Atypical stiff-person syndrome with spinal MRI findings, amphiphysin autoantibodies, and immunosuppression.

In an atypical case of stiff-person syndrome (SPS), spinal T2-weighted MRI revealed a hyperintense lesion extending from C2 to C7 that corresponded with the clinical symptoms and signs. CSF showed lymphocytic pleocytosis and oligoclonal bands. Amphiphysin autoantibodies were detected in serum and CSF; however, unlike other reported cases, no malignancy occurred during a 3-year observation period. Methylprednisolone and cyclophosphamide pulse therapy led to a marked reduction of symptoms.