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

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

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

A new perspective on the autophagic and non-autophagic functions of the GABARAP protein family: a potential therapeutic target for human diseases

Mammalian autophagy-related protein Atg8, including the LC3 subfamily and GABARAP subfamily. Atg8 proteins play a vital role in autophagy initiation, autophagosome formation and transport, and autophagy-lysosome fusion. GABARAP subfamily proteins (GABARAPs) share a high degree of homology with LC3 family proteins, and their unique roles are often overlooked. GABARAPs are as indispensable as LC3 in autophagy. Deletion of GABARAPs fails autophagy flux induction and autophagy lysosomal fusion, which leads to the failure of autophagy. GABARAPs are also involved in the transport of selective autophagy receptors. They are engaged in various particular autophagy processes, including mitochondrial autophagy, endoplasmic reticulum autophagy, Golgi autophagy, centrosome autophagy, and dorphagy. Furthermore, GABARAPs are closely related to the transport and delivery of the inhibitory neurotransmitter γ-GABAA and the angiotensin II AT1 receptor (AT1R), tumor growth, metastasis, and prognosis. GABARAPs also have been confirmed to be involved in various diseases, such as cancer, cardiovascular disease, and neurodegenerative diseases. In order to better understand the role and therapeutic potential of GABARAPs, this article comprehensively reviews the autophagic and non-autophagic functions of GABARAPs, as well as the research progress of the role and mechanism of GABARAPs in cancer, cardiovascular diseases and neurodegenerative diseases. It emphasizes the significance of GABARAPs in the clinical prevention and treatment of diseases, and may provide new therapeutic ideas and targets for human diseases. GABARAP and GABARAPL1 in the serum of cancer patients are positively correlated with the prognosis of patients, which can be used as a clinical biomarker, predictor and potential therapeutic target.

Autoimmune diseases of the spine and spinal cord

Magnetic resonance imaging (MRI) and clinicopathological tools have led to the identification of a wide spectrum of autoimmune entities that involve the spine. A clearer understanding of the unique imaging features of these disorders, along with their clinical presentations, will prove invaluable to clinicians and potentially limit the need for more invasive procedures such as tissue biopsies. Here, we review various autoimmune diseases affecting the spine and highlight salient imaging features that distinguish them radiologically from other disease entities.

Paraneoplastic stiff-person syndrome with lung cancer: a case report and literature review

Stiff person syndrome is a rare autoimmune disease of the central nervous system that manifests as stiffness and painful spasms of the trunk axis and lower limb muscles. Benzodiazepines are the first choice for the clinical treatment of the disease. We reported a case of SPS. The patient presented with stiffness and convulsions of lower limbs, weakness after convulsions, falling off easily, abdominal muscle stiffness, and painful spasms lasting for several minutes and alleviating spontaneously. This was caused or aggravated by fatigue or mental stimulation. Left stiffness and weakness of the muscle after relief was present. A chest-enhanced computed tomography scan (CT) suggested two large ground glass nodules in the upper lobe of the left lung. Biopsy pathology indicated the nodules as adenocarcinoma in situ. The patient's symptoms were significantly relieved after treatment with clonazepam and diazepam combined with pregabalin. The clinical manifestations of SPS vary among patients. The symptoms of the disease are mild or severe. Early identification and treatment can improve the prognoses of these patients.

Postoperative hypotonia in a patient with stiff person syndrome: a case report and literature review

PURPOSE

Stiff person syndrome (SPS), an autoimmune disease that manifests with episodic muscle rigidity and spasms, has anesthetic considerations because postoperative hypotonia may occur. This hypotonia has been linked to muscle relaxants and volatile anesthetics and may persist in spite of neostigmine administration and train-of-four (TOF) monitoring suggesting full reversal. We present a patient with SPS who experienced hypotonia following total intravenous anesthesia (TIVA), which was promptly reversed with sugammadex. These observations are considered in light of the relevant medical literature.

CLINICAL FEATURES

A 46-yr-old female patient with SPS underwent breast lumpectomy and sentinel node biopsy. Anesthesia consisted of TIVA (propofol/remifentanil) with adjunctive administration of rocuronium 20 mg to obtain adequate intubating conditions. Despite return of the TOF ratio to 100% within 30 min, hypotonia was clinically evident at conclusion of surgery two hours later. Sugammadex 250 mg reversed residual muscle relaxation permitting uneventful extubation. A literature review identified six instances of postoperative hypotonia (TIVA, n = 3; volatile anesthetics, n = 3) in spite of neostigmine administration (n = 2) and TOF monitoring suggesting full reversal (n = 4).

