Abstract
Objective.
The present study aimed to explore the prevalence of subconcussive head trauma, traumatic brain injury (TBI), potential hypoxic events, and hypoxic brain injury (HBI) in victims of physical intimate partner violence (IPV). The study also aimed to characterize the injury presentation and mechanisms of injury in this population.
Method.
A group of 47 female participants with a history of at least one relationship that included physical violence completed a structured interview assessing for subconcussive hits, TBI, and HBI. Participants ranged in age from 19 to 55, and had an average of 15.3 years of education. Forty-four participants completed the structured interview in person and three participants completed the interview over the phone.
Results.
The majority of participants reported sustaining at least one impact to the head and approximately half of the participants sustained at least one impact that resulted in a mild TBI. Approximately half of the participants experienced at least one incident of having difficulty breathing due to a violent act from their partner, and approximately one-third of participants reported symptoms consistent with mild HBI. The most common mechanisms of injury were being hit with a closed fist and being strangled.
Conclusions.
The high levels of head trauma observed in this study highlight the need for clinical and community providers to screen victims of physical IPV for head trauma. The unique characteristics of this population (female sex, high frequency of injuries, and presence of HBIs) indicate that research evaluating the cognitive effects of injuries in this population is needed.
Introduction
The CDC estimates that approximately 40% of women will be victims of intimate partner violence (IPV) in their lifetime, making IPV a serious public health concern (Black et al., 2011). Limiting the scope of abuse to physical violence, the numbers remain high, with approximately one-fourth (Breidin et al., 2014) to one-third (Thompson et al., 2006) of women in the United States estimated to be victims of physical violence by an intimate or ex-intimate partner in their lifetime. Research evaluating common mechanisms of injury in IPV victims shows that injuries are frequently incurred from punching, violent shaking, pushing, and strangulation, and up to 80% of IPV victims report sustaining injuries to their heads, necks, or faces (Sheridan & Nash, 2007). Across mechanism of injury, injuries to the head, neck, and face are so prevalent in IPV victims that it has been suggested that physicians use them as markers for potential IPV victimization (Wu et al., 2010). Given the mechanisms and locations of injury, it follows that victims of physical IPV are likely at high risk for sustaining traumatic brain injuries (TBI) and hypoxic brain injuries (HBI).
Prevalence of TBI and HBI in Victims of IPV
There is a growing body of literature evaluating the prevalence of TBI and HBI in victims of intimate partner violence. A 2011 critical review of TBI in victims of IPV yielded 6 empirical research articles and found a TBI prevalence rate of 30–74% (Kwako et al., 2011). One of the first studies to evaluate the prevalence of TBI and potential HBI due to strangulation in the same sample found that 68% of a sample of 99 IPV victims described a history of at least one mTBI, 10% reported at least one moderate to severe TBI, and 27% reported strangulation-induced hypoxia. Overall, approximately three-fourths of participants reported at least one brain injury and approximately half of the participants reported sustaining multiple head injuries (Valera & Berenbaum, 2003).
A more recent scoping review of head trauma in victims of intimate partner violence analyzed results from 42 studies. In the studies included in this review, the prevalence rates for history of violence that included impacts to the head neck and face ranged from 35% to 100% and estimated prevalence rates of IPV related TBI ranged from 19% to 75% (Haag et al., 2019). Several studies with large sample sizes have yielded consistently high prevalence rates for head trauma in this population. Specifically, a recent retrospective analysis of the National Trauma Data Bank found that in a sample of 16,575 trauma patients who had experienced IPV, 46.8% had sustained head injuries, making head injuries the most commonly observed injury in this sample (Joseph et al., 2015). Additionally, a recent large-scale self-report study of 901 female IPV victims recruited from outpatient clinics yielded a prevalence rate of 50% for probable TBI (including strangulation) (Campbell et al., 2018).
A large retrospective observational study evaluated the medical records of 893 sexual assault (SA) victims and 649 IPV victims who were examined and evaluated by a large medical center’s SA and IPV evaluation center over the course of four years (Mcquown et al., 2016). Results indicated a 38% prevalence rate of strangulation in IPV victims. Of these IPV victims who had been strangled, 25% had lost consciousness (Mcquown et al., 2016). In a smaller sample of 20 victims of IPV, 5 participants reported anoxic or hypoxic effects following strangulation and an additional participant reported alteration in consciousness following simultaneously being strangled and having her head hit against a wall (Valera & Kucyi, 2017).
