Document Detail


Dissociation of human thalamic and cortical SEP gating as revealed by intrathalamic recordings under muscle relaxation.
MedLine Citation:
PMID:  12468039     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
'Gating' refers to a reduction of cortical somatosensory evoked potentials (SEP) under multiple simultaneous afferent inputs. This study used the opportunity for intrathalamic recordings in patients with movement disorders to clarify to what extent cortical SEP gating is preceded by thalamic gating. Recordings were performed in 10 patients, narcotised by intravenous propofol when receiving implantation of a therapeutic deep brain stimulator system. SEP were elicited by an 8.1-Hz median nerve stimulation at twice motor threshold and were recorded simultaneously from both intrathalamic and scalp electrodes before and after the application of the depolarising muscle blocker succinylcholine which eliminated both the background muscular tone and the repetitive muscle twitches caused by the median nerve stimulation. Peripheral compound action potentials recorded at the upper arm remained unchanged after complete muscle relaxation, proving a continuously effective nerve stimulation. In contrast, the primary cortical SEP component (N20) was significantly increased under succinylcholine (+17%). This cortical release from gating was not paralleled, however, by an increased thalamic response; rather, the primary thalamic response (P16) showed a slight (-9%) but highly significant amplitude reduction. As the recordings were performed in narcotised patients, any potentially variable attentional bias on part of the subjects can be excluded as confounding factor when comparing the two experimental conditions with vs. without reafferent somatosensory inflow. Thus, given the high signal-to-noise ratio of intrathalamically recorded SEP, the present study shows a distinct thalamo-cortical dissociation with the primary somatosensory cortex representing the predominant level exhibiting SEP gating.
Authors:
Fabian Klostermann; René Gobbele; Helmut Buchner; Gabriel Curio
Related Documents :
1382949 - Dipole modelling of median nerve seps in normal subjects and patients with small subcor...
20508959 - Evoked potential and behavioral outcomes for experimental autoimmune encephalomyelitis ...
7319709 - On the relation between somatic evoked potentials and fields.
101279 - Electroencephalographic studies myoclonus.
6926379 - Changes in peripheral and central nerve conduction with aging.
2435519 - Cerebral magnetic responses to stimulation of ulnar and median nerves.
22501569 - The distance-dependence of interaural level difference cues to sound location and their...
1676929 - Pharmacological modulation of the pontine micturition center.
7515319 - Collateral axonal projections to limbic structures from ventrolateral medullary a1 nora...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Brain research     Volume:  958     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  2002 Dec 
Date Detail:
Created Date:  2002-12-06     Completed Date:  2003-02-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  146-51     Citation Subset:  IM    
Copyright Information:
Copyright 2002 Elsevier Science B.V.
Affiliation:
Neurophysics Group, Department of Neurology, Universitätsklinikum Benjamin Franklin, Freie Universitaet, Berlin, Germany. fkloster@zedat.fu-berlin.de
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Action Potentials / physiology
Afferent Pathways / physiology*
Aged
Electric Stimulation Therapy
Evoked Potentials, Somatosensory / physiology*
Female
Humans
Male
Median Nerve / physiology*
Middle Aged
Movement Disorders / therapy
Muscle Relaxation / drug effects,  physiology
Neural Conduction / physiology
Neural Inhibition / physiology*
Neuromuscular Depolarizing Agents / pharmacology
Reaction Time / physiology
Somatosensory Cortex / physiology*
Succinylcholine / pharmacology
Ventral Thalamic Nuclei / physiology*
Chemical
Reg. No./Substance:
0/Neuromuscular Depolarizing Agents; 306-40-1/Succinylcholine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The role of sex hormones on formalin-induced nociceptive responses.
Next Document:  TGF-beta1 increases tyrosine hydroxylase expression by a mechanism blocked by BMP-2 in human neurobl...