Functional MRI follow-up study of language processes in healthy subjects and during recovery in a case of aphasia.
OBJECTIVE
The goal of this study was to develop a functional MRI (fMRI) paradigm robust and reproducible enough in healthy subjects to be adapted for a follow-up study aiming at evaluating the anatomical substratum of recovery in poststroke aphasia.


METHODS
Ten right-handed subjects were studied longitudinally using fMRI (7 of them being scanned twice) and compared with a patient with conduction aphasia during the first year of stroke recovery.


RESULTS
Controls exhibited reproducible activation patterns between subjects and between sessions during language tasks. In contrast, the patient exhibited dynamic changes in brain activation pattern, particularly in the phonological task, during the 2 fMRI sessions. At 1 month after stroke, language homotopic right areas were recruited, whereas large perilesional left involvement occurred later (12 months).


CONCLUSIONS
We first demonstrate intersubject robustness and intrasubject reproducibility of our paradigm in 10 healthy subjects and thus its validity in a patient follow-up study over a stroke recovery time course. Indeed, results suggest a spatiotemporal poststroke brain reorganization involving both hemispheres during the recovery course, with an early implication of a new contralateral functional neural network and a later implication of an ipsilateral one.
Fernandez
Bruno
B
Service de Médecine Physique et Réadaptation, Université de Bordeaux 2, Bordeaux Cedex, France. b.fernandez@tiscali.fr
Cardebat
Dominique
D
Demonet
Jean-François
JF
Joseph
Pierre Alain
PA
Mazaux
Jean-Michel
JM
Barat
Michel
M
Allard
Michèle
M
D000161:Acoustic Stimulation; D000328:Adult; D018886:Aphasia, Conduction / Q000503:physiopathology* / Q000534:rehabilitation; D001041:Aphasia, Wernicke / Q000503:physiopathology* / Q000534:rehabilitation; D001931:Brain Mapping; D002531:Cerebellum / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D003289:Convalescence; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology; D015203:Reproducibility of Results; D012660:Semantics; D013702:Temporal Lobe / Q000502:physiology* / Q000503:physiopathology