Brain scans show just one head injury can put people at risk of dementia

By | September 4, 2019

A single head injury can trigger dementia decades later, scientists claim.

Scans revealed damaging clumps of a protein called tau were more common in patients who had suffered a significant head injury as far back as 51 years ago.

Tau is a sticky substance that adds structural support to nerve cells in the brain – but when cells become damaged it can form clumps.

It is known to be linked to dementia but can normally only be identified by postmortem dissection.

Brain scans can reveal a number of future issues – including the possibility of dementia


A team from Imperial College London and Glasgow University used brain scans combined with a substance that binds to tau to study it in 40 patients with an average age of 49.

Author Dr Nikos Gorgoraptis, of Imperial College London, said: “Scientists increasingly realise that head injuries have a lasting legacy in the brain and can continue to cause damage decades after the initial injury.

“Up until now most of the research has focussed on the people who have sustained multiple head injuries, such as boxers and American Football players.

“This is the first time we have seen in these protein tangles in patients who have sustained a single head injury.”

Head injuries were considered moderate to severe and mostly sustained in traffic accidents, as well as in physical assaults and by falling from height.

Tau normally helps provide structural support to nerve cells in the brain, acting as a type of scaffolding, but when brain cells become damaged it can form clumps, or “tangles”.

“While head injuries are something no one wants, in terms of dementia risk it’s better to focus on things you can control” says Dr James Pickett at the Alzheimer’s Society

Tau tangles are found in Alzheimer’s disease and other forms of dementia, and associated with progressive nerve damage. Not all people with tau tangles demonstrate any signs of cognitive decline.

Tau tangles can develop years before a person starts to develop symptoms such as memory loss.

Dr Mark Dallas, of University of Reading, added: “It should be noted this research does not suggest a single brain injury will automatically lead to dementia.”

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Dr James Pickett, head of research at Alzheimer’s Society, said: “While head injuries are something no one wants and we should take steps to avoid, in terms of dementia risk it’s better to focus on things you can control.

“This includes being physically active and following a good diet.”

Mirror – Health