Clinical features in antiglycine receptor antibody-related disease: a case report and update literature review.

Background and objectives: Antiglycine receptor (anti-GlyR) antibody mediates multiple immune-related diseases. This study aimed to summarize the clinical features to enhance our understanding of anti-GlyR antibody-related disease. Methods: By collecting clinical information from admitted patients positive for glycine receptor (GlyR) antibody, the clinical characteristics of a new patient positive for GlyR antibody were reported in this study. To obtain additional information regarding anti-GlyR antibody-linked illness, clinical data and findings on both newly reported instances in this study and previously published cases were merged and analyzed. Results: A new case of anti-GlyR antibody-related progressive encephalomyelitis with rigidity and myoclonus (PERM) was identified in this study. A 20-year-old man with only positive cerebrospinal fluid anti-GlyR antibody had a good prognosis with first-line immunotherapy. The literature review indicated that the common clinical manifestations of anti-GlyR antibody-related disease included PERM or stiff-person syndrome (SPS) (n = 179, 50.1%), epileptic seizure (n = 94, 26.3%), and other neurological disorders (n = 84, 24.5%). Other neurological issues included demyelination, inflammation, cerebellar ataxia and movement disorders, encephalitis, acute psychosis, cognitive impairment or dementia, celiac disease, Parkinson's disease, neuropathic pain and allodynia, steroid-responsive deafness, hemiballism/tics, laryngeal dystonia, and generalized weakness included respiratory muscles. The group of PERM/SPS exhibited a better response to immunotherapy than others. Conclusions: The findings suggest the presence of multiple clinical phenotypes in anti-GlyR antibody-related disease. Common clinical phenotypes include PERM, SPS, epileptic seizure, and paraneoplastic disease. Patients with RERM/SPS respond well to immunotherapy.

[Stiff person syndrome associated with thymoma]. / Síndrome de la persona rígida asociado a timoma.

Stiff-person syndrome is a rare neurological condition characterized by muscular rigidity of the trunk and extremities and muscle spasms triggered by sensory or emotional stimuli, which progresses towards prostration. It has a pathophysiogenic mechanism with an immunological basis, in which autoantibodies, such as antiGAD65, play a central role. Likewise, the detection of these antibodies corroborates the diagnosis in a patient with a suggestive clinical picture. Four to 6% of cases have underlying neoplasms. Treatment is based on symptomatic, immunomodulatory, and underlying disease management in paraneoplastic cases. We report a case of classic stiff person syndrome associated with thymoma and review the main characteristics of this entity.

El síndrome de persona rígida es un cuadro neurológico infrecuente caracterizado por rigidez muscular de tronco y extremidades y espasmos musculares gatillados por estímulos sensoriales o emocionales, que progresa hacia la postración. Cuenta con un mecanismo fisiopatogénico con base inmunológica, en el cual los autoanticuerpos, como el antiGAD65, cumplen un rol central. Asimismo, la detección de dichos anticuerpos corrobora el diagnóstico ante un paciente con cuadro clínico sugestivo. Un 4 a 6% de los casos tienen neoplasias subyacentes. El tratamiento se basa en el manejo sintomático, inmunomodulador y de la enfermedad de base en los casos paraneoplásicos. Reportamos un caso de síndrome de persona rígida clásico asociado a timoma y describimos las características principales de esta entidad.

Rare Association of Autoimmune Limbic Encephalitis and Stiff Person Syndrome.

Antibodies to Glutamic Acid Decarboxylase (GAD) have been implicated in the pathogenesis of both autoimmune Limbic Encephalitis (LE) and Stiff Person Syndrome (SPS). However, their association is quite rare. We present a case of a 48-year-old Caucasian female who presented with symptoms of recurrent severe headaches, behavioral and cognitive dysfunction, and an episode of seizure. She was found to have high titers of anti-GAD65 antibodies in both cerebrospinal fluid and serum. She was diagnosed with LE and SPS, and was started on immunosuppressive therapy with steroids and intravenous immunoglobulins (IVIG). The patient responded well to treatment with improvement in her symptoms.

Centripetal Nystagmus, Slow Saccades, Cerebellar Ataxia, and Parkinsonism in a Patient With Anti-GAD65-Associated Stiff Person Syndrome Spectrum Disorder.

