CEREBRAL EFFECTS OF A SINGLE-DOSE OF INTRAVENOUS VINPOCETINE IN CHRONIC STROKE PATIENTS - A PET STUDY

The effects of vinpocetine (Cavinton) on the cerebral glucose metaboli sm of chronic stroke patients are studied with positron emission tomog raphy. The regional and global cerebral metabolic rates of glucose (CM Rglu) and the kinetic constants related to them are quantified before and after single-dose intravenous vinpocetine treatment. These measure ments are completed with transcranial Doppler sonography and single ph oton emission computed tomography to explore the possible mechanisms u nderlying the resulting changes in glucose uptake and metabolism in th e brain. The authors' findings indicate that a single-dose vinpocetine treatment, although it does not affect significantly the regional or global metabolic rates of glucose, improves significantly the transpor t of glucose (both uptake and release) through the blood-brain barrier in the whole brain, the entire contralateral hemisphere, and in the b rain tissue around the infarct area of the symptomatic hemisphere. The se changes are in accord with increased blood flow in the entire contr alateral hemisphere as well as decreased blood flow velocity and incre ased peripheral vessel resistance in the entire symptomatic hemisphere .