Study on the Cumulative Effect of Acute Repetitive Traumatic Brain Injury: An Experimental Animal Research

Acute repetitive traumatic brain injury (rTBI) can occur in a pedestrian collision when the head hits the vehicle and the ground twice, as well as in a serial rear-ended collision in a very short period. This study established an animal model of acute rTBI to investigate the cumulative effects of repetitive brain injury under different combinations of impact levels. 117 adult male Sprague–Dawley (SD) rats (190±20g) were divided into control, single impact, and repeated impact groups, with the single impact group was divided into three subgroups of mild, moderate, and severe. And the repeated impact group was divided into nine subgroups by combining mild, moderate, and severe. The kinematic response parameters of the rat’s head were captured by a high-speed camera and acceleration sensors. Modified neurological severity score (mNSS) was performed at 6h after final injury, and the severity of injury was quantified using the abbreviated injury scale (AIS). The results showed that cumulative effects of rTBI were not simply linearly superimposed and there was a clear threshold of injury. As a conclusion, an animal model of acute rTBI was successfully established, and the cumulative effects of acute rTBI were preliminarily discussed, which can provide a reference for the biomechanical mechanism and protection of brain injury in road traffic accidents.