A case of progressive encephalomyelitis with rigidity and positive antiglutamic acid decarboxylase antibodies [corrected]

Progressive Encephalomyelitis With Rigidity and Myoclonus With Thymoma: A Case Report and Literature Review

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is part of the variant type of the Stiff Person Syndrome (SPS) and is a rare neurological disease. We report here a patient with PERM who had thymoma and was positive for anti-glutamic acid decarboxylase (anti-GAD) antibodies. Her symptoms improved after treatment with hormones and gamma globulin. We also summarized the literature review of patients with PERM accompanied by tumors reported.

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.

Stiff-Person Syndrome

The stiff-person syndrome is a disorder of persistent, painful muscle contractions predominately affecting the axial musculature. We describe a patient with this disorder and review its pathophysiology. Molecular biologic and immunologic techniques have recently added to the understanding of the mechanism of this disorder. Association with diseases such as diabetes, vitiligo and hypothyroidism have strengthened the auto-immune nature of this syndrome. Auto-antibodies against glutamic acid decarboxylase (GAD), an intraneuronal enzyme, have been implicated in the etiology of this unique disease. Therapeutic intervention with agents such as benzodiazepines that modify central GABAergic activity have demonstrated significant benefit in patients with stiff-person syndrome.

Progressive encephalomyelitis with rigidity: a case report

BACKGROUND/OBJECTIVE

The most prominent clinical features of progressive encephalomyelitis with rigidity (PER) are painful spasms and rigidity accompanied by clinical signs of brainstem and spinal cord involvement. In initial reports, PER had fatal outcome. Later, clinical improvement related to corticosteroid therapy has been described in some cases. The objective of this study was to signify a reputed clinical significance of corticosteroid therapy in PER.

METHODS

Case report.

RESULTS

A 50-year-old man developed progressive syndrome of tonic extensor spasms. Magnetic resonance imaging (MRI) showed areas of signal changes in cervical spinal cord and lower brainstem, whereas cerebrospinal fluid analysis indicated subacute encephalomyelitis. His condition dramatically improved on oral corticosteroid therapy. Clinical improvement was accompanied by normalization of MRI findings.

CONCLUSION

For this patient with PER, corticosteroid therapy was a dramatically effective and life-saving treatment, although initiated rather late in the course of the disease.

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.

Glutamic acid decarboxylase autoimmunity with brainstem, extrapyramidal, and spinal cord dysfunction

OBJECTIVE

To describe novel neurological manifestations associated with glutamic acid decarboxylase (GAD65) autoimmunity.

PATIENTS AND METHODS

This retrospective study (1987-2003) describes 62 patients Incidentally found to have a serum autoantibody that bound selectively to synapse-rich central nervous system tissues. The immunostaining pattern was determined to be GAD65-specific by radiolmmunoprecipitation assay. These cases were identified among samples submitted for paraneoplastic autoantibody evaluation using indirect immunofluorescence. In no case had GAD65 or any other islet cell antibody testing been requested.

RESULTS

In most cases, the patients' presentations were initially considered neurodegenerative or inflammatory (multiple sclerosis or paraneoplastic). Median age at onset was 50 years, and 77% were women. Of the 44 patients seen at the Mayo Clinic, 23% were African American; in contrast, less than 10% of Mayo Clinic's neurology patients are African American. Median follow-up was 24 months. The radioimmunoprecipitation assay values for GAD65 antibody were extremely high (median, 1429 nmol/L; Interquartile range, 643-3078 nmol/L) and correlated significantly with immunofluorescence titers (median, 3840; interquartile range, 1920-15,360; r = 0.81; P < .001). Neurological manifestations were multifocal in 41 patients and included cerebellar ataxia (63%), brainstem involvement (29%), seizures (27%), stiff-man phenomena (26%), extrapyramidal signs (16%), and myelopathy (8%). One third of the patients had type 1 diabetes mellitus, 53% had thyroid autoantibodies, and 16% had vitiligo. Eleven of 20 patients identified as African American had brainstem involvement. Some patients appeared to benefit from short-term immunosuppression (none received long-term therapy).

CONCLUSIONS

The neurological spectrum of GAD65 autoimmunity includes brainstem, extrapyramidal, and spinal cord syndromes. In our experience, African American patients were disproportionately affected. A patient with a presumed neurodegenerative disorder of new onset, with high levels of GAD65 antibody (>20 nmol/L), merits consideration of immunotherapy.

Le syndrome de l’homme raide : formes cliniques, traitement et profil évolutif

INTRODUCTION

Stiff-Man syndrome (SMS) is a rare neurological disease first described fifty years ago. There are several clinical forms, which are frequently misdiagnosed. The aim of this study is to review three of the main clinical forms.

