Research roundup: Concussions

This issue addresses some of the latest literature in the growing field of concussion research and treatment.

Numerous news reports regarding the high prevalence and potential serious impact of concussion have raised awareness of the necessity of evaluation following any sort of blow or trauma to the head. While neuropsychologists, rehabilitation psychologists and others have developed specialized expertise in this arena, the likelihood is high that most psychologists in practice will encounter some clients with a concussion history or that some individuals will sustain a concussion while receiving treatment for other issues.

Psychologists will likely want to become more familiar with the latest literature in this growing area in order to know when to seek additional assessment, refer for specialty care, or modify planned interventions in order to best serve those with a history of concussion.

In addition to reviewing the following research summaries, psychologists are encouraged to explore the literature more completely to determine what may be useful to them in practice.

Karr, J.E., Areshenkoff, C.N., & Garcia-Barrera, M.A. (2014). The neuropsychological outcomes of concussion: A systematic review of meta-analyses on the cognitive sequelae of mild traumatic brain injury. Neuropsychology, 28(3), 321-336.

Concussion, also referred to as Mild Traumatic Brain Injury (mTBI) is a common type of neurotrauma, especially among athletes and military personnel. Numerous meta-analyses have investigated the effects of concussion, and the authors conducted a systematic review in order to streamline this information, with the following objectives:

  • To assess neuropsychological outcomes of concussion in past studies.
  • To identify cognitive effect of concussion and potential variables.
  • To qualitatively combine past study findings in an effort to inform concussion research and policy in the future.

Eleven meta-analyses met the authors’ inclusion criteria. The data was then synthesized based on moderator variables, such as cognitive domain, time since injury, past head trauma, participant characteristics, comparison group, assessment technique and continuity of symptoms. 

The variability of design and sample characteristics in effect sizes across these meta-analyses yield four main conclusions:

  • Following concussion, long-term cognitive impact subsides in most people by 90 days post-injury although athletes may have more rapid recovery windows.
  • Being male, older and having more education resulted in smaller cognitive deficits within 14 days of concussion.
  • Recovery outlook is derived from an average estimate across all cognitive abilities. However, the path of recovery differs across cognitive domains. Effect sizes within most cognitive domains varied greatly across meta-analyses, demonstrating a narrow understanding of post-concussion deterioration.
  • An early meta-analysis characterized concussion as a frontal-executive injury. Yet, more recent studies have shown smaller effects for executive functions, although these self-regulatory capabilities seem to be hypersensitive to numerous concussions, perhaps suggesting that executive dysfunction is a marker of repeated head injury.
Echemendia, R.J., Iverson, G.L., McCrea, M., Macciocchi, S.N., Gioia, G.A., Putukian, M., & Comper, P. (2013). Advances in neuropsychological assessment of sport-related concussion. British Journal of Sports Medicine, 47, 294-298. Doi: 10.1136/bjsports-2013-092186.

With the aim of reviewing advances made in neuropsychological assessment, the authors performed a targeted literature search from 2000 to 2013 and identified articles containing the key words neuropsychological, neurocognitive, assessment, testing, and concussion and sports.

While there is no decisive evidence championing one method of neuropsychological assessment over another, traditional measures, computerized batteries and/or a combination of these approaches have their respective strengths and weaknesses.

Traditional testing has proven to be largely dependable and accurate when evaluating concussions, and can be tailored to the needs of the individual being assessed using large normative databases for comparisons. However, the need for face-to-face observation can lead to variance in test administration and traditional testing is time consuming.

Computerized tests, including the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) and Axon Sports, are portable and can be administered quickly. Recent studies show that computerized neuropsychological testing is efficacious when baseline data is unavailable. Unfortunately, computerized batteries rely on a small sample of cognitive functioning.

Concussed individuals can vary greatly in terms of symptoms, which can include physical and cognitive symptoms as well as serious psychological and emotional disturbances such as depression, anxiety, social isolation, frustration, anger and guilt. An individual may experience prominent symptoms in one domain, but only slight symptoms in another domain. Due to the complexity of concussions, neuropsychological instruments are essential but not the only method for determining when an athlete can return to normal activity.

