Subtle fatal manual neck compression.

A critical analysis of the postmortem diagnostic criteria for asphyxia leads to a difficulty that has significant implications for the forensic pathologist. The difficulty is that there are no universally recognized pathognomic signs of asphyxia, but pathologists frequently make this diagnosis based on observations that individually have indeterminate significance but combined together, in the appropriate context, have diagnostic value. This leads to the question: if asphyxia has no recognizable signs at autopsy how are we able to diagnose this entity in the latter circumstances? This problem can be solved by defining the minimally adequate diagnostic criteria for compressive neck injury. These criteria are potentially well-defined but currently lacking, in part, due to incomplete morphological characterization of the injuries that frequently occur in strangulation. The problem is especially challenging because the signs of strangulation form a spectrum of degree from minimal to marked and there is no consensus as to the minimal number and nature of lesions that is required to make the diagnosis of strangulation. In the present review of lesions that are commonly encountered in strangulation, intracartilaginous laryngeal haemorrhages and laryngeal cartilage microfractures are considered to have unrecognized diagnostic value, and these lesions are described in detail. A triad of haemorrhages (subepithelial laryngeal haemorrhage, intralaryngeal muscular haemorrhage, and intracartilaginous laryngeal haemorrhage) is discussed in the context of developing a definition of strangulation based on morphological criteria in the absence of overt mechanical injuries to the neck. Although definitive criteria for cases with minimal findings are still lacking, several lesions have putative diagnostic value.