Influence of somatosensory input on motor function in patients with chronic stroke.
In healthy volunteers, reduction of somatosensory input from one hand leads to rapid performance improvements in the other hand. Thus, it is possible that reduction of somatosensory input from the healthy hand can influence motor function in the paretic hand of chronic stroke patients with unilateral hand weakness. To test this hypothesis, we had 13 chronic stroke patients perform motor tasks with the paretic hand and arm during cutaneous anesthesia of the healthy hand and healthy foot in separate sessions. Performance of a finger tapping task, but not a wrist flexion task, improved significantly with anesthesia of the hand, but not the foot. This effect progressed with the duration of anesthesia and correlated with baseline motor function. We conclude that cutaneous anesthesia of the healthy hand elicits transient site-specific improvements in motor performance of the moderately paretic hand in patients with chronic stroke, consistent with interhemispheric competition models of sensorimotor processing.
Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20817, USA.
Agnes
A
Floel
Ulrike
U
Nagorsen
Konrad J
KJ
Werhahn
Shashi
S
Ravindran
Niels
N
Birbaumer
Stefan
S
Knecht
Leonardo G
LG
Cohen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000758:Anesthesia / Q000379:methods; D005260:Female; D005385:Fingers / Q000294:innervation / Q000503:physiopathology; D005528:Foot / Q000294:innervation / Q000503:physiopathology; D007839:Functional Laterality / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D016571:Neural Networks, Computer; D010147:Pain Measurement / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013003:Somatosensory Cortex / Q000503:physiopathology*; D020521:Stroke / Q000503:physiopathology*; D013997:Time Factors; D014953:Wrist / Q000294:innervation / Q000503:physiopathology