Risk of Multiple Sclerosis in Adulthood Increased by Concussions in Adolescents

Findings further strengthen the need to protect young people from head injury.

Teenagers who have had a concussion have an increased risk of developing multiple sclerosis (MS) later in life, according to a study published in the Annals of Neurology.

“MS is caused by a combination of genetic susceptibility and environmental exposures,” said lead investigator Scott Montgomery. “Most of the young people who experience a head trauma should not worry as they will not carry the necessary genes and other risks that will result in MS in later life.”

Investigators used medical records of children from birth to age 10 and aged 11 to 20 years, to identify individuals with concussions who were treated in the hospital. Next, they examined the risk of MS in later adulthood for the 2 groups.

The results of the study showed 1 concussion in adolescence increased the risk of MS in adulthood by 22%, and 2 or more concussions increased the risk by more than double at 133%. No association with MS for concussions was found in younger children.

“We think that concussion among adolescents can indicate the processes that cause the body’s immune system to attack the insulating layer of nerve cells which, over time, prevents them from functioning correctly,” Montgomery said.

How the brain develops in childhood and adolescence differ and may be the reason why concussion does not carry the same risk of MS between the 2 age groups, the authors noted.

“The rapidly developing brain in earlier childhood may be more able to avoid some delayed consequences of trauma than in later teenage years,” Montgomery said.

He believes the findings further demonstrate the importance of protecting teenagers from head injuries.

“Teenagers often take risks, like cycling without a helmet,” Montgomery said. “If they knew about the possible long-term consequences, they might think again; perhaps they wouldn’t think it’s so cool to ride without a helmet.

“Bicycle helmets is one way, we should consider head injury risk in sports played by adolescents.”

Montgomery stressed that this does not mean young people should avoid sports and physical activity, but rather, “consider ways to reduce the risk of head injuries, when participating in sport.”

As their research continues, the authors plan to investigate genetic influences, including how genes interact with other factors to determine MS risk.