CONCLUSIONS

Patients with SPS may show hypotonia regardless of general anesthetic technique (TIVA vs inhalational anesthesia), which can persist despite recovery of the TOF ratio and may be more effectively reversed by a chelating agent than with an anticholinesterase. If general anesthesia is required, we suggest a cautious approach to administering muscle relaxants including using the smallest dose necessary, considering the importance of clinical assessment of muscle strength recovery in addition to TOF monitoring, and discussing postoperative ventilation risk with the patient prior to surgery.

Stiff-person syndrome with paraneoplastic neurological syndrome: a case report and literature review

BACKGROUND

Stiff-person syndrome (SPS) manifests by progressive rigidity along with muscle spasms that affect the axial and limb muscles. First discovered in 1956, significant progress has been made in its clinical characterization, comprehension of pathogenesis, as well as effective treatment therapy.

CASE PRESENTATION

A 67-year old female patient presented with a 2-year history of progressive stiffness along with painful spasms in both legs, with her condition worsening over the previous year making it considerably difficult for her to stand and walk. Here, we report a Stiff-person syndrome patient (SPS) with lung adenocarcinoma who was positive for anti-glutamate decarboxylase (anti-GAD) antibodies. Treatment with hormones and gamma-globulin improved her symptoms. In addition, we present a literature review of SPS patients with tumors.

CONCLUSIONS

The diagnosis of autoimmune SPS was on the basis of clinical, electrophysiological, as well as immunological findings. Early SPS detection is critical to preventing long-term disability.

Paraneoplastic neurological syndrome: an evolving story

Paraneoplastic neurological syndrome (PNS) comprises a group of neurological disorders that result from a misguided immune response to the nervous system triggered by a distant tumor. These disorders frequently manifest before the diagnosis of the underlying neoplasm. Since the first reported case in 1888 by Oppenheim, the knowledge in this area has evolved rapidly. Several classic PNS have been described, such as limbic encephalitis, paraneoplastic cerebellar degeneration, encephalomyelitis, opsoclonus-myoclonus, sensory neuronopathy, Lambert-Eaton Myasthenic syndrome, and chronic gastrointestinal dysmotility. It is now recognized that PNS can have varied nonclassical manifestations that extend beyond the traditional syndromic descriptions. Multiple onconeural antibodies with high specificity for certain tumor types and neurological phenotypes have been discovered over the past 3 decades. Increasing use of immune checkpoint inhibitors (ICIs) has led to increased recognition of neurologic ICI-related adverse events. Some of these resemble PNS. In this article, we review the clinical, oncologic, and immunopathogenic associations of PNS.

Stiff-Person Syndrome: Seeing Past Comorbidities to Reach the Correct Diagnosis

Stiff-person syndrome (SPS) is a rare disorder seen in approximately one in one million people. Although it is rare, the symptoms and findings of a typical case should paint a clear clinical picture for those who are familiar with the disease. The primary findings in SPS include progressive axial muscle rigidity as well as muscle spasms. These symptoms most commonly occur in the setting of antibodies against Glutamic Acid Decarboxylase (GAD), the rate-limiting enzyme in the production of Gamma-Aminobutyric Acid (GABA), which is the primary inhibitory enzyme in the central nervous system. Here, we report the case of a 65-year-old African-American female with a past medical history of hypothyroidism, anxiety, and depression with psychotic features who presented with axial muscle rigidity and lactic acidosis. She had been symptomatic for several months and reported extensive workups performed at two previous hospitals without a definitive diagnosis. A complete neurological and musculoskeletal investigation yielded no positive findings except for the presence of GAD antibodies. The patient was treated with diazepam, tizanidine, and Intravenous Immunoglobulin (IVIG) with significant improvement, thus solidifying the diagnosis of SPS, a rare autoimmune and/or paraneoplastic syndrome.

Clinical spectrum of high-titre GAD65 antibodies

OBJECTIVE

To determine clinical manifestations, immunotherapy responsiveness and outcomes of glutamic acid decarboxylase-65 (GAD65) neurological autoimmunity.

