Maturation of central somatosensory conduction time in infancy and childhood.

To investigate the age-dependency of central conduction time somatosensible evoked potentials to median nerve stimulation were recorded in 80 infants and children from the age of one week to 20 years. It is shown that the central conduction time starts at about 14 ms in the neonatal period and then gradually declines until the 7th or 8th year of life to the normal adult value with an upper limit of 7 ms. By dividing the data into several groups with age delimiters at 0.5, 1, 3, 5 and 7 years it shows significant differences of the mean values for the central conduction times according to the Student's t-test. The graph itself can well be approximated by the exponential regression y = 6.099 + 7.55 X e-0.686 X x where y represents the CCT and x the age in years. This slow maturation kinetic is presumably due to the ongoing central myelinisation.