Changes in cerebral blood flow induced by passive and active elbow and hand movements

Transcranial Doppler ultrasonography (TCD) has been widely used to obtain i nformation about changes in cerebral perfusion during motor activity after stroke. This type of application is greatly limited when severe motor defic its are present that impede the performance of an active motor task. In thi s study, we explored the effect of performing passive arm movements on cere bral perfusion. Twenty healthy subjects were investigated. A bilateral TCD monitoring of the middle cerebral artery (MCA) now velocity was performed d uring the following experimental conditions: 1-min of active and passive fl exion-extension elbow movement and 1-min of active and passive dorsal exten sion hand movement. Each task was performed with both left and right arms. The percentage increase in flow velocity from rest to task performance was calculated. Each task produced a significantly greater increase in mean flo w velocity in the contralateral MCA with respect to the ipsilateral. When c omparing the effect of passive and active tasks, no significant difference in mean flow velocity changes recorded in the ipsilateral and the contralat eral MCA was detected regarding either elbow or hand movements. These findi ngs demonstrate the possibility of obtaining information about changes in h emispheric cerebral perfusion during passive movements involving elbow and hand. This type of application deserves further attention in the study of c erebral functional changes following cerebral lesions.