title: Conduction characteristics of somatosensory evoked potentials to peroneal, tibial and sural nerve stimulation in man.
abstract: Lumbar spine and scalp short latency somatosensory evoked potentials (SSEPs) to stimulation of the posterior tibial, peroneal and sural nerves at the ankle (PTN-A, PN-A, SN-A) and common peroneal nerve at the knee (CPN-K) were obtained in 8 normal subjects. Peripheral nerve conduction velocities and lumbar spine to cerebral cortex propagation velocities were determined and compared. These values were similar with stimulation of the 3 nerves at the ankle but were significantly greater with CPN-K stimulation. CPN-K and PTN-A SSEPs were recorded from the L3, T12, T6 and C7 spines and the scalp in 6 normal subjects. Conduction velocities were determined over peripheral nerve-cauda equina (stimulus-L3), caudal spinal cord (T12-T6) and rostral spinal cord (T6-C7). Propagation velocities were determined from each spinal level to the cerebral cortex. With both CPN-K and PTN-A stimulation the speed of conduction over peripheral nerve and spinal cord was non-linear. It was greater over peripheral nerve-cauda equina and rostral spinal cord than over caudal cord segments. The CPN-K response was conducted significantly faster than the PTN-A response over peripheral nerve-cauda equina and rostral spinal cord but these values were similar over caudal cord. Spine to cerebral cortex propagation velocities were significantly greater from all spine levels with CPN-K stimulation. These data show that the conduction characteristics of SSEPs over peripheral nerve, spinal cord and from spine to cerebral cortex are dependent on the peripheral nerve stimulated.
mesh_terms: D000328:Adult; D004553:Electric Conductivity; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D010543:Peroneal Nerve / Q000502:physiology*; D012535:Scalp; D013127:Spinal Nerves / Q000502:physiology*; D013131:Spine; D013497:Sural Nerve / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology*