[A case of Stiff-person syndrome with muscle tonicity of the extremities and neck after use of Dulvalumab for lung adenocarcinoma]

A 74-year-old woman taking dulvalumab for lung adenocarcinoma developed muscle tonicity in the extremities and trunk. Painful paroxysmal muscle spasms with profuse sweating were frequently observed, and surface electromyography showed simultaneous contraction of the active and antagonist muscles. Blood tests were strongly positive for anti-amphiphysin antibodies, and stiff-person syndrome (SPS) was diagnosed. Intravenous immunoglobulin therapy and clonazepam were initiated, and the paroxysmal painful muscle spasms disappeared. As the primary tumor was under control, and the onset occurred approximately six weeks after the resumption of immune checkpoint inhibitors, we considered SPS to be an immune-related adverse event. Although extremely rare, it should be considered a neuromuscular disease that can occur in association with immune checkpoint inhibitors.

Remimazolam and Remifentanil Anesthetics for an Adolescent Patient with Stiff-Person Syndrome: A Case Report

Stiff-person syndrome (SPS) is a rare autoimmune disease characterized by fluctuating rigidity and stiffness of the axial muscles. There are no reports on the use of remimazolam in a patient with SPS. A 16-year-old Japanese woman with SPS was scheduled to undergo intrathecal baclofen pump exchange. General anesthesia was induced and maintained using remimazolam, remifentanil, and intermittent rocuronium bromide. No intraoperative mobility or significant autonomic symptoms were observed. Additionally, electroencephalographic signature showed sufficient anesthetic depth. The patient's emergence from general anesthesia was uneventful. In conclusion, remimazolam could be considered an effective anesthetic drug for patients with SPS.

A case report of integrating Chinese and Western medicine: A new era in the treatment of stiff person syndrome

RATIONALE

At present, there are limitations to the treatment of stiff person syndrome (SPS). Current treatments are still ineffective or financially burdensome for some patients, so it is imperative to explore more appropriate treatments for patients. This is a case report of a SPS with a more significant effect of combined Chinese and Western medicine, which may provide new treatment ideas for other patients.

PATIENT CONCERNS

This patient presented with episodes of stiffness and pain in the lower back and lower extremities. His electromyography shows continued activation of normal motor units in the paraspinal and abdominal muscles. However, relevant laboratory tests including glutamic acid decarboxylase antibody and Amphiphysin antibody were negative. After a period of treatment including clonazepam, baclofen, prednisone and intravenous immunoglobulin, this patient experiences a shortened maintenance period of medication, accompanied by symptoms such as emotional anxiety and cognitive decline, which severely affects his life.

DIAGNOSES

This patient was diagnosed with SPS.

INTERVENTIONS

In May 2022 the patient decided to combine Chinese medicine for simultaneous treatment.

OUTCOMES

During the period of simultaneous treatment with Chinese and Western medicine, the patient experienced remission of clinical symptoms, reduction of concomitant symptoms and improved quality of life.

CONCLUSION

A combination of Western and Chinese medicine was effective in relieving this patient pain and stiffness and reducing the patient anxiety. Combined Chinese and Western medicine treatment may be able to bring better results to more patients with stiff person syndrome.

H - 38 Neuropsychological Evaluation and Cognitive Profile of Stiff Person Syndrome (SPS) in a Predominantly Spanish-Speaking Older Adult: Is Cognition Really Affected?

OBJECTIVE

Stiff Person Syndrome (SPS) is a rare autoimmune disorder that affects approximately one in every million people. It is characterized by progressive muscle rigidity and intense, episodic muscle spasms triggered by environmental and psychosocial (i.e., emotional stress) factors. While original diagnostic criteria for classical SPS included the absence of frank cognitive impairment (aside from what would be expected from seizures), more recent literature suggests a number of neurocognitive difficulties potentially associated with reduced GABA levels.

METHOD

The following case study presents a 73-year-old, predominantly Spanish-speaking man with 14 years of education. His medical history is notable for over 20 years with diagnosed SPS, hypertension well managed with medications, and the absence of other medical conditions that may contribute to cerebrovascular burden. He completed a comprehensive neuropsychological evaluation in Spanish.

RESULTS

Overall, his profile was notable for mild inefficiencies in frontal-subcortical functions, with a relative weakness in rote learning and retention. He performed remarkably well relative to his level of motor compromise. There was no evidence of either a mild or major neurocognitive disorder, and his clinical interview and behavioral inventories were suspicious for a personality disorder.

