Somatosensory cerebral evoked potentials in spinal cord diseases.

Cortical-evoked potentials (CEPs) induced by the stimulation of the tibial nerve, were investigated in 16 patients with localized myelopathy, and in five patients with generalised myelopathy, and compared with the results obtained in 30 healthy test subjects. The investigations show that the pulses that give rise to the CEP, are conducted mainly by the posterior columns. Damage to the ventrolateral tracts, in contrast, leads only to a reduction in the amplitude of the CEPs. If account is taken of possible artefacts and misinterpretations, the method described is highly suitable for determining the level of a lesion in complete paraplegia and for obtaining information as to the size and extent of spinal cord damage in myelopathies.