Slow cord dorsum potentials elicited by descending volleys in man.

Abstract

SUMMARY Human cord dorsum potential (CDP) was recorded from the posterior epidural space at the levels of cervical and lumbar enlargements, using epidural catheters as the recording electrodes, in 15 normal volunteers and six patients suffering from amyotrophic lateral sclerosis. In normal subjects the CDP elicited by descending volleys consisted of spike potentials followed by sharp negative and slow positive waves which were very similar to the P1, NI, and P2 potentials, respectively, of the CDP evoked segmentally. By contrast, in all patients with amyotrophic lateral sclerosis both the sharp negative and slow positive waves were absent in the CDP elicited by descending volleys, while the pattern of each component of the segmentally evoked CDP remained unchanged. Thus, the sharp negative and slow positive waves of human CDP elicited by descending volleys might reflect the activity of interneurones and primary afferent depolarisation respectively, produced by impulses through the corticospinal tract.

Electrically Evoked Compound Action Potentials in Spinal Cord Stimulation: Implications for Preclinical Research Models

“…This is the first study to record ECAPs in rats using specialized epidural leads. Importantly, the characteristics of the recorded ECAPs were consistent with previous studies in sheep 15 and humans [10][11][12][13][14]16 in several ways. First, the recorded ECAPs consisted of the neuronal response observed as a positive P1 peak followed by a negative deflection N1 and a second positive P2 peak.…”

“…Several studies have reported recordings of evoked spinal cord action potentials in animals using a needle lead inserted intrathecally 9 or an epidural lead. [10][11][12][13][14] Recently, with the use of epidural lead, electrically evoked compound action potentials (ECAPs) have been recorded in humans and sheep. 15,16 ECAPs represent a population of nerve fibers that fire synchronously in response to electrical stimulation from the SCS device and therefore, they have been shown as a novel tool to quantify the relationship between the stimulation delivered during SCS and the neural recruitment of the Aβ-fibers in the dorsal columns (DCs).…”

Measuring Spinal Cord Potentials and Cortico-Spinal Interactions After Wrist Movements Induced by Neuromuscular Electrical Stimulation

“…Measuring SCPs is a promising aid in the diagnosis of spinal cord diseases ( Yamada et al, 2004 ). In a study with six patients with typical amyotrophic lateral sclerosis (ALS) syndrome symptoms (e.g., muscle atrophy, muscle weakness or muscle twitch, among others), no slow, neither positive nor negative potentials could be detected ( Shimizu et al, 1979a , b ). In patients with spinal tumors a complete block of nerve conduction along the spinal cord after electrical stimulation of the cauda equina cord was found ( Shimizu and Shimoji, 2006 ).…”