Hyperexcitability of cervical motor neurons during neck flexion in patients with Hirayama disease.
We recorded the motor evoked potentials (MEPs) from the affected thenar muscles during neck flexion in 4 patients in the early progressive phase of Hirayama disease. The MEP size significantly increased during neck flexion in patients compared with normal controls. In 2 patients who were treated with a neck collar, the intrinsic muscle atrophy gradually recovered together with increased grip power, and the time course of changes in MEP during neck flexion became normal after treatment with a neck collar for 7-16 months. The technique described here would be useful for evaluating the vulnerability of cervical motor neurons and the therapeutic effect of the neck collar in Hirayama disease.
Imai
T
T
Department of Neurology, School of Medicine, Sapporo Medical University, Japan.
Shizukawa
H
H
Nakanishi
K
K
Kouge
N
N
Hiura
K
K
Kashiwagi
M
M
Chiba
S
S
Matsumoto
H
H
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001915:Braces; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005500:Follow-Up Studies; D006225:Hand / Q000503:physiopathology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008280:Magnetics; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009068:Movement; D018908:Muscle Weakness / Q000503:physiopathology / Q000628:therapy; D009333:Neck / Q000294:innervation* / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D009434:Neural Pathways / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted; D014897:Spinal Muscular Atrophies of Childhood / Q000503:physiopathology* / Q000628:therapy; D013933:Thumb / Q000294:innervation