CONCLUSIONS

Recent literature proposes SPS is related to impairment in verbal learning, retention, fluency, processing speed, and attention. The present case corroborated, at most, mild inefficiencies in these previously documented areas. Careful consideration should be used in the evaluation of studies on SPS and cognition, particularly in determining whether samples had high degrees of comorbid conditions (i.e., cerebrovascular burden) that could help explain positive findings related to cognition.

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.

[Isolated ACTH deficiency clinically presented as stiff-person syndrome, successfully treated by hormonal replacement: a case report]

A 65-year-old man was admitted to our hospital with a 6-year history of painful muscle stiffness in his trunk and lower limbs, preventing him from walking. Stiff-person syndrome (SPS) was diagnosed because the patient had symptoms of painful muscle spasms elicited by tactile stimulation without joint contracture. Although SPS- related autoantibodies in the serum, including anti-glycine R, anti-amphiphysin, anti-glutamic acid decarboxylase (GAD), anti-dipeptidyl peptidase-like protein (DPPX) and anti-γ-aminobutyric acid-A (GABA_A) R, were negative, the ACTH and cortisol levels were low. On the basis of additional loading tests for anterior pituitary function and ACTH, isolated ACTH deficiency (IAD) was diagnosed. Hormonal replacement therapy with hydrocortisone at 15 mg/day ameliorated the condition quickly, and the patient became asymptomatic after three months. Flexion contractures have been reported as musculoskeletal symptoms of IAD, but are not usually evident in patients with SPS. The present case illustrates that the painful muscle spasms elicited by tactile stimulation without joint contracture characteristic of SPS can also be symptoms of IAD.

Long-term Effectiveness of IVIg Maintenance Therapy in 36 Patients With GAD Antibody–Positive Stiff-Person Syndrome

Background and Objectives

IVIg has been the preferred immunotherapy in stiff-person syndrome (SPS) based on a 3-month controlled trial, but whether it is also effective in inducing long-term benefits or arresting disease progression is unknown. The information is needed because SPS is a progressively disabling disease and IVIg is liberally used as chronic therapy without efficacy data. The present study explores the long-term effects of IVIg in the largest cohort of well-characterized patients with SPS followed by the same clinicians over 10 years.

Methods

Data of 36 patients (32 glutamic acid decarboxylase [GAD] positive), diagnosed and treated with monthly maintenance IVIg by the same neurologists, were analyzed. Response was assessed by physician-observed changes, patients' reports of symptom improvement, modified Rankin Scale (mRS) scores, and dependency trials evaluating symptom recurrence after stopping IVIg, prolonging infusion frequency, decreasing monthly dose, or wearing-off effects in between doses. Clinically meaningful long-term response was defined by improved mRS scores, improvement in physician-assessed stiffness, balance and gait, and functional decline with dependency trials.

Results

Twenty-four of 36 (67%) patients had clinically meaningful response over a median 40-month period. Patients with improved mRS scores by 1–2 points manifested improved gait, posture, balance and decreased stiffness, spasms, and startle response; some patients using a wheelchair and those ambulating with devices walked unassisted. In 25% of responders, treatment benefit was sustained for a 40-month median period, but in 29.1%, it declined over a 39-month period; 12.5% exhibited a conditioning effect. Three of 5 patients with cerebellar GAD-SPS variant also improved over time. The 12 patients who did not respond the first 3 months remained unresponsive even if IVIg continued for several months.

Discussion

This is a large study in 36 patients with SPS demonstrating that monthly maintenance IVIg therapy offers long-term benefits in 67% of patients for a median 3.3-year period. Because 29.1% experienced diminishing benefit over time due to disease progression, the study highlights the need for more effective therapies.

Stiff-person Syndrome and GAD Antibody-spectrum Disorders: GABAergic Neuronal Excitability, Immunopathogenesis and Update on Antibody Therapies

Although antibodies against Glutamic Acid Decarboxylase (GAD) were originally associated with Stiff Person Syndrome (SPS), they now denote the "GAD antibody-spectrum disorders (GAD-SD)" that include Cerebellar Ataxia, Autoimmune Epilepsy, Limbic Encephalitis, PERM and eye movement disorder. In spite of the unique clinical phenotype that each of these disorders has, there is significant overlapping symptomatology characterized by autoimmune neuronal excitability. In addition to GAD, three other autoantibodies, against glycine receptors, amphiphysin and gephyrin, are less frequently or rarely associated with SPS-SD. Very high serum anti-GAD antibody titers are a key diagnostic feature for all GAD-SD, commonly associated with the presence of GAD antibodies in the CSF, a reduced CSF GABA level and increased anti-GAD-specific IgG intrathecal synthesis denoting stimulation of B-cell clones in the CNS. Because anti-GAD antibodies from the various hyperexcitability syndromes recognize the same dominant GAD epitope, the clinical heterogeneity among GAD-SD patients remains unexplained. The paper highlights the biologic basis of autoimmune hyperexcitability connected with the phenomenon of reciprocal inhibition as the fundamental mechanism of the patients' muscle stiffness and spasms; addresses the importance of high-GAD antibody titers in diagnosis, pinpointing the diagnostic challenges in patients with low-GAD titers or their distinction from functional disorders; and discusses whether high GAD-antibodies are disease markers or pathogenic in the context of their association with reduced GABA level in the brain and CSF. Finally, it focuses on therapies providing details on symptomatic GABA-enhancing drugs and the currently available immunotherapies in a step-by-step approach. The prospects of future immunotherapeutic options with antibody therapies are also summarized.

