Laughlin, Ruple S.

ABSTRACTIntroduction: The hallmark clinical presentation of inclusion‐body myositis (IBM) is slowly progressive weakness that characteristically affects the quadriceps and finger and wrist finger flexor muscles. Facial weakness can also occur, but it is typically mild and not a prominent finding. Methods: We describe the clinical features, laboratory investigations, and muscle biopsy findings in a 58‐year old man who presented with a 6‐year history of marked progressive symmetrical facial weakness. Examination also showed shoulder abduction and hip extensor weakness. Results: The patient's serum creatine kinase level was 655 U/L, and electromyography showed fibrillation potentials and myopathic motor unit potentials. A biopsy specimen of the left biceps muscle was pathognomonic for IBM. Conclusions: This patient did not have a typical presentation for IBM but rather fulfilled the pathological criteria for IBM. To our knowledge, facial diplegia has not been reported previously as a presenting manifestation of IBM. Muscle Nerve 49: 287–289, 2014