Hirayama Disease: Diagnosis to be Missed Without Flexion MRI

Hirayama disease, also known as monomelicamyotrophy (MMA), is a rare cervical myelopathy that manifests itself as a self-limited, asymmetrical, slowly progressive atrophic weakness of the forearms and hands predominantly in young males. The forward displacement of the posterior dura of the lower cervical dural canal during neck flexion has been postulated to lead to lower cervical cord atrophy with asymmetric flattening. We report a case of Hirayama disease in a 18- year-old male presenting with gradually progressive asymmetrical weakness and wasting of right hand and forearms