Transient Neurological Symptoms Preceding Cerebellar Ataxia with Glutamic Acid Decarboxylase Antibodies

A prompt diagnosis and treatment of patients with autoimmune cerebellar ataxia (CA) with antibodies against glutamic acid decarboxylase (GAD-Abs) may lead to a better prognosis. Herein, we report prodromal transient neurological symptoms that should raise clinical suspicion of CA with GAD-Abs. We initially identified a 70-year-old man who presented a first acute episode of vertigo, diplopia, and ataxia lasting 2 weeks. Two months later, he experienced a similar episode along with new-onset gaze-evoked nystagmus. After 4 months, downbeat nystagmus, left limb dysmetria, and gait ataxia progressively appeared, and an autoimmune CA was diagnosed based on the positivity of GAD-Abs in serum and cerebrospinal fluid (CSF). We searched retrospectively for similar presentations in a cohort of 31 patients diagnosed with CA and GAD-Abs. We found 11 (35.4%) patients (all women, median age 62 years; 8/11 [72.7%] with autoimmune comorbidities) with transient neurological symptoms antedating CA onset by a median of 3 months, including vertigo in 9 (81.8%; described as paroxysmal in 8) and fluctuating diplopia in 3 (27.3%) patients. The identification of transient neurological symptoms of unknown etiology, such as paroxysmal vertigo and fluctuating diplopia, should lead to GAD-Abs testing in serum and CSF, especially in patients with autoimmune comorbidities.

Neurologic syndromes related to anti-GAD65: Clinical and serologic response to treatment

OBJECTIVE

Antibodies against glutamic acid decarboxylase 65 (anti-GAD65) are associated with a number of neurologic syndromes. However, their pathogenic role is controversial. Our objective was to describe clinical and paraclinical characteristics of anti-GAD65 patients and analyze their response to immunotherapy.

METHODS

Retrospectively, we studied patients (n = 56) with positive anti-GAD65 and any neurologic symptom. We tested serum and CSF with ELISA, immunohistochemistry, and cell-based assay. Accordingly, we set a cutoff value of 10,000 IU/mL in serum by ELISA to group patients into high-concentration (n = 36) and low-concentration (n = 20) groups. We compared clinical and immunologic features and analyzed response to immunotherapy.

RESULTS

Classical anti-GAD65-associated syndromes were seen in 34/36 patients with high concentration (94%): stiff-person syndrome (7), cerebellar ataxia (3), chronic epilepsy (9), limbic encephalitis (9), or an overlap of 2 or more of the former (6). Patients with low concentrations had a broad, heterogeneous symptom spectrum. Immunotherapy was effective in 19/27 treated patients (70%), although none of them completely recovered. Antibody concentration reduction occurred in 15/17 patients with available pre- and post-treatment samples (median reduction 69%; range 27%-99%), of which 14 improved clinically. The 2 patients with unchanged concentrations showed no clinical improvement. No differences in treatment responses were observed between specific syndromes.

CONCLUSION

Most patients with high anti-GAD65 concentrations (>10,000 IU/mL) showed some improvement after immunotherapy, unfortunately without complete recovery. Serum antibody concentrations' course might be useful to monitor response. In patients with low anti-GAD65 concentrations, especially in those without typical clinical phenotypes, diagnostic alternatives are more likely.

C.292G>A, a novel glycine receptor alpha 1 subunit gene (GLRA1) mutation found in a Chinese patient with hyperekplexia: A case report

INTRODUCTION

Hyperekplexia is a rare hereditary neurological disorder; only 5 glycine receptor alpha 1 subunit gene (GLRA1) mutations have been reported in 5 Chinese patients. We report a Chinese infant with hyperekplexia and a novel mutation at c.292G > A.

PATIENT CONCERNS

A Chinese infant with hyperekplexia and a novel mutation at c.292G > A.

