Traumatic Brain Injuries and the Risk for Parkinson’s | MyParkinsonsTeam

Connect with others who understand.

sign up Log in
Resources
About MyParkinsonsTeam
Powered By

Traumatic Brain Injuries and the Risk for Parkinson’s

Medically reviewed by Amit M. Shelat, D.O.
Posted on January 3, 2022

Parkinson’s disease (PD) is associated with genetic and environmental risk factors. Among these factors, the most common nongenetic risk factor for PD is traumatic brain injury (TBI).

TBI is damage to the brain caused by head injuries such as:

  • Falling and hitting your head
  • Being hit in the head during sports (boxing or football)
  • Penetrating trauma, such as from a gunshot wound
  • Injuries that cause a skull fracture
  • Blast injuries seen in combat

TBI can occur without significant signs of external injury. Symptoms of TBI — such as loss of consciousness, confusion, blurred vision, difficulties with memory or concentration — can begin immediately after injury or days or weeks later. TBI is classified as mild, moderate, or severe based on symptoms caused by the injury. The more severe the injury is, the more severe the symptoms will be.

Numerous studies have found a significantly increased risk of PD after TBI.

What Does the Research Say?

One study that examined PD and TBI in twins — that is, people who would have the same genetic risk factors — found that mild TBI (concussion) increased the risk of PD, even if the injury occurred decades before PD developed. The researchers found that people with TBI developed PD earlier, and the risk of PD was higher in people with more than one head injury.

Another group of researchers looking at the connection between TBI and PD published a meta-analysis (review) of 22 different research studies including nearly 100,000 participants. The researchers found that people with a history of TBI were more than 1.5 times as likely to develop PD than people with no history of TBI.

A more recent study examined the risk of PD in people who experienced head injuries later in life, at age 55 years or older. Five to seven years after the head injury, older adults with TBI were almost 1.5 times more likely to develop PD than their peers without TBI. This study also found that moderate to severe TBI and repeated TBI were associated with a greater increase in PD risk.

Finally, a study of PD in military veterans aged 18 and older revealed that TBI significantly increased the risk of developing PD by 71 percent. Using data from more than 300,000 people, the study’s researchers found that mild TBI increased the risk of PD by 56 percent, and moderate to severe TBI increased the risk of PD by 83 percent. The researchers also saw a higher rate of comorbidities (other diseases occurring along with PD) in people with TBI compared to those without TBI.

How Does TBI Increase Risk of PD?

TBI is a risk factor for several neurodegenerative diseases, including PD, Alzheimer’s disease, amyotrophic lateral sclerosis, and chronic traumatic encephalopathy. The link between TBI and the risk of developing PD is clear: TBI affects the brain in some of the same ways as PD and other neurodegenerative diseases, causing the same types of damage to brain cells.

TBI causes metabolic disturbances, inflammation, and protein aggregation (buildup) in the brain cells, effects that can all cause immediate or long-term damage to the brain. All of these effects caused by TBI are also part of the disease processes seen in people with PD and certain other neurodegenerative diseases.

TBI can cause damage to the blood-brain barrier (BBB), the layer of cells in blood vessels in the brain that controls what substances can cross from the bloodstream into brain tissue. Damage to the BBB results in an inflammatory immune response and also disrupts normal metabolism in brain cells, causing long-term damage and cell death.

The immune system typically uses inflammation to help control and repair damage to tissue, but TBI can cause chronic inflammation in the brain. Chronic inflammation can lead to unintended consequences such as cell death and protein aggregation, the buildup of excess proteins in cells that can lead to cell dysfunction and cell death. TBI can cause aggregation of alpha-synuclein, amyloid-beta, tau proteins, and other proteins that are linked to neurodegenerative diseases including PD and Alzheimer’s disease.

Will You Develop PD if You’ve Had a TBI?

Research has uncovered much about how PD occurs, but not why PD occurs in some people and not others. Not everyone who experiences a TBI will develop PD, and not everyone with PD has a history of TBI. It is most likely that a combination of inherited factors and acquired factors, such as TBI, are needed for PD to develop. It is believed that TBI may contribute to PD risk by accelerating the damage that leads to PD. TBI may cause some people to reach a tipping point where they have accumulated enough damage to lead to PD.

