorders.

Stiff-man syndrome: case report

Stiff-man syndrome is a rare neurologic disorder characterized by progressive, fluctuating muscle rigidity with painful muscle contractions affecting predominantly the back and proximal extremities. In the ED, the diagnosis can be easily overlooked and misdiagnosed as acute or chronic low back pain and muscle spasm. This syndrome is often associated with diabetes, autoimmune diseases, and cancer. This report describes an illustrative case of a 39-year-old woman who presented to the ED with a two-year history of right leg spasms and low back pain that had become so severe in the preceding two days that she was unable to ambulate. Clues to the patient's proper diagnosis coincide with the diagnostic criteria for stiff-man syndrome: the presence of a slowly progressive stiffness of the axial muscles and proximal limb muscles, making ambulation difficult; hyperlordosis of the lumbar spine; episodic spasms precipitated by jarring or sudden movement; a normal intellectual, sensory, and motor examination when not in spasm; and a marked amelioration of symptoms with the IV administration of diazepam. High-dose oral diazepam is the maintenance drug of choice.

Brain L-glutamate decarboxylase. Inhibition by phosphorylation and activation by dephosphorylation

Previously we showed that the activity of the gamma-aminobutyric acid-synthesizing enzyme L-glutamate decarboxylase (GAD) in crude brain extract is inhibited by ATP and protein phosphatase inhibitors. We suggested that GAD activity is regulated by protein phosphorylation. In this paper we further present evidence to support our hypothesis that protein kinase A and calcineurin may be involved in regulation of GAD activity through phosphorylation and dephosphorylation fo GAD, respectively. In addition, the effect of neuronal stimulation on GAD activity in cultured neurons is also included. A model to link neuronal excitation and activation of GAD by Ca(2+)-dependent phosphatase is proposed.