Hirayama disease causing hand tremor on neck flexion.

A 21-year-old man presented with right-hand intrinsic muscle wasting and right-hand tremor on neck flexion. MR scan of cervical spine was normal in the neutral position, but on neck flexion showed anterior shift and flattening of the cervical cord, with prominent posterior epidural space and engorged epidural venous plexus. We diagnosed Hirayama disease and his condition stabilised with a neck collar and physiotherapy.