DIAGNOSIS

All exons of GLRA1 were sequenced in her parents and her, which revealed a mutation at c.1030C > T and another novel mutation at c.292G > A. Her diagnosis was confirmed as hereditary hyperekplexia with GlRA1 hybrid gene mutations based on the sequencing results.

INTERVENTIONS

She was treated with clonazepam.

OUTCOMES

Her muscle hypertonia recovered rapidly and the excessive startle reflex to unexpected stimuli was significantly reduced.

CONCLUSION

Genetic DNA sequencing is a crucial method for diagnosing hyperekplexia-related gene mutation.

Low-Dose Naltrexone reduces symptoms in Stiff-Person Syndrome

Stiff-Person Syndrome (SPS) is a rare neurologic disorder characterized by severe and progressively worsening muscle stiffness and rigidity. SPS can be very painful due to unpredictable muscle spasms which can be triggered by various stimuli, such as noise, touch, or emotional experiences. There is thought to be an autoimmune component to the disorder. We present the case of a 59-year-old woman diagnosed with SPS who appears to have experienced a dramatic reduction in her symptoms after being treated with Low-Dose Naltrexone (LDN). Prior to this treatment regimen, she had tried many treatments with only limited derived benefit. She was started on LDN and after 6 weeks, reported reductions in pain, anxiety, depression, agoraphobia, and muscle tightness. Upon multiple follow-ups, leading up to 12 months, she continually displayed reduced symptoms and improved quality of life. We conclude that LDN may have some utility in treating and managing the symptoms of SPS. We hypothesize that this may be possible due to LDN operating via anti-inflammatory pathways as well as acting as an opioid antagonist. We assert that further research as it relates to LDN and SPS in addition to other chronic pain conditions is warranted.

Stiff limb syndrome with lower limb myoclonus: A case report

RATIONALE

stiff limb syndrome (SLS) is a variant of stiff-man syndrome, primarily affecting a specific limb. Its diagnosis has always been challenging due to the lack of a specific confirmation test. We present a rare case of a patient with lower limb myoclonus and rigidity.

PATIENT CONCERNS

A 53-year-old male presented with a sudden onset of progressive left lower extremity myoclonus and muscle rigidity for 3 days. He rapidly showed signs of right lower limb involvement with severe joint stiffness and inability to walk.

DIAGNOSIS

The symptoms nature, physical examination, careful elimination of differential diagnosis suggested a diagnosis of stiff limb syndrome.

INTERVENTIONS

Intravenous infusion of gamma globulin 0.4 mg/kg coupled with baclofen and clonazepam were given after admission. He also received an injection of botulinum toxin A to relieve his muscle stiffness.

OUTCOMES

The patients' condition improved after the initial treatment with complete disappearance of muscle twitching. Further improvements were seen later on after the local administration of botulinum toxin A.

LESSONS

Stiff limb syndrome shares the same complex symptoms with many other conditions. Its diagnosis relies heavily on clinical presentations and on ruling out other conditions. However, unusual symptoms such as myoclonus can occur in few cases and together with the rarity of the condition, the prevalence of misdiagnosis is high. Therefore, being aware and recognizing the signs and symptoms is crucial for proper management. Additionally, EMG is a very important test if the present condition is suspected. However, a negative EMG result or a negative anti-glutamic acid decarboxylase antibody test should not exclude SLS diagnosis.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

A Case of Treatment Resistance and Complications in a Patient with Stiff Person Syndrome and Cerebellar Ataxia

Background

Antibodies against glutamic acid decarboxylase (GAD) are associated with Stiff Person Syndrome (SPS).

Case report

A 50-year-old woman presented with symptoms progressed over 9 years, resulting in a cerebellar ataxia and right upper limb tremor. Investigations revealed elevated serum and CSF anti-GAD antibody titres (98.6 and 53.4 μ/ml, respectively). Treatment included intravenous immunoglobulin and immunomodulation (infliximab and rituximab), improving her stiffness, but with no impact on the ataxia-related symptoms. Subsequent high-dose steroids led to diabetic ketoacidosis and unmasking of an insulin-dependent diabetes mellitus.

Discussion

This case illustrates several key features: (1) the combined clinical picture of SPS and cerebellar ataxia is a rare phenotype associated with anti-GAD antibodies; (2) the cerebellar ataxia described was progressive and poorly responsive to immunomodulatory therapy; and (3) the potential for development of further autoimmune sequelae in response to immunosuppression, namely, the development of insulin-dependent diabetes in response to treatment with high-dose oral steroids.

