The immunological basis for treatment of stiff person syndrome

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.

Use of subcutaneous immunoglobulin in stiff person syndrome: Case series

INTRODUCTION

Intravenous immunoglobulin (IVIG) has been shown to be effective for the treatment of stiff person syndrome (SPS). However, some patients might not tolerate it. We report the tolerability profile of subcutaneous immunoglobulin (SCIg) in patients with SPS who did not tolerate IVIG. To our knowledge, the use of SCIg in SPS has not been reported before in a case series.

PATIENT CONCERNS

The five patients included in this case series presented with various combinations of symptoms of spasms, axial and limb stiffness, and exaggerated responses to outside stimuli. These symptoms often lead to gait and functional impairment.

DIAGNOSIS

Patients were diagnosed with classic SPS as they met the clinical criteria, which require the presence of spasms, axial rigidity, and hyperexcitability.

INTERVENTIONS

Subcutaneous immunoglobulin infusion.

OUTCOMES

Five patients were identified that were treated with SCIg. Three tested positive for serum anti-glutamic acid decarboxylase 65 antibodies prior to any treatment. The mean age at SCIg initiation was 33 years (range: 22-47). The mean duration of SPS prior to SCIg initiation was 5.9 years (range: 2.5-7). All patients used IVIG for at least two months (up to 18 months) but switched to SCIg due to IVIG side effects. Duration of SCIg use ranged from 4 months to 6 years (mean, 19.2 months). Upon switching to SCIg, the SPS symptoms remained stable. SCIg was well-tolerated in most as only one patient discontinued SCIg due to side effects.

CONCLUSION

This case series highlights that SCIg could be a treatment option for patients with SPS, especially when IVIG is not feasible. Injection site reactions might be a limiting factor in some patients treated with SCIg. Prospective controlled studies are needed to confirm SCIg treatment durability and efficacy.

Autoimmune encephalitis: novel therapeutic targets at the preclinical level

INTRODUCTION

Antibody-mediated encephalitides (AE) with pathogenic autoantibodies (aAB) against neuronal surface antigens are a growing group of diseases characterized by antineuronal autoimmunity in the brain. AE patients typically present with rapidly progressive encephalitis and characteristic disease symptoms dependent on the target antigen. Current treatment consists of an escalating immunotherapy strategy including plasma exchange, steroid application, and B cell depletion.

AREAS COVERED

For this review, we searched Medline database and google scholar with inclusive dates from 2000. We summarize current treatment strategies and present novel therapeutic approaches of target-specific interventions at the pre-clinical level as well as immunotherapy directed at antibody-induced pathology. Treatment options include modulation of target proteins, intervention with downstream pathways, antibody modification, and depletion of antibody-secreting cells.

EXPERT OPINION

Although current therapies in AE are effective in many patients, recovery is often prolonged and relapses as well as persistent deficits can occur. Specific immunotherapy together with supportive target-specific therapy may provide faster control of severe symptoms, shorten the disease course, and lead to long-lasting disease stability. Among the various novel therapeutic approaches, modulation of targeted receptors by small molecules crossing the blood-brain barrier as well as prevention of aAB binding is of particular interest.

Improvement of stiff-person syndrome symptoms in pregnancy: Case series and literature review

Objective

To describe 2 cases from a single academic institution of improvement in stiff-person syndrome (SPS) symptoms during pregnancy and to review the clinical outcomes of SPS in 6 additional pregnancies described in the literature.

Methods

Evaluation of clinical symptoms and treatment changes of disease state during pregnancy.

Results

Seven patients with 9 pregnancies are described in women with a diagnosis of SPS. Six of 7 (86%) women were positive for glutamic acid decarboxylase (GAD65) antibody. In 5 of 9 (56%) pregnancies, symptomatic medications (antispasmodics) were significantly reduced with stabilization or improvement in symptoms through pregnancy. Nine live, healthy pregnancies resulted. All 7 (100%) women experienced worsening of symptoms after the birth of their children, and symptomatic therapies were resumed and/or increased.

