edoc

Task-dependent effects on motor-evoked potentials and on the following silent period

Mathis, J. and de Quervain, D. and Hess, C. W.. (1999) Task-dependent effects on motor-evoked potentials and on the following silent period. Journal of Clinical Neurophysiology, 16 (6). pp. 556-565.

Full text not available from this repository.

Official URL: http://edoc.unibas.ch/46544/

Downloads: Statistics Overview

Abstract

The silent period (SP) after transcranial stimulation is used as a diagnostic tool in various central nervous system disorders although no standardized experimental setup has been established. The aim of this study was to demonstrate the influence of an isotonic compared to an isometric experimental condition. The SP after transcranial magnetic brain stimulation in the biceps brachii and brachioradialis muscle was up to 130% longer when elicited during a maintain-position (isotonic) task as compared to a maintain-force task (isometric) when stimulus intensities of 5% to 25% above threshold were used. The mean SP duration in these muscles was positively correlated to the mean contraction time in both tasks. However, no such relationship was observed for the trials within the individual subjects. We speculate that the invariably longer SP of the maintain-position task was due to the different "motor set" which predictively determined the muscle behavior after the stimulus. In the maintain-position trials, the stimulus-induced long-lasting flexion movement is counteracted by a motor set aiming to relax the elbow flexors immediately after the stimulus. In the maintain-force task the contraction twitch is short and a force drop below the preset level must be prevented by a motor set aiming to contract the elbow flexors immediately after the stimulus. The latter may increase the synaptic input to the motoneuron pool and facilitate the reoccurrence of the electromyogram terminating the SP. At high-stimulus intensities the SP duration increased in both tasks, and the task-dependent differences disappeared. Therefore, when using the SP duration for diagnostic purposes, isometric conditions and high-stimulus intensities should be used.
Faculties and Departments:03 Faculty of Medicine > Bereich Psychiatrie (Klinik) > Erwachsenenpsychiatrie UPK > Kognitive Neurowissenschaften (de Quervain)
03 Faculty of Medicine > Departement Klinische Forschung > Bereich Psychiatrie (Klinik) > Erwachsenenpsychiatrie UPK > Kognitive Neurowissenschaften (de Quervain)
07 Faculty of Psychology > Departement Psychologie > Forschungsbereich Klinische Psychologie und Neurowissenschaften > Cognitive Neuroscience (de Quervain)
UniBasel Contributors:de Quervain, Dominique J.-F.
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Lippincott, Williams & Wilkins
ISSN:0736-0258
e-ISSN:1537-1603
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:26 Oct 2017 12:23
Deposited On:26 Oct 2017 12:23

Repository Staff Only: item control page