Autonomous nervous system-related vital reactions in short drop hangings

There are numerous anatomopathological signs forensic pathologists take into account in autopsy evaluation of deaths by hangings, having in mind one of the most important tasks: to prove the person was alive at the moment of suspension. Forensic medicine textbooks describe in detail many routinely observed findings, but some phenomena were not of particular interest. This may be due to the unreliability or impracticability of the findings interpretation. Nevertheless, some signs of vitality that may be related to the autonomous nervous system (ANS) in hangings could be useful. These can be considered as general ANS-related vitality phenomena associated with the agonal sequence, and those directly associated with the specific neck region injury by the ligature. The former is primarily the non-specific increase in blood catecholamine levels and the hypersalivation with saliva dropping on the facial skin from the lips' angles, associated with agonal convulsions and deep terminal "abdominal" respirations. The latter, probably more interesting, is the so-called faciès sympathique: the lesion of the sympathetic fibers in the neck region may lead to myosis and partial upper eyelid ptosis on the side of the lesion. However, this reaction/sign was not of great research interest and remained incompletely understood regarding the interpretation of postmortem appearance. This demands further studies, but if properly analyzed, it may prove useful as a proof of vitality and for reconstructing the event, too, in case the other findings are subtle or absent.