ABSTRACT: A 68-year-old woman with positional dizziness and progressive imbalance presented for vestibular evaluation. Examination was notable for spontaneous downbeat nystagmus (DBN), horizontal and vertical gaze-evoked nystagmus (GEN) with centripetal and rebound nystagmus, and positional apogeotropic nystagmus. There was also mild-moderate slowing of saccades horizontally and vertically and poor fast phases with an optokinetic stimulus. Further consultation by a movement disorder specialist uncovered asymmetric decrementing bradykinesia and rigidity, masked facies, and a wide-based stance without camptocormia. Screening serum laboratory results for metabolic, rheumatologic, infectious, heavy metal, endocrine, or vitamin abnormalities was normal. Surveillance imaging for neoplasms was unremarkable, and cerebrospinal fluid (CSF) analysis was negative for 14-3-3 and real-time quaking-induced conversion (RT-QuIC). However, her anti-glutamic acid decarboxylase-65 (GAD65) immunoglobulin G (IgG) level was markedly elevated in serum to 426,202 IU/mL (reference range 0-5 IU/mL) and in CSF to 18.1 nmol/L (reference range <0.03 nmol/L). No other autoantibodies were identified on the expanded paraneoplastic panel. The patient was referred to neuroimmunology, where torso rigidity, spasticity, and significant paravertebral muscle spasms were noted. Overall, the clinical presentation, examination findings, and extensive workup were consistent with a diagnosis of anti-GAD65-associated stiff person syndrome-plus (musculoskeletal plus cerebellar and/or brainstem involvement). She was subsequently treated with intravenous immunoglobulin (IVIg) and has been stable since commencing this therapy. In patients with centripetal nystagmus, especially in association with other cerebellar findings, an autoimmune cerebellar workup should be considered.

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.

Glutamic acid decarboxylase (GAD) antibody-positive paraneoplastic stiff person syndrome associated with mediastinal liposarcoma.

Stiff person syndrome (SPS) is a rare, debilitating neurological illness characterised by rigidity and spasms of the axial muscles, causing severe restrictions to mobility. SPS can be classic, partial or paraneoplastic. We report a case of a young woman who presented with seizures and painful spasms of the thoracolumbar muscles who was subsequently diagnosed with SPS. Serological work revealed glutamic acid decarboxylase (GAD) antibodies and imaging showed a large mediastinal mass. The patient underwent surgical resection of the mediastinal mass and final pathology revealed well-differentiated mediastinal liposarcoma. She received five sessions of plasma exchange and her neurological symptoms gradually improved after surgery. This case highlights a rare case of GAD antibody-positive paraneoplastic SPS associated with mediastinal liposarcoma.

Unusual presentation of stiff-person syndrome in a patient with type 1 diabetes mellitus.

Stiff-person syndrome (SPS) is a rare, autoimmune, neurological disorder that often occurs concurrently with other autoimmune disorders, such as type 1 diabetes mellitus, pernicious anaemia, vitiligo and Hashimoto's thyroiditis. It also can manifest as a paraneoplastic syndrome. Although SPS classically presents with truncal and appendicular stiffness and lumbar hyperlordosis, it can present focally in a single limb (termed stiff-limb syndrome). Here, we describe a woman with stiff-limb syndrome who initially presented with concerns about right foot swelling and pain. She also was positive for anti-GAD65 (anti-GAD2) antibodies. With treatment, she regained the ability to drive and ambulate without a walker, and she had a noted reduction in stimulus-induced spasms.

Thymoma-Related Stiff-Person Syndrome with Successfully Treated by Surgery.

INTRODUCTION: Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder. Paraneoplastic SPS associated with malignant tumors such as thymoma occurs in approximately 5% of all SPS cases. We present a rare case of thymoma accompanied by SPS successfully treated using surgery. PRESENTATION OF CASE: A 26-year-old woman presented with lower limbs convulsions and gait disturbance and complained of leg pain. Cerebrospinal fluid and blood test results showed a high level of anti-glutamic acid decarboxylase (GAD) antibodies. Computed tomography showed anterior mediastinal tumor suggestive of a thymoma. She underwent extended thymectomy, and her symptoms gradually improved after surgery. No evidence of recurrent thymoma and SPS has been observed over 44 months. CONCLUSION: Surgical treatment would be effective for patients with SPS and thymoma.

Stiff Person Syndrome and Encephalitis with GAD Antibodies with Severe Anterograde Amnesia in an Adolescent: A Case Study and Literature Review.

Antiglutamic acid decarboxylase (GAD65) encephalitis is rare and few pediatric cases have been reported, with variable clinical presentations. A 14-year-old female adolescent was managed in our department. She had been treated for several months for drug-resistant temporal lobe epilepsy and gradually presented major anterograde amnesia with confusion. Upon her arrival at the University Hospital Centre, she showed a classical form of stiff person syndrome. The brain magnetic resonance imaging showed bitemporal hyperintensities and hypertrophy of the amygdala. The blood and cerebrospinal fluid were positive for GAD65 antibodies. At 2 years of immunosuppressive treatment and rehabilitation, the course showed partial improvement of the memory and neuropsychiatric impairment, and epilepsy that continued to be active. GAD65 antibodies are associated with various neurological syndromes, and this presentation combining limbic encephalitis and stiff person syndrome is the first pediatric form published to date; there are also few cases described in adults.