MATERIAL AND METHODS

Case reports concerning three women suffering from different forms of SMS are presented, giving the main clinical features, their associations with other diseases, and the biological and electrophysiological findings.

RESULTS

The first patient presented a symmetric axial muscle rigidity, painful spasms and contractions of the trunk and limbs associated with anti-GAD antibodies. The common form of SMS was diagnosed and the patient was improved by intravenous immunoglobulin (IVIg). The second patient suffered from contractions and spasms localized to the lower limbs. In this patient, anti-GAD antibodies were absent. The Stiff-Leg syndrome was diagnosed and the patient was improved by intrathecal baclofen. The third patient presented rigidity of limb and trunk muscles associated with signs of encephalitis. In this patient, only anti-amphiphysin antibodies were present. The progressive encephalomyelitis with rigidity was diagnosed and the patient was improved by IVIg associated with corticosteroid.

CONCLUSION

Identifying patients with SMS makes it possible to propose appropriate medical management. There are several forms of the disease, and the severity of the evolution differs in each case. Treatment with GABA-ergic inhibitory drugs, IVIg and corticosteroid improve both the symptomatology and the quality of life of these patients.

Progressive encephalomyelitis with rigidity: a paraneoplastic presentation of oat cell carcinoma of the lung. Case report

Progressive encephalomyelitis with rigidity and myoclonus (PEWR) is a rare neurological disorder, characterised by muscular rigidity, painful spasms, myoclonus, and evidence of brain stem and spinal cord involvement. A 73-year-old white man was admitted with a 10-day history of painful muscle spasms and continuous muscle rigidity on his left lower limb. He had involuntary spasms on his legs and developed encephalopathy with cranial nerves signs and long tract spinal cord symptomatology. Brain CT scan and spinal MRI were normal. The CSF showed lymphocytic pleocytosis and no other abnormalities. EMG showed involuntary muscle activity with 2-6 seconds of duration, interval of 30-50 ms and a frequency of 2/second in the left lower limb. Anti-GAD antibodies were detected in the blood. We detected radiological signs of lung cancer during the follow-up, which proved to be an oat cell carcinoma. The patient died two weeks after the diagnosis of the cancer.

Stiff man syndrome and related conditions

The stiff man syndrome (SMS) and its variants, focal SMS, stiff limb (or leg) syndrome (SLS), jerking SMS, and progressive encephalomyelitis with rigidity and myoclonus (PERM), appear to occur more frequently than hitherto thought. A characteristic ensemble of symptoms and signs allows a tentative clinical diagnosis. Supportive ancillary findings include (1) the demonstration of continuous muscle activity in trunk and proximal limb muscles despite attempted relaxation, (2) enhanced exteroceptive reflexes, and (3) antibodies to glutamic acid decarboxylase (GAD) in both serum and spinal fluid. Antibodies to GAD are not diagnostic or specific for SMS and the role of these autoantibodies in the pathogenesis of SMS/SLS/PERM is the subject of debate and difficult to reconcile on the basis of our present knowledge. Nevertheless, evidence is emerging to suggest that SMS/SLS/PERM are manifestations of an immune-mediated chronic encephalomyelitis and immunomodulation is an effective therapeutic approach.

Progressive encephalomyelitis with rigidity presenting as a stiff-person syndrome

Diagnosis criteria of stiff-person syndrome (SPS) include progressive, fluctuating muscular rigidity and spasms with normal neurological examination. The presence of unusual features such as prominent limb rigidity with segmental signs and contracture, evidence of brainstem dysfunction, profound autonomic disturbances, CSF pleiocytosis or MRI abnormalities in patients with SPS presentation allows to classify these patients as progressive encephalomyelitis with rigidity (PER). We report a 50 year-old woman suffering from severe painful spasms of abdominal wall and limb muscles. Neurological examination showed pyramidal signs. EMG disclosed continuous muscle activity with superimposed discharges. Treatment with high doses of diazepam and baclofen led to moderate improvement of generalised stiffness. However, the right arm became more rigid with oedema and vasomotor changes. Subsequently, bilateral nystagmus and internuclear opthalmplegia appeared. There was mild CSF pleiocytosis. Associated auto-immune thyroiditis was found with positive anti-microsome antibodies and decreased thyroid hormones. Search for profound neoplasm was negative. The patient had three subacute bouts then she improved with methylprednisolone. The initial clinical presentation mimicking a SPS with subsequent diffuse involvement of the central nervous system and a striking localisation of a severe rigidity to one arm allowed to suspect the diagnosis of PER. The relationship between SPS and PER remains unclear because of the rarity of these disorders. The observation reported in this paper gives evidence that both the disorders are probably two clinical presentations of the same pathogenic process.

