Dangerous Intersections: Traumatic Brain Injury, TIA and Stroke

I learned about the connections between traumatic brain injury (TBI) and stroke when I had my first transient ischemic attack (TIA) just a few short weeks after my TBI.  A transient ischemic attack is defined as acute episode of temporary neurologic dysfunction usually lasting less than an hour and resulting from interrupted blood flow specific to the brain, spinal cord, or eyes ⁽¹⁾.  Although a TIA is frequently referred to as a mini stroke, it falls short of being an actual stroke.  A TIA resolves in a short time, so there is typically no permanent damage resulting from cell death in the impacted areas.

Transient Ischemic Attack

Studies show that transient ischemic attacks are a common outcome after a TBI.  My first TIA occurred while I was driving, luckily it was a country road and I was going about 20 miles per hour at the time.  When I was suddenly hit with double vision and vertigo, I put on the brakes and pulled off the road to try to get a handle on what was happening to me.  Once I was several minutes into the experience, I decided it was time to call my doctor’s office and when I called, I was quickly connected to the triage nurse.  As she asked a series of pointed questions, I noticed the symptoms were going away, disappearing just as suddenly as they had appeared.  At this point the triage nurse communicated her belief that I was a having a transient ischemic attack and asked me to come into the doctor’s office right away for a closer examination.

My second TIA happened almost a year later, but this time I an idea as to what was happening, and the timing was such that I was sitting in my back yard.  As with my first TIA, this one cleared up in a matter of ten or fifteen minutes.  Again, I immediately called my doctor and went in for a follow up exam.  Since then, I haven’t had a subsequent TIA, and I hope it stays that way.

Cerebrovascular Accident

The American Stroke Association web site calls TIA events a stroke warning, indicating that a large percentage of patients who have a TIA will have a full-blown stroke within the next 90 days.  Cerebrovascular accident (CVA) is the medical term for a stroke.  A CVA is when blood flow to a part of your brain is stopped either by a blockage (ischemic stroke) or the rupture of a blood vessel (hemorrhagic stroke).  Stroke survivors have a high risk of having another stroke within the first 30 days following a stroke.

Around 80% of strokes are ischemic in nature.  Unlike a transient ischemic attack, the loss of blood flow can occur long enough to cause lasting brain damage, long-term disability or even death.  In fact, stroke is the number 5 most common cause of death and the leading cause of disability in the US.

Dangerous Intersections

Studies show that TBI is an independent risk factor for subsequent ischemic stroke ⁽²⁾ and is associated with an increased lifetime risk of acute ischemic stroke, and particularly after high velocity events ⁽³⁾.  It’s important to understand that this risk is regardless of the traumatic brain injury severity or type ⁽⁴⁾.  This means that whether you have a minor, medium or severe brain injury, you are at risk.  Another significant risk factor is age.  There is as much as a six-fold increase in the rate of hemorrhagic stroke following a TBI in adults 65 years and older ⁽⁵⁾.

And this is a two-way street.  Studies also show an increased risk of TBI to stroke survivors, as well as a significantly higher post-TBI mortality ⁽⁶⁾.  Stroke survivors’ mobility is often impacted and can lead to occasional or even recurrent falls.  Any time a person falls there is some risk of a head impact, and most significantly if there is physical weakness present and they are unable to break their fall using arms and hands.  Post-stroke cognitive impacts can also increase the risk of falls, and this is an outcome for up to one third of stroke survivors.

A study of TBI survivors showed that within the first year there is more than a 5% chance of a recurrent brain injuries that require medical attention, with most of these occurring in the first six months ⁽⁷⁾.  The same study also demonstrated that shorter interval between injuries are associated with greater disability because the brain is still healing from the previous injury.

As the data presented here shows, TIA, stroke and TBI have clear intersections – to one another and to recurrence.  This is a clear indicator that for our best outcomes, we need to take preventative measures where possible to reduce our risks.