Conclusions

The immune pathogenesis of SPS continues to be explored. Immunomodulatory shifts during pregnancy may influence changes of clinical SPS symptoms and provide insight into the unique pathogenesis of SPS. Some women with SPS may be able to reduce symptomatic medications related to clinical improvement during pregnancy. Women with SPS may safely carry pregnancies to term, delivering healthy and unaffected babies.

Stiff person syndrome with Anti-GAD65 antibodies within the national veterans affairs health administration

INTRODUCTION

Stiff person syndrome (SPS) is a neurological disorder characterized by muscle rigidity primarily in the truncal muscles, commonly associated with autoantibodies to the glutamic acid-decarboxylase 65 kD receptor (GAD65). There is limited epidemiological information on patients with SPS.

METHODS

We performed a retrospective case review using the National United States Veterans Affairs Health Administration electronic medical record system. We analyzed prevalence, demographics, disease characteristics, and treatment outcomes in SPS patients who were anti-GAD65 antibody positive.

RESULTS

Fifteen patients met our criteria. Point prevalence was 2.06 per million, and period prevalence was 2.71 per million. Men to women ratio was 14:1. All patients benefitted from treatment with symptomatic antispasmodic agents. Ten of 15 patients received intravenous immunoglobulin, with a majority demonstrating stable or improved modified Rankin scores.

DISCUSSION

This investigation was a large North American epidemiological study of SPS with predominantly male patients. Symptomatic therapy was beneficial for most patients, with less clear sustained benefit of immunotherapy. Muscle Nerve 58:801-804, 2018.

Evaluation of Treatment Outcomes in Patients with Stiff Person Syndrome with Rituximab vs. Standard of Care

Stiff Person Syndrome (SPS) is a rare neurological disorder that primarily affects the ability to relax musculature. This results in affected muscle groups remaining in constant contracture, leading to painful spasms that have significant morbidity and impact the patient's quality of life. Disease prevalence is one to two persons in a million, and as a result, very few randomized controlled studies have examined the efficacy of various treatment regimens. One notable study examined intravenous immunoglobulin (IVIG) and its efficacy in the treatment of SPS. This study found that using IVIG was of significant benefit in improving stiffness in SPS. However, beyond this, immune modulating therapy is limited by lack of peer-reviewed evidence. The use of rituximab has been reported in cases of SPS that are refractory to treatment with IVIG and has had mixed outcomes. Our search of the literature involved examining case reports of patients with diagnosed SPS, who had been initially treated with the standard of care and were then placed on treatment with rituximab. Our review of the available case reports demonstrates an increase in SPS remission correlating with the frequency of dose. However, the limited number of case reports available limits conclusions related to the treatment of SPS. More studies are needed to assist in guiding therapy for SPS.

Anti-glutamic acid decarboxylase antibody positive neurological syndromes

A rare kind of antibody, known as anti-glutamic acid decarboxylase (GAD) autoantibody, is found in some patients. The antibody works against the GAD enzyme, which is essential in the formation of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter found in the brain. Patients found with this antibody present with motor and cognitive problems due to low levels or lack of GABA, because in the absence or low levels of GABA patients exhibit motor and cognitive symptoms. The anti-GAD antibody is found in some neurological syndromes, including stiff-person syndrome, paraneoplastic stiff-person syndrome, Miller Fisher syndrome (MFS), limbic encephalopathy, cerebellar ataxia, eye movement disorders, and epilepsy. Previously, excluding MFS, these conditions were calledhyperexcitability disorders. However, collectively, these syndromes should be known as "anti-GAD positive neurological syndromes." An important limitation of this study is that the literature is lacking on the subject, and why patients with the above mentioned neurological problems present with different symptoms has not been studied in detail. Therefore, it is recommended that more research is conducted on this subject to obtain a better and deeper understanding of these anti-GAD antibody induced neurological syndromes.

