Stiff-person Syndrome Research Articles

Navigating the Complexity of Stiff Person Syndrome: A Case Report and Literature Review

Navigating the Complexity of Stiff Person Syndrome: A Case Report and Literature Review

Not One-in-a-million: A Single-Center Case Series of Patients with Stiff Person Syndrome

Not One-in-a-million: A Single-Center Case Series of Patients with Stiff Person Syndrome

Characterize GAD65-specific T cell Responses in Patients with Stiff-Person Syndrome and Type-I Diabetes.

Characterize GAD65-specific T cell Responses in Patients with Stiff-Person Syndrome and Type-I Diabetes.

GAD-positive Stiff Person Syndrome (GAD-SPS) with Autoimmune Retinopathy (AR): Argonaute-2 but not GAD as Potential Targeted Retinal Antigen

GAD-positive Stiff Person Syndrome (GAD-SPS) with Autoimmune Retinopathy (AR): Argonaute-2 but not GAD as Potential Targeted Retinal Antigen

6674 Non-Progressive Diabetes Leading to Neurologic Diagnosis

Abstract Disclosure: F.L. Thelmo: None. M. Murugesh: None. B. Simon: None. Introduction: The autoantibody GAD (anti-glutamic acid decarboxylase) is highly associated with Type 1 diabetes (T1DM) and Latent Autoimmune Diabetes in Adulthood (LADA). If GAD is detected before the onset of overt diabetes, typically 80% of patients with abnormal glucose tolerance progress to insulin deficiency and the need for insulin treatment after 5 years.[1] Stiff Person Syndrome (SPS) is also associated with GAD antibodies, but in SPS, the GAD antibodies are believed to be different epitopes that target GABA production in neuromuscular pathways. We present a case of presumed LADA that did not progress for 30 years, with progressive neurologic symptoms leading to a diagnosis of SPS in later adulthood.Case: A 52-year-old female presented for evaluation of T1DM and worsening neuropathies. She had a long history of prediabetes, with mildly elevated glucose values noted on labs since her early twenties. There was no family history of T1DM or autoimmune conditions. Six years ago, she sought endocrine evaluation. HgbA1c values were 6.1 to 6.6%. Intermittent use of continuous glucose monitoring (CGM) revealed post-prandial hyperglycemia up to 180mg/dL, occasionally (but rarely) exceeding 200mg/dL. She recalls being told that she had positive antibodies (unclear which ones tested) and given a diagnosis of T1DM. She declined insulin and maintained glycemic control with carbohydrate restriction and exercise; there were no episodes of diabetic ketoacidosis. She then developed neurologic symptoms: fullness, tightness and bloating in the abdomen (diagnosed with gastroparesis on scanning) and after a COVID 19 booster in 2021, muscle spasms in the legs and back with worsening abdominal tightness. At the time of her current presentation, A1C was 6.4%, glycated albumin was 14.4% (prediabetes range 13.6 - 15.5%) and CGM time in range was 99%. A non-fasting C-peptide was 3.6 ng/mL (1.1- 4.4ng/mL) with glucose of 119 mg/dL. Repeat antibody testing revealed undetectable IA-2 and ZnT8 antibodies, but GAD was grossly elevated at 1,015.3 U/mL. Given the unusually high GAD titer, SPS was suspected, and this diagnosis was confirmed on referral to neurology. The patient was advised to liberalize diet and will be monitored with HgbA1c and serial C-peptide levels to assess progression in the future. Discussion: While high GAD antibody levels are associated with progression to insulin dependence in adults with LADA, in SPS the GAD titers tend to be even higher2. The presence of only one auto-antibody for T1DM (and not multiple), long-standing non-progressive hyperglycemia, and normal C-peptide pointed away from autoimmune diabetes being the etiology for mild glucose intolerance in this patient. If neurologic symptoms are present, high GAD should prompt the evaluation for other syndromes associated with GAD antibody epitopes such as SPS. Presentation: 6/2/2024