METHODS

We identified 323 Mayo Clinic patients with high-titre (>20 nmol/L in serum) GAD65 antibodies out of 380 514 submitted anti-GAD65 samples (2003-2018). Patients classified as having GAD65 neurological autoimmunity after chart review were analysed to determine disease manifestations, immunotherapy responsiveness and predictors of poor outcome (modified Rankin score >2).

RESULTS

On review, 108 patients were classified as not having GAD65 neurological autoimmunity and 3 patients had no more likely alternative diagnoses but atypical presentations (hyperkinetic movement disorders). Of remaining 212 patients with GAD65 neurological autoimmunity, median age at symptom onset was 46 years (range: 5-83 years); 163/212 (77%) were female. Stiff-person spectrum disorders (SPSD) (N=71), cerebellar ataxia (N=55), epilepsy (N=35) and limbic encephalitis (N=7) could occur either in isolation or as part of an overlap syndrome (N=44), and were designated core manifestations. Cognitive impairment (N=38), myelopathy (N=23) and brainstem dysfunction (N=22) were only reported as co-occurring phenomena, and were designated secondary manifestations. Sustained response to immunotherapy ranged from 5/20 (25%) in epilepsy to 32/44 (73%) in SPSD (p=0.002). Complete immunotherapy response occurred in 2/142 (1%). Cerebellar ataxia and serum GAD65 antibody titre >500 nmol/L predicted poor outcome.

INTERPRETATION

High-titre GAD65 antibodies were suggestive of, but not pathognomonic for GAD65 neurological autoimmunity, which has discrete core and secondary manifestations. SPSD was most likely to respond to immunotherapy, while epilepsy was least immunotherapy responsive. Complete immunotherapy response was rare. Serum GAD65 antibody titre >500 nmol/L and cerebellar ataxia predicted poor outcome.

Effectiveness of Combined Immunoglobulin and Glucocorticoid Treatments in a Patient With Stiff Limb Syndrome: Case Report and Review of the Literature

Stiff limb syndrome (SLS) is a rare autoimmune-related central nervous system disorder, resulting in stiffness and spasms of limbs since onset with rare involvement of the truncal muscles. However, SLS patients will gain notable effects by appropriate therapy focusing on symptomatic treatment and immunotherapy. We reported on a 55-year-old female who showed typical painful spasms in both lower limbs and abduction of the right eyeball that partially responded to low-dose diazepam and had high-titer anti–glutamic acid decarboxylase (anti-GAD) antibody. Electromyography (EMG) only showed continuous motor unit activity (CMUA) in the anterior tibialis and right triceps. Eventually, our patient was diagnosed with SLS and treated with intravenous immunoglobulin (IVIG) and glucocorticoid combined simultaneously. She obtained notable effects. We also review and summarize the current literature on clinical characteristics, coexisting disease, treatment, and outcome of 40 patients with SLS. We hope that this report will provide a basis for further understanding of SLS and promote the formation of more advanced diagnosis and treatment processes.

Retinal pathology occurs in stiff-person syndrome

OBJECTIVE

To evaluate whether structural and functional changes occur in the afferent visual system of patients with stiff-person syndrome (SPS) and whether these changes correlate with disease burden, given the high concentration of γ-aminobutyric acid receptors, which are generally thought to be involved in SPS pathogenesis, in the retina.

METHODS

In this single-center, cross-sectional study, patients with SPS and healthy controls (HCs) underwent optical coherence tomography (OCT), with a subset undergoing high- and low-contrast visual acuity (VA) assessments. Burden of disease was assessed via the number of body regions affected. Individuals with uncontrolled hypertension or comorbid neurologic or ophthalmologic disorders were excluded. Statistical analyses were performed using mixed-effects linear regression models.

