POSITRON EMISSION TOMOGRAPHIC STUDIES OF CEREBRAL BENZODIAZEPINE-RECEPTOR BINDING IN CHRONIC-ALCOHOLICS

Positron emission tomography was used with [C-11]flumazenil (FMZ) and [F-18] fluorodeoxyglucose to study GABA type A/benzodiazepine (GABA-A/ BDZ) receptors and cerebral metabolic rates for glucose (lCMlglc) in 1 7 male patients with severe chronic alcoholism (ALC), 8 with (ACD) and 9 without alcoholic cerebellar degeneration (non-ACD). In comparison with male normal controls of similar ages, the ALC group had significa ntly reduced FMZ ligand influx (K-1), FMZ distribution volume (DV), an d lCMRglc bilaterally in the medial frontal lobes, including superior frontal gyrus and rostral cingulate gyrus; the ACD group had significa nt reductions of K-1, DV, and lCMRglc bilaterally in the same distribu tion, and also in the superior cerebellar vermis; and the non-ACD grou p had significant reductions of K-1, DV, and lCMRglc bilaterally in th e same regions of the frontal lobes but not in the superior cerebellar vermis. When compared with the non-ACD group, the ACD group had signi ficant reductions of K-1 and DV bilaterally in the superior cerebellar vermis. The results suggest that severe chronic alcoholism damages ne urons containing GABA-A/BDZ receptors in the superior medial aspects o f the frontal lobes, and in patients with clinical signs of ACD, neuro ns containing GABA-A/BDZ receptors in the superior cerebellar vermis.