Stiff person spectrum disorders: An illustrative case series of their phenotypic and antibody diversity

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.

Expanding clinical profiles and prognostic markers in stiff person syndrome spectrum disorders

OBJECTIVE

To describe the clinical features of a cohort of individuals with stiff person syndrome spectrum disorders (SPSD) and identify potential early predictors of future disability.

BACKGROUND

There is a need to better understand the full spectrum of clinical and paraclinical features and long-term impact of SPSD.

DESIGN/METHODS

Observational study from 1997 to 2022 at Johns Hopkins. Clinical phenotypes included classic SPS, partial SPS (limb or trunk limited), SPS-plus (classic features plus cerebellar/brainstem involvement), and progressive encephalomyelitis with rigidity and myoclonus (PERM). Outcome measures were modified Rankin scale (mRS) and use of assistive device for ambulation. Multivariate logistic regression was used to assess significant predictors of outcomes.

RESULTS

Cohort included 227 individuals with SPSD with mean follow-up of 10 years; 154 classic, 48 SPS-plus, 16 PERM, and 9 partial. Mean age at symptom onset was 42.9 ± 14.1 years, majority were white (69.2%) and female (75.8%). Median time to diagnosis was 36.2 months (longest for SPS-plus and PERM) and 61.2% were initially misdiagnosed. Most had systemic co-morbidities and required assistive devices for ambulation. Female sex (OR 2.08; CI 1.06-4.11) and initial brainstem/cerebellar involvement (OR 4.41; CI 1.63-14.33) predicted worse outcome by mRS. Older age at symptom onset (OR 1.04; CI 1.01-1.06), female sex (OR 1.99; CI 1.01-4.01), Black race (OR 4.14; CI 1.79-10.63), and initial brainstem/cerebellar involvement (OR 2.44; CI 1.04-7.19) predicted worse outcome by use of assistive device. Early implementation of immunotherapy was associated with better outcomes by either mRS (OR 0.45; CI 0.22-0.92) or use of assistive device (OR 0.79; CI 0.66-0.94).

CONCLUSIONS

We present the expanding phenotypic variability of this rare spectrum of disorders and highlight potential predictors of future disability.

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

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

Anti-glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus initially presenting with one-sided stiff face: A case report

BACKGROUND

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a subtype of stiff-person syndrome, a rare cerebrospinal disease that causes brainstem symptoms, myoclonus, muscle rigidity, and hyperekplexia.

CASE PRESENTATION

A 71-year-old man experienced left-sided stiff face, and was subsequently admitted to our hospital because of the appearance of left-dominant lower limb myoclonus. Muscle rigidity followed 3 days later. Magnetic resonance imaging revealed no abnormality. An electrophysiological examination showed a toughness of the antagonistic muscle following evocation of the Achilles tendon reflex, and a tonic phenomenon affecting the left facial muscles during the blink reflex. The patient's serum was positive for anti-glycine receptor (anti-GlyR) antibody, suggesting PERM. The patient was administered steroids, immunoglobulin therapy, and immunosuppressive drugs. He gradually improved after these therapies and became able to walk using a walker.

CONCLUSIONS

We conclude that this was a rare case of anti-GlyR antibody-positive PERM with unilateral brainstem symptoms, myoclonus, and muscle rigidity.

Stiff person syndrome spectrum disorders; more than meets the eye

Stiff person syndrome spectrum disorders (SPSD) are a group of rare neuroimmunological disorders that often include painful spasms and rigidity. However, patients have highly heterogeneous signs and symptoms which may reflect different mechanistic disease processes. Understanding subsets of patients based on clinical phenotype may be important for prognosis and guiding treatment. The goal of this review is to provide updates on SPSD and its expanding clinical spectrum, prognostic markers, and treatment considerations. Further, we describe the current understanding in immunopathogenesis and highlight gaps in our knowledge appropriate for future research directions. Examples of revised diagnostic criteria for SPSD based on phenotype are also presented.

Idiopathic generalised tremor syndrome in dogs

BACKGROUND

Idiopathic generalised tremor syndrome (IGTS) causes tremor and often vestibulocerebellar signs. Previous publications on IGTS in dogs are restricted to case reports or lack exclusion of structural causes.

METHODS

Medical records of 75 dogs diagnosed with IGTS that had undergone magnetic resonance imaging (MRI) of the brain were collected retrospectively.

