| Abstract: | We report a 42-year-old female with continuous muscle stiffness and painful muscle spasms of the right leg. The symptoms developed suddenly and worsened over the week after onset. At hospitalization, the right leg had a fixed posture of extension and the foot was plantar-flexed and internally rotated. Neurological examination revealed hyperreflexia of the right knee with positive Chaddock's sign, and stiffness and painful spasms located in the right leg, exaggerated by sudden auditory and tactile stimuli or by emotional stress. She could not walk due to her stiffness. There were no signs of rigidity in the left leg, upper extremities, or truncal muscles. Electrophysiological examinations revealed continuous muscle discharge. High titers of anti-glutamic decarboxylase (GAD) antibodies were detected in serum (140,000 U/ml) and cerebrospinal fluid (1,347 U/ml), confirming that the patient suffered from stiff-leg syndrome. Systemic evaluation revealed no malignant neoplasm, but revealed euthyroid Hashimoto's disease. Stiff-leg syndrome in this case was unresponsive to pharmacotherapy with diazepam and was unchanged for the first month of hospitalization. Plasma exchange therapy alleviated the clinical symptoms and decreased the anti-GAD antibody titer. After IVIg therapy, the symptoms and signs have dramatically disappeared to date but the titer of anti-GAD antibodies in serum recurred after an initial fall. To our knowledge, this is the first case of stiff-leg syndrome in Japan. |