12452 Unraveling An Intriguing Clinical Sequence: Thyrotoxicosis Antecedent To Stiff Person Syndrome

Abstract Disclosure: A. Jain: None. M.N. Rayan: None. Title: Unraveling an Intriguing Clinical Sequence: Thyrotoxicosis Antecedent to Stiff Person Syndrome Background: Stiff Person Syndrome (SPS) is an autoimmune phenomenon resulting in the progressive rigidity of limbs and trunk muscles. It is associated with GAD-positive antibodies in the CSF and serum and is linked to Type 1 Diabetes, Celiac disease, and other autoimmune diseases. Clinical Case: A 34-year-old female with no past medical history was brought into the ED by family for paranoia, suicidal ideations, and visual and auditory hallucinations. She was found to be tachycardic and altered in the ED. Endocrinology was initially consulted for concerns of hyperthyroid pathology due to lab work showing a TSH of <0.008 uIU/mL and free T4 of 4 pg/mL. Thyroid ultrasound revealed heterogeneous, hypervascular thyroid tissue. Further investigation revealed TRAB 4.05 IU/L (n 0-0.9 IU/L) and TSI 3 IU/L (n < 0.577 IU/L). A diagnosis of Graves’ disease was made, and she was started on methimazole 20mg daily and metoprolol 25mg daily. Due to a lack of response to methimazole, other organic causes were investigated including psychiatric and neurological etiology. The patient's symptoms continued to worsen, with new tremors of the upper and lower extremities. Thyroid labs showed improvement, and hence thyrotoxicosis was not thought to be the underlying etiology of her encephalopathy. Neurology was consulted, and EEG and MRI Brain were performed which were unrevealing. Lumbar puncture revealed elevated oligoclonal bands and GAD-65 antibodies, suggesting autoinflammatory encephalitis. High-dose steroids were started, with no improvement. Due to the failure of steroids to treat her symptoms, she was given 5 days of plasmapheresis and a dose of rituximab. Slowly, the patient began to improve and could follow commands and communicate with staff. A formal diagnosis of SPS was made at this time. Upon seeing her in follow-up 1 month after discharge, her TRAB and TSI antibodies were negative, and she was able to be titrated off of methimazole. Conclusion: SPS is strongly associated with autoimmune diseases, with up to 30-40% having T1DM. The association between hyperthyroidism and SPS, however, is exceedingly rare and the etiology remains unclear. Presentation: 6/1/2024

Acupuncture as an Adjunct Treatment in Stiff Person Syndrome

Acupuncture as an Adjunct Treatment in Stiff Person Syndrome

ID: 328073 Peripheral Nerve Stimulator as a Possible Treatment Modality for Stiff Person Syndrome

ID: 328073 Peripheral Nerve Stimulator as a Possible Treatment Modality for Stiff Person Syndrome

A rare presentation of stiff-person syndrome with a nonspecific focal myositis: A case report

Introduction. The stiff-person syndrome (SPS) is a rare disease whose incidence is estimated at approximately 1 in a million individuals in the general population. Diagnosis relies on a combination of clinical, immunological, and electromyographic items. We present the case of a patient diagnosed with the idiopathic SPS, initially misdiagnosed as focal paravertebral myositis. Case presentation. A 36-year-old patient was referred to us for the investigation of subacute dorsal myalgias. The patient reported a severe torticollis seven months ago, which resolved spontaneously after one month, and some episodes of back stiffness. On examination, the patient was afebrile, had hyperlordosis with a paravertebral contracture and tenderness. Neurological and cognitive examinations were normal. C-reactive Protein was at 137 mg/l. The rest of laboratory investigations, including creatine phosphokinase (CPK), were within normal range. Spinal MRI revealed T2 hyperintensity in the semispinalis muscle, erector spinae muscle, trapezius muscle, as well as the intervertebral muscles. Therefore, focal paravertebral myositis was suspected. The electromyogram (EMG) revealed the presence of a continuous motor unit activity in agonist and antagonist muscles, suggestive of stiff-person syndrome. Antinuclear antibodies, anti-glutamic acid decarboxylase 65 and onconeuronal antibodies were negative. Analysis of the cerebrospinal fluid, including anti-glutamic acid decarboxylase 65 test, was normal. We noticed that the paravertebral contracture became less noticeable when the patient was commenced on diazepam. Diagnosis of SPS was established according to Dalakas criteria. Investigations for an underlying neoplasm, were normal. Associated autoimmune disorders have been ruled out. The MRI description was rather explained by the continuous contraction of the affected muscles. Treatment included diazepam, baclofen, intravenous immunoglobulin and corticosteroids. The patient showed important signs of improvement. Conclusion. SPS is a rare condition whose diagnosis can be delayed. Recognizing and managing SPS as early as possible is crucial. It is based on clinical reasoning, imaging, biological features and EMG.

