COCAINE DECREASES RELATIVE CEREBRAL BLOOD-VOLUME IN HUMANS - A DYNAMIC SUSCEPTIBILITY CONTRAST MAGNETIC-RESONANCE-IMAGING STUDY

Cocaine has substantial effects on cerebral hemodynamics which may par tly underlie both its euphorigenic and toxic effects. Dynamic suscepti bility contrast magnetic resonance imaging (DSC-MRI) was used to deter mine whether a dose-effect relationship could be detected between coca ine administration and cerebral blood volume reduction in human brain. Twenty-three healthy and neurologically normal adult males with a his tory of recreational cocaine use (3-40 lifetime exposures) participate d. Subjects underwent DSC-MRI measurements of relative cerebral blood volume (rCBV) at baseline and 10 min after IV double-blind placebo or cocaine (0.2 or 0.4 mg/kg) administration. Placebo administration resu lted in superimposable rCBV curves with post-placebo CBV averaging 104 +/- 4% (mean +/- SE) of baseline, indicating no CBV change. Both coca ine doses induced CBV decreases which were statistically equivalent an d postcocaine CBV averaged 77 +/- 4% of baseline (P < 0.002), when mea sured 10 min following drug administration. These data suggest that DS C-MRI can detect cocaine-induced CBV reductions indicative of vasocons triction, and that it may be useful for evaluating treatments designed to reduce the cerebrovascular effects of cocaine.