Clinical Application of Peripheral, Spinal and Central Conduction Velocities Following Stimulation of the Posterior Tibial Nerve

Abstract

The spinal and scalp somatosensory evoked potentials induced by left posterior tibial nerve stimulation were recorded from 49 normal children of 1 to 16 years of age. The point of stimulation to spine (PCV: peripheral conduction velocity), spine to spine (SVC: spinal conduction velocity) and spine to scalp propagation velocities (CCV: central conduction velocity) were calculated. Three surface spine bipolar channels (L₄-L₂, T₁₂-T₁₀, C₇-C₅) and 1 scalp bipolar channel (Cz'-Fz) were performed. This method was then investigated in 41 patients with diseases of peripheral nerve and spinal cord, and diffuse or multifocal leasions of the central nervous system. C₇ and scalp potentials were absent in a case of Guillain-Barré syndrome; spine and scalp potentials absent in transverse myelitis (T₁₀), Friedreich ataxia and Leigh's syndrome (one case each); scalp potentials absent in C₁-C₂ dislocation, Tay-Sachs disease and congenital muscular dystrophy (Fukuyama type) (one case each). PCV and SCV were slow in one of five cases with diabetic neuropathy; PCV and CCV slow in a case of globoid cell leukodystrophy; CCV slow in opsoclonus-polymyoclonia syndrome, spike and wave stupor (Lennox syndrome) and Wilson's disease (one case each). The technique described in this report gave useful information on pathological lesions involving the afferent pathways throughout the peripheral and central nervous systems.