Rheoencephalographic and electroencephalographic studies on flunarizine

The effect of flunarizine on the rheoncephalogram (REG) and on spontaneous electroencephalographic activity (EEG) was studied in acute experiments in cats. The following REG parameters were assayed: amplitude, anacrotic section of the curve and its relative part, and dicrotic index. EEG spectra were derived from 10-sec samples of EEG and the relative amplitudes were estimated at 2 Hz-intervals from 0-40 Hz. The REG study showed that flunarizine (2.5 and 5 mg/kg i.v.) caused an increase of the amplitude and a decrease of the anacrote, of its relative part, and the dicrotic index, changes indicating a lowering of the cerebrovascular resistance. EEG study showed a decrease of the amplitudes of the alpha-frequency band, and an increase of the fast-waves amplitudes, most pronounced at 5 mg/kg, changes showing enhancement of the activation processes in the brain cortex.