[Pathophysiology of the glutamate and the glycine transporters: new therapeutic targets]

INTRODUCTION

The amino acids glutamate and glycine, apart from their role in protein synthesis, are two fundamental neurotransmitters in the central nervous system of mammals. The first one is ubiquitous and is involved in excitatory pathways of the neocortex, the retina and the cerebellum, and the second is involved in inhibitory pathways of brain caudal areas. However, both share their way of acting by integrating into the functioning of glutamate receptors of the NMDA type fundamentals in the regulation of motor, sensory and cognitive systems.

AIM

To highlight the need for a fine regulation of glutamate and glycine concentrations in the intracellular and extracellular spaces of the nervous system through the action of very specific transporters for both neurotransmitters located in the plasma membrane of neurons and glial cells.

DEVELOPMENT

The role of the glutamate and glycine transporters in glutamatergic and glycinergic neurotransmission and in the functioning of the nervous system is described. The pathological consequences of imbalances in these signaling pathways are pointed out. We also describe its involvement in pathologies such as schizophrenia, chronic pain, cerebral ischemia, diseases such as hereditary hyperekplexia and the non-ketotic hyperglycinemia, and neurodegenerative disorders.

CONCLUSIONS

The knowledge at molecular level of the way of acting of these transporters for glutamate and glycine is allowing the identification and development of new therapeutic strategies for pathologies such as those described above and the development of new drugs.

Stiff-person Syndrome with Waldenström Macroglobulinemia

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

A Case of Stiff Person Syndrome: Immunomodulatory Effect of Benzodiazepines: Successful Rituximab and Tizanidine Therapy

Stiff person syndrome (SPS) is a rare autoimmune disease. Most patients have high-titer antibodies against glutamate decarboxylase (GADAb), which is without practical value in disease monitoring. Benzodiazepines are the first line drugs, but long-term use is not well characterized. This report demonstrates ineffective benzodiazepine therapy of SPS that prompts tachyphylaxis, loss of responsiveness, and finally benzodiazepine withdrawal syndrome. Convulsion and anxiety correlate with high level of creatine phosphokinase (CK). Although tonus and spasm attacks were successfully controlled by tizanidine, glutamate release inhibitor, the immune response, and autoimmune diabetes development require the plasmapheresis, mycophenolat mofetil, and rituximab therapy that results in a significant decrease of GADAb, impaired glucose tolerance (IGT), lactate dehydrogenase (LDH), and CK normalization. Unfortunately, reintroduction of benzodiazepine was a source of rapid and high increase of CK, LDH, GADAb titer (up to 1:15,000), IGT, and SPS relapse. Contrary to previous publications, we observed IGT that correlated with high anti-GAD level, but without high immunogenetic susceptibility to haplotype human leukocyte antigens-DR3, DQw2. This preliminary observation and the last finding of immunomodulatory properties of peripheral benzodiazepine receptor suggest that increased antigenic stimulation during benzodiazepine therapy and glutamatergic hyperactivity could account for convulsions observed in SPS. Benzodiazepine withdrawal prompted alternative muscle relaxant therapy (tizanidine). Muscular and brain abnormalities observed in SPS indicate that noncardiac CK level may be a useful tool in SPS therapy monitoring.

Anaesthetic management of Stiff Man syndrome

Stiff Man syndrome or stiff-person syndrome is a rare autoimmune disorder. It is characterized by increased axial muscular tone and limb musculature, and painful spasms triggered by stimulus. The case is presented of a 44-year-old man with stiff-person syndrome undergoing an injection of botulinum toxin in the urethral sphincter under sedation. Before induction, all the surgical team were ready in order to minimise the anaesthetic time. The patient was monitored by continuous ECG, SpO2 and non-invasive blood pressure. He was induced with fractional dose of propofol 150 mg, fentanyl 50 μg and midazolam 1mg. Despite careful titration, the patient had an O2 saturation level of 90%,which was resolved by manual ventilation. There was no muscle rigidity or spasm during the operation. Post-operative recovery was uneventful and the patient was discharged 2 days later. A review of other cases is presented. The anaesthetic concern in patients with stiff-person syndrome is the interaction between the anaesthetic agents, the preoperative medication, and the GABA system. For a safe anaesthetic management, total intravenous anaesthesia is recommended instead of inhalation anaesthetics, as well as the close monitoring of the respiratory function and the application of the electrical nerve stimulator when neuromuscular blockers are used.

