Experimental Head Injury with Lateral Impact Using Monkeys (Preliminary Report)

The authors obtained the following results in an experiment of 30 lateral head impacts applied to 10 monkeys. 1.Lateral impact tolerance which is an index of concussion was estimated to be about twice as high as sagittal impact tolerance, but more experimental cases in the future will be required to decide the proper tolerance level. 2.Concussions had three types of effects on the cardiopulmonary system, and significant mutual correlations and correlation with concussion severity were shown. 3.It is characteristic of lateral impact that, although the tolerance level appears to be high, there are diverse and characteristic pathological changes, and it is assumed that contusions such as gliding contusion and Zentrale Hirnschaden (or intermediary contusions) are apt to occur in cases of lateral impact.