Study on ischemic changes of brain neurons in sudden death during bathing

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K10563
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58040:Forensics medicine-related
• Research Institution: Kitasato University
• Principal Investigator: Satoh Fumiko 北里大学, 医学部, 教授 (70328128)
• Co-Investigator(Kenkyū-buntansha): 入江 渉 北里大学, 医学部, 講師 (80597352)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 入浴中の急死 / Calbindin-D28k / VFGF / HIF-1α / 溺死 / 免疫染色 / 法医解剖

Outline of Final Research Achievements

Fatalities during bathing occur frequently in the elderly.
We investigated whether ischemic changes in Purkinje cells of the cerebellum were observed using immunostaining. 31 cases of sudden death while bathing, 21 cases of multiple trauma. Eleven cases of drowning and 21 cases of circulatory system disease were immunostained with Calbindin-D28k, HIF-1α, and VEGF antibodies to show the percentage of positive Purkinje cells. The anti-Calbindin-D28k antibody showed a high value of more than 80% for each of the cases of sudden death during bathing, while only drowning showed a low value in the 30%'s. The anti-Calbindin-D28k antibody showed a low value in the 30%'s. The difference was significant at p>0.05 in the case of drowning compared to the cases of sudden death during bathing. It is thought that the patients died from inhalation of drowning water before cerebral ischemia occurred, due to loss of consciousness by the thermal effect of the bath water, or arrhythmia, etc.

Free Research Field

法医病理学

Academic Significance and Societal Importance of the Research Achievements

入浴中の急死は日本では、冬場に高齢者に多発している。企業は、脱衣場や、浴室に暖房を付けたりし、冬期に浴室や脱衣所を暖め、部屋と浴室の気温差をなくしたり、浴槽を浅くしたり、手すりをつけたりして、浴槽内での溺死を予防している。しかし、入浴中の急死は、高齢社会の日本では、高齢者の人数が増加しており、死亡者が減少しているかは疑問である。研究者が少ない分野であり、脳虚血がどの程度発生しているかを明らかにして、発生原因に考察できたことは価値があると思われる。