The chronic aftermath of recurrent intimate partner violence-related brain injuries: Insights from rat models of traumatic brain injury and non-fatal strangulation

Abstract

Intimate partner violence (IPV) is a serious global health concern that primarily affects women. Traumatic brain injury (TBI; e.g., concussion) and non-fatal strangulation (NFS) are common forms of IPV-related brain injuries which often occur in combination and are highly repetitive in nature. While our understanding of the consequences of repetitive TBI (rTBI) has improved due to research in sport and military settings, little is known about the repercussions of repetitive NFS (rNFS) or rTBI+rNFS. We recently developed the first rat model of NFS and found that rats exposed to a single TBI + NFS event had exacerbated deficits and pathophysiology than the injuries in isolation. In the current study we utilized these models to investigate the more clinically relevant setting of recurrent IPV-related brain injuries. Female Sprague-Dawley rats were assigned to repeated sham, rTBI, rNFS, and rTBI+rNFS groups. The rats received five exposures to their injury regime, with each exposure 24 h apart, followed by a 12-week recovery before behavioral testing and ex vivo MRI. Only rTBI+rNFS rats had persisting social deficits, while both groups with rTBI had cognitive deficits and anhedonia. Advanced diffusion MRI analysis found that the rTBI+rNFS rats had reduced fiber density and cross-section, an indication of reduced white matter integrity, compared to all other groups. Tensor-based morphometry and region of interest MRI analysis revealed that both groups with rTBI had brain areas with a statistically significant reduction in volume. These findings indicate that rTBI+rNFS results in worse social deficits and white matter damage and provides further evidence that IPV-related brain injuries can result in long-term debilitating consequences.