Diagnosing concussion

In a CMAJ practice article, Tator states that "the diagnosis of concussion is not easy."1 However, the current diagnostic criteria for concussion2 are remarkably rudimentary and state that a single symptom (from a 22-item Likert scale) experienced after head shake, should prompt a clinician to diagnose concussion and institute treatment. Tator does not discuss the difficulty caused by the lack of specificity of the diagnostic criteria for concussion, as they are currently defined.2 Individuals with whiplash, depression, benign vertigo and other disorders all meet the diagnostic criteria for concussion. The problem is that once feelings of everyday life are attributed to a brain injury, concussion is not easily "undiagnosed." Tator's1 review of concussion is welcomed. When writing about concussions, the popular press has created a belief held by the public and many medical professionals that a cause-and-effect link has been shown between repeated or frequent concussions or subconcussive blows and chronic traumatic encephalopathy (CTE). This very question was hotly debated in Zurich in 2012, following a presentation on CTE by Dr. McKee, from the Boston University Center for the Study of Traumatic Encephalopathy.2 The audience contested the idea that repeated concussions and CTE were cause-and-effect, although the relationship between the 2 entities was readily admitted. The consensus statement3 reported on CTE as follows: The following point appears in Box 4 of Tator's article:1 "Any alteration of mental functioning after a blow to the head or body is a concussion." That blows to the body that produce pressure on the solar plexus can result in significant physical and mental dysfunction on a temporary basis is well known. Such dysfunction does not constitute a concussion. Individuals who experience a sudden unexpected traumatic experience can have an alteration in their memory and even experience frank amnesia. Psychogenic amnesia is one of the diagnostic criteria for post-traumatic stress disorder. In my opinion, one has to be cautious in attributing a concussion or brain injury to "any alteration in mental functioning."