Concomitant Unilateral Hirayama Disease and Contralateral Disc Protrusion of the Cervical Spine

Full Article

WCS Chan, JPK Tsang, MK Yuen

Hong Kong J Radiol 2015;18:e7-11

DOI: 10.12809/hkjr1514285

Hirayama disease is a type of cervical myelopathy affecting young men and causing wasting of the small muscles of the hand. The underlying pathophysiology is thought to be due to disproportionate growth of the vertebral column and the spinal canal resulting in a tight dural sac. The presentation of Hirayama disease is usually that of muscular atrophy with no sensory symptoms. Hirayama disease is not progressive. Magnetic resonance imaging with flexion views is required to make the diagnosis, and demonstrates the distended epidural venous plexus that results from the disproportionate growth and compresses on the spinal canal. The distended venous plexus can be unilateral or bilateral, but is usually unilateral. The underlying cause is unknown, and it is not known why Hirayama disease is usually unilateral. This report presents a patient with a magnetic resonance diagnosis of Hirayama disease with atypical clinical features. Magnetic resonance imaging with flexion views confirmed unilateral Hirayama disease and concomitant contralateral disc protrusion. We propose that these two findings may be inter-related.