Atrophy of the parahippocampal gyrus and regional cerebral blood flow in the limbic system in chronic alcoholic patients

Abstract 

This study investigated regional cerebral flood flow (CBF) in chronic alcoholic patients, focusing primarily on the limbic system, including the hippocampus and the callosomarginal region, because of their susceptibility to damage in such patients. The degree of hippocampal atrophy in such patients was also examined. Regional CBF and the degree of parahippocampal gyrus atrophy were studied in 22 chronic alcoholic male patients with no neurological or psychological symptom (mean age, 59.3±4.1 years). Their findings were compared with those of 22 age-matched, male, normal controls (mean age, 59.7±3.9 years). Single-photon emission computed tomography was performed using the ^99mTc-ethylcysteinate dimer ( ^99mTc-ECD) Patlak Plot method, and the three-dimensional stereotaxic region of interest (ROI) template (3DSRT) and the fine stereotaxic ROI template (fine SRT) developed by Takeuchi et al were used to evaluate regional CBF, focusing primarily on the limbic system. These methods make it possible to precisely and objectively measure the details of regional CBF. The voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) was used to determine the degree of parahippocampal gyrus atrophy in chronic alcoholic patients. VSRAD is a method developed by Hirata et al for evaluating the degree of atrophy of the parahippocampal gyrus. The results were analyzed using Z scores (>2 indicating significant atrophy). Blood flows in the callosomarginal region, pericallosal region, thalamus, hippocampus, parahippocampal gyrus, amygdaloid body, anterior cingulate gyrus, and middle cingulate gyrus were lower in the chronic alcoholic group than in the control group. Parahippocampal gyrus atrophy was not observed in the control group (average Z score, 0.62±0.29). In contrast, an atrophic tendency was observed in the chronic alcoholic group (average Z score, 1.88±0.44). Clinically intact, chronic alcoholic patients with no neurological or psychological symptom had decreased CBF in the limbic system and a tendency to parahippocampal gyrus atrophy.

Keywords: Chronic alcoholic, Cerebral blood flow, Limbic system, Parahippocampal gyrus, SPECT, VSRAD