Over the past 1-2 decades the research has emphasized that symptoms after concussion begin within a context. The biopsychosocial model is commonly referred to after brain injury. What this model means is that there are biological factors, psychological factors, and social context factors that affect recovery. Some interpret this to mean that symptoms are first initiated by a neurologic event but then maintained by other factors. This is a good place for neuropsychologists to offer opinions because of their training in both psychological assessment and brain-behavior relationships.
If we take a look at the World Health Organization definition of brain injury, this tells us that a brain injury entails receiving an external force or blow to the head. If abnormalities such as loss of consciousness, amnesia, and confusion/disorientation are transient and focal signs, seizures, and intracranial lesion not observed or requiring surgery, concussion will likely be diagnosed in the ER. Usually the patient will be given a Glasgow Coma Scale score of 13-15. Neuroimaging is almost always negative in these cases. In concussion some brain metabolic changes occur, with changes in the levels of calcium and potassium. This may not lead to lasting damage to brain tissue but to temporary changes in metabolism for 6-10 days. This abnormality in metabolism normalizes or resolves itself in most cases, so symptoms should be brief in a single uncomplicated concussion.
After concussion, people can experience physiological symptoms (headaches, for example), affective symptoms (anger, sad mood), and cognitive (memory) changes. There can be other changes among these symptom clusters, such as dizziness, fatigue, and light sensitivity, or problems in visual tracking. We can see decreased recent memory and changes in speed of thinking, and/or trouble attending to more than one conversation. I will sometimes hear people describe their experience as though they are “in a fog.” The most common emotional symptoms I hear about are irritability, sad mood, and anxiety. Symptoms are vague and non-specific, and rely on self-report in many cases. However, these symptoms occur in a wide percentage of other disorders, such as posttraumatic stress disorder or chronic pain. Also, participation in litigation to lead to elevated symptoms. In one interesting study, Meares et al. (2011) looked and individuals who experienced concussion and trauma controls without TBI. They found that 50% of trauma controls were diagnosed with postconcussive symptoms, whereas 40% of people with mild TBI were diagnosed with postconcussive symptoms. Simply experiencing a trauma itself generates these symptoms and stress, it appears. Some have concluded that postconcussive symptoms are often due to psychosocial factors as a result of this and other studies. This is especially felt to be the case when we look at studies of athletes, who typically recover from a single concussion within 7-10 days.
When we look at the biopsychosocial model, we think about the following in terms of contribution to concussion:
- Biological: neurometabolic cascade, orthopedic pain, medication effects, age, history of prior TBI
- Social: people may overestimate their functioning pre-TBI, may have developed expectations about recovery based on what they have heard in the media, or may make misattributions (“I cannot remember why I went in a room – it must be concussion”)
- Psychological: symptoms of depression, personality factors, drug and alcohol abuse, not feeling engaged with the assessment process
Neuropsychology can help us understand the nature and strength of any causal connection between the concussion and functional abilities (day to day abilities) and current symptoms. Neuropsychologists help to identify the person’s ability to carry out important functions in daily life, and consider the biopsychosocial model as they do so.