[Stiff person syndrome associated with dermatitis herpetiformis: a case report]. / Syndrome de la personne raide associé à une dermatite herpétiforme: à propos d'un cas.

Stiff person syndrome (SPS) is a rare disease affecting the central nervous system which can be autoimmune, paraneoplastic or idiopathic in origin. Its typical classic presentation is characterized by progressive stiffness of the trunk and limbs, associated with spasms. The diagnosis is supported by the existence of continuous and spontaneous muscle activity on electroneuromyogram detection, the presence of serum anti-GAD antibodies, and a response to benzodiazepines. We report the case of a 46-year-old patient with a classic form of autoimmune stiff person syndrome associated with dermatitis herpetiformis.

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.

Anti-amphiphysin positive stiff-person syndrome due to invasive ductal carcinoma in a male patient.

Stiff-person syndrome (SPS) is a rare progressive neurological disorder characterised by painful muscle spasms and progressive muscle rigidity, leading in some cases to impaired ambulation. Anti-amphiphysin positive SPS is a paraneoplastic variant, frequently associated with breast carcinomas and small cell lung cancers. We report the case of a 53-year-old patient who developed symptoms of anti-amphiphysin positive SPS 3 years before being diagnosed with invasive ductal carcinoma. Specifically, computed tomography (CT) of the chest, abdomen and pelvis, positron emission tomography-CT (PET-CT), mammogram, colonoscopy and magnetic resonance imaging (MRI) did not identify malignancy during the 3 years following the onset of symptoms. Following diagnosis of invasive ductal carcinoma and completion of curative-intent oncological treatment, the patient experienced improvement, though not complete resolution, in his SPS symptoms. This case highlights the importance of thorough oncological workup when clinical presentation and diagnostic testing are suggestive of anti-amphiphysin positive SPS.

The case of a 30-year-old man with subacute gait instability, weakness, and muscle spasms.

A 30-year-old healthy man presents after a fall with diffuse weakness and pain and recent onset left eye ptosis in the setting of three weeks of progressive bilateral leg weakness, gait instability, and difficulty washing his hair due to upper extremity weakness. He had also developed stiffness in his neck and shoulders and uncontrollable muscle spasms. Exam was notable for ptosis, fatiguing weakness in extremities, increased tone, hyperreflexia with clonus, and spastic gait. A mediastinal mass was found on chest CT (Fig. 1), and biopsy confirmed an invasive thymoma with positive nodes. Serum testing was positive for antibodies to acetylcholine receptors as well as glutamic acid decarboxylase.

Síndrome de persona rígida: presentación de caso clínico y abordaje terapéutico / Stiff man Syndrome Clinical case presentation and therapeutic approach

Introducción: El síndrome del hombre rígido representa una rara enfermedad neuromuscular caracterizada por rigidez muscular progresiva y espasmos musculares dolorosos que afecta a 1 persona por cada millón de habitantes por año en el mundo. En la mayoría de los pacientes se encuentran niveles elevados de anticuerpos descarboxilasa del ácido glutámico. En Colombia solo se han publicado alrededor de 3 casos, lo que motiva la presentación de un nuevo informe que aporte a la discusión actual en el campo de la neurología clínica. Caso clínico: Paciente de sexo femenino de 35 años con cuadro clínico progresivo de varios años, caracterizado por contracciones paroxísticas dolorosas, parestesias y pérdida de fuerza. Se documentó la presencia de anticuerpos anti-GAD compatibles con el síndrome del hombre rígido. Tras un tratamiento integral, que incluyó la infusión farmacológicamente intratecal con baclofeno, se obtuvo mejoría clínica en el índice de Barthel. Conclusiones: El síndrome del hombre rígido es una condición infradiagnosticada que se asocia a un deterioro de la calidad de vida de quienes lo padecen.

Introduction: Stiff man syndrome represents a rare neuromuscular disease characterized by progressive muscle rigidity and painful muscle spasms that affects 1 person for every million habitants per year in the world. High levels of glutamic acid antibodies decarboxylase are found in most patients. In Colombia, only around 3 cases have been published, which motivates the presentation of a new report that contributes to the current discussion in the field of clinical neurology. Clinical Case: 35-year-old female patient with a progressive clinical picture of several years, characterized by painful paroxysmal contractions, paresthesias and loss of strength. The presence of anti-GAD antibodies was documented, compatible with Stiff man syndrome. After comprehensive treatment, which included pharmacologically intrathecal infusion with baclofen, clinical improvement was obtained in the Barthel index. Conclusions: Stiff man syndrome is an underdiagnosed condition which is associated with a deterioration in the quality of life for those who suffer from it.

Neurological Syndromes Associated with Anti-GAD Antibodies.

