Somatosensory evoked potentials following tibial nerve stimulation. Method and normal values in relation to physical variables

Somatosensory evoked potentials were recorded in 40 healthy subjects (age: 22-63 years) with gluteal, lumbar, cervical and cortical surface electrodes after stimulation of the tibial nerve. Normal latency values were established in relationship to height and also for the amplitudes of the different components; the latencies of the cortical P40, N50 and P60 were significantly dependent on height, the latency of the cervical N33, the lumbar N22 and the gluteal Ng were dependent on the distance (stimulation--to recording point). The central conduction time showed no dependence on back length. Age dependence (in relation to normal height) was found only in the case of cortical P60.