Tags

Type your tag names separated by a space and hit enter

Cortical connectivity after subcortical stroke assessed with functional magnetic resonance imaging.
Ann Neurol. 2008 Feb; 63(2):236-46.AN

Abstract

OBJECTIVE

This study aimed at identifying the impact of subcortical stroke on the interaction of cortical motor areas within and across hemispheres during the generation of voluntary hand movements.

METHODS

Twelve subacute stroke patients with a subcortical ischemic lesion and 12 age-matched control subjects were scanned using 3-Tesla functional magnetic resonance imaging. Subjects performed visually paced hand movements with their left, right, or both hands. Changes of effective connectivity among a bilateral network of core motor regions comprising M1, lateral premotor cortex, and the supplementary motor area (SMA) were assessed using dynamic causal modeling.

RESULTS

The data showed significant disturbances in the effective connectivity of motor areas in the patients group: Independently from hand movements, the intrinsic neural coupling between ipsilesional SMA and M1, and the interhemispheric coupling of both SMAs was significantly reduced. Furthermore, movements of the stroke-affected hand showed additional inhibitory influences from contralesional to ipsilesional M1 that correlated with the degree of motor impairment. For bimanual movements, interhemispheric communication between ipsilesional SMA and contralesional M1 was significantly reduced, which also correlated with impaired bimanual performance.

INTERPRETATION

The motor deficit of patients with a single subcortical lesion is associated with pathological interhemispheric interactions among key motor areas. The data suggest that a dysfunction between ipsilesional and contralesional M1, and between ipsilesional SMA and contralesional M1 underlies hand motor disability after stroke. Assessing effective connectivity by means of functional magnetic resonance imaging and dynamic causal modeling might be used in the future for the evaluation of interventions promoting recovery of function.

Authors+Show Affiliations

Department of Neurology, University of Cologne, Cologne, Germany. christian.grefkes@uk-koeln.deNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17896791

Citation

Grefkes, Christian, et al. "Cortical Connectivity After Subcortical Stroke Assessed With Functional Magnetic Resonance Imaging." Annals of Neurology, vol. 63, no. 2, 2008, pp. 236-46.
Grefkes C, Nowak DA, Eickhoff SB, et al. Cortical connectivity after subcortical stroke assessed with functional magnetic resonance imaging. Ann Neurol. 2008;63(2):236-46.
Grefkes, C., Nowak, D. A., Eickhoff, S. B., Dafotakis, M., Küst, J., Karbe, H., & Fink, G. R. (2008). Cortical connectivity after subcortical stroke assessed with functional magnetic resonance imaging. Annals of Neurology, 63(2), 236-46.
Grefkes C, et al. Cortical Connectivity After Subcortical Stroke Assessed With Functional Magnetic Resonance Imaging. Ann Neurol. 2008;63(2):236-46. PubMed PMID: 17896791.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cortical connectivity after subcortical stroke assessed with functional magnetic resonance imaging. AU - Grefkes,Christian, AU - Nowak,Dennis A, AU - Eickhoff,Simon B, AU - Dafotakis,Manuel, AU - Küst,Jutta, AU - Karbe,Hans, AU - Fink,Gereon R, PY - 2007/9/28/pubmed PY - 2008/4/4/medline PY - 2007/9/28/entrez SP - 236 EP - 46 JF - Annals of neurology JO - Ann Neurol VL - 63 IS - 2 N2 - OBJECTIVE: This study aimed at identifying the impact of subcortical stroke on the interaction of cortical motor areas within and across hemispheres during the generation of voluntary hand movements. METHODS: Twelve subacute stroke patients with a subcortical ischemic lesion and 12 age-matched control subjects were scanned using 3-Tesla functional magnetic resonance imaging. Subjects performed visually paced hand movements with their left, right, or both hands. Changes of effective connectivity among a bilateral network of core motor regions comprising M1, lateral premotor cortex, and the supplementary motor area (SMA) were assessed using dynamic causal modeling. RESULTS: The data showed significant disturbances in the effective connectivity of motor areas in the patients group: Independently from hand movements, the intrinsic neural coupling between ipsilesional SMA and M1, and the interhemispheric coupling of both SMAs was significantly reduced. Furthermore, movements of the stroke-affected hand showed additional inhibitory influences from contralesional to ipsilesional M1 that correlated with the degree of motor impairment. For bimanual movements, interhemispheric communication between ipsilesional SMA and contralesional M1 was significantly reduced, which also correlated with impaired bimanual performance. INTERPRETATION: The motor deficit of patients with a single subcortical lesion is associated with pathological interhemispheric interactions among key motor areas. The data suggest that a dysfunction between ipsilesional and contralesional M1, and between ipsilesional SMA and contralesional M1 underlies hand motor disability after stroke. Assessing effective connectivity by means of functional magnetic resonance imaging and dynamic causal modeling might be used in the future for the evaluation of interventions promoting recovery of function. SN - 1531-8249 UR - https://www.unboundmedicine.com/medline/citation/17896791/Cortical_connectivity_after_subcortical_stroke_assessed_with_functional_magnetic_resonance_imaging_ L2 - https://doi.org/10.1002/ana.21228 DB - PRIME DP - Unbound Medicine ER -