Gastrointestinal and Urologic Sphincter Dysfunction in Stiff Person Syndrome

OBJECTIVES

Stiff person syndrome is a neurologic disorder characterized by axial rigidity leading to progressive disability, with broad clinical spectrum.

METHODS

We report 2 cases with unique clinical presentation.

RESULTS

Two young men suffered progressive urinary retention requiring bladder catheterization, anorectal spasms and constipation, complicated subsequently with lower extremity trigger-induced spasms, and gait instability. Associated symptoms revealed brainstem involvement (vertigo, diplopia, and cranial neuropathies) and dysautonomia (abnormal sweating and orthostatic hypotension). Anal manometry demonstrated incomplete relaxation of the anal sphincter. The first case was associated with diabetes mellitus type I, did not respond to classical therapies, but was responsive to rituximab. The second case responded to intravenous immunoglobulin infusions. Paraneoplastic profiles were negative, and anti-GAD65 antibody titers remained elevated despite successful therapeutic responses.

CONCLUSIONS

We want to raise awareness that stiff person syndrome can present with esophageal, anorectal, and urethral sphincter disturbance. Rituximab is a good therapeutic option in intractable cases.

Neuronal central nervous system syndromes probably mediated by autoantibodies

In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients' antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies.

Clinical Spectrum of Stiff Person Syndrome: A Review of Recent Reports

Background

“Classic” stiff person syndrome (SPS) features stiffness, anti-glutamic acid decarboxylase (anti-GAD) antibodies, and other findings. Anti-GAD antibodies are also detected in some neurological syndromes (such as ataxia) in which stiffness is inconsistently present. Patients with otherwise “classic” SPS may either lack anti-GAD antibodies or be seropositive for others. Hence, SPS cases appear to fall within a clinical spectrum that includes conditions such as progressive encephalomyelitis with rigidity and myoclonus (PERM), which exhibits brainstem and autonomic features. We have compiled herein SPS-spectrum cases reported since 2010, and have segregated them on the basis of likely disease mechanism (autoimmune, paraneoplastic, or cryptogenic) for analysis.

Methods

The phrases “stiff person syndrome”, “PERM”, “anti-GAD antibody syndrome”, and “glycine receptor antibody neurological disorders” were searched for in PubMed in January 2015. The results were narrowed to 72 citations after excluding non-English and duplicate reports. Clinical descriptions, laboratory data, management, and outcomes were categorized, tabulated, and analyzed.

Results

Sixty-nine autoimmune, 19 paraneoplastic, and 13 cryptogenic SPS-spectrum cases were identified. SPS was the predominant diagnosis among the groups. Roughly two-thirds of autoimmune and paraneoplastic cases were female. Anti-GAD antibodies were most frequently identified, followed by anti-amphiphysin among paraneoplastic cases and by anti-glycine receptor antibodies among autoimmune cases. Benzodiazepines were the most commonly used medications. Prognosis seemed best for cryptogenic cases; malignancy worsened that of paraneoplastic cases.

Discussion

Grouping SPS-spectrum cases by pathophysiology provided insights into work-up, treatment, and prognosis. Ample phenotypic and serologic variations are present within the categories. Ruling out malignancy and autoimmunity is appropriate for suspected SPS-spectrum cases.

