Association between cerebral perfusion and neurocognitive dysfunction in cocaine dependent patients. Value of Wisconsin Card Sorting Test neuroactivation

Objectives Chronic cocaine consumption is a cause of brain perfusion abnormalities and neurocognitive dysfunction. Wisconsin card sorting test (WCST) assesses the latter and produces prefrontal activation in healthy subjects. Perseverative behavior assessed during WCST is a neurocognitive damage indicator. Our goal was to determine association between WCST results and specific cortical activation measured by brain SPECT.

Methods We studied 27 DSM-IV cocaine dependent patients with proven recent consumption. Mean age: 31±7 years; 85% males; dependence time: 7±4 years and a mean estimated consumption of 1.9 g/d. All had a baseline and a post WCST 99mTc-ECD SPECT at admission and repeated after a month of strict abstinence, regional cerebral blood flow (rCBF) changes were assessed with SPM.

Results Baseline prefrontal hypoperfusion correlated with consumption years (r=0.63; p:0.0004). In WCST, perseverative errors (PE) and perseverative answers (PA) averages did not change (p=ns) after detoxification, but non perseverative errors (NPE) diminished (p=0.0064). SPM shows WCST induced right prefrontal activation (Brodmann area 9) only after detoxification (See figure). This area was positively correlated with PE and PA when used as covariates, but not with NPE.

Conclusions Perseverative behavior as well as cortical hypoperfusion is still present in cocaine dependents after a month of strict abstinence. SPM was able to pinpoint rCBF changes after WCST activation in right prefrontal cortex when related with perseverative behavior. This could be helpful to recognize potential responders to specific therapies.

Research Support FONDECYT Grants 1080253/111041