Motor system activation after subcortical stroke depends on corticospinal system integrity.

Détails

ID Serval
serval:BIB_3D5FC0089773
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Motor system activation after subcortical stroke depends on corticospinal system integrity.
Périodique
Brain
Auteur⸱e⸱s
Ward N.S., Newton J.M., Swayne O.B., Lee L., Thompson A.J., Greenwood R.J., Rothwell J.C., Frackowiak R.S.
ISSN
1460-2156 (Electronic)
ISSN-L
0006-8950
Statut éditorial
Publié
Date de publication
2006
Volume
129
Numéro
Pt 3
Pages
809-819
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Résumé
Movement-related brain activation patterns after subcortical stroke are characterized by relative overactivations in cortical motor areas compared with controls. In patients able to perform a motor task, overactivations are greater in those with more motor impairment. We hypothesized that recruitment of motor regions would shift from primary to secondary motor networks in response to impaired functional integrity of the corticospinal system (CSS). We measured the magnitude of brain activation using functional MRI during a motor task in eight chronic subcortical stroke patients. CSS functional integrity was assessed using transcranial magnetic stimulation to obtain stimulus/response curves for the affected first dorsal interosseus muscle, with a shallower gradient representing increasing disruption of CSS functional integrity. A negative correlation between the gradient of stimulus/response curve and magnitude of task-related brain activation was found in several motor-related regions, including ipsilesional posterior primary motor cortex [Brodmann area (BA) 4p], contralesional anterior primary motor cortex (BA 4a), bilateral premotor cortex, supplementary motor area, intraparietal sulcus, dorsolateral prefrontal cortex and contralesional superior cingulate sulcus. There were no significant positive correlations in any brain region. These results suggest that impaired functional integrity of the CSS is associated with recruitment of secondary motor networks in both hemispheres in an attempt to generate motor output to spinal cord motoneurons. Secondary motor regions are less efficient at generating motor output so this reorganization can only be considered partially successful in reducing motor impairment after stroke.
Mots-clé
Adult, Aged, Brain Mapping/methods, Humans, Image Processing, Computer-Assisted/methods, Magnetic Resonance Imaging, Male, Middle Aged, Motor Cortex/physiopathology, Motor Neurons/physiology, Motor Skills, Movement, Neural Pathways/physiopathology, Neuronal Plasticity, Recovery of Function, Spinal Cord/physiopathology, Stroke/pathology, Stroke/physiopathology, Transcranial Magnetic Stimulation/methods
Pubmed
Web of science
Open Access
Oui
Création de la notice
11/09/2011 18:14
Dernière modification de la notice
20/08/2019 13:33
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