Link between head trauma sustained during sport and dementia

Scottish scientists have discovered for the first time exactly how a single sporting or car accident brain injury can develop years later into life-changing dementia.

Around 3,000 people in Scotland under the age of 65 have some form of dementia

A landmark study published in the journal Brain from the Mario Negri Institute for Pharmacological Research of Milan and the University of Glasgow provides first evidence that just one traumatic brain injury can generate an abnormal form of the dementia associated protein tau that can slowly spread through the brain, resulting in memory deficits and neuronal damage.

Dr Elisa Zanier, who led the team along with Dr Roberto Chiesa, said: “Traumatic brain injury is a leading cause of death and disability in young adults.

“Even in milder cases, it represents a risk factor for dementia such as chronic traumatic encephalopathy (CTE). Understanding the mechanism linking an acute mechanical event to a progressive, degenerative brain disease would help development of new therapies.”

In Europe, more than five million people live with a physical and/or psychological disability due to moderate or severe traumatic brain injury.

The new study identifies tau propagation as a possible mechanism responsible for the long-term disability of traumatic brain injury patients, and suggests blocking tau propagation may have therapeutic effects.

Dr Willie Stewart, from the University of Glasgow said the team analysed brain specimens from patients surviving a year or more after a single, severe traumatic brain injury.

He added: “We saw evidence of much more widespread deposits of abnormal tau proteins in brain injured patients than in normal control brains.”

In a healthy brain, the tau protein has an important function, acting as a form of ‘scaffolding’ to keeps cells stable. But in Alzheimer’s, tau loses its normal form and breaks away from the cell.

Kirsty Yanik, acting head of policy for Alzheimer Scotland, said: “Dementia doesn’t just affect older people. Around 3,000 people in Scotland under the age of 65 have some form of dementia.

“It is important that these younger people have access to information, care and supports appropriate to their needs in the communities where they live.

“Whilst welcoming this study, we could call for much more research into the causes of dementia, treatments and supports that allow people to live well with dementia, as well as seeking to prevent and even cure the condition.”