Case report: Stiff person syndrome with thymoma

Abstract

Stiff person syndrome is a rare neurological syndrome characterized by fluctuat¬ing muscle rigidity and painful spasms. About 5-8% of stiff person syndrome cases are associated with malig¬nant tumors, and the symptoms can manifest as a para-neoplastic disorder. Case. We herein report a 68-year-old man who was referred to our hospital with a chief com¬plaint of gait disturbance due to painful muscle rigidity in both legs. Examinations of the head and spine showed no abnormalities. However, on chest computed tomogra¬phy, an anterior mediastinal tumor was seen, and blood tests showed a high titer of anti-glutamic acid decarbox-ylase antibody. These findings suggested that his symp¬toms could be attributed to paraneoplastic neurological syndrome associated with the mediastinal tumor. Fur¬thermore, characteristic symptoms and laboratory find¬ings also indicated stiff person syndrome. These symp¬toms were not affected by initial treatment with ster-oids, but they were improved by benzodiazepine and ba-clofen treatment. The pathological diagnosis after radi¬cal thymectomy was type B2 thymoma. The patient's postoperative course was uneventful. His medications were decreased, and his symptoms gradually improved. Conclusion. Thymectomy might offer symptomatic re¬lief for stiff person syndrome associated with thymoma.