Hirayama's Disease: About a Clinical Observation.

Hirayama disease, also known as non-progressive juvenile spinal muscular atrophy of the upper limbs, brachial monomelic amyotrophy, or benign focal atrophy, affects the C7 D1 myotomes; an electromyogram (EMG) shows neurogenic damage in the C7-C8-T1 territories. It causes weakness and amyotrophy of the distal upper limb. Although it usually occurs on one side only, bilateral symmetric cases of Hirayama disease have occasionally been described. It is a slow, progressive disease, and its evolution can have a good prognosis when detected early in the process. We describe a clinical observation of Hirayama disease, including its clinical and paraclinical peculiarities, and compare it to data from previous studies.