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 partly underlie both its euphorigenic and toxic effects. Dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) was used to determine whether a dose-effect relationship could be detected between cocaine administration and cerebral blood volume reduction in human brain. Twenty-three healthy and neurologically normal adult males with a history of recreational cocaine use (3-40 lifetime exposures) participated. Subjects underwent DSC-MRI measurements of relative cerebral blood volume (rCBV) at baseline and 10 min after i.v. double-blind placebo or cocaine (0.2 or 0.4 mg/kg) administration. Placebo administration resulted in superimposable rCBV curves with post-placebo CBV averaging 104+/-4% (mean+/-SE) of baseline, indicating no CBV change. Both cocaine doses induced CBV decreases which were statistically equivalent and post-cocaine CBV averaged 77+/-4% of baseline (P < 0.002), when measured 10 min following drug administration. These data suggest that DSC-MRI can detect cocaine-induced CBV reductions indicative of vasoconstriction, and that it may be useful for evaluating treatments designed to reduce the cerebrovascular effects of cocaine.