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Vinpocetine increases cerebral blood flow and oxygenation in stroke patients: a near infrared spectroscopy and transcranial Doppler study.
Bonoczk P, Panczel G, Nagy Z.
Chemical Works of Gedeon Richter Ltd.
Budapest, Hungary
Eur J Ultrasound 2002 Jun;15(1-2):85-91
Abstract
OBJECTIVE: To investigate the effect of vinpocetine on cerebral blood flow (CBF) in the compromised circulation of a stroke affected hemisphere using transcranial Doppler (TCD) and near infrared spectroscopy (NIRS) methods.
METHODS: 43 patients with ischemic stroke were randomized into vinpocetine and placebo group in a double blind, placebo-controlled study of the effect of a single-dose i.v. infusion of vinpocetine on cerebral blood perfusion and oxygenation. In the
vinpocetine group 20 mg vinpocetine in 500 ml saline, in the placebo group 500 ml saline alone were administered. The concentrations of oxy-, reduced- and total hemoglobin were measured by NIRS frontolaterally on the side of lesion while the mean cerebral blood flow velocity (CBFV), the pulsatility index (PI) and Doppler spectral intensity (DSI) were monitored by TCD in the middle cerebral artery on the same side. Values were averaged for the first 5 min prior to the infusion and for the last 5 min of infusion and they were compared between groups.
RESULTS: The concentration of all three chromophores increased during infusion in the vinpocetine group (mean dHbT = 1.03, CI(95) = 0.84, P = 0.058; mean dHbO = 0.92, CI(95) = 0.91, P = 0.071; mean dHb = 0.10, CI(95) = 0.21, P = 0.297). The HbT and HbO showed a substantially smaller increase in the placebo group (mean dHbT = 0.31, CI(95) = 0.74, P = 0.22; mean dHbO = 0.57, CI(95) = 0.80, P = 0.094) while the Hb decreased (mean dHb = -0.26, CI(95) = 0.29, P = 0.05). Comparing to the placebo group Hb increased significantly in the
vinpocetine group (P = 0.027) while the increase of HbO and HbT did not reach the level of significance (P = 0.29 and 0.11). DSI showed a significantly larger increase in the vinpocetine than in placebo group (dDSI=25.8 CI(95)=8.8
[vinpocetine ]; dDSI =3.3, CI(95) = 3.7 [Placebo], P < 0.005). The CBFV and PI did not differ significantly between groups. (dVm = 5.02.98 cm/s [vinpocetine], dVm = 4.12.57 cm/s [Placebo], P = 0.28; dPI = 0.08
[vinpocetine], dPI = 0.09 [Placebo]; P = 0.47).
CONCLUSION: vinpocetine increases cerebral perfusion and parenchymal oxygen extraction as well. The increased perfusion was indicated by NIRS and by TCD measurement of DSI while conventional velocity and pulsatility measurements failed to detect theses effects. NIRS is a sensitive, feasible method of measuring changes in regional blood flow and tissue oxygenation in the superficial cortex. |
