Neurological Implications of Nonfatal Strangulation and Intimate Partner Violence

Keywords::

• abuse
• femicide
• strangulation

Intimate partner violence (IPV) remains a human rights and public health issue, and recent attention has focused on neurological deficits following IPV, particularly traumatic brain injury (TBI) [1,2]. Another common mode of assaultive behavior with IPV that can cause neurological damage is nonfatal strangulation (NFS) [3,4]. These types of injuries have been noted by domestic violence shelter staff, victims agencies and on a limited basis – medical professionals – for over 20 years [5–7]. Yet identification, assessment and standardized approaches for healthcare providers have yet to be employed universally, despite the development of several assessment measures [8,9]. The potential for mortality and long-term negative sequelae following this type of assault remains high [1–8]. However, responses to this issue by law enforcement and domestic violence programs have ‘outpaced scholarly investigation of nonfatal strangulation’ [4]. This brief review highlights the scope of the problem and the medical, psychological, physical and disabling conditions issues post IPV/NFS [10], and what healthcare providers can do.

Scope of the problem

The National Intimate Partner and Sexual Violence Survey (NISVS) indicates that one in three women has experienced IPV during her lifetime and nearly one in ten, or 11.6 million women have been strangled by an intimate partner [11,12]. Previous research indicates that NFS is a highly gendered type of violence, generally utilized in a controlling context [13–16]. The financial costs of IPV are staggering with figures calculated for the USA at more than 8.3 billion annually [17].

The American Academy of Neurology (ANN) has identified IPV as a public health issue underscoring the devastating consequences [18]. Many individuals do not seek law enforcement assistance, medical services and/or counseling/support services; therefore, data do not reflect the magnitude of this ongoing issue [1–8]. A landmark study conducted in Los Angeles in 2001 highlighted that 89% of victims experienced NFS during the course of IPV, yet 50% of the cases had no visible injuries [19]. Several different categories of strangulation exist: hanging; ligature strangulation; manual strangulation and positional strangulation [20]. All of these categories involve mechanically cutting off the airway and subsequent neurological insult unless interrupted.

The Institute of Medicine (IOM) and Department of Health and Human Services, recommends screening regarding current and past IPV in both private and government-funded programs [21–26]. However, TBI and NFS, in particular, are not routinely identified and assessed [27,28]. A study conducted on women who disclosed IPV indicated that 75% disclosed only when asked; most women did not disclose but stated they would have, if asked [29]. A history of NFS is highly indicative of femicide [12,19]. Glass et al. indicate that prior NFS was associated with more than a sixfold odds ratio of becoming an attempted homicide and over a sevenfold odds of becoming a completed homicide [30,31].

As several researchers point out, while law enforcement and legislative reforms have made advancement to address the issue of NFS, scholarly efforts at systematically researching the sequelae of this form of violence are sparse and the area is under-researched [4]. Thus far, 30 states consider NFS a felony [12].

Medical/neurological issues

The terms strangulation and choking are used interchangeably by the lay pubic, and healthcare professionals should be alert on how these terms are used by patients. Strangulation is defined as pressure placed externally on the person’s neck constricting blood flow to the brain and/or airway, causing the inability to breathe. Campbell et al. [32] studied 901 women (n = 543 confirmed cases of IPV and n = 358 controls, never abused) in Baltimore, MD and the US Virgin Islands for TBI and CNS symptoms. They state, “The prevalence of reported probable TBI (from injury to the head or strangulation) in women who experienced IPV was 50% in this sample.” The head, neck and face are the most commonly injured body parts in IPV, and NFS is acknowledged as creating serious negative health outcomes such as carotid artery dissection, stroke and seizures [33]. Orbital, mandibular and nasal fractures are common with most injuries occurring to the left side of the face as 90% of the population is right-handed [34].

Strangulation generally occurs during chaotic and violent interactions [27,35]. Women have reported that the batterer strangled them with their hands, a rope or scarf, or they have been placed in choke hold [36]. As noted by Sorenson, Joshi and Sivitz [3], strangulation is an extremely painful way to die and creates terror in the victim.