RESULTS

Thirty-five patients with SPS and 40 age- and sex-matched HCs underwent OCT. A subset of 23 patients with SPS and 28 HCs underwent VA assessments. Relative to HCs, patients with SPS had lower ganglion cell + inner plexiform layer (GCIPL) thicknesses (SPS: 74.36 µm [SD 5.7]; HCs: 76.33 µm [SD 4.2]; p = 0.005), inner nuclear layer thicknesses (SPS: 44.37 µm [SD 2.7]; HCs: 45.18 µm [SD 2.2]; p = 0.042), and 100% (SPS: 53 [SD 9.6]; HCs: 57.5 [SD 6.1]; p = 0.005), 2.5% (SPS: 24.35 [SD 10.1]; HCs: 30.16 [SD 7.7]; p = 0.006), and 1.25% contrast (SPS: 16.41 [SD 10.6]; HCs: 20.84 [SD 8.6]; p = 0.034) letter acuity scores. GCIPL thicknesses correlated with the number of body regions affected in SPS (decrease of 1.25 µm [95% confidence interval, -2.2 to -0.3 µm; p = 0.008] per additional body region affected).

CONCLUSIONS

Retinal neuronal pathology can occur in SPS. OCT may have utility as a biomarker of disease burden in SPS.

Autoimmune musicogenic epilepsy associated with anti-glutamic acid decarboxylase antibodies and Stiff-person syndrome

Epilepsy should be suspected in patients with Stiff-person syndrome and new onset paroxysmal episodes. Musicogenic epilepsy may be a manifestation of anti-GAD-Ab spectrum, supporting an autoimmune workup in these patients. Appropriate treatment is not well established, and immunotherapy should be considered in patients with only partial response to antiepileptic drugs.

Exogenous Insulin Injection-Induced Stiff-Person Syndrome in a Patient With Latent Autoimmune Diabetes: A Case Report and Literature Review

Stiff-person syndrome (SPS) is highly associated with anti-glutamic acid decarboxylase (GAD) antibody. However, GAD antibodies alone appear to be insufficient to cause SPS, and they possibly are involved in only part of its pathophysiology. It is suspected that the symptoms of SPS get precipitated by external stimuli. Here, we briefly introduce the case of a patient with latent autoimmune diabetes who developed SPS through the action of subcutaneously injected insulin. A 43-year-old man was diagnosed with diabetes and initially well-controlled with oral hypoglycemic agents but progressed to requiring insulin within 1 year of diagnosis. Two months after the initiation of basal insulin therapy, he presented with abdominal stiffness and painful muscle spasms, involving the lower limbs, which resulted in walking difficulty, and thus, he refused insulin injections thereafter. He had been treated with oral anti-diabetic agents instead of insulin for 10 years until premixed insulin twice daily was started again due to poor diabetes control. Immediately after insulin injection, abdominal muscle rigidity and spasms were noted. When insulin was not administered, frequent episodes of diabetic ketoacidosis occurred. Serum GAD antibody test was positive and there was no positivity for islet antigen-2 antibody. A glucagon stimulation test demonstrated relative insulin deficiency, indicative of latent autoimmune diabetes in adults (LADA). Tolerable muscle rigidity was achieved when the dosage of basal insulin was split into two separate daily injections with lower amounts of units per injection. This case highlights a different form of autoimmune diabetes in SPS. To our knowledge, this is the first report of SPS described shortly after the initiation of insulin therapy that required basal insulin to achieve tolerable muscle symptoms and better glucose control, without the development of diabetic ketoacidosis.

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.

Improving Ambulation and Minimizing Disability with Therapeutic Plasma Exchange in a Stiff-person Syndrome Patient with Recurrent Falls

Stiff-person syndrome (SPS) is a rare, autoimmune, neuromuscular disorder that manifests with axial and proximal muscle stiffness, rigidity, and painful muscle spasms, often causing progressive disability due to limited movement. First-line therapies comprise symptomatic management with γ-aminobutyric acid-modulating drugs such as benzodiazepines and baclofen. Patients resistant to these treatments are often given intravenous immunoglobulin (IVIg). Severe disease refractory to first-line therapy and IVIg may be treated with therapeutic plasma exchange (TPE) or immunomodulatory agents such as rituximab. Current evidence derived from case reports and case series has shown that roughly half of SPS patients treated with TPE report benefits. Here, we report the case of a 68-year-old man with a 20-year history of severe SPS and recurrent falls who was admitted to the emergency department for a traumatic hip fracture. He had significant rigidity in the axial and extremity muscles with persistent spasms of the quadriceps femoris muscle. Postoperatively, he was unable to participate in physical therapy (PT) due to these symptoms. He previously failed treatment with diazepam, baclofen, and monthly IVIg. Under our care, he underwent seven TPE treatments. By the end of treatment, he reported significant improvement in mobility with a resolution of muscle spasms and was able to be discharged to inpatient rehabilitation. This suggests that TPE may offer an effective, safe treatment modality for patients with severe refractory SPS that may significantly improve mobility and disability associated with the disease.

