Differential tolerance of frontal and temporal lobes to contusion induced by angular acceleration

Frontal and temporal lobe contusions that were caused by a single sagittal plane angular acceleration impulse were analyzed. At neuropathological exam the depth, extent, and location of contusions were mapped and described according to a classification previously developed for human use. Of 30 rhesus monkeys subjected to a single angular acceleration impulse, 13 had no frontal or temporal contusion (Group 1), 8 had only frontal contusion (Group 2) and 9 had temporal contusions (Group 3). Some of the results suggested that as mechanical input increased, frontal contusions occur before temporal contusions and that the threshold for frontal contusion is less than that for temporal contusion. In fact, in Group 3, 8 of the 9 animals with temporal contusion also had frontal contusion. Furthermore, the frontal contusions in Group 3 were statistically more extensive than either the frontal contusion of Group 2 or than the temporal contusions of Group 3.