A clinical study of Hirayama disease in Taiwan.
The purpose of this study was to review the clinical manifestations of 40 patients who fulfilled the clinical criteria for Hirayama disease (juvenile muscular atrophy of distal upper extremities), identified in our neuromuscular clinic between February 1995 and December 2005. Of these 40 patients, 87.5% were male. The mean age at onset was 16.8 years, which was 4.5 years later than the peak age of the normal growth curve. Progressive muscle weakness and wasting were characteristic and occurred predominantly in the distal part of the right upper limb. Neurogenic symptoms ceased to progress within 5 years in most patients (92.5%). About one third of patients had participated frequently in heavy physical activity before onset of muscle symptoms. Reduced amplitude of the compound muscle action potential of the ulnar nerve was the most prominent finding in nerve conduction studies. Electromyography showed acute or chronic neurogenic changes, most frequently in muscles supplied by the C7-T1 segments. Magnetic resonance imaging showed anterior shifting of the posterior dura and engorged posterior venous plexus at the cervical level in 95% of patients. Our results support the belief that Hirayama disease is a self-limited, focal lower motor neuron disease involving the lower cervical segments. Disproportionate growth between the vertebral column and the contents of the spinal canal may be the underlying cause, and strenuous physical activity may be a precipitating factor.
Huang
Ying-Chih
YC
Department of Neurology, Chang Gung Memorial Hospital, Chiayi, Taiwan.
Ro
Long-Sun
LS
Chang
Hong-Shiu
HS
Chen
Chiung-Mei
CM
Wu
Yih-Ru
YR
Lee
Jian-Der
JD
Lyu
Rong-Kuo
RK
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D002574:Cervical Vertebrae / Q000473:pathology; D002648:Child; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009133:Muscular Atrophy / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D014897:Spinal Muscular Atrophies of Childhood / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D013624:Taiwan / Q000453:epidemiology