The functional status of the descending motor pathways was assessed in
malnourished children using transcranial electromagnetic stimulation
of the cortex. Twenty children with different severities of malnutriti
on and 20 control subjects were studied electrophysiologically. The ci
rcular coil of a Dentac MAG 2 magnetic stimulator was applied tangenti
ally over the vertex to stimulate the cortex. The muscle evoked potent
ial in the children's arms was recorded from the abductor pollicis bre
vis muscle and in their legs from the extensor digitorum brevis muscle
on both sides of the body using surface electrodes. The muscle evoked
potential of the abductor pollicis brevis and extensor digitorum brev
is muscles was further obtained using root stimulation by applying the
coil at the cervical and lumbar spine, respectively. The indices of c
ortical threshold, cortical latency, and central motor conduction time
(ms) were evaluated in both arm and leg muscles on both sides. The re
sults showed an increased cortical threshold (mean (SD) 1232.5 (134.06
) in the study group v 1147.5 (99.31) in the control group) for the ab
ductor pollicis brevis muscle and for the extensor digitorum brevis mu
scle (1325.00 (115.70) in the study group v 1190.0 (125.24) in the con
trol group). Similarly, significant prolongation of the central motor
conduction time (ms) (study group 6.67 (0.91) v control group 5.71 (0.
74)) in the abductor pollicis brevis muscle was seen in malnourished c
hildren.