[Stiff baby syndrome is a rare cause of neonatal hypertonicity]

Stiff baby syndrome (hyperekplexia) is a rare genetic disorder. The condition can easily be misdiagnosed as epilepsy or severe sepsis because of hypertonicity and seizure-like episodes and has an increased risk of severe apnoea and sudden infant death. Tapping of the nasal bridge inducing a startle response is the clinical hallmark. We report cases of two sisters born with stiff baby syndrome with hypertonicity, exaggerated startle reaction and cyanosis. The syndrome has a good prognosis if treated with clonazepam and both cases were developmental normal after one year.

[Stiff person syndrome--case report]

Stiff person syndrome (SPS) is the rare disease and cause great inefficient. It is characterized by progressive stiffness muscles of trunk and the limbs on which the cramps of muscles overlap. In the electrophysiological investigation of the patients the involuntary discharge of motor unit potentials find and also simultaneous contraction agonistic and antagonistic muscles. SPS is presented with insulin-dependent diabetes mellitus often or is the symptom of the paraneoplastic syndrome. It is commonly associated with high anti-glutamic acid decarboxylaze (GAD) antibody titters in the serum of the blood of patients. Establishing the diagnosis can cause difficulties. We observed the patient in the last period about the atypical course the disease. The diagnosis was confirmed occurrences of the high titters of antibodies anti-GAD, the discharge of motor unit potential in paraspinal muscles in the rest and good response the treatment with diazepamem.

Une lombalgie révélatrice d’un syndrome de l’homme raide

Le syndrome de l'homme raide est une pathologie neurologique rare. Son diagnostic est souvent très retardé à cause de sa présentation trompeuse. L′expression clinique est purement motrice, progressive avec une hypertonie axiale et des racines des membres, une hyperlordose souvent douloureuse, et un examen neurologique normal en dehors d'une augmentation des réflexes ostéotendineux. Le diagnostic est confirmé par l'examen électromyographique des muscles para-spinaux lombaires avec persistance d'une activité au repos de potentiel d'unité motrice d'allure normale, et une augmentation des anticorps anti acide glutamique décarboxylase (GAD). Le traitement de référence est le diazépam. Les immunoglobulines intraveineuses ont amélioré la qualité de vie des patients. L′évolution est longue et, si l′aggravation peut être stoppée, l′amélioration est souvent incomplète. Nous rapportons une observation de syndrome de l'homme raide, découvert à l'occasion de lombalgies mécaniques chroniques résistantes aux antalgiques améliorées par des cures d'immunoglobulines intraveineuses.

[Successful treatment with rituximab in a refractory Stiff-person syndrome]

Stiff person syndrome is a rare autoimmune disorder characterized by axial and limb progressive stiffness with surimposed spasms and production of autoantibodies to glutamic acid decarboxylase (GAD). We report a case of a 50-year-old woman who developed a stiff person syndrome resistant to conventional immunosuppressive treatments. Eight months after treatment, indexes of stiffness and spasm frequency improved, while however, the blood and CSF rates of anti-GAD increased. This observation illustrates the complexity of stiff person syndrome immunopathogenesis as well as the relevance of rituximab in this indication.

Presumed case of "stiff-horse syndrome" caused by decreased gamma-aminobutyric acid (GABA) production in an American Paint mare

Glutamic acid decarboxylase (GAD) converts glutamic acid into the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Increased serum GAD (auto) antibody concentrations were found in a mare with increased postural musculature tone resulting in stiffness and recumbence. The mare was treated with dexamethasone which resulted in resolution of clinical signs and decreased GAD antibody concentrations.

Long-lived plasma cells and memory B cells produce pathogenic anti-GAD65 autoantibodies in Stiff Person Syndrome

Stiff person syndrome (SPS) is a rare, neurological disorder characterized by sudden cramps and spasms. High titers of enzyme-inhibiting IgG autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GAD65) are a hallmark of SPS, implicating an autoimmune component in the pathology of the syndrome. Studying the B cell compartment and the anti-GAD65 B cell response in two monozygotic twins suffering from SPS, who were treated with the B cell-depleting monoclonal anti-CD20 antibody rituximab, we found that the humoral autoimmune response in SPS is composed of a rituximab-sensitive part that is rapidly cleared after treatment, and a rituximab-resistant component, which persists and acts as a reservoir for autoantibodies inhibiting GAD65 enzyme activity. Our data show that these potentially pathogenic anti-GAD65 autoantibodies are secreted by long-lived plasma cells, which may either be persistent or develop from rituximab-resistant memory B lymphocytes. Both subsets represent only a fraction of anti-GAD65 autoantibody secreting cells. Therefore, the identification and targeting of this compartment is a key factor for successful treatment planning of SPS and of similar autoimmune diseases.