Preventative Measures

For anyone who has experienced a TIA, a TBI, or a stroke, it’s important try to avoid further injury in the ways we are able.  If your injury has impacted your mobility, then it’s important to modify your home environment in the ways you can in order to match your needs.  This may be as simple as keeping the floor clear of obstacles that you might trip over, or having handrails installed in high fall risk areas such as bathrooms.

Every TBI and every stroke is unique, so talk with your medical and therapeutic professionals to discover what you can do to help prevent falls.  For a while after my TBI, I received physical therapy and used trekking poles to help me walk.  These tools helped me avoid more than a few falls during that unsteady period.

Another consideration is hypertension, or high blood pressure, which is also a risk factor for both TIA and stroke.  If you have been diagnosed with hypertension, it’s important to pursue the paths defined by your medical professionals to help keep it in check.

Having a plan

I am very fortunate that both of my TIA events were minor and produced no lasting symptoms… but every TIA should be considered a medical emergency.  A TIA is only transient if our body manages to restore blood flow before cell death occurs in the impacted area – but we can’t know ahead of time if it’s going to resolve in time to avoid permanent damage.

• Immediately contact emergency medical services if you believe you are having either a TIA or a stroke!

Being at risk means that you need to know the warning signs of TIA and stroke and you need to have a plan.  Do you and your family all know who to call if you have an ischemic event?  In the US we have 911, in the UK it’s 999 or 112, many European countries use 112, in Australia it’s 000 or 112 on a cell phone and China uses 120.  The US Department of State publishes a list of 911 equivalent numbers by country (911 Abroad), be sure that you and those near you know who to call.

References

1. Supreet Khare, (2016), Risk Factors of Transient Ischemic Attack: An Overview
2. James F. Burke, MD, MS,corresponding author Jessica L. Stulc, MD, MPH, Lesli E. Skolarus, MD, MS, Erika D. Sears, MD, MS, Darin B. Zahuranec, MD, MS, and Lewis B. Morgenstern, MD, (2013), Traumatic Brain Injury may be an Independent Risk Factor for Stroke
3. Robert G. Kowalski, MBBCh, MS, Juliet K. Haarbauer-Krupa, PhD, Jeneita M. Bell, MD, MPH, John D. Corrigan, PhD, Flora M. Hammond, MD, Michel T. Torbey, MD, MPH, Melissa C. Hofmann, PhD, Kristen Dams-O’Connor, PhD, A. Cate Miller, PhD, and Gale G. Whiteneck, PhD, (2018), Acute Ischemic Stroke After Moderate to Severe Traumatic Brain Injury
4. Grace M Turner, Christel McMullan, Olalekan Lee Aiyegbusi, Danai Bem, Tom Marshall, Melanie Calvert, Jonathan Mant, Antonio Belli, (2021), Stroke Risk Following Traumatic Brain Injury: Systematic Review and Meta-Analysis
5. Jennifer S. Albrecht, PhD, Xinggang Liu, MD, PhD, Gordon S. Smith, MB, ChB, MPH, Mona Baumgarten, PhD, Gail B. Rattinger, PharmD, PhD, Steven R. Gambert, MD, Patricia Langenberg, PhD, and Ilene H. Zuckerman, PharmD, PhD, (2016), Stroke Incidence Following Traumatic Brain Injury in Older Adults
6. Yi-Chun Chou, Chun-Chieh Yeh, Chaur-Jong Hu, Nai-Hsin Meng, Wen-Ta Chiu, Wan-Hsin Chou, Ta-Liang Chen, Chien-Chang Liao, (2014), Risk and Mortality of Traumatic Brain Injury in Stroke Patients: Two Nationwide Cohort Studies
7. Oliver Lasry, MDCM, MSc, Erin Y. Liu, MSc, Guido Antonio Powell, MSc, Jessica Ruel-Laliberté, MD, MSc, Judith Marcoux, MD, MSc, and David L. Buckeridge, MD, PhD, (2017), Epidemiology of Recurrent Traumatic Brain Injury in the General Population