COVID-19 risk factors and outcomes in individuals with stiff person syndrome spectrum disorders before and after omicron

BackgroundStiff person syndrome spectrum disorders (SPSD) are rare, disabling disorders of the nervous system that are associated with risk factors for Coronavirus disease 2019 (COVID-19). However, limited data exist on the overall impact of COVID-19 on SPSD.MethodsPatients with SPSD and COVID-19 who are followed at Johns Hopkins SPS Center were included. Demographics and SPSD characteristics along with COVID-19-specific data were recorded.ResultsThirty-five cases of SPSD with COVID-19 cases were reported during the study time period. Mean age of the cohort was 56 (SD ± 10) and most were female (66.7%). Eighty percent of the COVID-19 cases were confirmed with testing, and the rest were highly suggestive of COVID-19. COVID-19 comorbidities among patients were hypertension (n = 6), diabetes (n = 6), obesity (n = 5), and cardiovascular disease (n = 4). The majority of participants were on immune therapies and/or benzodiazepines. Out of the cases reported, only 2 required hospitalization, both of whom had diabetes, and one was on immunosuppressive therapy. The majority of cases were post-full-vaccination cases. Fever was the most common COVID-19-associated symptom. Transient neurological symptoms were also reported.ConclusionRisk factors for developing severe COVID-19 in SPSD appear to be the same as historical data in the general population. Importantly, COVID-19 did not appear to be associated with worsening SPSD post-COVID-19. Vaccination may have played a role in preventing severe cases of COVID-19.

Stiff-person syndrome and related disorders - diagnosis, mechanisms and therapies.

Stiff-person syndrome (SPS) is the prototypical and most common autoimmune neuronal hyperexcitability disorder. It presents with stiffness in the limbs and axial muscles, stiff gait with uncontrolled falls, and episodic painful muscle spasms triggered by anxiety, task-specific phobias and startle responses, collectively leading to disability. Increased awareness of SPS among patients and physicians has created concerns about diagnosis, misdiagnosis and treatment. This Review addresses the evolving diagnostic challenges in SPS and overlapping glutamic acid decarboxylase (GAD) antibody spectrum disorders, highlighting the growing number of overdiagnosesand focusing on the progress made in our understanding of SPS pathophysiology, antibodies against GAD and other inhibitory synaptic antigens, and the fundamentals of neuronal hyperexcitability. It considers the role of impaired GABAergic or glycinergic inhibition in the cortex and at multiple levels in the neuraxis; the underlying autoimmunity and involvement of GAD antibodies; immunopathogenic mechanisms beyond antibodies, including environmental triggers; familial and immunogenetic susceptibility; and potential T cell cytotoxicity. Finally, the mechanistic rationale for target-specific therapeutic interventions is presented along with the available therapeutic approaches, including enhancers of GABA signalling drugs and immunotherapies.

Spectrum of neurological manifestations, existence of diabetes mellitus, and 5-year mortality and cancer association outcomes in a cohort of Omani patients with positive anti- GAD autoimmunity

ABSTRACT Objectives There is scarce data in the literature concerning the anti-GAD65 antibodies (GAD-Abs) autoimmunity in the Omani population. Methods Retrospective cohort study included GAD-Abs positive patients (n = 444) presented to a tertiary referral center in Oman from January 2005 until January 2018, with a five-year follow-up to study the cancer association and mortality outcomes. Results Out of 444 patients, 27 patients (6.1%) showed GAD-Abs related neurological disorders. Adult age group was significantly associated with more GAD-Abs related neurological manifestations compared to pediatric and adolescents age group (p = 0.045). There was no association between the presence or absence of neurological manifestations with diabetes mellitus nor the titer level of GAD-Abs. Refractory status epilepticus and stiff person syndrome were the main causes of death in patients with neurological manifestations over five years and none of them found to have associated cancer. Conclusion The GAD-Abs autoimmunity represents a spectrum of neurological manifestations with variable severity and outcome among Omanis with positive GAD-Abs testing. The results of this study will serve as a platform for future studies to address the impact of GAD-Abs autoimmunity on the morbidity, mortality and treatment efficacy in the Omani population.

A patient presenting with a panic attack and lower back pain diagnosed as stiff person syndrome: A case report

We present a case of a 43-year-old man diagnosed with hypothyroidism, autoimmune hepatitis and steroid-induced diabetes, presenting with a panic attack and backache for three months duration. He had a stiff back with right lower limb stiffness and hyperreflexia. He was confirmed to have stiff person syndrome with positive electromyography and the presence of a high titre of glutamic acid decarboxylase (GAD) antibodies. With a background history of autoimmune diseases and stiffness of limbs, it is important to have a high index of suspicion of stiff person syndrome (SPS), not to miss a treatable organic disorder.