Successful treatment with rituximab in a patient with stiff-person syndrome complicated by dysthyroid ophthalmopathy

We report a patient with stiff-person syndrome and insulin-dependent diabetes mellitus with anti-glutamic acid decarboxylase (GAD) antibody, who suddenly complained of diplopia due to dysthyroid ophthalmopathy. Therapeutic efficacy of plasmapheresis and high-dose intravenous immunoglobulin was transient. After starting administration of rituximab, the patient showed obvious improvement of muscle spasms due to stiff-person syndrome and ophthalmoplegia following quick depletion of CD20-positive cells in peripheral blood. The anti-GAD and anti-thyroid antibodies decreased slowly. This drug might be a potent therapeutic option for refractory patients with stiff-person syndrome, particularly in those associated with dysthyroid ophthalmopathy.

Successful intrathecal baclofen therapy for seronegative stiff-person syndrome: a case report

We reported a 27-year-old man presenting with progressive muscle rigidity and intermittent spasms for six years. The diagnosis of stiff-person syndrome was based on the clinical features and neuroelectrophysiologic findings of continuous motor unit activities. Autoantibody against glutamic acid decarboxylase in our patient was absent either in serum or in cerebrospinal fluid. The patient was successfully treated with intrathecal baclofen therapy after a series of unsatisfactory traditional medical treatments. From our experience, we propose that intrathecal baclofen could be a considerable alternative treatment for patients with refractory stiff-person syndrome.

Anaesthetic implications of hyperekplexia--'startle disease'

This report describes anaesthesia for consanguineous siblings with the rare genetic condition hyperekplexia. This condition is also known as 'stiff baby syndrome' or 'startle disease'. Hyperekplexia can present in major and minor forms and is caused by a mutation in chromosome 5 which results in a defect in the alpha-1 subunit of the inhibitory glycine receptors in the caudal pontine reticular formation leading to neuronal hyperexcitability. The patients present with a potentially life-threatening exaggerated startle reflex. Life-threatening spasms may be terminated by forced flexion of the head and legs towards the trunk. Anaesthesia management should avoid stimuli which trigger the reflex. Clonazepam and diazepam are used to prevent and control the spasms. Propofol and other agents with the ability to potentiate both GABA-ergic and glycinergic transmission may be appropriate choices for anaesthesia. Reaction to neuromuscular blockers may be unpredictable. Both our patients had relatively prolonged but otherwise uneventful recovery.

Stiff-person syndrome with acute recurrent peripheral vertigo: possible evidence of gamma aminobutyric acid as a neurotransmitter in the vestibular periphery

OBJECTIVE

We report a case of a 58-year-old man suffering from stiff-person syndrome and recurrent peripheral vertigo.

METHOD

A case report and a review of the recent literature on stiff-person syndrome are presented.

RESULTS

The patient presented with recurrent episodes of vertigo with a pure peripheral pattern and with concomitant episodes of burning muscle pain, muscle twitching, weight gain and fatigue, worsening with tension or stress that also occurred in periods without vertigo. Cochlear examinations only showed presbyacusis-like hearing loss. The diagnosis of stiff-person syndrome was made with electromyographic examination and from findings in the blood and cerebrospinal fluid of high titres of anti-glutamic acid decarboxylase (GAD67) autoantibodies. In a two-year follow-up period, therapy for stiff-person syndrome abolished episodes of both stiffness and vertigo.

CONCLUSION

As far as we know, no other clinical case of acute vestibular damage with a possible correlation with anti-glutamic acid decarboxylase antibodies has been described. Peripheral vertigo possibly related to a lack of gamma aminobutyric acid underlines a possible role of gamma aminobutyric acid as a neurotransmitter in the peripheral vestibular system.

[Stiff-person syndrome with elevated anti-Epstein-Barr virus antibody]

Stiff-person syndrome, a relatively rare disease with a poor prognosis, presents as muscle stiffness, rigidity, and spasm. We reported a patient with this syndrome who was treated successfully. The patient was a 56-year-old Japanese man with respiratory infection-like prodromal symptoms. Episodes of painful spasm in both legs on extension and lordosis occurred spontaneously or were triggered with touch or pinprick stimuli at or below spinal level C3, and progressed subacutely. Tendon reflexes were hyperactive, Babinski's sign was positive, and vibration sense was reduced in the legs. Episodes of spasm were alleviated using diazepam. Even after discontinuing diazepam, these symptoms did not exacerbate. In this patient, although anti-glutamic acid decarboxylase (GAD) antibody was negative, anti-EB virus antibody was positive. No previous reports have described stiff-person syndrome with EB virus infection. However, a few cases of this syndrome associated with viral infection were recently reported and viral gene mimicity with GAD has been postulated. Viral infection might be considered as a probable cause of this syndrome.