Sequelae of TBI and Risk Factors for Prolonged Recovery
Research on TBI in athletes has shown that post-injury symptoms of mild TBI can include somatic, cognitive, and/or emotional symptoms and full resolution of symptoms is expected within 10 days for athletes (though it has been noted that a subset of athletes take significantly longer) (McCrory et al., 2017). Recovery of objective cognitive functioning as well as subjective complaints has been found to often take longer in non-athletes, with the majority of individuals recovering within 3 months and full recovery expected within one year (Carroll et al., 2014; Cassidy et al., 2014). Moderate and severe TBIs are less common in athletes and these injuries confer risk for persistent cognitive dysfunction, emotional difficulties, and physiological changes.
Research in athletes has also yielded important information on risk factors for prolonged recovery from mTBI that are particularly relevant for victims of IPV. Specifically, research has consistently shown that the presence of premorbid and post-injury psychopathology confers risk for prolonged recovery from mTBI (Broshek et al., 2015). Additionally, research in military personnel has shown that co-occurring PTSD and mTBI can lead to greater severity of some cognitive symptoms (Combs et al., 2015; Dolan et al., 2012). Victims of physical IPV are at high risk for PTSD (Pill et al., 2017) and other mental health issues (Oram et al., 2017). It is therefore likely that they are at an elevated risk for acute cognitive changes following TBI, as well as prolonged recovery from TBI.
Long Term Sequelae of Repetitive Head Trauma
Research on long-term sequelae of mTBI in athletes has focused on repetitive head trauma, which has been found to be associated with a neurodegenerative tauopathy that was first recognized in boxers, leading to the original name of Dementia Pugilistica (McKee et al., 2009). The disease name has since been changed to Chronic Traumatic Encephalopathy (CTE) and has been diagnosed post-mortem in a large sample composed of primarily contact sport athletes and military personnel (Mez et al., 2013). The study of CTE has expanded the focus of sports head injury research to include subconcussive head trauma, which are blows to the head that do not result in visible signs or symptoms of neurological impairment, but that, particularly when sustained repetitively, may lead to cumulative damage to the brain. The study of subconcussive hits is particularly relevant in victims of physical IPV, where there is high potential for repetitive subconcussive hits both within and across episodes of violence. The potential for IPV-related head trauma to result in CTE was highlighted in a 1990 case study of a 76-year-old victim of IPV, where post-mortem neuropathological studies were noted to be consistent with a diagnosis of Dementia Pugilistica, or CTE (Roberts et al., 1990).
Sequelae of HBI
In addition to being at elevated risk for poor outcome and long-term sequelae of mTBI and subconcussive impacts, victims of physical IPV are also at elevated risk of strangulation, which is not typically observed in athletes and military personnel and is not captured in traditional definitions of TBI. Strangulation can lead to a reduction of oxygen in the brain through venous obstruction, arterial occlusion, and airway collapse (Bruce et al., 2009). HBI is therefore sustained through reduced oxygen in the brain due to both reduced ability to take in oxygen from the environment and reduced blood flow to the brain. Brain regions with higher metabolic demands, such as the hippocampus, and regions fed by more distal vasculature are the most vulnerable to hypoxia. Damage to these regions due to hypoxia has been found to lead to impairments in memory, learning, attention, processing speed, and executive functioning (Bruce et al., 2009; Gale & Hopkins, 2004).
Study Objectives
In their 2019 review, Haag et al. (2019) highlighted the need to evaluate the scope of this problem beyond shelters and emergency departments and the present study aimed to build upon previous research by using a structured interview to explore the prevalence of TBI and HBI in a community-based sample of victims of physical IPV. Given evidence for risks associated with repetitive subconcussive head trauma, the present study additionally aimed to characterize the amount and frequency of head trauma, including potential hypoxic events, that does not meet criteria for a TBI or HBI diagnosis. The study also aimed to characterize the injury presentation and mechanisms of injury in this population.
