Analysis of different post mortem assessment methods for cerebral edema

Abstract

While cerebral edema is a live-threatening condition in living persons, also an edema-like fluid redistribution can occur post mortem. In deceased, usually macroscopic signs are evaluated during autopsy in order to determine the presence or absence of cerebral edema. As a quantitative and objective classification is beneficial, an already existing method (Radojevic et al., 2017), which is based on a mathematical formula using the intracranial dimensions and the cerebral weight, was compared to the evaluation of macroscopic signs in 31 cases. The results showed an excellent agreement for the comparison between the raters as well as the measurement methods (at opened skull or in CT images). However, both measurement methods only poorly agree with the macroscopic edema evaluation. In order to find a more concordant method, the normalized cerebral weight, which puts the cerebral weight in relation to the intracranial volume, was calculated for 115 cases. This method resulted in an excellent agreement with the macroscopic rating and showed a clear numerical difference between the edematous and nonedematous group. While the influence of the post mortem time and the cooling time was found to be negligible, the age at death might confound the edema classification due to pre-existing cerebral atrophy leading to lower cerebral weights. In summary, the present study compared different assessment methods to classify cerebral edema and developed a rater independent, objective and quantitative classification method, which was as reliable as the rating of the forensic pathologists.

Keywords: Autopsy; Cerebral edema; Computed tomography; Forensic medicine; Normalized cerebral weight; Post mortem.