RESULTS

Crossbreeds were affected most commonly (41.3%), followed by West Highland white terriers (14.7%) and cocker spaniels (10.7%). A higher proportion of females were affected than males (68.0%). Median age of the affected dogs was 17 months (range 6-121 months), and median bodyweight was 9.15 kg (range 2.9-26 kg). All dogs presented with tremors and most experienced concomitant neurological signs (93.3%). Seventeen (22.7%) were hyperthermic and 31 (41.3%) had gastrointestinal signs. MRI of the brain was normal in most of the cases, and cerebrospinal fluid analysis frequently revealed mild pleocytosis. All animals were treated with prednisolone, and 39 (51.3%) also received diazepam. Median follow-up time was 13 months (range 0-134 months). The overall outcome was good, although 16 (21.3%) patients were reported to have relapsing clinical signs and 10 (13.2%) patients experienced persistent mild clinical signs.

CONCLUSIONS

IGTS should be suspected in any dog with generalised tremor and vestibulocerebellar signs with younger and smaller dogs more commonly affected.

Catatonic Schizophrenia Associated With Cerebrospinal GAD65 Autoantibodies: Case Report and Literature Review

Background

GAD65 autoimmunity is reported to be associated with schizophrenia and bipolar disorder. However, there has been no evidence that glutamic acid decarboxylase 65 (GAD65) autoantibodies in cerebrospinal fluid (CSF) are associated with akinetic catatonia in schizophrenia patients.

Methods

We report the case of a 28-year-old man who underwent diagnostics including brain MRI, neuropsychological testing, and electroencephalography (EEG) as well as a tumor search via CT of the abdomen and thorax, as well as colonoscopy and gastroscopy. For clinical characterization, his patient files were retrospectively examined.

Results

Our patient presented catatonia that responded somewhat to benzodiazepines in combination with previously taken antipsychotics such as risperidone for prediagnosed paranoid schizophrenia. Diagnostics revealed GAD65 autoantibodies in his serum and CSF. MRI revealed no brain lesion, and the tumor search had no malignancy. We diagnosed catatonic schizophrenia. Furthermore, as he had not fully recovered, he was given immunotherapy entailing two cycles of intravenous immunoglobulins. Subsequent neuropsychological testing due to subjective cognitive complaints after immunotherapy revealed no objective cognitive deficits.

Conclusions

We present the novel finding of an association between GAD65 autoantibodies in the serum and CSF with catatonia in a patient suffering from prediagnosed chronic schizophrenia. Due to the presence of CSF GAD65 antibodies and the catatonia factor in prediagnosed schizophrenia, we suspect that his catatonia has an autoimmune origin. Immunotherapy stabilized the catatonia that had initially responded to lorazepam treatment. Further research should be done to characterize patients' responses to immunotherapy and standard treatment in a large cohort of patients with GAD65 antibody-associated catatonia and schizophrenia.

Immune Mechanism of Epileptogenesis and Related Therapeutic Strategies

Immunologic and neuroinflammatory pathways have been found to play a major role in the pathogenesis of many neurological disorders such as epilepsy, proposing the use of novel therapeutic strategies. In the era of personalized medicine and in the face of the exhaustion of anti-seizure therapeutic resources, it is worth looking at the current or future possibilities that neuroimmunomodulator or anti-inflammatory therapy can offer us in the management of patients with epilepsy. For this reason, we performed a narrative review on the recent advances on the basic epileptogenic mechanisms related to the activation of immunity or neuroinflammation with special attention to current and future opportunities for novel treatments in epilepsy. Neuroinflammation can be considered a universal phenomenon and occurs in structural, infectious, post-traumatic, autoimmune, or even genetically based epilepsies. The emerging research developed in recent years has allowed us to identify the main molecular pathways involved in these processes. These molecular pathways could constitute future therapeutic targets for epilepsy. Different drugs current or in development have demonstrated their capacity to inhibit or modulate molecular pathways involved in the immunologic or neuroinflammatory mechanisms described in epilepsy. Some of them should be tested in the future as possible antiepileptic drugs.

