This study was conducted to acquire normal data of motor evoked potentials(MEP) recorded from the tibialis anterior muscle. Observations were made on 50 healthy adult subjects (25 men and 25 women)ranging in age from 22 to 68 years and height
form
147
to 183cm.
MEP were evoked by magnetic stimulation over the vertex and the L4-5 intervertebral space and were recorded from the tibialis anterior muscle, and central motor conduction time (CMCT) was calculated.
Normal values of the latencies of cortical, spinal MEPs and CMCT were 31.2±2l.68 msec, 13.3±1.62 msec and 17.9±2.26 msec, respectively, and the amplitudes of cortical and spinal MEPs were 749.0±424.6μνand 526.0 ±261.0μν, respectively.
A contraction of the target muscle reduced the latency and increased the amplitude significantly after transcranial stimulation.
No significant differences of the latency and amplitude were found between right and left side of MEP.
The latency of cortical MEP and CMCT were influenced by age and height, and the latency of spinal MEP was influenced by age. The amplitude of cortical MEP was independent of age, sex and height, and the amplitude of spinal MEP was influenced by
age
and
sex.
There were no serious complications of magnetic stimulation.
|