A comparison of ethanol concentrations in the occipital lobe and cerebellum

While many publications have addressed the issue of ethanol concentration in brain tissue as a better indicator of impairment than blood alcohol concentration (BAC), very few have looked at the regional distribution of ethanol in the brain and its possible significance in postmortem sampling. This paper reports on the analysis of occipital pole and cerebellar hemisphere for ethanol in 25/brain samples obtained at autopsy from the brain collection of the National Institutes of Mental Health/Stanley Foundation. When available, these concentrations were compared to BAC. The average ratio of occipital lobe alcohol concentration (OAC) to BAC for cases which also had blood samples (18/24) was 0.9, SD = 0.5, with a range of 0-1.8; the average ratio of cerebellar alcohol concentration (CAC) to BAC for these cases was 0.6, SD = 0.4, range = 0-1.2. When only those cases with a BAC > or = 0.04 g/dl (14/18 cases) were considered, the average OAC/BAC and CAC/BAC ratios were 0.8 (SD = 0.4) and 0.7 (SD = 0.4), respectively. These distribution ratios are well within the ranges reported by other authors and do not significantly differ from each other. The cortical brain region available or selected for postmortem ethanol analysis is probably not critical.