Eye Movement Disorders in Movement Disorders

Oculomotor assessment is an essential element of the neurological clinical examination and is particularly important when evaluating patients with movements disorders. Most of the brain is involved in oculomotor control, and thus many neurological conditions present with oculomotor abnormalities. Each of the different classes of eye movements and their features can provide important information that can facilitate differential diagnosis. This educational review presents a clinical approach to eye movement abnormalities that are commonly seen in parkinsonism, ataxia, dystonia, myoclonus, tremor, and chorea. In parkinsonism, subtle signs such as prominent square wave jerks, impaired vertical optokinetic nystagmus, and/or the "round the houses" sign suggest early progressive supranuclear gaze palsy before vertical gaze is restricted. In ataxia, nystagmus is common, but other findings such as oculomotor apraxia, supranuclear gaze palsy, impaired fixation, or saccadic pursuit can contribute to diagnoses such as ataxia with oculomotor apraxia, Niemann-Pick type C, or ataxia telangiectasia. Opsoclonus myoclonus and oculopalatal myoclonus present with characteristic phenomenology and are usually easy to identify. The oculomotor exam is usually unremarkable in isolated dystonia, but oculogyric crisis is a medical emergency and should be recognized and treated in a timely manner. Gaze impersistence in a patient with chorea suggests Huntington's disease, but in a patient with dystonia or tremor, Wilson's disease is more likely. Finally, functional eye movements can reinforce the clinical impression of a functional movement disorder.

Case Report: Amphiphysin Antibody-Associated Stiff-Limb Syndrome and Myelopathy: An Unusual Presentation of Breast Cancer in an Elderly Woman

Background: Paraneoplastic stiff-limb syndrome (SLS) is a rare manifestation of underlying malignancy and could have distinctive features different from the classic stiff-person syndrome (SPS).

Case Description: We present a case of anti-amphiphysin antibody (Ab)-associated paraneoplastic SLS, in an 83-year-old woman with invasive ductal carcinoma of the breast. She presented with stiffness, painful spasms of the distal legs, and asymmetrical fixed posturing of the foot. There are coexisting long-tract disturbance and lower-extremity weakness. Treatment with diazepam provided symptomatic relief while plasma exchange (PLEX) did not lead to significant clinical improvement. The patient was bedridden within 3 months and passed away within 6 months from symptom onset.

Conclusion: This case highlights the importance of recognition of uncommon presentation of SPS and its oncological significance. This entity requires a high degree of suspicion for initiation of the proper workup. The rapid identification and treatment of the underlying tumor might offer the best chance for recovery.

Neural autoantibodies in delirium

BACKGROUND

Delirium in hospitalized and intensive care unit patients is an emerging condition due to its rapid-onset requiring fast action to mitigate a worse clinical outcome. Although several causes and conditions are known, the association between delirium and neural autoantibodies has often been neglected in cohort studies and reviews as causing delirium. The aim of our review is to delineate the occurrence and type of neural autoantibodies and to depict other biological markers of autoimmunity in relationship to delirium.

METHODS

For this narrative review Pubmed research was done to select articles about delirium and neural autoantibodies.

RESULTS

We can report on several cell-surface autoantibodies such as anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, anti-contactin associated protein 2, anti-Leucin rich glioma inactivated protein 1, anti-dipeptidyl-peptidase-like 6 protein, anti-glycine receptor and anti-myelin autoantibodies, as well as intracellular autoantibodies such as anti-glutamic acid decarboxylase 65 (GAD65), anti-CV2 and anti-Hu associated with delirium in patients. Our case reports and case series screening revealed that 20 of 63 patients with delirium presented neural autoantibodies, thus revealing a 32% frequency of autoantibody-associated delirium in delirium patients. Our main finding is that delirium's hyperactive form is associated with neural autoantibodies. Diagnosing delirium differentially is difficult, as in patients with delirium and GAD65 autoantibodies, as it must be distinguished from other psychopathological excitation states such as mania. We also describe autoimmune delirium's potential pathophysiologic pathways.

CONCLUSIONS

The existence of neural autoantibodies in delirious patients is scientifically and clinically highly relevant in its diagnosis, therapy, and pathogenesis. More large-scale studies should be conducted to evaluate their significance and prevalence in delirium.

Autoimmune encephalitis: the first observational study from Iran

BACKGROUND

Even within the most populous countries in the Middle East, such as Iran, autoimmune encephalitis cases have been rarely reported.

OBJECTIVE

We aimed to describe the demographic, clinical, and paraclinical characteristics of Iranian patients with autoimmune encephalitis positive for anti-neuronal autoantibodies.

METHODS

This cross-sectional study included all patients diagnosed with autoimmune encephalitis and referred to our hospital, in Isfahan, Iran, from March 2016 to May 2020. Patients' demographic, clinical, laboratory, radiological, and electroencephalographic features were obtained from their medical records.

RESULTS

We identified a total of 39 (21 females, 53.8%) patients with autoimmune encephalitis (mean age = 34.9 ± 12.8 years). The most commonly detected antibody was anti-NMDAR (n = 26, 66.7%), followed by anti-GABA_BR (n = 8, 20.5%), anti-Zic4 (n = 4, 10.3%), and anti-GAD65 (n = 1, 2.6%) antibodies, in descending order of frequency. Two anti-NMDAR-positive patients had a history of systemic lupus erythematosus (SLE), and four had a prior history of herpes simplex encephalitis. Clinical presentations in patients positive for anti-Zic4 antibodies included cognitive decline (n = 4, 100%), seizures (n = 3, 75%), parkinsonism (n = 1, 25%), and stiff-person syndrome (n = 1, 25%).

