Post-concussion Syndrome - Controversy

Controversy

No definition of PCS is accepted by all health professionals, and doubt exists about the validity of the diagnosis. One reason for this is that symptoms of PCS also occur in people who have no history of head injury, but who have other medical and psychological complaints. In one study, 80% of healthy, uninjured people reported having three or more symptoms similar to those found after concussion. In another study, 64% of people with TBI met the criteria set out by the ICD-10 for post-concussion syndrome, but so did 40% of people that had injuries not to the head; 11% of those with brain injuries and 7% of those with other injuries met the DSM-IV criteria for post-concussion syndrome (see diagnosis, below).

Headaches is one of the criteria for PCS, but it is notably controversial where these headaches come from. Couch, Lipton, Stewart & Scher (2007) argue that headaches, one of the hallmarks of PCS, occur in a variety of injuries to the head and neck. Further, Lew et al. (2006) reviewed ample studies examining headaches with post-traumatic headaches and found that there is wide heterogeneity in the source and causes of headaches. They point out that the International Headache Society lists 14 known causes of headaches, as well. Further, the headaches may be better accounted for by medical causes, such as whiplash, which is often mistook for PCS. An additional possibility is that Post-traumatic Stress Disorder can better account for PCS, not just because of the headaches, but for emotional regulation as well.

Having depression, post-traumatic stress disorder, or chronic pain virtually guarantees that a person will report symptoms resembling those of PCS. One study found that while people with chronic pain without TBI do report many symptoms similar to those of post-concussion syndrome, they report fewer symptoms related to memory, slowed thinking, and sensitivity to noise and light than people with MTBI do. Additionally, it has been found that neuroendocrinology may account for depressive symptoms and stress management due to irregularities in cortisol regulation, and thyroid hormone regulation. Lastly, there is evidence that major depression following TBI is quite common, but may be better accounted for with a diagnosis of dysexecutive syndrome

In a syndrome, a set of symptoms is consistently present, and symptoms are linked such that the presence of one symptom suggests that of others. Because PCS symptoms are so varied and many can be associated with a large number of other conditions, doubt exists about whether the term "syndrome" is appropriate for the constellation of symptoms found after concussion. The fact that the persistence of one symptom is not necessarily linked to that of another has similarly led to doubt about whether "syndrome" is the appropriate term.

A longstanding controversy surrounding PCS concerns the nature of its etiology – that is, the cause behind it – and the degree to which psychological factors and organic factors involving brain dysfunction are responsible. The debate has been referred to as 'psychogenesis versus physiogenesis' (psychogenesis referring to a psychological origin for the condition, physiogenesis to a physical one).