Youth upper limb distal muscular atrophy

Juvenile myoatrophy of distal upper extremity in young people was first described by Japanese scholar Hirayama Hiroshi (1959), so it is also called Hirayama disease. This disease is a benign self-limiting motor neuron disease. It is clinically similar to motor neuron disease with amyotrophic lateral sclerosis and progressive spinal muscular atrophy. The age of onset was young, and most of the affected sites were unilateral distal upper limb hand muscles. The electromyogram showed neurogenic damage, and the course of the disease was benign, which could be stopped on its own.