[Cerebral activation during movement of both hands. A study with transcranial Doppler].
OBJECTIVE
In healthy persons, the force carried out by a group of muscles doing bilateral exercise with maximum effort is less than that done during unilateral exercise. The nervous control of movement is probably different in these two cases. Our objective was to study and compare cerebral activation on movement of one and of both hands by means of transcranial Doppler (TCD).


METHODS
We studied 30 healthy volunteers (19 men and 11 women; average age 65.4 +/- 9.5 years). Using transtemporal TCD we assessed the relative changes in average velocity of flow in both middle cerebral arteries during the exercise of sequential opposition of the fingers of one hand and of both hands.


RESULTS
The activity due to the exercise of the hand contralateral to the hemisphere being studied was greater than that due to exercise of both hands together, both on the right side (p < 0.001) and on the left (p < 0.001).


CONCLUSIONS
The functional activity of each cerebral hemisphere is not necessarily greater when both hands are exercised than when the contralateral hand is used, and may even be less. The possible increase in activity due to the additional contribution to ipsilateral movement in the first case may be compensated by simultaneous transhemispherical inhibition.
Cuadrado
M L
ML
Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Madrid, España. m.cuadrado@cs.urjc.es
Arias
J A
JA
González-Gutiérrez
J L
JL
Egido
J A
JA
Varela de Seijas
E
E
D000328:Adult; D000368:Aged; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000098:blood supply*; D009068:Movement / Q000502:physiology*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*