Brain perfusion is abnormal in cocaine-dependent polydrug users: a study using technetium-99m-HMPAO and ASPECT.

Cocaine abuse is widespread and has been associated with serious neurovascular complications. We studied a group of cocaine-dependent polydrug users with 99mTc-HMPAO and high-resolution SPECT and compared their perfusion pattern to cerebral perfusion in a group of older control subjects. Sixteen of 18 cocaine-dependent polydrug users had abnormal perfusion characterized primarily as small focal defects involving inferoparietal, temporal, and anterofrontal cortex and basal ganglia. Psychometric testing was abnormal in all 18 cocaine-dependent subjects. No relation was found between the severity of SPECT abnormalities and mode of administration or frequency or length of cocaine use. All 15 older normal subjects had normal cerebral perfusion. While the focal perfusion abnormalities to the cortex and basal ganglia could be explained by the profound vasoconstrictor effects of cocaine, the combinational use of multiple substances including cannabis and alcohol may play a contributory role. This study documents the high incidence of functional brain abnormalities in cocaine-dependent chronic polydrug users without corresponding abnormalities on imaging studies of cerebral anatomy and morphology.