Lipoma Compressing the Sciatic Nerve in a Patient With Suspicious Central Post-stroke Pain

Lipomas are mostly located in the subcutaneous tissues and rarely cause symptoms. Occasionally, peripheral nerve compression by lipomas is reported. We describe a case of a 59-year-old man with a left-middle cerebral artery infarction who was newly diagnosed as right basal ganglia and thalamic intracranial hemorrhage. He had neuropathic pain in the left arm and leg that was suspected to be central post-stroke pain. The administration of pain medication brought only temporary symptom relief. Nerve conduction and electromyography studies revealed left L5 radiculopathy and he showed a positive 'sign of the buttock' in the left hip. Left-hip magnetic resonance imaging revealed an intermuscular lipoma compressing the sciatic nerve. After surgery, the range of motion in the left hip joint was significantly increased, and the patient's pain was relieved.