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 17 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 significantly reduced FMZ ligand influx (K-1), FMZ distribution volume (DV), and lCMRglc bilaterally in the medial frontal lobes, including superior frontal gyrus and rostral cingulate gyrus; the ACD group had significant reductions of K-1, DV, and lCMRglc bilaterally in the same distribution, and also in the superior cerebellar vermis; and the non-ACD group had significant reductions of K-1, DV, and lCMRglc bilaterally in the same regions of the frontal lobes but not in the superior cerebellar vermis. When compared with the non-ACD group, the ACD group had significant reductions of K-1 and DV bilaterally in the superior cerebellar vermis. The results suggest that severe chronic alcoholism damages neurons containing GABA-A/BDZ receptors in the superior medial aspects of the frontal lobes, and in patients with clinical signs of ACD, neurons containing GABA-A/BDZ receptors in the superior cerebellar vermis.