Abstract
(Aim) VSRAD can measure the volume of the hippocampus and parahippocampal gyrus in patients over 55 years of age, and is used not only for Alzheimer's disease but also for hippocampal sclerosis etc. To statistically analyze the correlation between the hippocampal and parahippocampal gyrus volume and cognitive functions in elderly schizophrenia, elderly depression and Alzheimer’s disease . (Methods) At Kikuchi Hospital, the authors diagnosed schizophrenia in 89 patients, depression in 50 patients and Alzheimer’s disease in 113 patients at the time of the first visit of the patients to our hospital in 10years. The study was conducted in three groups of patients that were roughly matched with each other in terms of the mean age and group size, i.e., the schizophrenia group (n = 19), the depression group (n = 18), and the Alzheimer’s disease group (n = 20). (Results)The VSRAD Z-score increased in the order of Alzheimer’s disease group > schizophrenia group > depression group, with statistically significant inter-group differences (P < 0.05). In other words, the hippocampal and parahippocampal gyrus volume decreased statistically significantly in the same order①. The hippocampal and parahippocampal gyrus volume was significantly smaller in the schizophrenia group than that in the depression group (P < 0.05), even though the mean age was lower in the schizophrenia group②. In the depression group(rs = 0.24), the cognitive functioning level did not decrease despite the decreased the hippocampal and parahippocampal gyrus volume③. In the schizophrenia group(rs = 0.26), as in the Alzheimer’s disease group(rs = 0.31), the cognitive functioning level decreased as the hippocampal and parahippocampal gyrus volume became smaller④. (Conclusion) The hippocampus and parahippocampal gyrus is a brain region that plays a crucial role in the cognitive decline associated with schizophrenia.