The stiff-man syndrome and related disorders

The stiff-man syndrome (SMS) is characterised by rigidity and spasm of predominantly axial and proximal limb muscles. The cause of the condition is unknown but the finding of antibodies to glutamic acid decarboxylase (GAD) in approximately 60% of patients has suggested an autoimmune basis. Pathological findings are limited to a small number of cases which are reviewed in this paper. In some, evidence of an inflammatory aetiology has been found, and there appears to be overlap with progressive encephalomyelitis with rigidity (PER) which may present with a similar clinical picture. The spontaneous muscle activity in SMS and PER is of central origin, related to release of polysynaptic spinal and brainstem reflexes. The SMS is readily distinguished from the continuous muscle activity, spasm and cramps of Isaac's syndrome and neuromyotonia which originate in the peripheral nervous system. Fasciculations, myokymia, myotonia and complex repetitive discharges are characteristic of these peripheral neuromuscular disorders.

GAD65-Reactive T cells in a non-diabetic stiff-man syndrome patient

GAD65 (glutamic acid decarboxylase) is an important autoantigen in both type 1 (insulin-dependent) diabetes mellitus (IDDM) and the neurological autoimmune disease stiff-man syndrome (SMS), and is expressed in pancreatic islets as well as the nervous system. Still, only 30% of SMS patients also have type 1 diabetes. To study regulation of T cell responsiveness to GAD65, we investigated a non-diabetic SMS patient with HLA-DR3/7 (predisposing to type 1 diabetes) and high levels of type 1 diabetes-associated autoantibodies against GAD65 and islet cells, and compared the results with those of her diabetic son and two other SMS patients. T cell responses to GAD65 were repeatedly absent in primary stimulation, whereas IA-2, islet antigen and tetanus toxoid induced significant T cell proliferation. However, after in vitro restimulation, GAD65 reactive T cell lines and clones were obtained that were HLA-DR3 restricted, and cross-reactive with a homogenate of purified human pancreatic islets. These T cells produced the immunoregulatory cytokine IL-10 in combination with IFN-gamma and IL-4 (Th0). The dominant T cell epitope was mapped to the central region of GAD65. Although no primary response to whole GAD65 was detectable, the naturally processed GAD65 peptide epitope was recognized vigorously in the primary stimulation assay. The lack of detectable primary T cell responses to GAD65, together with the GAD65-specific cytokine production of restimulated T cells, suggest that GAD65-specific cellular autoimmunity in this patient is suppressed and may be related to the absence of diabetes despite humoral autoreactivity and genetic predisposition.

Review of 23 patients affected by the stiff man syndrome: clinical subdivision into stiff trunk (man) syndrome, stiff limb syndrome, and progressive encephalomyelitis with rigidity

OBJECTIVE

To investigate whether the stiff limb syndrome may be separated from the stiff man syndrome and progressive encephalomyelitis with rigidity on simple clinical grounds, and whether such a distinction has implications for aetiology, treatment, and prognosis.

METHODS

Twenty three patients referred over a 10 year period with rigidity and spasms in association with continuous motor unit activity, but without evidence of neuromyotonia, extrapyramidal or pyramidal dysfunction or focal lesions of the spinal cord were reviewed. The patients were divided into those with an acute or subacute illness, leading to death within 1 year, and those with a chronic course. The latter were divided into those in whom rigidity and spasms dominated in the axial muscles, or in one or more distal limbs, at the time of their first assessment.

RESULTS

This simple division identified three distinct groups of patients. (1) Progressive encephalomyelitis with rigidity: two patients had a rapidly progressive condition characterised by widespread rigidity which resulted in death within 6 and 16 weeks. One patient had negative anti-GAD and anti-neuronal antibodies, but had markedly abnormal CSF and widespread denervation. The principal pathological findings in this case were a subacute encephalomyelitis which primarily affected the grey matter. In the remaining patient anti-GAD antibodies were not tested, and postmortem was refused. (2) Stiff man syndrome: eight patients had rigidity and painful spasms of the lumbar paraspinal, abdominal, and occasionally proximal leg muscles associated with a lumbar hyperlordosis. There was no involvement of the upper limbs, distal lower limbs, sphincters or cranial nerves. Seven had anti-GAD antibodies and most had additional evidence of autoimmune disease. Neurophysiologically there was continuous motor unit activity with abnormal exteroceptive reflexes, but a normal interference pattern during spasms. The patients all responded to baclofen/diazepam and remained ambulant. (3) Stiff limb syndrome: thirteen patients had rigidity, painful spasm, and abnormal postures of the distal limb, ususphincter or brainstem involvement. Generalised myoclonic jerks were not a feature. Only two had truncal rigidity, and another two had anti-GAD antibodies. Most had no evidence of autoimmune disease. Neurophysiologically they had continuous motor unit activity in the affected limb, abnormal exteroceptive reflexes, and abnormally segmented EMG activity during spasms. The disease ran a protracted course, and most patients had only a partial response to baclofen or diazepam. About half became wheelchair bound.

