Intracranial Pressure and Experimental Model of Diffuse Brain Injury in Rats

Objective: In this study, we present a simple closed head injury model as a two-stage experiment. The height of the weight drop enables gradation of head trauma severity. Methods: The head injury device consists of three parts and there are three adjustable parameters-weight (100-600 g). height of fall (5-100 cm) and elasticity of the springs. Thirty male Wistar rats underwent monitoring of intracranial pressure with and without induction of the head injury. Results: The weight drop from 45 to 100 cm led to immediate seizure activity and early death of the experimental animals. Severe head injury was induced from 40 cm weight drop. There was 50% mortality and all surviving rats had behavioral deterioration. Intracranial pressure was 9.3${\pm}$3.76 mmHg. Moderate head injury was induced from 35 cm, mortality decreased to 20-40%, only half of the animals showed behavioral pathology and intracranial pressure was 7.6${\pm}$3.54 mmHg. Weight drop from 30 cm caused mild head injury without mortality and neurological deterioration. Intracranial pressure was slightly higher compared to sham group- 5.5${\pm}$0.74 mmHg and 2.9${\pm}$0.81 mmHg respectively. Conclusion: This model is an eligible tool to create graded brain injury with stepwise intracranial pressure elevation.