Hirayama disease in children from mainland of China.

Hirayama disease is characterized by asymmetrical focal weakness and atrophy of the distal upper limbs with onset in the teens and early 20s. This retrospective study aims to review clinical features of the children (onset before the age of 18 years) with Hirayama disease from mainland of China. Sixty-five children who fulfilled the clinical criteria for Hirayama disease were enrolled. The mean age of onset was 15.7 years, 3.3 years later than the peak age for the normal growth curve. Electrophysiology studies showed chronic denervation changes in C7-T1 segments with normal sensory nerve conduction. Flexion cervical magnetic resonance imaging (MRI) showed forward shifting of the posterior dural sac and engorgement of the posterior epidural venous plexus. Therapeutic intervention with cervical collar can induce a premature arrest of disease progression. Knowledge and awareness of Hirayama disease will facilitate diagnosis and therapeutic intervention in its early stages.