[A stiff-legged man with a bizarre gait]

BACKGROUND

Stiff person syndrome (SPS) is a rare neurological disorder characterized by simultaneous contraction of agonistic and antagonistic muscles. SPS can easily be confused with a psychogenic movement disorder, but the frequent finding of autoantibodies against glutamic acid decarboxylase (GAD65), positive response to immunomodulatory treatment and association with other autoimmune diseases strongly suggests an immununological pathogenesis.

CASE REPORT

A 43-year-old man was admitted with a three-year history of stiffness and painful spasms in the left leg, causing walking problems and frequent falls. A clinical examination revealed a bizarre gait, pes equinovarus, and simultaneous contraction of agonistic and antagonistic muscles, but no other neurological deficits. Electromyography was normal except for simultaneous contraction of agonistic and antagonistic muscles. Magnetic resonance imaging of the neuraxis and routine examinations of blood and cerebrospinal fluid were normal. A diagnosis of conversion neurosis was considered, but was not supported by positive evidence. The symptoms gradually evolved to affect the back and both legs. Elevated levels of antibodies against GAD65 in serum and cerebrospinal fluid confirmed the diagnosis SPS three and a half years after symptom debut. Both stiffness and muscle cramps responded excellently to diazepam.

CONCLUSION

This report calls attention to a rare neurological disease, in which absence of specific neurological deficits may lead to an erroneous diagnosis of a psychogenic disorder.

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.

Hyperekplexia in two siblings

Hyperekplexia is a rare, hereditary, non-epileptic disorder characterized by an exaggerated startle reaction to unexpected auditory, somatosensory and visual stimuli. The authors describe a one-day-old term neonate, who presented with jitteriness and episodic tonic spasms, and his elder sister with hyperekplexia. Hyperekplexia though is a rare disorder is one of the differential diagnoses for refractory tonic spasms in infancy. The prognosis is generally good in hereditary hyperekplexia. Recent molecular studies have revealed many associated mutations in the glycine receptor alpha and beta subunit genes.

Anesthetic management of a patient with stiff person syndrome

We describe the successful anesthetic management of a patient with stiff-person syndrome (SPS) undergoing a right inguinal hernia repair, using a somatic paravertebral block supplemented with conscious sedation. We also present the implications of general anesthesia in patients with SPS. The use of regional anesthetic techniques in patients with SPS has the advantage of avoiding exposure to muscle relaxants. The use of general anesthesia in patients with SPS carries the risk of postoperative hypotonia due to enhancement of gamma-aminobutyric acid action on synaptic transmission by drugs that have a gamma-aminobutyric acid agonistic action.

Stiff person syndrome with cerebellar disease and high-titer anti-GAD antibodies

We report five of 38 patients with stiff person syndrome (SPS), who also had cerebellar disease, gait ataxia, dysarthria, and oculomotor dysfunction (SPS-Cer). Cerebellar manifestations either preceded SPS or occurred concurrently. Brain MRI was normal. The intrathecal production of glutamic acid decarboxylase antibodies was elevated. Gamma-aminobutyric acid-enhancing drugs and immunotherapies improved only the stiffness. SPS-Cer is a distinct subset of SPS causing a more severe and complex clinical phenotype.

[The use of intravenous immunglobulin in the treatment of autoimmune neuromuscular diseases]

Intravenous immunglobulin given in autoimmune neuromuscular disorders modulates the immune system by complex actions, including, 1. the modification of the expression and function of Fc receptors, 2. interference with the activation of the complement and the cytokine network, 3. neutralisation of antiidiotypic antibodies, 4. effects on the activation, differentiation and effector functions of the T and B cells. Controlled trials have shown that intravenous immunglobulin is effective as first-line therapy in patients with Guillain-Barré syndrome and multifocal motor neuropathy. In case of steroid resistance or coexisting diabetes mellitus, intravenous immunglobulin can be the first line therapy in chronic inflammatory demyelinating polyneuropathy as well. As an alternative therapy it can be a second-line choice in dermatomyositis, myasthenia gravis, Lambert-Eaton myasthenic syndrome, and stiff person syndrome. While it has a remarkably good safety record for long-term administration the following side effects have been observed: headache, skin rash, thromboembolic events and renal tubular necrosis. In some disorders, the appropriate dose and frequency of infusions that maintain a satisfactory therapeutic response is well defined on the basis of data of evidence-based medicine, whereas in others it still remains to be defined. For the analysis of pharmacoeconomical aspects and the mechanism(s) of response differences in the same disease categories, further studies are necessary.