Interactions of Human Autoantibodies with Hippocampal GABAergic Synaptic Transmission - Analyzing Antibody-Induced Effects ex vivo

Autoantibodies (aAB) to the presynaptic located enzyme glutamate decarboxylase 65 (GAD65) are a characteristic attribute for a variety of autoimmune diseases of the central nervous system including subtypes of limbic encephalitis, stiff person-syndrome, cerebellar ataxia, and Batten’s disease. Clinical signs of hyperexcitability and improvement of disease symptoms upon immunotherapy in some of these disorders suggest a possible pathogenic role of associated aAB. Recent experimental studies report inconsistent results regarding a direct pathogenic influence of anti-GAD65 aAB affecting inhibitory synaptic transmission in central GABAergic pathways. We here provide a method for direct evaluation of aAB-induced pathomechanisms in the intact hippocampal network. Purified patient IgG fractions containing aAB to GAD65 together with fixable lipophilic styryl dyes (FMdyes) are stereotactically injected into the hilus and the dentate gyrus in anesthetized mice. Twenty-four hours after intrahippocampal injection, acute hippocampal slices are prepared and transferred to a patch-clamp recording setup equipped with a fluorescence light source. Intraneural incorporated FMdyes show correct injection site for patch-clamp recording. Whole-cell patch-clamp recordings are performed from granule cells in the dentate gyrus and extracellular stimulation is applied in the border area of the dentate gyrus-hilus region to stimulate GABAergic afferents arising from parvalbumin positive basket cells. GABA-A receptor mediated inhibitory postsynaptic currents (IPSC) and miniature IPSC are recorded after blocking glutamatergic transmission. This approach allows investigation of potential aAB-induced effects on GABA-A receptor signaling ex vivo in an intact neuronal network. This offers several advantages compared to experimental procedures used in previous studies by in vitro AB preincubation of primary neurons or slice preparations. Furthermore, this method requires only small amounts of patient material that are often limited in rare diseases.

Role of Osteopathic Manipulative Treatment in the Management of Stiff Person Syndrome

Stiff person syndrome (SPS) is a rare and disabling central nervous system disorder first described in 1956 and characterized by fluctuating rigidity and stiffness, gait impairment, and painful spasms of the axial and limb musculature. Although an underlying mechanism of impaired synaptic γ-aminobutyric acid–ergic inhibition has been proposed, the exact mechanism remains unclear. The glutamic acid decarboxylase antibody, a marker for SPS, is a strong indication of disease and has been reported in approximately 70% of patients. The current treatment of choice is benzodiazepines and baclofen, both of which reduce motor unit potential firing and, therefore, decrease stiffness and spasms. However, patients continue to have substantial disability with pharmacologic therapy alone. This case report demonstrates the potential of osteopathic manipulative treatment as an adjunct to medication in the management of SPS. By decreasing somatic dysfunction and reducing the frequency of exacerbations, osteopathic manipulative treatment may alleviate the symptoms and overall morbidity associated with this disease.

Stiff-person syndrome: case series

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

Molecular and cellular mechanisms underlying anti-neuronal antibody mediated disorders of the central nervous system

Over the last decade multiple autoantigens located on the plasma membrane of neurons have been identified. Neuronal surface antigens include molecules directly involved in neurotransmission and excitability. Binding of the antibody to the antigen may directly alter the target protein's function, resulting in neurological disorders. The often striking reversibility of symptoms following early aggressive immunotherapy supports a pathogenic role for autoantibodies to neuronal surface antigens. In order to better understand and treat these neurologic disorders it is important to gain insight in the underlying mechanisms of antibody pathogenicity. In this review we discuss the clinical, circumstantial, in vitro and in vivo evidence for neuronal surface antibody pathogenicity and the possible underlying cellular and molecular mechanisms. This review shows that antibodies to neuronal surface antigens are often directed at conformational epitopes located in the extracellular domain of the antigen. The conformation of the epitope can be affected by specific posttranslational modifications. This may explain the distinct clinical phenotypes that are seen in patients with antibodies to antigens that are expressed throughout the brain. Furthermore, it is likely that there is a heterogeneous antibody population, consisting of different IgG subtypes and directed at multiple epitopes located in an immunogenic region. Binding of these antibodies may result in different pathophysiological mechanisms occurring in the same patient, together contributing to the clinical syndrome. Unraveling the predominant mechanism in each distinct antigen could provide clues for therapeutic interventions.

