Statistical comparison of mean latencies between the N18/20 in the present study and data reported in the literature revealed no significant difference (significance level of 0.05).

N denotes the number of nuclei with occurrence of the N18/20, Latency (ms): Mean ± standard deviation (SD) (range), Amplitude (μV): Mean ± SD (range), NA “not available”. This finding provides support for the used methodology, namely forehead rather than linked earlobes/mastoids for monopolar reference and filtering methods (Notch and 40 Hz high cut-off), in eliciting somatosensory evoked potentials (SSEPs).