Hirayama Disease: Escaping From the Quotidian Imaging.

Hirayama disease is a rare type of neurological disease commonly manifesting as brachial monomelic amyotrophy in young males of Asian origin, easily understood as juvenile non-progressive cervical amyotrophy. The first case was reported by Hirayama in 1959. The pathogenesis is attributed towards chronic compression of cervical spinal cord during flexion movements of neck in cases where there is detachment of posterior dura mater. This chronic event, invariably leads to features of cord atrophy along with other MRI features. We report a case of 21-year-old male who presented with atrophy of distal muscles of his right hand and was sent for MRI of cervical spine which revealed prominent posterior epidural venous plexus without significant cord atrophy. Clinico-radiologic profile of the patient leads toward the diagnosis of Hirayama disease which was considered as borderline because of asymmetrical cord atrophy which is a not a routine imaging feature of the entity.