CONCLUSION

This was the first case series of Iranian patients with autoimmune encephalitis with some interesting observations, including SLE-associated anti-NMDAR encephalitis, as well as an unusual concurrence of anti-Zic4 antibody positivity and cognitive problems, seizures, parkinsonism, and stiff-person syndrome.

Progressive encephalomyelitis with rigidity: A Taiwanese case and review of literature

INTRODUCTION

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare disorder. However, the outcome is still variable with different serological and tumor associations, and the elements to good response with less relapse is yet to be elucidated.

METHOD

We present a case and obtain a literature review of patients with PERM and make comparisons based on different serological groups. We also analyze patients with idiopathic PERM that had detailed medical records.

RESULTS

81 patients were collected and analyzed. The largest group were glycine receptor-antibody (GlyR-Ab)-positive (70%), and the seropositive-GlyR-Ab-negative group had better response to immunotherapy. Malignancy can occur up to 2 years from the presentation of PERM. Among the 18 cases with detailed records, the patients who had good outcome initiate immunotherapy within 2 months from presentation. 9 of the 12 patients who experienced no relapse had non-steroid immunotherapy. The maximal interval time of relapse was 24 months.

CONCLUSION

We recommend tumor surveillance up to 2 years in patients with PERM and early administration of immunotherapies and maintain with non-steroid immunotherapy with or without oral corticosteroid for a minimum of 2 years to reduce the risk of relapse in GlyR-Ab-positive patients.

Defining the Expanding Clinical Spectrum of Pediatric-Onset Stiff Person Syndrome

BACKGROUND

We aimed to characterize the spectrum of clinical features and examination findings in pediatric-onset stiff person syndrome.

METHODS

Medical records were reviewed for all patients treated for stiff person syndrome with symptom onset in childhood at a tertiary medical center between March 2001 and February 2019.

RESULTS

Of the 15 individuals who met inclusion criteria, 11 (73%) were female and 13 (87%) were Caucasian. Median age at symptom onset was 14.8 years (range 8.4 to 16.9), and median latency from symptom onset to diagnosis was 6.2 years (range 0.4 to 15.0). Nine individuals (60%) were not diagnosed until adulthood. The most common presenting features were painful spasms (n = 12, 80%), hyper-reflexia (n = 11, 73%), axial rigidity (n = =9, 60%), lower extremity rigidity or spasticity (n = 8, 53%), gait abnormalities (n = 6, 40%), and hyperlordosis (n = 6, 40%). Other noted features included anxiety (n = 5, 33%), dysautonomia (n = 3, 20%), and cranial neuropathies (n = 3, 20%). Personal (n = 9, 60%) and family history (n = 9, 60%) of autoimmune conditions was common. Serum antiglutamate decarboxylase 65 antibodies were found in 13 individuals (87%). Nearly all individuals received immunotherapy (n = 14, 93%), symptomatic medications (n = 15, 100%), and nonpharmacologic therapies (n = 14, 93%). However, most had persistent physical limitations, particularly impaired walking (n = 7, 47%) and inability to carry out previous activities (n = 14, 93%).

CONCLUSIONS

There is a wide spectrum of typical and less common features seen in individuals with pediatric-onset stiff person syndrome. Despite symptom onset in childhood, diagnosis is often delayed until adulthood, at which point disability accrual is frequently seen. Early recognition is vital to address symptoms and may potentially limit future disability.

Severe Chin-on-Chest Cervical Spine Deformity in the Setting of Stiff-Person Syndrome: A Case Report

CASE

Stiff-person syndrome (SPS) presents with progressive muscle rigidity, postural instability, and periodic debilitating spasms. Reports of axial hyperextension exist, but kyphotic deformities have not been described. We surgically treated a patient with debilitating SPS and severe cervicothoracic hyperkyphosis with posterior spinal fusion and instrumentation. At 1-year follow-up, the patient displayed better upright gait and forward gaze, 18° cervical lordosis, and improved patient-reported outcome scores.

CONCLUSION

SPS can lead to extreme spinal deformity and disease, including hyperkyphosis of the cervicothoracic spine, and can successfully be managed with a multidisciplinary team and a posterior-only correction with spinal instrumentation and fusion.