While advancements in symptom scales that can be effectively used with children have been made, more psychometrically sound, age-appropriate tests that are sensitive to the symptoms of concussion in children are needed. Though key assessment domains between children and adults are similar, critical differences need to be considered, including children’s cognitive, physical and emotional development. Additionally, a child’s ability to serve as the primary reporter of their symptoms must be taken into account. While more evidence is needed, computerized batteries including CogSport, Pediatric ImPACT, and CNS Vital Signs show promise in assessing concussive symptoms in children under 12.

Broshek, D.K., DeMarco, A.P., & Freeman, J.R. (2015). A review of post-concussion syndrome and psychological factors associated with concussion. Brain Injury, 29(2), 228-237. Doi: 10.3109/02699052.2014.974674.

Nonspecific symptoms described by a concussed individual that continue beyond the “normal” recovery period are referred to as post-concussion syndrome (PCS). These can include difficulty concentrating, sleep disturbances, fatigue, irritability, headaches, vertigo, depression and/or anxiety. It is often estimated that 10-20 percent of patients who experience a concussion will experience PCS. However, it’s difficult to qualify these estimates due to the lack of precision when defining PCS symptoms. Some studies have shown that individuals with intense anxiety sensitivity, or a fear response related to one’s own bodily sensations and a belief that such sensations predict negative ramifications, may increase the risk of PCS due to how the injury is perceived. Attribution may play a part in the evolution of PCS for some patients as they assume such symptoms are simply a normal part of recovery.

In their latest Consensus Statement on Concussion in Sport, the Concussion in Sport Group (CISG) recognized that psychological issues are frequently disclosed as an effect of concussion and should be addressed when managing those who have suffered a sports-related concussion. Some evidence shows that, regardless of the severity of the brain injury, neurobiological and pathophysiological changes can occur and bring on psychological symptoms. This is found to be most common in sports-related concussion.

Intracranial abnormalities after a concussion often involve the frontal and temporal lobes, and the frontal-limbic-subcortical structures are believed to be associated with depression, suggesting a pathway for concussion to leads to depression — as it often does. It is estimated that approximately 12-44 percent of people with a concussion experience depression within the first  three months of their injury. Much like depression, anxiety symptomology is frequently seen in concussed individuals due to damage done to the prefrontal cortex, ventral frontal lobe, and the anterior temporal lobe, all areas of the brain believed to play a role in the recognition of emotionally relevant stimuli and the management of reactions to that stimuli.

Studies have found that inordinate amounts of rest — both cognitively and physically — may lengthen PCS. Treatment that includes carefully managed and gradual activity, techniques to reduce anxiety, CBT for any cognitive biases or misattribution, and teaching patients how to handle any psychological factors impeding rehabilitation, may be the most effective approach for getting individuals back to daily life.

Clinical Implications

Much of the literature on assessment of concussion and evaluation of impact derives from sports-related, and to a lesser extent other blunt force trauma, brain injuries. Much less is known about best practices related to assessment and recovery from blast injuries, common among service members.

However, all psychologists are likely to encounter individuals who have sustained a concussion, even if the focus of treatment is other issues. While some may have the appropriate training and tools for proper assessment, other psychologists may wish to refer for more comprehensive neuropsychological evaluation.

Regardless, familiarity with potential cognitive, psychological and emotional symptoms and the expected rate of recovery is useful for all psychologists. Psychologists will want to ensure that a full range of cognitive difficulties are evaluated post trauma and monitored for recovery. Additionally, psychologists will want to be attuned to the psychological and environmental pressures individuals may face. For instance, athletes may push to return to play in order to be part of their peer group, be “tough” and participate in a sport that provides a sense of identity, even if they may not be fully recovered. On the other hand, activity may be a stress management tool, so appropriate levels of activity may be useful in managing some of the psychological stresses during the recovery phase. 

Psychologists can help all patients (and family members) develop additional stress management tools, understand the risk of concussion, particularly multiple concussions, and manage expectations during the recovery phase.