21 Concussion, chronic trauma encephalopathy and dementia – what the newspapers say and what we really (don’t) know

Abstract

My interest in neuropsychiatry began during a spell working in Kenya as a Wellcome Research Registrar conducting a study on the psychiatric and cognitive effects of HIV infection. I then completed my higher training in Edinburgh, under the guidance of Professors Michael Sharpe and Charles Warlow, where I developed an interest in functional neurological symptoms. I currently work as a Consultant Neuropsychiatrist in Edinburgh split between the brain injury units at the Astley Ainslie Hospital and the Regional Neurosciences Unit at the Western General Hospital. My collaboration with Michael and Charles has continued and I hold a post as part time Senior Lecturer at Edinburgh University where, along with Dr Jon Stone, we are engaged in the Scottish Neurological Symptoms Study a multi-centre, prospective cohort study of 4000 new neurology outpatients examining the outcome of functional neurological symptoms. There has been a large media interest over recent years in the long term health effects of concussive injuries sustained by sportsman, culminating in a Hollywood movie ‘Concussion’ starring Will Smith. Hardly a week goes by without further studies being announced in the media and creating considerable interest in social media. The message is that concussion is a dangerous condition that causes a complex neuropsychiatric disorder, chronic traumatic encephalopathy (CTE), with a neuropsychiatric phenotype of mood change, irritability and suicidal behaviour which develops over time into a neurodegenerative disorder and death. Increasing alarm has followed and it has been suggested that this is not just a disorder of elite sportsman but a problem for youth sport and that even heading a football (soccer) may cause dementia; a terrifying prospect for those parents trying to decide whether to allow their children to participate in sports. But, in my clinical work as a neuropsychiatrist specialising in brain injury rehabilitation and functional neurological disorders I have personally reviewed over 2000 cases of mild brain injury and I simply never see anything that resembles these description. By contrast what i see is entirely in keeping with what Lishman so eloquently described as “what has initially been based in physiogenic disturbance readily thereafter becomes prolonged, and nonetheless disabling, by virtue of a complicated interplay of psychogenic factors.” And i am left wondering if these catastrophic claims of CTE are really true. To tackle this question more objectively than twitter allows we might examine what evidence is available on the concept of CTE, its relationship to concussion, and its neuropsychiatric phenotype; what the evidence on outcome of mild traumatic brain injury in general is; and what cohort studies on the risk factors for Alzheimer’s disease (AD) can tell us? Reference . Concussion, dementia and CTE: are we getting it very wrong? Carson A JNNP 2017 in press.