Methods
This study was approved by the university’s Institutional Review Board. All study personnel were graduate students in clinical psychology, or licensed psychologists, and had been trained to respond therapeutically to emotional distress. Further, mental health resources were provided for participants who reported high levels of depression or suicidality and women’s resource center and shelter resources were offered to participants who reported currently feeling unsafe in their relationship. Participants who were still involved in violent relationships were encouraged to not take a copy of the consent form if there was a risk of their partner finding it, in order to minimize the risk that their abuser could learn of their involvement in this study. Additionally, the study email address did not reference violence or relationships and was chosen specifically to not disclose the nature of the study.
Participants
Participants included 47 female victims of physical violence by an intimate or ex-intimate partner who were screened for inclusion in a study evaluating the effects of head trauma on neuropsychological test performance in victims of intimate partner violence. Participants were recruited through online advertisements on the university research website and other local websites. Additional recruitment occurred through flyers in women’s resource centers, Women, Infants, and Children (WIC) offices, and local businesses. Recruitment materials advertised for women who had experienced stress in their current or previous relationships and screening for physical violence was included in the initial phone screen. A neutral study email address that did not reference violence or relationships was used.
The majority of participants (37 participants, 79%), were recruited from online advertisements; 33 participants were recruited from the university research website and an additional 4 participants were recruited through advertisements on Craigslist.com. The remainder of participants (n = 10, 21%) were recruited from flyers. Out of 47 participants, 44 additionally participated in an in-person neuropsychological testing study. This study is beyond the scope of the current paper, but included completion of a battery of paper-and-pencil and computer-based neuropsychological tests assessing executive functioning, processing speed, attention, and memory. The remaining three participants did not participate in the neuropsychological testing due to being ineligible due to a neurological condition (n = 2) and being unable to travel to the testing site (n = 1).
Participant Characteristics.
Procedures
Following the phone screen for the neuropsychological testing study, verbal consent was obtained for the three participants who were not participating in the neuropsychological testing study. The clinical interview was administered over the phone for these participants. The remaining 44 participants completed the clinical interview in person when they came in for the neuropsychological testing study. Informed consent was obtained prior to conducting the clinical interview; participants currently in violent relationships were encouraged not to take a copy of the consent form home with them. All interviews were conducted between November 2016 and July 2017.
Measures
Previous research has found that currently available TBI screening measures are often not applicable to victims of physical IPV, due to the unique mechanisms of injury in this group (Goldin et al., 2016). A clinical interview that assessed for subconcussive impacts, TBI, potential hypoxic events, and HBI was developed for this study and was conducted either over the phone or in person.
The following definitions were used to determine the presence of IPV and to establish the severity of TBI and HBI. IPV refers to sexual violence, physical violence, emotional abuse, and/or stalking. Because we were interested in evaluating the prevalence and effects of physical injuries, we limited our evaluation of IPV victims to only those who have experienced physical violence from an intimate or ex-intimate partner. The study included both women currently experiencing physical violence in their relationships and women who had previously been the victims of violence by intimate or ex-intimate partners.
The American Congress of Rehabilitation Medicine (ACRM) guidelines were used to establish the presence and severity of TBI (Mild Traumatic Brain Injury Committee of the American Congress of Rehabilitation Medicine Head Injury Interdisciplinary Group, 1993). Specifically, mild TBI was defined by an alteration in mental state (confusion, disorientation), loss of consciousness (LOC) lasting less than 30 minutes, loss of memory for events immediately before or after the injury lasting less than 24 hours, and/or focal neurologic deficit(s) following trauma to the head from external forces or acceleration/deceleration forces. Moderate TBI was defined by LOC for greater than 30 minutes but less than 24 hours and/or post-traumatic amnesia (PTA) of more than 24 hours but less than 7 days. Severe TBI was defined by LOC for greater than 24 hours and/or PTA of more than 7 days (Mild Traumatic Brain Injury Committee of the American Congress of Rehabilitation Medicine Head Injury Interdisciplinary Group, 1993). Additional post-injury symptoms, including emotional, physical, cognitive, and sleep-related symptoms, were assessed; however, injuries that resulted in post-injury symptoms in the absence of the above criteria, were not characterized as TBIs.
