Chronic Traumatic Enceophalopathy
Chronic traumatic encephalopathy (CTE), particularly in retired athletes from the National Football League in the USA, has received significant media attention.
CTE can only be diagnosed by post-mortem observation, and it is described by McKee et al 2009 as a ‘progressive neurodegeneration clinically associated with memory disturbances, behavioural and personality change, Parkinsonism, and speech and gait abnormalities’.
Neuropathological criteria for the diagnosis of CTE has recently been defined to be the abnormal accumulation of hyperphosphorylated tau protein in the brain.
Properly designed prospective studies, which control for potential confounding variables, are required to improve our understanding of CTE and any potential link to prior concussion.
- Some researchers have presented preliminary evidence that repeated head trauma causes the condition, but there is significant selection bias in many of the reported cases.
- The link between sport-related concussion and CTE is based on low-level evidence. Research is limited to case reports, case series and retrospective analyses which cannot adequately determine causality or risk factors.
- The potential contribution of confounders, such as genetic predisposition, psychiatric illness, alcohol and drug use or co-existing dementia, is not adequately accounted for in the current literature.
- While there is significant concern about CTE and its possible relationship with concussion, it is important to note that no causative link has been clearly established.