Just three blows to head playing football could cause brain damage

By Mark Waghorn via SWNS

Just three blows to the head playing football or rugby could cause brain damage in young people, according to new research.

Multiple concussions alter how neurons communicate in the 'default mode network' (DMN) - which allows us to perform tasks on autopilot.

They are active when we are daydreaming - or thinking about the past or future.

The study adds to evidence that concussions may trigger long-lasting mental problems.

Major international trials have linked them to chronic traumatic encephalopathy (CTE) - which leads to dementia.

Lead author Dr. Thomas Johnson, a neurologist at Rochester University in New York, said: "I think of the default mode network as the idle state of the brain - similar to an idling engine."

It is involved in wakeful rest and internal thoughts - and was disrupted in those who had suffered three to five concussions.

In the study 142 male and female patients in their teens and 20s were enrolled at the university's medical center.

They had persistent symptoms such as headaches, dizziness, fatigue and irritability.

Their brains were analyzed using a special technique called resting-state functional magnetic resonance imaging (fMRI).

Dr. Johnson said: "In the last 20 years, the public awareness of concussion and its long-term effects on the brain has increased and so has research into the topic.

"But there has been scant research using resting state fMRI at the intersection of the adolescent/young adult population and athletes with multiple concussions."

The DMN is a collection of brain regions including the hippocampus, which controls memory.

Changes have been associated with a wide number of diseases and mental disorders - including Alzheimer's.

Participants were scanned while doing nothing but keeping their eyes open during the process.

It enabled the researchers to evaluate the DMN by identifying which areas were switched on during imaging.

Dr. Johnson explained: "When certain areas of the brain get active blood flow increases.

"Using a data analysis technique we're able to create a map for each individual that shows how activity was distributed in space and over time."

In those who had three to five concussions, the maps detected differences. There were none in those who had experienced one or two.

This was compared to healthy controls who were matched by age and sex and had suffered no concussions.

Dr. Johnson said: "We're seeing evidence of a two-tier disease. Experiencing several concussions is a very different pathology."

The results give clues as to the threshold at which concussions cause effects.

They may inform protocols for playing contact sports following a concussion.

Dr. Johnson said: "Suffering three to five concussions has the potential for long-term disruption of cognitive processes.

"We need to determine our tolerance for concussions. When do we say no more contact sports? We need more evidence to set some limits for people."

He plans to conduct follow-up research by scanning the same group in five years to determine if the problems persist.

Dr. Johnson said: "Trying to determine the cognitive impacts of concussion over the long-term is tricky to tease out.

"Typically, we use standard paper tests. Using fMRI is an advanced mathematical way of looking at the networks in the brain."

In the meantime, it may be helpful as a tool to monitor recovery in patients with prolonged post-concussion syndrome.

Dr. Johnson said: "The current standard for evaluating concussive patients is based on symptoms.

"I envision this technique being used to help inform and guide the clinical course of patients."

Children under the age of 12 in England, Scotland and Northern Ireland are now banned from heading footballs during practice or training.

The new rule brought in last year has been backed by former England player Ryan Mason.

He was forced to retire after fracturing his skull during a challenge in a Premier League game.

He is now Tottenham Hotspur's head of player development - and has called for children to use sponge balls to learn the technique.

One recent study found footballers are three and a half times more likely to die of dementia.

The latest findings are being presented at a virtual meeting of the Radiological Society of North America.