Problem: An extremely prevalent, yet under-reported problem in North America is intimate partner violence (IPV). Reports have estimated >10 000 000 people in North America experience domestic abuse each year, and 29% of women (51 900 000) and 10% of men (18 000 000) are likely to experience physical violence, stalking or rape from an intimate partner at some point in the lives. Traumatic brain injuries (TBI) are thought to range between 30% and 74% in IPV survivors, as the face, head and neck are among the most commonly reported targets of the physical assault. Additionally this is often a recurrent issue as ~25% of survivors are report being hit in the head more than 20 times in the past 5 years. Given these injury mechanisms, it is understandable some of the mental health challenges faced by IPV survivors may be rooted in alterations in brain/autonomic function.

Objectives: The objective of this investigation is to understand the physiological changes underlying TBI symptoms and neurocognitive deficits in women who have experienced IPV. Hypothesis: TBI as a result of IPV will lead to quantifiable impairments in autonomic regulation (i.e. heart rate variability and cardiac baroreceptor sensitivity).

Methods: Eighteen female IPV survivors (35.4 ± 8.7 years; BMI 25.5 ± 7.4 kg/cm2) with 13.4 ± 1.7 years of education participated in this investigation. The survivors were tested on 2 separate days. The first day consisted of the psychopathological self-reported and semi-structured interviews performed by a trained clinician. The second day consisted of the SCAT5 and a series of laboratory based examinations including an assessment of autonomic function. 

Results: All of the IPV survivors demonstrated impairments (as compared to normative control population data) in at least one of the autonomic function metrics assessed in the current protocol. In particular, 89% showed elevated resting sympathetic tone (indexed via low frequency heart rate variability spectrum); 89% displayed blunted cardiac baroreceptor sensitivity (indexed via low frequency cardiac BRS gain); and 72% demonstrated suppressed vagal tone (indexed via RMSSD heart rate variability). 

Conclusion: The augmented sympathetic tone, blunted parasympathetic tone, and reduced blood pressure regulation in IPV survivors provides objective evidence of autonomic dysregulation in this population This, in turn, may contribute to the challenges women who have experienced IPV face in trying to break free from the cycle of abuse.

Intimate Partner Violence-Induced TBI Alters Autonomic Function Metrics