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

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

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

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

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

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

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

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

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

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

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

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

Anaesthetic implications of hyperekplexia--'startle disease'

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

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

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

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

[A stiff-legged man with a bizarre gait]

BACKGROUND

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

CASE REPORT

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

CONCLUSION

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

Rigidity and spasms from autoimmune encephalomyelopathies: stiff-person syndrome

Stiff-person syndrome (SPS) is a disorder characterized by progressive muscle rigidity with superimposed painful muscle spasms and gait impairment due to continuous motor activity. Evidence has accumulated in favor of SPS representing an autoimmune, predominantly encephalomyelopathic disorder resulting from B-cell-mediated clonal production of autoantibodies against presynaptic inhibitory epitopes on the enzyme glutamic acid decarboxylase (GAD) and the synaptic membrane protein amphiphysin. Recognition of the clinical spectrum of SPS is important, particularly the upper-limb, cervical, and cranial nerve involvement that occurs in paraneoplastic variants. The correlation between antibody levels and severity of disease offers evidence for a pathogenic role for the anti-GAD and anti-amphiphysin autoantibodies. The scarcity of neuropathological correlates stand in sharp contrast with the severity of the disability in affected individuals and suggests that functional impairment of inhibitory circuits without structural damage is sufficient to develop the full clinical spectrum of SPS. The rarity of this condition limits the feasibility of controlled clinical trials in the treatment of SPS, but the available evidence suggest that drugs that increase cortical and spinal inhibition such as benzodiazepines and drugs that provide immune modulation such as intravenous immunoglobulin, plasmapheresis, and prednisone are effective treatments.

Hyperekplexia in two siblings

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

Anesthetic management of a patient with stiff person syndrome

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

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

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

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

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