[Suspected Hirayama disease. Presentation of a case and a clinical review].

Hirayama's disease, or juvenile muscular atrophy of distal upper extremity, is a cervical myelopathy. It affects adolescent males, and is characterized by progressive muscle weakness and atrophy of the distal upper extremities, followed by slow paralysis. Although the cause remains unclear, radiological findings suggest neuropathic forward displacement of the posterior cervical dural sac during neck flexion, causing compression of the cervical cord, resulting in atrophic changes and ischemic disease of the medullar anterior horn. Since the bending of the neck was recognized as a cause of the disease, cervical orthosis, spinal fusion, and duraplasty combined with fusion, have been proposed as treatment. A solid understanding of Hirayama disease is critical as early recognition and effective treatment can stop the deterioration.