Stiff-Man Syndrome

Abstract

IA. Sharoqi, Stiff-Man Syndrome. 1998; 18(2): 158-159 Stiff-man syndrome (SMS) is a rare disorder of the central nervous system characterized by progressive rigidity and painful intermittent spasms.1,2 The muscle stiffness starts insidiously in the axial and proximal musculature, with a steady, slow progression over months or years. Muscle spasms are early complaints and may dominate the clinical presentation. These are often precipitated by tactile or emotional stimuli, volitional movements and startling noises. Neurologic examination usually reveals no abnormalities other than rigidity and spasms in the affected muscles. The etiology of the disease is unknown, although the association of SMS with diseases such as diabetes, vitiligo and hypothyroidism, and the detection of auto-antibodies against (γ-aminobutyric acid) GABA-ergic neurons in serum and cerebrospinal fluid (CSF) suggest that the disease has an autoimmune nature. [3][4][5] This is a report of a patient with stiff-man syndrome with unusual presentation, high titers of anti-GAD (glutamate acid decarboxylase) antibodies in serum and CSF, other organ-specific auto-antibodies and a favorable response to vigabatrin. Case ReportA 66-year-old man presented with a two-year history of progressive stiffness and painful intermittent spasms of his right lower limb that started distally, and gradually involved the proximal muscles and the lumbosacral paraspinal muscles one year later. His stiffness continued without daily fluctuation and the painful spasms were mainly precipitated by volitional movements and tactile stimuli of his right leg. This gradually affected his gait and he became unable to walk without assistance. His left lower limb was not affected. He had had insulin-dependent diabetes mellitus for the previous nine years.Clinical examination revealed prominent stiffness of all muscles of the right leg and the lumbosacral paraspinal muscles. The left leg tone was normal. Tendon reflexes were normal and plantar responses were on a downward trend. No sensory deficit was detected apart from loss of vibration sense at ankle bilaterally. He could walk with some assistance, but his movements were interrupted by painful spasms in the affected muscles. His higher mental functions, cranial nerves and upper limbs were entirely normal on examination.MRI of the head and spinal cord were unremarkable. Oligoclonal IgG bands were detected in serum and CSF. An assay based on immunoprecipitation of 125 I-recombinant GAD was used to measure anti-GAD antibodies. 10 High titers of anti-GAD antibodies were detected in the serum and CSF (Figure 1). In addition, the patient had positive pancreatic islet cell and gastric parietal cell antibodies. EMG showed continuous motor unit activity that reduced markedly when the patient fell asleep during the test. The patient was put on 15 mg of diazepam and 60 mg of baclofen daily, resulting in an improvement in the spasms and, to a lesser extent, in the rigidity, but the patient was still unable to walk unassisted. However, the ma...