Brain injuries from a car crash

Disclosure:

Medical Disclaimer: The content shared in this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you’ve heard on this podcast.

Legal Disclaimer: Similarly, the legal information provided is not a substitute for legal advice. Laws and regulations can vary widely by jurisdiction, and the application of the law depends on the specific circumstances of each situation. Please consult a licensed attorney for personalized legal advice pertaining to your case.

The majority of injuries I see in my office, that have the potential to go to litigation would be from MVCs.  I do see a fair amount of worker’s compensation and some malpractice, but the majority is from MVC.  I was able to find a new article that discusses MVC and injuries.  This article was published in the Neurosurgical focus 14^th edition in 2024.  This was written by Vikas Vattipally et al. titled Motor vehicle collision characteristics and hospitalization outcomes associated with mild traumatic brain injury and concomitant whiplash injury.   

This study was done to quote “determine 1 factors associated with concomitant whiplash among patients with mTBI after an MVC and 2 estimate the effect of concomitant whiplash on hospitalization, length of stay (LOS) and discharge dispositions” end quote.   This is a retrospective study using a national database. 

I find a lot of useful information in this type of study, but have one hesitation to share this type of study.  I have seen both sides of litigation use studies like this to show that injuries did happen or that injuries couldn’t happen.  They incorrectly assume that if a study shows high likelihood of something that it must have happened to their patient.  On the other side if the study showed that an injury is uncommon then the defense has used the studies to show that since it is uncommon that the injury couldn’t have happened to the patient. 

Although this information is helpful each patient must have their own workup to assess what actually did or did not happen to the patient.  Even if an injury is likely we need to assess that it did happen to the patient.  If an injury is unlikely, we still need to assess if the injury did not happen.  Studies like this are helpful to assess things like safety features in a vehicle and care pathways. 

A classic example given in this article is that earlier studies suggested that hyperextension of the cervical spine leads to injury and this influenced development of head restraints to block hyperextension.  This change in head restraints was shown to only reduce neck injuries by 20%.  Although 20% reduction is a reduction it was also able to show that injuries also occur with other mechanisms of injury. 

Although I think this study has some flaws, I also think it has some valuable information.  They reported that there are nearly 4 million emergency room visits for MVC a year.  They performed a retrospective study looking back on Emergency room visits in adult populations.  They included only people with a mTBI.  They included anyone with a scale of 13-8.  A score of 15-13 represents minor brain injury.  A scale of 9-12 represents a moderate brain injury and a 3-8 is a severe brain injury. 

This study should catch mostly moderate brain injury patients and few minor and few severe injuries.  They then assessed how many of these patients also had a cervical sprain or whiplash injury.  This was defined as a sprain diagnosis in the emergency room.  This brings me to what is in my opinion the first flaw of this study.  I read a lot of emergency room records every week.  I find it very uncommon that the diagnosis of cervical sprain is seen in the notes.  This diagnosis is left out most of the time even when cervical spine pain is present.  For some reason I see cervical strain more common and no sprain.  I also see that the emergency room physician often leaves out diagnoses for every complaint and often only gives diagnosis for more serious complaints such as a brain injury. 

This study by design would only include patients with moderate brain injuries.  It is my opinion that the emergency room doctor would be less concerned about a cervical sprain for these patients and may often leave this diagnosis out.  It is also common that cervical sprains are not very painful initially and may have not been reported in the emergency room.  It is also likely that with more serious injuries such as a moderate brain injury that the patient may not have been concerned about their cervical spine and did not report problems to the emergency room physician.  Either way I feel like this is a major flaw in this study since it likely under estimated the amount of cervical sprains seen with the moderate brain injury patients.  In fact this study reported that only 3.3% of moderate brain injury patients had cervical sprains.  In my opinion there is no way this is accurate.

This study also assessed if the patient had a blood alcohol content above the federal driving limit of 0.08%, was wearing a seatbelt and if the airbag deployed.  This study reported that mTBIs can be devastating and quote “nearly a quarter of patients experiencing long-term physical, cognitive, emotional, or behavioral symptoms, resulting in annual healthcare spending of around $17 billion in the united states” end quote.  This study went on to show that 40-70% of patients with mTBIs also have polytraumas, such as sprains, fractures, neck or trunk injuries. 

This study included 22,213 patients.  Of which 16% had an illegal blood alcohol level, 67% were using seatbelts and 61% had airbags deployed.  There study showed patients with a mTBI and a cervical sprain had increased odds of hepatization compared to mTBI patients without cervical sprain.  This study also showed that patients with mTBIs who wore seatbelts were more likely to have cervical sprains while mTBI patient’s without seatbelt had a lower likelihood of cervical sprains.  This study showed that mTBI patients with airbag deployment had a lower likelihood of cervical sprains. 

Before we removed seatbelts from vehicles they reported quote “While seatbelt use may increase the presence of minor whiplash injuries, it overall protects patients from more severe injuries” end quote.    This study did show that seatbelt use lowered the odds of hospitalization and shorter hospital length of stay and an increased likelihood of favorable discharge disposition. 

