Abstracts

Rationale: The drowning is one of the exclusion criteria of sudden unexpected death in epilepsy (SUDEP). The sudden death in bathtub of patients with epilepsy was considered to be drowning, therefore SUDEP in bathtub (BSUDEP) was never classified as SUDEP based on the conventional definition. The autopsy can differentiate causes of BSUDEP from the drowning. The aim of this study is to verify whether the cause of BSUDEP is drowning or not. We hypothesize that BSUDEP is identical to SUDEP, but not drowning in bathtub. Methods: Tokyo medical examiner’s office conducts postmortem examination for all cases of sudden and unexpected death within the central part of Tokyo. For the past 20 years, we had 45 autopsy cases of BSUDEP, 44 autopsy cases of SUDEP outside bathtub, and 76 cases of sudden death in bathtub (BSD) of patients without epilepsy. We analyzed gender, age, seasons of death, discovered postures, and organ weights of brain, heart, and bilateral lungs. Results: 45 BSUDEP consisted of 23 men and 22 women with the mean age of 43.0 years. BSUDEP more often occurred in winter (n=17, 37.8%) than spring (n=13, 28.9%). The body was found in the bathtub in a sitting posture (n=16, 35.6%) and with leg extension outside the bathtub (n=14, 31.1%). The mean organ weights consisted of heart, 330g, brain, 1,379g, and lung with plural effusion, 565g in left and 632g in right. 44 SUDEP consisted of 25 men and 19 women with the mean age of 42.6 years. SUDEP occurred more often in spring (n=15, 34.1%) and summer (n=12, 27.3%) than winter (n=8, 18.2%). The body was found in a prone (n=20, 45.5%) and spine (n=16, 36.4%) posture. The mean organ weights consisted of heart, 350g, brain 1,390g, and lung with plural effusion, 569g in left and 662g in right. 76 BSD consisted of 50 men and 26 women with the mean age of 73.8 years. BSD occurred more often in winter (n=35, 46.1%) and spring (n=22, 28.9%). The body was found in bathtub in a sitting posture (n=49, 64.5%), in a lateral decubitus posture (n=10, 13.2%), and with leg extension outside the bathtub (n=3, 3.9%). The mean organ weights consisted of heart, 373g, brain 1,319g, lung with plural effusion 608g in left and 713g in right. The causes of BSD consisted of the diseases preceding drowning (n=44, 57.9%) and the drownings (n=32, 42.1%).  Conclusions: The mean ages of BSUDEP and SUDEP were identical, and younger than that of BSD. BSUDEP and BSD tended to occur in the winter. The pathognomonic posturing of BSUDEP was leg extension outside the bathtub even in a Japanese style small bathtub, which suggested a possible generalized tonic extension posturing at SUDEP compared to sitting posture in BSD. As the lung weights of 3 groups showed less difference, BSUDEP can be distinguished from the cause of drowning. Funding: None.