HBI was defined as obstruction of airway or pressure on a victim’s neck that results in loss of consciousness of any duration, PTA of any duration, alteration of consciousness, and/or focal neurologic deficit(s). Following the methodology of Valera & Berenbaum, severity of HBI was assessed using the same criteria used for TBI (Valera & Berenbaum, 2003). Similar to TBI, injuries that resulted only in post-injury symptoms in the absence of the above criteria were not characterized as HBI.
The clinical interview was completed by a clinical psychology graduate student. The interview assessed for head trauma that could lead to TBI or HBI, by asking for the number of episodes of violence that included impacts to the head from a partner’s open hand, a partner’s closed hand, or an object, experiences of being shaken, experiences of being pushed into something that caused them to hit their head (e.g., wall, furniture, floor), experiences of being strangled, and other experiences that caused them to have difficulty breathing. Participants were given the option of reporting average monthly or weekly head trauma if they were unable to report confidently on the total amount. They were then asked to specify if each incident of sustaining an impact to the head typically included a single impact (e.g., one closed fist hit to the head) or if it typically included multiple impacts (e.g., multiple closed fist hits to the head) within the incident. Participants were then asked to report how often the above incidents resulted in signs of TBI or HBI, including LOC, PTA, alterations in consciousness, and focal neurological deficits to determine if each injury met criteria for TBI or HBI. Participants were also asked to report how often impacts to their head and potential hypoxic events resulted in post-injury symptoms, including physical, cognitive, emotional, and sleep-related symptoms. See Appendix 1 for sample interview items.
Data Analysis
Descriptive statistics were used to establish the average number of mild, moderate, and severe TBIs and the average number of mild, moderate, and severe HBIs. The prevalence of loss of consciousness, anterograde, and retrograde amnesia, alterations in consciousness, focal neurological deficits, and post-concussion symptoms was determined. The prevalence of mechanisms of injury was assessed. The prevalence of head trauma, regardless of whether it resulted in a diagnosable TBI or HBI, was additionally assessed. The frequency of head trauma was established by dividing the total number of head impacts by the number of months in relationships that included violence.
Results
Subconcussive Head Trauma and Traumatic Brain Injury
Mechanism of Injury for Subconcussive Impacts and Potential Hypoxic Events.
Prevalence and Frequency of Head Trauma.
Note. aEpisodes of violence that included subconcussive hits.
Distribution of Number of Reported mTBIs.
Potential Hypoxic Events and Hypoxic Brain Injuries
Nearly half of the participants reported at least one incident of having difficulty breathing due to a violent act from their partner (Table 2). There was marked variability in the number of estimated incidents including potential hypoxic events (range 0–408) and the frequency of potential hypoxic events (0–9 potential hypoxic events per month) (Table 3).
Approximately one-third of participants (29.8%) reported at least one mild HBI (Table 5). No participants reported injuries consistent with moderate or severe HBIs. All participants who sustained at least one HBI also sustained subconcussive head impacts and the majority of these participants also sustained at least one mTBI. The number of HBIs sustained ranged from 0 to 39 and the frequency ranged from 0–4 per month (Table 3). The most common mechanism of injury was being strangled (94%), followed by being held down by the neck (5%). When the mechanism of injury for TBI and HBI were evaluated simultaneously, being hit with a closed fist was the most common mechanism of injury (60%), and being strangled was the second most common mechanism of injury (17%) (Figure 1).

Note. Prevalence of reported mechanisms of injury based on all reported injuries that met criteria for TBI and HBI.
Distribution of Number of Reported HBIs.
Approximately one-third of participants who met criteria for HBI reported at least one HBI with loss of consciousness (35.71% of HBI participants, 10.6% of total participants). As with TBIs, emotional symptoms were the most commonly reported (76.33% of potential hypoxic events), followed by sleep-related symptoms (67.15%), physical symptoms (45.80%), and cognitive symptoms (8%).
Discussion
The results of the present study are largely consistent with previous research indicating high levels of head trauma in IPV victims. The 49.8% prevalence of mTBI is slightly lower than previous studies, and the absence of any moderate or severe TBI in the present study is notable. Importantly, previous research on this topic has relied largely on samples recruited from shelters and hospital emergency departments while the present study utilized a community-based sample. The recruitment method and subsequent sample characteristics therefore may account for the slightly lower prevalence of mTBI and absence of moderate and severe TBI. The common mechanisms of injury found in our sample—punching, violent shaking, pushing, and strangulation—are consistent with those found in previous studies (Sheridan & Nash, 2007). The similarities in these results speak to the generalizability of previous research in this area to diverse samples.