Stiff person syndrome

Recognizing stiff person syndrome is clinically important. It is uncommon, characterized by body stiffness associated with painful muscle spasms, and varies in location and severity. It is subdivided into stiff trunk versus stiff limb presentation, and as a progressive encephalomyelitis. Stiff person-type syndrome also reflects a paraneoplastic picture. Most patients demonstrate exaggerated lumbar lordosis. Roughly 60% of patients have antiglutamic acid decarboxylase antibodies in the blood and the cerebrospinal fluid. The differential diagnosis includes many severe conditions. There are reports of response to muscle relaxants, immunosuppressants, intravenous gamma globulin, plasma exchange, a number of anticonvulsants, and botulinum toxin.

Human Stiff person syndrome IgG-containing high-titer anti-GAD65 autoantibodies induce motor dysfunction in rats

Stiff person syndrome (SPS) is an autoimmune CNS disorder characterized by muscle rigidity, spasms and anxiety. The majority of patients have high-titer autoantibodies (ab) against glutamate decarboxylase (GAD65). A pathogenic role of SPS-associated IgG with ab against GAD65 has been shown for anxiety-like behavior but not for the core motor signs. We repetitively injected the purified IgG fraction of an SPS patient with severe motor impairment but without anxious comorbidity containing high titers of anti-GAD65 ab (SPS-IgG) into the lateral ventricle (i.c.v.) or intrathecally (i.th.) at the spinal level in experimental rats. We analyzed the effects on motor and anxiety-like behavior. Non-SPS human IgG fractions served as controls. Animals injected i.c.v. with SPS-IgG showed stiffness-like behavior with impaired walking ability and reduced grip strength of the upper limbs as well as postural and sensorimotor dysfunction. Testing for anxiety-like behavior revealed no significant differences between SPS and control IgG-treated rats. IgG deposits were found only in rats treated with SPS-IgG and were localized predominantly in CNS structures involved in motor control including globus pallidus, internal capsule, striatum and anterior thalamus. Double immunofluorescence staining revealed that predominantly GABAergic interneurons were positive for i.c.v. injected SPS-IgG. Rats injected i.th. with SPS-IgG did not present obvious motor symptoms and had a normal synaptic transmission at the spinal level. We conclude that SPS-like motor dysfunction can be induced in rats by passive transfer of IgG from an SPS-patient with high titer of anti-GAD65 ab. GABAergic dysfunction in supraspinal motor pathways rather than in the spinal cord may lead to motor deficits observed in the rats contrasting observations made in SPS with amphiphysin antibodies.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

Conventional apheresis therapies: a review

This article reviews advances in the scientific basis and medical practice of plasmapheresis and cytapheresis therapies. Newly-characterized autoantibodies in neuromyelitis optica, Guillain-Barre variants, anti-neutrophil cytoplasmic antibody (ANCA) vasculitides, etc., exemplify the modern molecular biology which now provides a rigorous framework of understanding for the clinical practice of plasmapheresis. Clinical trials continue to clarify the appropriate use of therapeutic plasmapheresis (TPE) in these and other diseases. Centrifugal (cTPE) and membrane filtration (mTPE) types of plasmapheresis are compared, with details of the plasmapheresis prescription, anticoagulation choices, replacement fluids and other practical considerations. Plasma removal is more efficient with cTPE; mTPE systems have a lower plasma extraction ratio, and therefore require higher blood flow rates or longer procedure times. Autoantibodies and other pathogenic macromolecules targeted for removal by plasmapheresis can be depleted predictably when the plasma is discarded, as in conventional TPE. On-line plasma processing to regenerate the patient's own plasma avoids the need for replacement albumin solutions or plasma transfusion, but is inherently less efficient at removing the target molecule, so usually requires a longer procedure. Therapeutic white cell reduction (leukapheresis), platelet reduction (thrombocytapheresis) and red cell exchange (erythrocytapheresis) require centrifugal apheresis systems.

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

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