Treatment-induced cortical reorganization after stroke in humans.
OBJECTIVE
Injury-induced cortical reorganization is a widely recognized phenomenon. In contrast, there is almost no information on treatment-induced plastic changes in the human brain. The aim of the present study was to evaluate reorganization in the motor cortex of stroke patients that was induced with an efficacious rehabilitation treatment.


METHODS
We used focal transcranial magnetic stimulation to map the cortical motor output area of a hand muscle on both sides in 13 stroke patients in the chronic stage of their illness before and after a 12-day-period of constraint-induced movement therapy.


RESULTS
Before treatment, the cortical representation area of the affected hand muscle was significantly smaller than the contralateral side. After treatment, the muscle output area size in the affected hemisphere was significantly enlarged, corresponding to a greatly improved motor performance of the paretic limb. Shifts of the center of the output map in the affected hemisphere suggested the recruitment of adjacent brain areas. In follow-up examinations up to 6 months after treatment, motor performance remained at a high level, whereas the cortical area sizes in the 2 hemispheres became almost identical, representing a return of the balance of excitability between the 2 hemispheres toward a normal condition.


CONCLUSIONS
This is the first demonstration in humans of a long-term alteration in brain function associated with a therapy-induced improvement in the rehabilitation of movement after neurological injury.
Liepert
J
J
Department of Neurology, Friedrich-Schiller-University of Jena, Germany. liepert@neuro.uni-jena.de
Bauder
H
H
Wolfgang
H R
HR
Miltner
W H
WH
Taub
E
E
Weiller
C
C
D000328:Adult; D000344:Afferent Pathways / Q000503:physiopathology; D000368:Aged; D001925:Brain Damage, Chronic / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation; D001931:Brain Mapping; D003289:Convalescence; D004292:Dominance, Cerebral; D004574:Electromagnetic Fields; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006225:Hand / Q000294:innervation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000294:innervation; D009473:Neuronal Plasticity; D010291:Paresis / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D026741:Physical Therapy Modalities; D020521:Stroke / Q000150:complications / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D016896:Treatment Outcome