Previous research in this area has focused on the presence of diagnosable TBI and HBI. While the present study assessed for these injuries, the additional assessment of potential hypoxic events and subconcussive impacts yields important information. There is an increasing amount of focus on subconcussive hits in TBI research, as research has indicated that repetitive impacts to the head, even in the absence of mTBI, may contribute to neurodegenerative processes later in life (Gavett et al., 2011). The high prevalence of episodes of violence that included impacts to the head (89.4%) and the frequency of incidents including impacts to the head (M = 3.34 per month, SD = 4.27), indicate that assessing for repetitive subconcussive head impacts is particularly important in this population.
The reported prevalence and injury characteristic data indicate important distinctions between head trauma in IPV victims and head trauma in populations where it is more commonly studied. First, the majority of sports-related and military-related TBI research has been conducted on male participants. While IPV victims include both males and females, there are more female victims, and female victims who sustain violence from male partners are particularly vulnerable to injury (Schafer et al., 1998).
Secondly, when athletes and military personnel sustain head injuries, they are removed from situations that put them at risk for sustaining additional head trauma. There is no mechanism for victims of physical IPV to be removed from the abusive situation following head trauma and they are therefore at risk for sustaining additional head injuries before recovering from the initial head injury. This is reflected both in our findings that 70.4% of participants reported multiple impacts to their head within an episode of violence, and in the range of observed frequency data indicating that in our sample some victims were sustaining multiple mTBIs within days-to-weeks of each other.
Thirdly, the high prevalence of HBI is unique to this population. Of participants who sustained at least one mTBI, 52% sustained at least one HBI and an additional 13% experienced potential hypoxic events. Thus, nearly two-thirds of those with mTBI additionally experienced potential hypoxic events or HBI. The above differences in individual and injury characteristics highlight the need for more research on the effects of head trauma in victims of physical IPV.
The high prevalence of emotional and sleep related symptoms following injuries is not surprising given the nonspecific nature of these symptoms and the emotional distress inherent in the observed mechanisms of injury. While it is not uncommon to develop emotional (Kontos et al., 2016) and sleep-related (Jaffee et al., 2015) symptoms following mTBI alone, these symptoms are also prominent in individuals experiencing psychological distress and trauma. This finding highlights the difficulty in disentangling the effects of psychological trauma from head trauma. It additionally underscores the relevance of previous research showing that psychopathology predicts poor outcome from mTBI for this population (Broshek et al., 2015; McCauley et al., 2013).
Limitations
The present study contributes to the growing knowledge about mechanisms and clinical presentations of head injuries in victims of physical IPV, however, several limitations should be noted. First, due to the lack of TBI screening measures appropriate for use in this sample (Goldin et al., 2016), an interview was developed for this study and has not been validated. Additionally, the use of retrospective reporting does not allow for full confidence in the reported prevalence rates. There was significant variability in the length of time since participants had experienced violence in their relationship(s); participants were on average 5 years out from the relationship, which increases the difficulty of accurate retrospective reporting. Signs and symptoms of TBI and HBI are particularly difficult to assess retrospectively in this population due to the influence of trauma at the time of and following their injuries. Additionally, many symptoms of mTBI overlap with those of psychopathology and disentangling the roles of head trauma and psychological trauma in symptom development is difficult. To mitigate these influences, we chose not to include post-injury symptoms, including emotional and sleep-related symptoms, in our diagnostic criteria for TBI and HBI. It should be noted that common methods of confirming mTBI, such as informant report in sports-related concussion and hospital records for motor-vehicle accident related mTBI, are not possible in this population. There are obvious safety concerns of seeking informant reports and research has found that only 25 (Valera & Berenbaum, 2003) to 35% (Rajaram et al., 2020) of IPV victims who have sustained head trauma receive medical treatment. Additionally, some participants reported high frequencies of impacts to their head over long periods of time that made assessment for signs and symptoms of each potential TBI or HBI impossible to conduct. In these cases, participants were asked to estimate the average number of impacts to their head and potential hypoxic events over the course of a typical week or month of their relationship(s). The interviewer worked with each participant to establish time lines of their relationship (e.g., moving in together, times apart, discrete periods of increased violence or absence of violence) to account for fluctuations in this frequency and to adjust the estimates accordingly.