Machine learning characterization of a rare neurologic disease via electronic health records: a proof-of-principle study on stiff person syndrome

BackgroundDespite the frequent diagnostic delays of rare neurologic diseases (RND), it remains difficult to study RNDs and their comorbidities due to their rarity and hence the statistical underpowering. Affecting one to two in a million annually, stiff person syndrome (SPS) is an RND characterized by painful muscle spasms and rigidity. Leveraging underutilized electronic health records (EHR), this study showcased a machine-learning-based framework to identify clinical features that optimally characterize the diagnosis of SPS.MethodsA machine-learning-based feature selection approach was employed on 319 items from the past medical histories of 48 individuals (23 with a diagnosis of SPS and 25 controls) with elevated serum autoantibodies against glutamic-acid-decarboxylase-65 (anti-GAD65) in Dartmouth Health’s EHR to determine features with the highest discriminatory power. Each iteration of the algorithm implemented a Support Vector Machine (SVM) model, generating importance scores—SHapley Additive exPlanation (SHAP) values—for each feature and removing one with the least salient. Evaluation metrics were calculated through repeated stratified cross-validation.ResultsDepression, hypothyroidism, GERD, and joint pain were the most characteristic features of SPS. Utilizing these features, the SVM model attained precision of 0.817 (95% CI 0.795–0.840), sensitivity of 0.766 (95% CI 0.743–0.790), F-score of 0.761 (95% CI 0.744–0.778), AUC of 0.808 (95% CI 0.791–0.825), and accuracy of 0.775 (95% CI 0.759–0.790).ConclusionsThis framework discerned features that, with further research, may help fully characterize the pathologic mechanism of SPS: depression, hypothyroidism, and GERD may respectively represent comorbidities through common inflammatory, genetic, and dysautonomic links. This methodology could address diagnostic challenges in neurology by uncovering latent associations and generating hypotheses for RNDs.

Stiff Person Syndrome and GAD Antibody-Spectrum Disorders.

Antibodies against glutamic acid decarboxylase (GAD), originally associated with stiff person syndrome (SPS), define the GAD antibody-spectrum disorders that also include cerebellar ataxia, autoimmune epilepsy, limbic encephalitis, progressive encephalomyelitis with rigidity and myoclonus (PERM), and eye movement disorders, all of which are characterized by autoimmune neuronal excitability. This article elaborates on the diagnostic criteria for SPS and SPS spectrum disorders, highlights disease mimics and misdiagnoses, describes the electrophysiologic mechanisms and underlying autoimmunity of stiffness and spasms, and provides a step-by-step therapeutic scheme. Very-high serum GAD antibody titers are diagnostic for GAD antibody-spectrum disorders and also predict the presence of GAD antibodies in the CSF, increased intrathecal synthesis, and reduced CSF γ-aminobutyric acid (GABA) levels. Low serum GAD antibody titers or the absence of antibodies generates diagnostic challenges that require careful distinction in patients with a variety of painful spasms and stiffness, including functional neurologic disorders. Antibodies against glycine receptors, first found in patients with PERM, are seen in 13% to 15% of patients with SPS, whereas amphiphysin and gephyrin antibodies, seen in 5% of patients with SPS spectrum disorders, predict a paraneoplastic association. GAD-IgG from different SPS spectrum disorders recognizes the same dominant GAD intracellular epitope and, although the pathogenicity is unclear, is an excellent diagnostic marker. The biological basis of muscle stiffness and spasms is related to autoimmune neuronal hyperexcitability caused by impaired reciprocal γ-aminobutyric acid-mediated (GABA-ergic) inhibition, which explains the therapeutic response to GABA-enhancing agents and immunotherapies. It is essential to distinguish SPS spectrum disorders from disease mimics to avoid both overdiagnoses and misdiagnoses, considering that SPS is treatable if managed correctly from the outset to prevent disease progression. A step-by-step, combination therapy of GABA-enhancing medications along with immunotherapies ensures prolonged clinical benefits.

