CORRELATIONS OF FLOW VELOCITY CHANGES DURING MENTAL ACTIVITY AND RECOVERY FROM APHASIA IN ISCHEMIC STROKE

Mean flow velocity in the middle cerebral arteries (MCAs) during a res t period and during execution of a word-fluency task were measured by means of bilateral transcranial Doppler ultrasonography in 26 stroke p atients with Broca's aphasia and in 25 healthy controls. Changes in fl ow velocity were calculated as percentage of increase from rest to men tal activity. In patients, the evaluation was made within 21 days from onset of symptoms and after 2 months of speech therapy, when they wer e classified into two groups on the basis of extent of recovery from a phasia: absent or slight recovery (group 1, 10 patients) and good reco very (group 2, 16 patients). During the word-fluency task in the first evaluation, the increase in flow velocity in the left MCA was similar in controls and in group 2 patients. In both groups the increase was higher than in group 1 patients (p < 0.0001). Changes in mean flow vel ocity on the right side were slight and comparable in the three groups of study subjects. After speech therapy, group 1 patients showed a he modynamic pattern on both sides similar to that observed in the first examination. In group 2 patients, comparison between values of the fir st and second evaluations showed that the increase of flow velocity in the left MCA was similar. On the night side, the increase was higher in the second than in the first examination (p < 0.01). These data fur ther support the involvement of cerebral areas contralateral to the le sion in functional recovery after stroke. Moreover, the presence of an activation of areas in the lesioned hemisphere, soon after stroke ons et, seems to be a predictor of recovery from aphasia.