Outward signs of NFS such as petechia and red marks around the neck assist in diagnosis; however, physical signs may be absent. For darker-skinned women, alternate light sources may aid in detection of bruises or injury [8]. Consequently, inquiry regarding the details of the injury is imperative in making an accurate assessment.

Strangulation can have immediate and late medical sequelae. The interruption of cerebral blood flow coupled with hypoxia from respiratory arrest, if severe enough, can lead to immediate loss of consciousness and later, a persistent disorder of consciousness [37]. Seizures, strokes, cardiac arrest, cortical edema and intracerebral hemorrhages may occur in the acute phase. In less severe cases, it is probable that cognitive deficits common in other forms of hypoxic–ischemic encephalopathy, in other words, impairments of memory and executive function – especially attention and processing speed – occur [38], although no studies of long-term sequelae in NFS have been carried out. In addition to direct hypoxic–ischemic damage from NFS, mechanical trauma to the cervical blood vessels and the airway can cause delayed neurological sequelae. Arterial dissections may occur, leading to stroke weeks later, making it difficult for the victim and healthcare providers to relate the stroke to the NFS event. Similarly, airway trauma can cause delayed airway obstruction from tissue swelling, compounding the initial hypoxic insult [39].

Mechanisms underlying hypoxic–ischemic brain damage

Experimental models of hypoxic/ischemic injuries in neuronal culture have demonstrated that oxygen and glucose deprivation cause neuronal death largely mediated by excessive glutamate release (excitotoxicity), calcium overload and free radical formation [40–42]. Interestingly, different brain regions and neuronal populations show varying levels of vulnerability, with the hippocampal formation (specifically the pyramidal neurons of the CA1 field) succumbing to short periods of ischemia (∼5 min), which do not affect other brain regions [43,44]. This regional sensitivity has been demonstrated in postmortem studies of human brains [45–47] as well as studies of glutamate toxicity in neuronal cultures derived from different brain regions [48]. As the duration of transient global ischemia increases, neuronal death can be observed in additional regions such as the thalamus and cortex. Since the hippocampus plays a crucial role in memory formation [49,50], this mechanism supports the development of cognitive deficits in IPV victims that may contribute to the failure of many victims to sense the dangerousness of their situation and/or leave the abusive relationship.

Recommendations

IPV literature contains voluminous data on the health/help seeking behaviors of women that experience IPV including the increase of women seeking medical assistance [23–25]. However, many do not, for a variety of reasons: the abuser would not let them; they are ashamed; they do not have transportation and they do not have health insurance [51–53]. Research on neurological difficulties for this population and addressing the serious gaps in service needs, delivery and rehabilitation is an important area of research inquiry.

Consequently, the following steps are recommended to help address this problem:

1. Universal screening in all healthcare settings, domestic violence shelters and community mental health/victim agencies inquiring about IPV and types of injuries particularly to the head and neck. These types of inquiries should be conducted in private and safely away from any second party. Failure to do so may put the patient at jeopardy for further abuse.

2. Healthcare professionals need to educate the patient regarding the dangerousness of the situation. Unfortunately, many individuals believe that this event, as scary as it is, is a one-time event and do not understand the neurological, physical and psychological toll this type of trauma induces. Moreover, many women do not understand that chronicity of neurological insult will negatively impact their memory, attention, reasoning and ability to make informed decisions. Healthcare offices should have information on community resources for IPV and rehabilitation specialists familiar with IPV.

3. Several NFS/lethality questionnaires exist and can be utilized such as the Abuse Assessment Screen which was originally developed in 1987 to assess for IPV and later revised by Coker [10] to include NFS. For further information refer to Laughon et al. [9], Mcquown et al. [54], Campbell et al. [32,55] and Messing et al. [56].

4. More training is needed for specialty courts, for example, family courts, domestic violence courts and drug courts. Judges, lawyers, court officers, legislators and court advocates need to become familiar with the lethality aspects of NFS and the long-term neurological deficits that can emanate from this type of criminal behavior during IPV.

5. A fuller examination regarding IPV and the health and mental health status of ethnic minority women is needed. For an excellent review see: Stockman et al. 2015 [57].

6. For more information on NFS visit: www.strangulationtraininginstitute.com

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript. The financial disclosure is correct.