"Ecstasy"-induced changes of cerebral glucose metabolism and their correlation to acute psychopathology - An 18-FDG PET Study

The aim of this study was to determine the acute effects of the "Ecstasy" a nalogue MDE (3,4-methylene dioxyethamphetamine) on cerebral glucose metabol ism (rMRGlu) of healthy volunteers and to correlate neurometabolism with ac ute psychopathology. In a randomized double-blind trial, 15 healthy volunte ers without a history of drug abuse were examined with fluorine-18-deoxyglu cose ((18)FDG) positron emission tomography (PET) 110-120 min after oral ad ministration of 2 mg/kg MDE (n=7) or placebo (n=8). Two minutes prior to ra diotracer injection, constant cognitive stimulation was started and mainta ined for 32 min using a word repetition paradigm to ensure constant and com parable mental conditions during cerebral glucose uptake. Individual brain anatomy was represented using T1-weighted 3D flash magnetic resonance imagi ng (MRI), followed by manual regionalization into 108 regions of interest a nd PET/MRI overlay. After absolute quantification of rMRGlu and normalizati on to global metabolism, normalized rMRGlu under MDE was compared to placeb o using the Mann-Whitney U-test. Acute psychopathology was assessed using t he Positive and Negative Syndrome Scale (PANSS) and rMRGlu was correlated t o PANSS scores according to Spearman. MDE subjects showed significantly dec reased rMRGlu in the bilateral frontal cortex: left frontal posterior (-7.1 %, P<0.05) and right prefrontal superior (-4.6%, P<0.05). On the other hand , rMRGlu was significantly increased in the bilateral cerebellum (right: +1 0.1%, P<0.05; left: +7.6%, P<0.05) and in the right putamen (+6.2%, P<0.05) . There were positive correlations between rMRGlu in the middle right cingu late and grandiosity (r=0.87, P<0.05), both the right amygdala (r=0.90, P<0 .01) and the left posterior cingulate (r=0.90, P<0.01) to difficulties in a bstract thinking, and the right frontal inferior (r=0.85, P<0.05), right an terior cingulate (r=0.93, P<0.01), and left anterior cingulate (r=0.85, P<0 .05) to attentional deficits. A negative correlation was found between the left frontal operculum (Broca's area) and attentional deficits (r=-0.85, P< 0.05). The present study revealed acute neurometabolic changes under the "E cstasy" analogue MDE, indicating a frontostriatocerebellar imbalance parall eling other psychotropic substances or various psychiatric disorders.