Concussion, Post-Concussion Syndrome and CTE


There has been a lot of news recently about the role of concussion in a condition known as chronic traumatic encephalopathy (CTE), originally identified in American sportspeople.

This has been fuelled in part by the release of the movie, ‘Concussion’, starring Will Smith. There is also a CTE related legal challenge against World Rugby taking place at present, involving a number of British and international rugby union players, including at least one New Zealander. While we are watching these developments, it is our belief that very few people are likely to be affected by CTE here in Aotearoa.

ABI Rehabilitation is a New Zealand rehabilitation service for people with traumatic brain injuries of all severities. ABI runs community based concussion rehabilitation services, and our doctors and therapists treat many hundreds of people diagnosed with concussion every year.

ABI is concerned about how the diagnosis of CTE is made, and who makes that diagnosis.  At this stage CTE can only be diagnosed by pathological analysis of brain tissue, which means a diagnosis is made after death. There are no agreed clinical signs or symptoms for CTE yet, which means that it cannot be diagnosed with certainty by treating doctors, clinicians or the patients themselves.

CTE has been commonly described as a dementia. There are many causes of dementia, and these can generally be diagnosed before death on the basis of memory tests, clinical signs, brain scans and blood tests. Other forms of dementia need to be tested for, before CTE can be considered.

Dementias are common progressive conditions occurring in older people, particularly over the age of 65. According to the Lancet Commission 2020, the risk of Alzheimer’s disease (AD) is known to be increased by 3% in those with a history of traumatic brain injury of all severities. Other conditions can also increase the risk of AD, like smoking (5%), hypertension (2%) and physical inactivity (2%).

We know that some patients with a history of concussion or their families suspect CTE because of a personality change, psychological issues like depression or anxiety, memory difficulties or frequent headaches. These conditions commonly occur after concussion and in a small proportion of patients are longer lasting. We know that severe concussions or multiple concussions make persistence of these symptoms more likely. All of these symptoms are likely to improve with input from therapists, concussion doctors and with certain medications. Because they are treatable, these symptoms are better described as relating to post-concussion syndrome, not CTE.

ABI urges anyone suspecting that they have CTE after sustaining concussions to consult with specialist concussion services or with a neurologist to get a medical diagnosis. In our view, people with persistent symptoms after concussion are more likely to have post-concussion syndrome, a treatable condition, rather than CTE.

Reference:  Livingston G et al. Dementia prevention, intervention and care. 2020 report of the Lancet Commission. Lancet 2020; 396: 413–46

If you are worried, please see your general practitioner who can refer you to a specials service such as ABI Rehabilitation. Click here to contact us