There study showed that patients with mTBIs and an illegal blood alcohol level had a decrease in cervical sprains.  In my opinion this may be due to the lack of reporting cervical pain by these drunk patients in the emergency room.  They did report that these results may be due to quote “potentially poorer ability of intoxicated patients to accurately report symptoms consistent with whiplash to the care team” end quote.  The GCS would be easy to assess with these patients and more of them may have ended up in the study without being able to report cervical spine pain. 

They reported that the decrease risk of cervical sprains in drunk patients could be due to decreased muscle reaction to the MVC.  They reported that a cervical sprain may be due to muscle contraction while it is stretched as a reflex.  They reported that alcohol may slow the reflexes leading to less cervical sprains.  They reported that often drunk driver’s fail to wear seatbelts and have a significantly higher odds of being in a serious or fatal MVC.  These more serious injuries were no included in this study.

They did show that patients with mTBI and whiplash were less likely to be discharged directly to home from the emergency room and had increased odds of requiring hospitalization compared to mTBI patients without whiplash. 

There are a few take aways for me from this study.  Of significant interest is that they were able to show that seatbelt use increases the likelihood of cervical strains.  They reported that seatbelts have been used to tether the driver with the vehicle.  This tethering has been shown to protect patients from more severe injuries and lowers the odds of hospitalization.  They went on to show that the seatbelt doesn’t restrain the head and cervical spine.  This leaves the cervical spine and head particularly vulnerable to injury when wearing a seatbelt.  In my opinion wearing a seatbelt is a large indicator of increased cervical spine injuries.  Please don’t get me wrong I do wear my seatbelt and advocate that everyone wears them.  The risk of severe injuries without seatbelts is too great of a risk to not wear them. 

The other take away for me is that over 22,000 people in the USA had moderate mTBIs in a year.  This excluded people that have other problems such as HTN, diabetes, COPD, coronary artery disease.  This study also excluded children.  This is a narrow population given the age restrictions and comorbidity restrictions.  Our society is full of comorbidities.  This means that there are a lot of moderate mTBIs from MVC every year.  Also this study excluded the mild mTBI and severe.  This shows that a lot of MVC do cause brain injuries.  This study showed up to 70% these patients had other injuries besides a moderate brain injury.  This is very common in my practice and doing IMEs that most people do have a brain injury of some sort and always seem to have other injuries. 

Another take away for me has to do with slowed reflexes from blood alcohol.  We have covered the reflexive control ligaments have on muscles multiple times in prior podcasts.   This study showed that alcohol may slow these reflexes and inhibit muscular contraction to protect a joint.  While this may lead to a decrease in cervical muscle injuries as seen in this study it likely leads to more damage to the ligaments. 

A study on ligaments in 2005 titled Normal ligament structure, physiology and function published in the Sports Medicine and Arthroscopy journal showed ligaments have 4 times less sensory neuropeptides as muscles and ligaments have a much higher concentrations of opioid peptides compared to muscles. 

 This shows that ligaments have a much lower ability to sense pain as muscles and a much higher ability to control pain with opioid peptides than muscles.  For this reason, ligament damage is much less painful than muscles.  The blood alcohol content likely slowed the reflexive control ligaments have over muscles and this led to less muscle damage and pain right after the MVC.  This is likely why they saw less cervical pain right after a MVC in drunk drivers.  It would be interesting to see if over time these patients had cervical spine pain and ligament damage.  I see a delay in pain a lot when there is significant ligament damage. 

Real World

In my experience brain injuries are the most serious injuries that should have the most value in an injury case, but rarely add value.  Although both plaintiff and defense would agree that a brain injury is serious there are a lot of disputes about objective evidence showing a brain injury. 

I had the opportunity to attend spine rounds at the common spirit hospital at Mountain Point.  With a boardroom full of spine providers there was a discussion and a presentation given about TBIs and blood work.  I have been hearing about this for a while, but not in any great detail.

The discussion was centered around emergency room testing for TBIs and if these new blood tests could decrease the amount of CT scans taken.  When negative these blood tests would show with very high confidence that there was no brain injury.  When positive these blood tests were not as good.  Positive tests would include people without TBIs.  This seems perfect for the emergency department when negative to help rule out brain injury.  These tests need to be done within 24 hours of any injury. 

The presentation and discussion centered around having a decrease in CT scans.  Every CT scan is equivalent to 200 x-rays.  If there was a way to decrease CT scans there is a potential for cost saving and radiation exposure decrease.  This type of testing would also be helpful on an injury case.  If there was a TBI injury objectively showing this type of injury is difficult.  The CT scans typically just look for bleeding which is often not present with brain injuries.  If the blood work test was done this could be a good objective test showing there was a brain injury. 

We spoke about a lot of other blood tests and biomarkers that are being done now.  There are some new ones coming out that can be done months or years after injury.  This type of testing may be a great way to objectively show brain injuries.  I think it is still a long way off before this type of testing is understood and accepted in a person injury case.  I think this is something I need to learn more about and will change the personal injury world as far as objective evidence of brain injuries.