Hirayama disease: a frequently undiagnosed condition with simple inexpensive treatment.

Hirayama disease is a non-progressive asymmetric juvenile muscular atrophy involving C7-T1 myotomes leading to weakness and atrophy of intrinsic muscles of hand and forearm with relative sparing of the brachioradialis muscle. This benign focal cervical poliopathy is believed to be caused by forward displacement of the posterior cervical dural sac. In this case report we highlight the importance of dynamic MRI of cervical spine for diagnosis of the above condition and the use of hard cervical collar to prevent further flexion injury.