Cervical magnetic stimulation in children and adolescents: normal values and evaluation of the proximal lesion of the peripheral motor nerve in cases with polyradiculoneuropathy.
Cervical magnetic stimulation was used to establish the normal values of the peripheral motor nerve conduction of the upper extremity muscle in normal children and adolescents. Seven patients with peripheral neuropathy were also examined to evaluate a lesion in the proximal site of the peripheral motor nerve. In normal subjects, onset latencies and negative wave durations tended to increase with age. The developmental profile of the latency, corrected for arm length, revealed a significant decline until the age of about 5 years. In 4 cases with polyradiculoneuropathy, motor evoked potentials following cervical magnetic stimulation showed increased latencies, prolonged durations and polyphasic shapes. The time differences between latencies by magnetic stimulation and peripheral motor conduction times by F technique were significantly prolonged. Motor evoked potentials obtained in 3 cases of axonal degeneration, on the other hand, showed slightly increased latencies and normal durations. The time differences between latencies and peripheral motor conduction times were within the normal range. Thus, we consider that cervical magnetic stimulation is a useful method for study of peripheral motor conduction in children and adolescents, and in particular to evaluate the proximal lesion of the nerve in patients with polyradiculoneuropathy.
Maegaki
Y
Y
Division of Child Neurology, Faculty of Medicine, Tottori University, Japan.
Inagaki
M
M
Takeshita
K
K
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D008280:Magnetics; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009132:Muscles / Q000503:physiopathology*; D009333:Neck; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*; D011129:Polyradiculoneuropathy / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values