PD is a complex condition, but research is constantly expanding our knowledge of how and why it occurs. Understanding more about how TBI and related conditions cause damage to brain cells may lead to better treatments for PD and other neurodegenerative diseases. Additionally, knowing that TBI can contribute to the risk of developing PD can help doctors identify people who are at higher risk, potentially allowing for earlier diagnosis and intervention.

Talk With Others Who Understand

For people with Parkinson’s and other chronic diseases, understanding more about your condition can help you cope with it. Knowledge may not always give you more control over your disease, but it can be empowering to understand what is happening inside your body.

MyParkinsonsTeam is the social network for people with Parkinson’s. More than 81,000 members come together to ask questions, give advice, and share their stories with others who understand life with Parkinson’s.

Have something to add to the conversation? Share your experience in the comments below, or start a conversation by posting on MyParkinsonsTeam.

Posted on January 3, 2022
All updates must be accompanied by text or a picture.

Become a Subscriber

Get the latest articles about Parkinson's disease sent to your inbox.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Amit M. Shelat, D.O. is a fellow of the American Academy of Neurology and the American College of Physicians. Review provided by VeriMed Healthcare Network. Learn more about him here.
Kristopher Bunting, M.D. studied chemistry and life sciences at the U.S. Military Academy, West Point, and received his doctor of medicine degree from Tulane University. Learn more about him here.

Related Articles

It’s natural to be afraid of the side effects of the COVID-19 vaccine. However, the risks of gett...

Do COVID-19 Vaccines Worsen Parkinson’s Symptoms? What We Currently Know

It’s natural to be afraid of the side effects of the COVID-19 vaccine. However, the risks of gett...
Both Parkinson’s disease and Huntington’s disease are progressive neurodegenerative disorders tha...

Parkinson’s vs. Huntington’s Disease: What’s the Difference?

Both Parkinson’s disease and Huntington’s disease are progressive neurodegenerative disorders tha...
Whether you’re living with Parkinson’s disease or caring for a family member or loved one who has...

Can You Prevent Parkinson’s Disease?

Whether you’re living with Parkinson’s disease or caring for a family member or loved one who has...
The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...

What People With Parkinson’s Disease Should Know About Getting a Second COVID-19 Booster Shot

The Centers for Disease Control and Prevention (CDC) has approved a second COVID-19 booster shot...
Vascular parkinsonism is a movement disorder and a type of atypical parkinsonism. Some of the sy...

Vascular Parkinsonism Explained

Vascular parkinsonism is a movement disorder and a type of atypical parkinsonism. Some of the sy...
Parkison’s disease research has come a long way over the past two centuries. (Yes, there’s still...

The History of Parkinson’s Disease

Parkison’s disease research has come a long way over the past two centuries. (Yes, there’s still...

Recent Articles

Welcome to MyParkinsonsTeam — the place to connect with others living with Parkinson's disease. ...

Getting Started on MyParkinsonsTeam (VIDEO)

Welcome to MyParkinsonsTeam — the place to connect with others living with Parkinson's disease. ...
People with Parkinson’s disease may develop a symptom called hypomimia, which is a loss or reduct...

Facial Masking (Hypomimia) With Parkinson’s Disease: Causes and Management

People with Parkinson’s disease may develop a symptom called hypomimia, which is a loss or reduct...
In a survey of caregivers on MyParkinsonsTeam, 88 percent reported feeling stressed watching thei...

Survey Results: Stresses and Rewards of Parkinson’s Caregiving

In a survey of caregivers on MyParkinsonsTeam, 88 percent reported feeling stressed watching thei...
Your body needs just the right balance of vitamins and minerals to function properly. When you’re...

Magnesium and Parkinson’s Disease: Are Supplements Beneficial?

Your body needs just the right balance of vitamins and minerals to function properly. When you’re...
Yogurt, cheese, sauerkraut, pickles — what do these foods have in common? They’re all fermented p...

Probiotics and Parkinson’s Disease: What You Need To Know

Yogurt, cheese, sauerkraut, pickles — what do these foods have in common? They’re all fermented p...
Do you find yourself digging through the snack cabinet at night for a cookie or piece of chocolat...

Sugar and Parkinson’s: 7 Facts To Know

Do you find yourself digging through the snack cabinet at night for a cookie or piece of chocolat...
MyParkinsonsTeam My Parkinson's disease Team

Thank you for subscribing!

Become a member to get even more:

sign up for free

close