Utility of Botulinum Injections in Stiff-Person Syndrome

Stiff-person syndrome (SPS) is an uncommon neurological disorder characterized by significant rigidity and muscle spasms primarily affecting the truncal and proximal musculature. Furthermore, a wide-based gait with functional impairment is generally seen. High-dose benzodiazepines or baclofen are widely considered the optimal initial therapy; however, major adverse effects often preclude adequate dosing. Refractory cases may be treated with intravenous immunoglobulins (IVIG), plasma exchange, or B-cell depletion with rituximab, although these are also associated with major, sometimes fatal, adverse reactions. Several reports have validated the safety and utility of botulinum injections in this setting, yet botulinum remains markedly underutilized in this cohort. Below, a case report and review of the literature show botulinum can decrease pain and stiffness, improve gait and balance, and decrease dependence on powerful systemic treatments in this group.

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.

Trismus as a Presenting Symptom in a Case of Progressive Encephalopathy with Rigidity and Myoclonus

In this report we present a clinical case of trismus. The patient in question showed symptoms of trismus for 3 days, rapidly leading to respiratory insufficiency. Afterwards she developed myoclonus and progressive encephalopathy. Neurological workup showed no relevant abnormalities. A CT of the abdomen revealed a mass in the lower abdomen, which turned out to be an ovarian teratoma. Progressive encephalopathy with rigidity and myoclonus (PERM) was diagnosed clinically. Treatment with corticosteroids, benzodiazepines, and levetiracetam did not ameliorate the patient's condition. Only after the introduction of plasmapheresis was there a spectacular improvement in her clinical state. In this case we could not detect associated antibodies. The most likely cause of PERM is paraneoplastic disease secondary to ovarian teratoma. This type of tumor has been associated with multiple paraneoplastic neurological conditions, but this is the first case associated with PERM. To date there is only one publication on trismus as a sole presenting sign, with a quite similar disease course.

Anti-GAD Antibody-associated Syndrome Presenting with Limb Myoclonus

Background

The clinical spectrum of anti-glutamic acid decarboxylase (GAD) antibody-associated neurologic syndromes is expanding, with focal, generalized, and atypical forms.

Case Report

We describe a 59-year-old female showing continuous right lower limb myoclonus and mild encephalopathy. These symptoms started 2 weeks prior to evaluation. The patient had great improvement with intravenous steroids. An autoantibody panel was positive for anti-GAD.

Discussion

Various clinical manifestations, including myoclonus, may relate to anti-GAD antibodies. The treatment options available include symptomatic drugs, intravenous immunoglobulin, steroids, and other immunosuppressant agents.

Chronic intestinal pseudo-obstruction with dilated biliary tract as a spectrum of stiff person syndrome in a nondiabetic patient

Stiff person syndrome (SPS) is a rare and challenging neuromuscular junction disorder with typical musculoskeletal manifestations associated with anti-GAD65 antibodies, extra rheumatological manifestations, including neuropsychiatric symptoms and severe dysautonomic troubles. Chronic intestinal pseudo-obstruction (CIPO) is also a rare condition corresponding to a sub-occlusive syndrome, resulting from the functional or structural impairment of smooth neuromuscular tissues of the intestinal tract. In the clinical spectrum of SPS, CIPO has rarely been described and dilated biliary tract has never been described. This present report is therefore the first in the context of anti-GAD65 antibodies with the additional involvement of the biliary tract. Here, we report the case of a 44-year-old woman hospitalized for a rapidly progressive CIPO associated with dilated biliary tract, revealing a typical SPS with slowly progressive rheumatologic complaints relegated to the background. The concomitant improvement of the neuromuscular function on skeletal, intestinal and biliary tree systems with the good outcomes of anti-GAD65 titer under immunosuppressant drugs, allowed us to link all three organic involvements to the antibody pathogenicity on the respective neuromuscular junctions. Therefore, we discussed their common pathogeny based on our patient's treatment outcome.

