Average Cerebral Evoked Potentials in the Evaluation of Lesions of the Sensory Nerves and of the Central Somatosensory Pathway1

2015 ◽  
pp. 352-371
Author(s):  
J. E. Desmedt ◽  
P. No�l
Keyword(s):  
Evoked Potentials ◽  
Sensory Nerves ◽  
Cerebral Evoked Potentials

Cerebral evoked potentials after endorectal mechanical stimulation in humans

1988 ◽  
Vol 254 (4) ◽  
pp. G477-G482 ◽  
Author(s):  
L. Collet ◽  
P. Meunier ◽  
R. Duclaux ◽  
S. Chery-Croze ◽  
P. Falipou
Keyword(s):  
Evoked Potentials ◽  
Mechanical Stimulation ◽  
Evoked Potential ◽  
Rectal Wall ◽  
International System ◽  
Rectal Sensation ◽  
Rectal Balloon ◽  
Female Age ◽  
Cerebral Evoked Potentials ◽  
Stimulation Of

Although numerous clinical studies have proved that impaired rectal sensation is a major factor in fecal continence dysfunctions, objective studies in this field are still lacking. To provide information on normal rectal afferents, a study of cerebral potentials evoked by mechanical stimulation of the rectal wall was carried out in 10 healthy volunteers (5 male, 5 female; age, 33–52 yr). The stimulating device consisted of a rectal balloon rhythmically inflated and deflated by means of an animal breathing ventilator. Recordings were obtained 2 cm behind the vertex (C'z, International system 10–20). The responses were averaged from 300 to 800 sweeps. The average was triggered either on inflation ("on effect") or on deflation ("off effect"). Inflation volume and pressure were adjusted to induce a clear but not painful pulsing sensation. Reproducible responses were recorded by both on and off effects. The evoked potentials were polyphasic with a succession of positive and negative waves (peak latencies between 78 and 310 ms). The shape of the response (morphology, latency, and amplitude) was perfectly reproducible in the same subject. With regard to intrasubject reproducibility, variability was displayed: only the early waves (latency less than 100 ms) were perfectly reproducible; late waves exhibited variable latency and morphology. The present findings are the first demonstration of the possibility of recording an evoked potential on the scalp after a mechanical stimulation of the rectum.

Octreotide reduces perception of rectal electrical stimulation by spinal afferent pathway inhibition

1995 ◽  
Vol 269 (6) ◽  
pp. G821-G826 ◽  
Author(s):  
W. D. Chey ◽  
A. Beydoun ◽  
D. J. Roberts ◽  
W. L. Hasler ◽  
C. Owyang
Keyword(s):  
Electrical Stimulation ◽  
Evoked Potentials ◽  
Evoked Potential ◽  
Double Blind ◽  
Afferent Pathways ◽  
Normal Volunteers ◽  
Site Of Action ◽  
Cerebral Evoked Potentials ◽  
Pathway Inhibition ◽  
Irritable Bowel

Octreotide reduces perception of rectal distension in normal volunteers and irritable bowel patients. To localize octreotide's site of action, perceptual and evoked potential responses to rectal electrical stimulation were tested in seven normal volunteers after double-blind octreotide (100 micrograms 2) or placebo. After octreotide, the currents needed to elicit threshold perception of square-wave impulses delivered to the rectum were 29% higher than after placebo. When electrical stimulation was delivered at constant currents 50% above threshold, rectal perception scores were significantly reduced after octreotide compared with placebo. Rectal electrical stimulation led to characteristic and reproducible cerebral evoked potentials. Octreotide had no effect on latencies, but reduced peak-to-peak amplitudes by 35% compared with placebo. Rectal electrical stimulation also led to characteristic and reproducible spinal evoked potentials. Octreotide had no effect on spinal latencies, but reduced peak-to-peak amplitudes by 51%. In conclusion, octreotide reduces perception of rectal electrical stimulation, which is associated with inhibition of cerebral and spinal evoked potential amplitude, indicating effects on spinal afferent pathways.

Cerebral evoked potentials (EPs) after rectal stimulation

1990 ◽  
Vol 99 (4) ◽  
pp. 1220 ◽  
Author(s):  
V. Loening-Baucke ◽  
N. Read ◽  
T. Yamada
Keyword(s):  
Evoked Potentials ◽  
Cerebral Evoked Potentials
Sign in / Sign up

Export Citation Format

Share Document