CONCLUSIONS

The stiff limb syndrome seems distinct from the stiff man syndrome or progressive encephalomyelitis with rigidity, and is an important cause of rigidity and spasm in the setting of continuous motor unit activity.

Alpha interferon treatment in myasthenia gravis: effects on natural killer cell activity

The efficacy of recombinant interferon-alpha (rIFN alpha), on natural killer (NK) cell cytotoxic activity, CD3+, CD4+, CD8+, CD56+, HLA-DR+ lymphocyte counts, anti-acetylcholine receptor antibody (AChR Ab) levels, single fibre electromyography findings (SFEMG) and clinical course were evaluated in patients with myasthenia gravis (MG). During the IFN alpha treatment (3 mu, subcutaneous, 3 times a week), NK cell cytotoxicity and CD4+/8+ ratio increased, NK cell count remarkably decreased, and no significant clinical or SFEMG changes were observed. This preliminary open study in MG patients has demonstrated enhanced NK activity per unit NK cell after IFN alpha therapy. Although lymphocyte phenotypes and NK function approached normal levels during therapy, a higher dose of IFN alpha may be required for a significant clinical response. It has been also concluded that 6 months of IFN alpha therapy seems to be safe in MG, though in patients with malignancy, IFN alpha may cause increased autoimmunity, AChR positivity and MG.

PCR detected hepatitis C virus genome in the brain of a case with progressive encephalomyelitis with rigidity

A case of progressive encephalomyelitis with rigidity (PEWR) associated with hepatitis C virus (HCV) is reported. A 58 year-old woman presented with a clinical picture of progressive quadriparesis, sensory loss, sphincter dysfunction, painful muscle spasms in the upper and lower limbs and continuous muscle unit activity in electromyography. She developed hepatitis, pancreatitis and HCV-RNA was detected in the plasma by reverse transcription-polymerase chain reaction (RT-PCR). Postmortem histopathological examination showed encephalomyelitis with perivascular lymphocyte cuffing, infiltration and neuronal loss mainly affecting the brainstem and cervical spinal cord. The RT-PCR analysis of the postmortem brain, brainstem, liver, pancreas, plasma and CSF samples revealed the presence of HCV genome in all specimens except CSF. Clinical features, postmortem histopathology and PCR results and the possible etiopathogenesis of PEWR are briefly discussed.

Progressive encephalomyelitis with rigidity responsive to plasmapheresis and immunosuppression

The stiff-man syndrome is reported in a 55-year-old woman who also had signs of severe bulbar musculature hypercontraction. These clinical features correspond to the progressive encephalomyelitis with rigidity syndrome. Diazepam was minimally beneficial, but after treatment with plasmapheresis and corticosteroids, she was still asymptomatic when seen 5 years later.

Stiff man syndrome: clinical and laboratory findings in eight patients

The clinical, biochemical, neuroimaging and neurophysiological findings of eight patients with stiff man syndromes (SMS) [four of six being tested with autoantibodies against glutamic acid decarboxylase (GAD)] are presented. In two patients (one GAD-positive, one GAD-negative), transient oculomotor disturbances suggested progressive encephalomyelitis with rigidity and myoclonus (PERM) as differential diagnosis. The catalogue of characteristic clinical symptoms of SMS is extended by three new symptoms: (1) an aura-like feeling reported by five patients to precede spontaneous spasmodic attacks; (2) a stereotyped motor pattern seen in seven patients during spasmodic jerks, consisting of brief opisthotonos, stiffening of the slightly abducted legs and inversion of the plantar-flexed feet; (3) a paroxysmal fear when crossing a free space unaided, or even thinking of it. Clinical findings did not enable us to discriminate between patients tested GAD-positive or GAD-negative. Cerebrospinal fluid contained elevated immunoglobulin levels or cell counts, or both, in the majority of patients. Autopsy of one patient revealed scattered lymphocyte cuffs around leptomeningeal, intracerebral and particularly intraspinal vessels, suggesting a mild inflammatory process. Whether SMS and PERM are closely related is discussed; they are possibly both manifestations of a spectrum of encephalomyelopathies having autoimmunity against GABAergic neurons in common.