Le syndrome de l'homme raide : bonne évolution sous bolus de méthylprednisolone

Stiff-man syndrome (SMS) is a rare neurological disease characterized by axial and proximal limb rigidity with painful muscle spasms, trunk and limbs contractions. We report the case of a 61-year-old man who presented axial muscle rigidity, painful spasms of the trunk and upper limbs. The neurological examination revealed paraspinal and abdominal muscle contraction with severe lumbar rigidity associated with adrenergic autonomic dysregulation. Electroneuromyography showed continuous motor unit activity in limb and axial muscle. Routine hematological and biochemical blood tests were normal; the patient was negative for anti-GAD and antineuronal antibodies; search for malignancy was negative. The diagnosis of common SMS was retained. Good improvement was noted after methylprednisolone pulse therapy associated with symptomatic treatment combined diazepam, baclofen and physical therapy. The pathogenesis of SMS is unknown but the cause is likely to be autoimmune because of the association with specific autoantibodies (anti-GAD), other autoimmune diseases, paraneoplasic syndrome and response to immunomodulatory therapy. Treatment with GABA-ergic inhibitory drugs with immunomodulation, intravenous immunoglobulin (IVIg), plasmapheresis, and corticosteroids improves both the symptoms and the quality of life of these patients.