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 report of rigidity and recurrent lower limb myoclonus: progressive encephalomyelitis rigidity and myoclonus syndrome, a chameleon

BACKGROUND

Progressive encephalomyelitis with rigidity and myoclonus (PERM) syndrome is a rare neurological condition. Its clinical characteristics include axial and limb muscle rigidity, myoclonus, painful spasms and hyperekplexia. Diagnosis of this disease can be very challenging and optimal long-term treatment is unclear.

CASE PRESENTATION

We report a case of a 62 year old patient admitted for repetitive myoclonus and rigidity in the lower limbs progressing since 10 years, associated with a fluctuating encephalopathy requiring stays in Intensive Care Unit. Multiple diagnostics and treatment were proposed, unsuccessfully, before the diagnosis of PERM syndrome was established. In association with the clinical presentation, a strong positive result for GAD (glutamic acid decarboxylase) antibodies lead to the diagnosis of PERM syndrome.

CONCLUSIONS

PERM syndrome is a rare disease and its diagnosis is not easy. Once the diagnosis is established, the correct treatment should follow and could be lifesaving, regardless of a delayed diagnosis. Maintenance of long-term oral corticotherapy is suggested to prevent relapses.

Expert recommendations for diagnosing cervical, oromandibular, and limb dystonia

BACKGROUND

Diagnosis of focal dystonia is based on clinical grounds and is therefore open to bias. To date, diagnostic guidelines have been only proposed for blepharospasm and laryngeal dystonia. To provide practical guidance for clinicians with less expertise in dystonia, a group of Italian Movement Disorder experts formulated clinical diagnostic recommendations for cervical, oromandibular, and limb dystonia.

METHODS

A panel of four neurologists generated a list of clinical items related to the motor phenomenology of the examined focal dystonias and a list of clinical features characterizing neurological/non-neurological conditions mimicking dystonia. Thereafter, ten additional expert neurologists assessed the diagnostic relevance of the selected features and the content validity ratio was calculated. The clinical features reaching a content validity ratio > 0.5 contributed to the final recommendations.

RESULTS

The recommendations retained patterned and repetitive movements/postures as the core feature of dystonia in different body parts. If present, a sensory trick confirmed diagnosis of dystonia. In the patients who did not manifest sensory trick, active exclusion of clinical features related to conditions mimicking dystonia (features that would be expected to be absent in dystonia) would be necessary for dystonia to be diagnosed.

DISCUSSION

Although reliability, sensitivity, and specificity of the recommendations are yet to be demonstrated, information from the present study would hopefully facilitate diagnostic approach to focal dystonias in the clinical practice and would be the basis for future validated diagnostic guidelines.

Stiff person syndrome with elevated titers of antibodies against cardiolipin and β2 glycoprotein 1: a case report and literature review

We reported a Stiff person syndrome (SPS) patient with elevated autoantibodies against cardiolipin and β2 glycoprotein 1 but without glutamic acid decarboxylase (GAD) antibodies. A 40-year male was admitted due to limited mouth opening for 1 week. His blood routine, biochemical, infectious diseases, tumor markers, radiographic examinations were all normal. At day 3 (D3) after admission, he developed paroxysmal systemic muscle rigidity. At D6, the on-duty physician occasionally gave oral clonazepam, which effectively relieved the symptom. At D13, the titers of cardiolipin and β2 glycoprotein 1 autoantibodies elevated but the remaining autoantibodies were all in normal ranges. After clonazepam treatment for 1 week, the symptoms were basically relieved, and the titers of these two antibodies returned to normal range with the relief of symptoms. During the 3 years of follow-up, the symptoms did not present again, and the titers of both antibodies were stable in the normal ranges. He had no tumor and other immune system diseases. In summary, we reported a SPS case with elevated cardiolipin and β2 glycoprotein 1 autoantibodies. The patient was highly responsive to clonazepam therapy, and had favorable outcome in the 3 years follow-up. Our report is helpful for better understand the heterogeneous feature of SPS.

Inpatient care for stiff person syndrome in the United States: a nationwide readmission study

Background

Stiff person syndrome (SPS) is a progressive neurological disorder characterized by axial muscle rigidity and involuntary spasms. Autoimmune and neoplastic diseases are associated with SPS. Our study objectives were to describe inpatient care for SPS in the United States and characterize 30-day readmissions.

