Cortical and spinal somatosensory evoked potentials (SEP) were recorded in healthy individuals following stimulation of digits I, III, and V with an intensity below discomfort level. Peak latency of the earliest cortical negativity (N1) was found to be the most consistent and easily measured parameter, whereas a spinal potential (Cv) was not elicited in all subjects. Descriptive statistics, Student's paired t-test as well as simple and multiple regression, were used for computer analysis of N1 and Cv peak latencies and central conduction time. The results show a strong correlation between the peak latencies of spinal and cortical potentials and height and arm length of the subjects, with a mild but significant correlation with age. Using multiple regression for N1 and Cv latencies significantly improved the standard deviation. The data may provide reference values for neurophysiological evaluation of patients with cervical spine disorders.
Copyright 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 533-538, 2002