Journal Article

PreJuSER-8806

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Modulating cortical connectivity in stroke patients by rTMS assessed with fMRI and dynamic causal modeling

Grefkes, C. ; Nowak, D. A. ; Wang, L. E.FZJ* ; Dafotakis, M. ; Eickhoff, S. B.FZJ* ; Fink, G. R.FZJ*

2010
Academic Press Orlando, Fla.

This record in other databases:    

Please use a persistent id in citations: doi:10.1016/j.neuroimage.2009.12.029

Abstract: Data derived from transcranial magnetic stimulation (TMS) studies suggest that transcallosal inhibition mechanisms between the primary motor cortex of both hemispheres may contribute to the reduced motor performance of stroke patients. We here investigated the potential of modulating pathological interactions between cortical motor areas by means of repetitive TMS using functional magnetic resonance imaging (fMRI) and dynamic causal modeling (DCM). Eleven subacute stroke patients were scanned 1-3 months after symptom onset while performing whole hand fist closure movements. After a baseline scan, patients were stimulated with inhibitory 1-Hz rTMS applied over two different locations: (i) vertex (control stimulation) and (ii) primary motor cortex (M1) of the unaffected (contralesional) hemisphere. Changes in the endogenous and task-dependent effective connectivity were assessed by DCM of a bilateral network comprising M1, lateral premotor cortex, and the supplementary motor area (SMA). The results showed that rTMS applied over contralesional M1 significantly improved the motor performance of the paretic hand. The connectivity analysis revealed that the behavioral improvements were significantly correlated with a reduction of the negative influences originating from contralesional M1 during paretic hand movements. Concurrently, endogenous coupling between ipsilesional SMA and M1 was significantly enhanced only after rTMS applied over contralesional M1. Therefore, rTMS applied over contralesional M1 may be used to transiently remodel the disturbed functional network architecture of the motor system. The connectivity analyses suggest that both a reduction of pathological transcallosal influences (originating from contralesional M1) and a restitution of ipsilesional effective connectivity between SMA and M1 underlie improved motor performance.

Keyword(s): Adult (MeSH) ; Cerebral Cortex: physiopathology (MeSH) ; Female (MeSH) ; Frontal Lobe: physiopathology (MeSH) ; Hand: physiology (MeSH) ; Humans (MeSH) ; Magnetic Resonance Imaging: methods (MeSH) ; Male (MeSH) ; Middle Aged (MeSH) ; Models, Neurological (MeSH) ; Motor Activity: physiology (MeSH) ; Motor Cortex: physiopathology (MeSH) ; Neural Pathways: physiopathology (MeSH) ; Paresis: physiopathology (MeSH) ; Stroke: physiopathology (MeSH) ; Time Factors (MeSH) ; Transcranial Magnetic Stimulation: methods (MeSH) ; Young Adult (MeSH) ; J ; FMRI (auto) ; DCM (auto) ; Rehabilitation (auto) ; Transcranial magnetic stimulation (auto)

Note: S.B.E. was funded by the Human Brain Project (R01-MH074457-01A1) and the Initiative and Networking Fund of the Helmholtz Association within the Helmholtz Alliance on Systems Biology (Human Brain Model).

---

Contributing Institute(s):

1. Molekulare Organisation des Gehirns (INM-2)
2. Kognitive Neurowissenschaften (INM-3)

Research Program(s):

1. Funktion und Dysfunktion des Nervensystems (FUEK409) (FUEK409)
2. 89572 - (Dys-)function and Plasticity (POF2-89572) (POF2-89572)

Appears in the scientific report 2010

---