A final limitation that is important to highlight, is the small sample size and limited diversity in educational attainment, sexual orientation, and ethnicity of the sample. Although IPV has been viewed as a universal phenomenon, research has shown that individuals with marginalized identities are disproportionally affected by IPV (Sokoloff & Dupont, 2005; Stockman et al., 2015). Thus, the lack of diversity in the obtained sample limits the generalizability of findings.
Future Research Directions
It will be important to continue to study the prevalence of TBI and HBI, and mechanisms of injury in this population. The current study should be replicated in a larger and more diverse population to better estimate the overall prevalence of these injuries in IPV victims. The sample used in this study was unique among similar studies in its use of non-sheltered women. Additionally, the sample was composed of primarily highly educated participants, with an average education attainment of 15.3 years. These sample characteristics should be acknowledged when generalizing the results to other samples of IPV victims. Future studies should additionally replicate the evaluation of subconcussive hits and potential hypoxic events to help establish the amount of cumulative head trauma in victims of physical IPV. Additional work should focus on how best to screen for head trauma in this population, focusing both on thoroughness and efficiency of measures. In addition to continuing to study the prevalence of these injuries, there is a need for research evaluating the cognitive, physical, and psychological effects of these injuries in this population. A recent publication detailed the establishment of an international interdisciplinary working group focused on studying head trauma in victims of IPV. Given the heterogeneity of participant and injury characteristics in this population, and the potential issues with recruitment, one of the goals of this working group is to collect harmonized data for use in meta and mega-analysis and this publication includes suggestions for behavioral surveys, cognitive measures, neuroimaging parameters, and genetics (Esopenko et al., 2021)
Clinical Implications
This is an important topic that merits significant attention from providers in the medical, social support, legal and law enforcement fields. Given the high prevalence of IPV, and our findings that nearly half of the participants reported at least one mTBI and nearly one third reported at least one HBI, the number of women affected by these injuries is likely very high. Clinicians who regularly see victims of physical IPV and community resources such as women’s resource centers, should work to establish methods of screening for these injuries. A recent study highlighted the need for IPV-related TBI screening measures to include prompts relevant to typical mechanisms of injury in this population, to ensure safe endorsement of injuries, and to be easily administered (Goldin et al., 2016).
Screening for head trauma in IPV victims is only helpful if there is a system in place for helping victims who screen positive for TBI or HBI. The Barrow Neurological Institute has established partnerships with local domestic violence and homeless shelters and may serve as a preliminary model for partnerships between medical providers and community providers (Zieman et al., 2017). All new residents of the associated shelters are screened for TBI and everyone who screens positive for suspected brain injury is referred to the neurology clinic. The neurologist meets with each patient and then refers them to relevant services as necessary, including neuroimaging, psychiatry, physical therapy, occupational therapy, speech therapy, and neuropsychological testing (Zieman et al., 2017).
Recent research by Nemeth and colleagues highlighted the discrepancy between prevalence of head trauma in victims of physical IPV and service providers’ knowledge about brain injury and its impact on service utilization (Nemeth et al., 2019). This article additionally highlighted the lack of resources and access to health services available to address brain injury in this population. Just as there is a need for interdisciplinary research in this area there is an immediate need for clinical collaboration between community providers working with victims of physical IPV and medical professionals familiar with TBI.
Footnotes
Declaration of Conflicting Interests
Funding
The author(s) disclosed receipt of the following financial support for the research and/or authorship of this article: This work was supported by the American Psychological Association Science Directorate and the American Psychological Association of Graduate Students.
Supplemental material
Author Biographies
Jessica E. Meyer received her PhD in Clinical Psychology from Pennsylvania State University. She completed a two-year postdoctoral fellowship in Clinical Neuropsychology at University Hospitals Cleveland Medical Center. She is currently a Clinical Neuropsychologist at Summa Health in Akron, Ohio.
References
Supplementary Material
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