Methods

We queried the 2014 Nationwide Readmission Database for hospitalizations where a diagnosis of SPS was recorded. For readmission analyses, we excluded encounters with missing length of stay, hospitalization deaths, and out-of-state and December discharges. National estimates of index hospitalizations and 30-day readmissions were computed using survey weighting methods. Unconditional logistic regression was used to examine associations between demographic, clinical, and hospital characteristics and readmission.

Results

There were 836 patients with a recorded diagnosis of SPS during a 2014 hospitalization. After exclusions, 703 patients remained, 9.4% of which were readmitted within 30 days. Frequent reasons for index hospitalization were SPS (27.8%) and diabetes with complications (5.1%). Similarly, readmissions were predominantly for diabetes complications (24.2%) and SPS. Most readmissions attributed to diabetes complications (87.5%) were to different hospitals. Female sex (OR, 3.29; CI: 1.22–8.87) and routine discharge (OR, 0.26; CI: 0.10–0.64) were associated with readmission, while routine discharge (OR, 0.18; CI: 0.04–0.89) and care at for-profit hospitals (OR, 10.87; CI: 2.03–58.25) were associated with readmission to a different hospital.

Conclusions

Readmissions in SPS may result from disease complications or comorbid conditions. Readmissions to different hospitals may reflect specialty care, gaps in discharge planning, or medical emergencies. Studies are required to determine if readmissions in SPS are preventable.

Difficult to Treat Focal, Stiff Person Syndrome of the Left Upper Extremity

Background

Stiff person syndrome (SPS) is a rare neurologic disorder characterized by muscle rigidity. It is a disorder of reduced GABA activity leading to increased muscle tone and often painful spasms. It generally presents in the axial musculature but rarely can involve only one limb, typically a lower extremity. In rare cases it can be paraneoplastic which generally resolves on treatment of the underlying neoplasm.

Case Report

A 46-year-old male with a history of Hodgkin's Lymphoma in remission presented with left upper extremity pain secondary to a diagnosis of Stiff Person Syndrome limited to his left upper extremity. He had previously benefitted from plasmapheresis and was on diazepam and baclofen at home with relatively good control of his symptoms. SPS had previously been diagnosed with EMG and anti-GAD-65 antibody titers and was confirmed by an elevated anti-GAD-65 antibody titer. He was treated with plasmapheresis and maximum doses of medical treatment including botulinum toxin with only transient mild improvement in his symptoms.

Conclusion

This case represents a case of a rare disease that was refractory to all known therapies. It outlines the need for further understanding of this disorder in order to provide better symptomatic treatment or potentially more definitive care.

Autoimmune Movement Disorders: a Clinical and Laboratory Approach

Autoimmune movement disorders are caused by an aberrant immune response to neural self-antigens. These disorders may be paraneoplastic, parainfectious, or (most commonly) idiopathic. The neurological presentations are diverse, and sometimes multifocal. Movement disorders can occur as part of the spectrum with phenotypes including chorea, myoclonus, ataxia, CNS hyperexcitability (including stiff-person syndrome), dystonia, and parkinsonism. Symptoms are subacute in onset and may have a fluctuating course. The best characterized disorders are unified by neural autoantibodies identified in serum or cerebrospinal fluid. The antibody specificity may predict the association with cancer and the response to immunotherapy. In this article, we review autoimmune-mediated movement disorders, associated cancers, diagnosis, and treatment.

Clinical Approach to Supranuclear Brainstem Saccadic Gaze Palsies

Failure of brainstem supranuclear centers for saccadic eye movements results in the clinical presence of a brainstem-mediated supranuclear saccadic gaze palsy (SGP), which is manifested as slowing of saccades with or without range of motion limitation of eye movements and as loss of quick phases of optokinetic nystagmus. Limitation in the range of motion of eye movements is typically worse with saccades than with smooth pursuit and is overcome with vestibular–ocular reflexive eye movements. The differential diagnosis of SGPs is broad, although acute-onset SGP is most often from brainstem infarction and chronic vertical SGP is most commonly caused by the neurodegenerative condition progressive supranuclear palsy. In this review, we discuss the brainstem anatomy and physiology of the brainstem saccade-generating network; we discuss the clinical features of SGPs, with an emphasis on insights from quantitative ocular motor recordings; and we consider the broad differential diagnosis of SGPs.