Given the ever-growing number of traumatic brain injury cases every year, the research surrounding the recovery and outcome of subjects has both greatly expanded and advanced. MRI T1-weighted images are used to determine the anatomical deficits caused by the injuries and the brain regions most affected. The hippocampus atrophies following an injury include decreased volume and diminished memory, attention, and cognitive functions. In previous neuroscience research, genetic variations have been observed to influence the recovery and outcome of injury patients. Despite the research surrounding genetics and injuries, few studies have been conducted to examine the genetic risk factors of the BDNF alleles predicting the hippocampal volume. The current study examines the effects of the val66met BDNF polymorphism on hippocampal volume and atrophy of traumatic brain injury subjects. Memory and attention deficits of TBI subjects positive for the BDNF polymorphism and TBI subjects negative for the polymorphism were also assessed through the Visual Search and Attention Test and the Digit Span Forward and Backwards Test. Findings reveal that the injury severity of TBI subjects interacts with the BDNF genetic predisposition to predict hippocampus volume. Given a larger sample size, the presence of the val66met BDNF polymorphism may be used to significantly predict hippocampal atrophy following a traumatic brain injury.
