You could recover from a concussion but still develop related dementia later in life, according to new study

By Claire Wolters | Fact-checked by Jessica Wrubel
Published September 12, 2023

Key Takeaways

  • A new study found that people who had a concussion early in life were at risk for cognitive issues like dementia later in life.

  • The study adds to existing research on how head injuries can increase risks for cognitive issues.

  • Addressing risks with patients at a time that works best for that individual and advising them to follow proper recovery protocols can benefit healing.

People who undergo concussions may have elevated risks for developing cognitive issues in life, including dementia, a new study finds.[]

The study was conducted over 12 years and looked at 8,662 World War II veterans who were men and twins. Participants took a thinking test skill at the beginning of the study, when they were around an average of 67 years old, and repeated this test three more times over 12 years. The researchers evaluated how test scores changed over the years and compared results between people who did or didn't have a traumatic brain injury or concussion history.[]

Study researchers say their results highlight how concussions can have long-term health impacts even for people who once appeared to be fully recovered.[]

Study author Marianne Chanti-Ketterl, PhD, MSPH, of Duke University in Durham, North Carolina, said in a press release that the “findings indicate that even people with traumatic brain injuries in earlier life who appear to have fully recovered from them may still be at increased risk of cognitive problems and dementia later in life.”[]

Chanti-Ketterl added that even “among identical twins, who share the same genes and many of the same exposures early in life, we found that the twin who had a concussion had lower test scores and faster decline than their twin who had never had a concussion.”

Long-term concussion risks

Ilan Danan, MD, MSc, a sports neurologist and pain management specialist at the Center for Sports Neurology and Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, California, says “there's no question that studies have identified links between head injuries or repetitive head injuries with neurodegenerative conditions as a whole.”

In addition to the risks of dementia, other studies have tied concussions to increased risks of developing mood and anxiety disorders, hyperactivity disorder (ADHD), and Parkinson’s.

People who have experienced more than one head injury or who have lost consciousness during a concussion can be at greater risk for consequences, Dr. Danan says.[]

Importance of proper recovery

The new study suggests that even people who feel recovered from a concussion may experience cognitive side effects. But doctors say that good recovery can reduce risks.

Dr. Danan says proper recovery is essential for long-term healing from a concussion. However, over the years, there has been flawed information about how to best recover from a concussion. 

Previously, and for years, prescribed rest was given as a standard of care for concussion treatment. Among other methods, some doctors advised that people follow “dark room” or “cocoon therapy” methods to assist in recovery. This involved largely limiting physical movement and social interactions while healing. This is no longer recommended.

“In years past, the thought process was: if you suffered a concussion, you isolate yourself from the world, from stimulation—visual stimulation, auditory stimulation, physical stimulation in the sense of getting your heart rate up, and then wait for your symptoms to resolve on their own,” Dr. Danan says. “We know that to no longer be the case. But unfortunately, at no fault of the patient, it was a means of addressing concussion for years.”

According to the American Medical Society for Sports Medicine (AMSSM), the cocoon therapy method may produce detrimental effects. Studies have noted negative impacts of cocoon therapy methods and shown that people who followed strict rest after a concussion may have an increased chance of prolonged symptoms.[][]

Instead, the AMSSM recommends sports medicine physicians and other doctors who diagnose concussions to prescribe patients a “brief period of rest” but then encourage them to “gradually and progressively increase physical and cognitive activity while staying below their symptom-exacerbation thresholds.” In cases of prolonged symptoms, a multidisciplinary team effort may be needed, they say.[]

It may be worth noting that the men in the study, who were around 67 at their first thinking assessment, may have been following the out-of-date recovery method for their concussions. The participants' exact recovery protocols were not reported in the new study, as the researchers evaluated the men years after their concussion incidents.

Going forward, Dr. Danan says doctors should educate themselves on updated recommendations or refer patients to up-to-date specialists for the best care.

Addressing risks with patients

It is always important to be transparent with patients about what they are experiencing and how you are treating them, Dr. Danan says. The extent to which you should address the possibility of dementia with all your concussion patients, however, may come down to personal judgment and ethics, he adds.

Talking about this risk with a patient prone to reckless behaviors and who has had multiple concussions may be a productive conversation if it helps them grasp the gravity of the situation and inspires them to act more cautiously, he explains. For someone who is more prone to anxiety and perhaps experiencing their first concussion, this may be less necessary or perhaps harmful to their recovery, he adds. In situations like the latter, it is best to consider whether the information can help the patient. Remember: even if you do not discuss the issue right away, you can always revisit a conversation after the patient is further along with their recovery.

What this means for you

Studies say that concussions could increase the risks of developing cognitive diseases like dementia. It is important to discuss these risks with patients on a case-by-case basis. In some cases, talking to concussion patients about these risks may encourage them to take measures to reduce their risks of developing other concussions. However, in others, conversations could induce unnecessary fear.

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