Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare and severe syndrome characterized by rigidity of the limb and truncal muscles, brainstem signs, myoclonus, and hyperekplexia. Iliopsoas hematoma is a serious complication of bleeding disorders that occurs most commonly in patients with hemophilia and also in association with anti-coagulant drug treatment. We herein present a case of PERM complicated with bilateral iliopsoas hematomas. His neurological symptoms improved after immunotherapy, and thereafter the iliopsoas hematomas disappeared. Neurologists should consider iliopsoas hematomas as a serious potential complication of PERM.
Keywords: PERM, progressive encephalomyelitis with rigidity and myoclonus; glycine receptor antibodies; hypercontraction; iliopsoas hematomas.