Article

AIM: To compare neurophysiological parameters of central nervous system
excitability in healthy children/adolescents with those of healthy adults.
METHOD: Two experimental protocols were used in 19 healthy children/adolescents
(10 males and 9 females, mean age 9y 11mo [SD 2y 9mo], range 5-15y) and 19
healthy adults (8 males and 11 females, mean age 36y 6mo [SD 7y 9mo], range
27-51y). First, we administered repetitive trains of innocuous electrical
stimulation of the median nerve and analysed habituation (progressive
attenuation) of the cervical and cortical responses. Second, we administered
several blocks of two closely timed electrical innocuous stimuli of the median
nerve (with interstimulus intervals set at 5, 10, and 20ms in each block) and
analysed the recovery index (the percentage of the response to the second
stimulus with respect to that to the first). RESULTS: Clear-cut
neurophysiological signs of cortical hyper-excitability were found in
children/adolescents but not in adults. In contrast with the adults, the
children/adolescents did not attenuate cortical responses to repetitive
stimulation, and presented with extremely shortened recovery cycle. At baseline,
both groups presented with comparable cortical responses. INTERPRETATION: Healthy
children/adolescents present cortical hyper-excitability compared with healthy
adults. These findings agree with previous findings that show an overall
imbalance of excitatory and inhibitory neuronal and neurochemical mechanisms in
favour of excitatory ones, in the healthy developing cerebral cortex.
CI - (c) 2016 Mac Keith Press.

Langue : ANGLAIS