Hirayama Disease with Isolated Spinal Cord Atrophy

Abstract

This report presents a young-aged man with Hirayama disease who had muscle atrophy and weakness strictly confined to the C8/T1 myotome that consistently accorded with electromyographic results. In the magnetic resonance imaging (MRI) evaluation, there was only a prominent isolated spinal cord atrophy without any typical flexion MRI features of Hirayama disease. We speculate that it may be possible to have only isolated spinal cord atrophy as a limited form in Hirayama disease even in the absence of anterior displacement of the dura in the flexed position. These findings emphasize the importance of understanding both typical and atypical limited findings of the MRI imaging features of Hirayama disease, because it’s critical to distinguish Hirayama disease, mostly showing benign course, from fatal conditions like amyotrophic lateral sclerosis.