Glutamic acid decarboxylase (GAD) is an intracellular enzyme whose physiologic function is the decarboxylation of glutamate to gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter within the central nervous system. GAD antibodies (Ab) have been associated with multiple neurological syndromes, including stiff-person syndrome, cerebellar ataxia, and limbic encephalitis, which are all considered to result from reduced GABAergic transmission. The pathogenic role of GAD Ab is still debated, and some evidence suggests that GAD autoimmunity might primarily be cell-mediated. Diagnosis relies on the detection of high titers of GAD Ab in serum and/or in the detection of GAD Ab in the cerebrospinal fluid. Due to the relative rarity of these syndromes, treatment schemes and predictors of response are poorly defined, highlighting the unmet need for multicentric prospective trials in this population. Here, we reviewed the main clinical characteristics of neurological syndromes associated with GAD Ab, focusing on pathophysiologic mechanisms.

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.

Síndrome de persona rígida confundido por trastorno conversivo: un error común. caso clínico / Stiff-person syndrome mistaken for conversive disorder: a common error

Stiff-person syndrome is characterized by persistent muscle spasms, involving agonist and antagonist muscles simultaneously, starting in the lower limbs and trunk. It tends to occur in the fourth to sixth decade of life, presenting with intermittent spasms that later become continuous and usually painful. Minor sensory stimuli, such as noise or light touch, precipitate severe spasms. Spasms do not occur during sleep and only rarely involve cranial muscles. We present a case that for two years was diagnosed and treated as a conversion disorder associated with depression. After two years she was admitted to another hospital with an unmistakable picture of stiff-person syndrome with hypertrophy and rigidity of lower limb muscles, compatible electrophysiology and positive anti-GAD antibodies. She had autoimmune hypothyroidism, that should have raised the suspicion of stiff-person syndrome earlier. She responded to intravenous immunoglobulin and mycophenolate mofetil and and to tranquilizers that have muscle relaxant properties.

The neurological syndromes associated with glutamic acid decarboxylase antibodies.

A number of neurological syndromes have been described in patients with positive serum antibodies (Abs) against the enzyme glutamic acid decarboxylase (GAD), the rate limiting step in the synthesis of GABA (γ-aminobutyric acid). These disorders include: classical stiff-person syndrome and variants, cerebellar ataxia, limbic and extra-limbic encephalitis, nystagmus/oculomotor dysfunction, drug-resistant epilepsy, paraneoplastic stiff-person syndrome and progressive encephalopathy with rigidity and myoclonus (PERM), the latter two are mainly related to amphiphysin and the glycine receptor Abs respectively; but patients may also have positive GAD-Abs. Although observations are consistent with an autoimmune response in these patients and there is evidence of GABAergic dysfunction in some cases; the pathogenic role of GAD-Abs in the nervous system has not been clarified and it is a matter of debate. The diagnosis of these syndromes is based on clinical grounds plus the presence of GAD-Abs in serum and CSF with demonstration of intrathecal secretion. Although some presentations may be negative for GAD-Abs, such as stiff-person syndrome; positive GAD-Abs are required for the diagnosis in patients with cerebellar ataxia, encephalitis, and epilepsy. Immunotherapy is required for most patients. Intravenous immunoglobulins, oral or IV steroids and plasma exchange are considered the first line options, aimed to induce remission, but chronic immunosuppression is usually required. Symptomatic therapy should also be provided, aimed to control muscle spasms, seizures, delirium, etc. Prognosis varies among patients; but it is considered intermediate between that of patients with neurological syndromes associated with neural Abs against membrane antigens and those with onconeural Abs.

Síndrome de la persona rígida / Stiff-man syndrome

El síndrome de la persona rígida es un trastorno neurológico infrecuente y desconcertante, caracterizado por contractura progresiva, rigidez y espasmos dolorosos que afectan la musculatura axial, lo que imposibilita la deambulación del paciente. Se presenta un paciente masculino de 22 años de edad con manifestaciones clínicas y electromiográficas compatibles con esta entidad nosológica. El tratamiento descrito para la enfermedad no produjo mejoría de los síntomas. Con respecto a los casos descritos en la literatura científica, es el primer paciente con diagnóstico de síndrome de la persona rígida que ha recibido una dosis de diazepam de 500 mg diarios por vía oral sin efectos adversos y una dosis en bolo de propofol de 800 mg para lograr la relajación muscular(AU)

Stiff-Man Syndrome is an uncommon and disturbing neurological disorder characterized by progressive contracture, stiffness and painful spasms that affect the axial musculature, making it impossible for the patient to walk around. We present a 22-year-old male patient with clinical and electromyographic manifestations compatible with this nosological disease. The treatment described for the disease did not produce an improvement in symptoms. Regarding the cases described in the scientific literature, this is the first patient diagnosed with Stiff-Man Syndrome who has received a dose of diazepam of 500 mg daily orally without adverse effects and a bolus dose of 800 mg of propofol to achieve muscle relaxation(AU)