Morphological analysis of astrocytes in the hippocampus in mechanical asphyxiation

The present study investigated the morphology of astrocytes in the hippocampus and serum S100B levels in cases of mechanical asphyxia due to neck compression (n = 23: atypical hanging, n = 7; ligature/manual strangulation, n = 16) with regard to the classical autopsy findings, compared with those of other types of asphyxiation (n = 9) and acute myocardial infarction/ischemia (AMI, n = 20). The decrease in intact astrocyte number, as shown by S100 and GFAP-immunostaining, was larger for asphyxiation due to neck compression compared with that for other asphyxiation and AMI, showing a correlation with the increase in the serum S100B levels. The decrease in intact astrocyte number and increase in serum S100B were closely related to the severity of conjunctival petechial hemorrhage and fracture(s) of the hyoid bone and/or thyroid cartilage in asphyxia due to neck compression. These findings suggest that hippocampal astrocyte injury is caused by cerebral hypoxia accompanied by congestion, especially in mechanical asphyxia due to neck compression.