Stiff-Person Syndrome: Results of the First Nationwide Survey in Japan

Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder characterized by progressive axial muscle stiffness, central nervous system hyperexcitability, and painful stimulus-sensitive muscle spasms. A nationwide survey performed in 2018 showed the estimated prevalence of SPS was 0.2 per 100,000 population. Most patients with SPS had antibodies against glutamic acid decarboxylase 65, followed by antibodies to the glycine receptor α-subunit. Usually, patients with SPS showed favorable outcomes; however, some studies have reported intractable SPS. Early diagnosis and aggressive immunotherapy are necessary for management of patients with SPS.

Physiotherapy rehabilitation in patients with Stiff Person Syndrome: Integrative Review

Physiotherapy rehabilitation in patients with Stiff Person Syndrome: Integrative Review

The Role of Chimeric Antigen Receptor T-Cell Therapy in Immune-Mediated Neurological Diseases.

Despite the use of 'high efficacy' disease-modifying therapies, disease activity and clinical progression of different immune-mediated neurological diseases continue for some patients, resulting in accumulating disability, deteriorating social and mental health, and high economic cost to patients and society. Although autologous hematopoietic stem cell transplant is an effective treatment modality, it is an intensive chemotherapy-based therapy with a range of short- and long-term side-effects. Chimeric antigen receptor T-cell therapy (CAR-T) has revolutionized the treatment of B-cell and other hematological malignancies, conferring long-term remission for otherwise refractory diseases. However, the toxicity of this treatment, particularly cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and the complexity of production necessitate the need for a high level of specialization at treating centers. Early-phase trials of CAR-T therapies in immune-mediated B cell driven conditions, such as systemic lupus erythematosus, neuromyelitis optica spectrum disorder and myasthenia gravis, have shown dramatic clinical response with few adverse events. Based on the common physiopathology, CAR-T therapy in other immune-mediated neurological disease, including multiple sclerosis, chronic inflammatory polyradiculopathy, autoimmune encephalitis, and stiff person syndrome, might be an effective option for patients, avoiding the need for long-term immunosuppressant medications. It may prove to be a more selective immunoablative approach than autologous hematopoietic stem cell transplant, with potentially increased efficacy and lower adverse events. In this review, we present the state of the art and future directions of the use of CAR-T in such conditions. ANN NEUROL 2024;96:441-452.

Expanding the Understanding of Stiff-Person Syndrome: Insights from 17 Cases in India.

Stiff-person syndrome (SPS) is a rare and complex neurologic disorder characterized by progressive muscle stiffness, painful spasms, and gait difficulties. In this report, we describe a case of SPS who presented with a relapse while on maintenance immunosuppressive treatment. In addition, we review the literature of 16 previously reported cases of SPS from India, highlighting the diverse clinical features, comorbidities, treatment response, and relapse. The occurrence of paraneoplastic SPS emphasizes the need for early recognition and diagnosis.

Characterization of Anti-GAD65-Associated Neurological Syndromes: Clinical Features and Antibody Titers.

Anti-GAD65 antibodies are associated with several neurological phenotypes. Antibody titers are increasingly recognized as useful in diagnosis and prognosis. To describe a Portuguese cohort of patients with anti-GAD65-associated neurological syndromes. Retrospective analysis of all patients with positive anti-GAD65 antibodies and associated neurological syndromes followed in a tertiary referral center. Nineteen anti-GAD65 antibody-positive neurological patients were identified, 62.3% female, with a mean age of onset of 56.0 (SD = 13.3) years. Comorbid autoimmune disorders were present in seven patients. Six patients had limbic encephalitis (31.6%), four had epilepsy (21.1%), four had cerebellar ataxia (21.1%), and three had stiff-person syndrome (15.8%). Two patients presented with isolated cognitive dysfunction (executive and mnesic) in the absence of other neurological symptoms. The mean follow-up time was 24.0 (14.0-42.0) months, at the end of which the mean modified Rankin Scale (mRS) value was 2.0 (1.0-4.0). Screening for malignancies was negative in all patients. Serum quantitative analysis was carried out in 18 patients, 10 of whom showed titers above previously defined cut-off points (>10,000 IU/L for ELISA and >20 mmol/L for RIA). Quantitative CSF analysis was performed in nine patients, with four showing above-threshold titers. There was no association between anti-GAD65 levels and clinical phenotype or the final mRS values. High-dose intravenous methylprednisolone and oral prednisolone were the most common acute and chronic treatment regimens, respectively. Anti-GAD65 antibodies are associated with varied neurological syndromes, and antibody titers alone should not be used to exclude a disease.