Bump on the head ‘doubles’ risk of dementia

LONDON: A bump on the head can double the risk of getting dementia, even if you do not lose consciousness, researchers have warned.

More than two-thirds of traumatic brain injuries in England and Wales are classed as “mild”.

Often caused by falls or minor car crashes, these cases can go unreported because victims fail to realise they have suffered a significant injury.

But a study of more than 350 000 people has found such blows to the head raise the risk of getting dementia by more than double and the risk is similar to that of being knocked unconscious.

Researchers led by the University of California in San Francisco tracked army veterans who had suffered blows to the head for an average of just over four years.

Dr Kristine Yaffe, a senior author of the study, said: “There are several mechanisms that may explain the association between traumatic brain injury and dementia.

“There’s something about trauma that may hasten the development of neurodegenerative conditions.

“One theory is that brain injury induces or accelerates the accumulation of abnormal proteins that lead to neuronal death associated with conditions like Alzheimer’s disease.

“It’s also possible that trauma leaves the brain more vulnerable to other injuries or ageing processes.”

Falls

Brain injuries are most common in people aged between 80 and 90, who are vulnerable to falls, and also peak in those aged 20 to 30, who suffer about 15% of these injuries, often from traffic collisions. Traumatic brain injuries do not always cause concussion and a mild brain injury often does not cause loss of consciousness, but can cause temporary amnesia for up to a day.

Researchers found the risk of dementia almost quadrupled if there was a moderate to severe brain injury.

But a brain injury without loss of consciousness raised the risk by 2.36 times which is similar to the 2.51 times increased risk for people who lost consciousness.

The findings were published in the journal JAMA Neurology. – Daily Mail