EFFECTS OF SEX, HEIGHT AND AGE ON MOTOR EVOKED-POTENTIALS WITH MAGNETIC STIMULATION

Magnetic stimulation of the brain and cervical and lumbar spinal roots was performed on I S healthy subjects in order to investigate the eff ects of sex, height and age oil motor evoked potentials (MEPs), The co mpound muscle action potentials were recorded from the abductor pollic is brevis and abductor hallucis muscles. The central motor conduction time (CMCT) was measured between the cerebral cortex and the cervical root and also between the cerebral cortex and the lumbar root. A multi ple regression analysis was used to determine which of the physical va riables, namely sex, height and age. were significant. X significant g ender difference was observed in the MEP latencies and CMCT of the leg , but not in those of the hand, Both height and age had a significant effect on the leg MEP latencies with a lesser effect on the hand MEP l atencies, The leg C;MCT was also significantly influenced by height an d age, while.the hand CMCT was not. These results thus suggest that ph ysical variables are very important in defining normal MEPs, especiall y in the lower limbs. Therefore, when we assess motor function in pati ents with neurological disorders, both the patients and control groups should be matched for sex, height and age distribution.