A rare complication of dysarthria in a patient with inclusion body myositis: A case report

Abstract

We reported a 71-year-old man with inclusion body myositis with clinically overt dysarthria. He had been suffering from gradual progression of weakness in the hand muscles and lower extremities as well as dysarthria three years before admission. His neurological examination revealed muscle atrophy and weakness in the tongue, the forearm flexors, and the vastus medialis muscles. He had dysarthria to a moderate degree, while he denied any dysphasia. A biopsy from vastus lateralis muscle showed variation in fiber size, infiltration of mononucleated cells, and numerous fibers with rimmed vacuoles, leading to the diagnosis of definite inclusion body myositis. The EMG findings of the tongue demonstrated low amplitude motor unit potentials during voluntary contraction, abundant fibrillation potentials at rest, and preserved interference pattern at maximal contraction, implying myogenic changes. We surmised the dysarthria seen in this patient, an atypical clinical feature in IBM, presumably caused by muscle involvement in the tongue muscle. Dysphasia is common symptom in IBM patient and has been much reported previously. But dysarthria in IBM patient has not been aware, for this reason this report should be the rare case.