Traumatic Brain Injury - How Severe Was It?

I discuss something  that is likely to present itself to a physician long after the fact: a single mild brain injury.  This episode focuses on how to classify the severity of a single brain injury.  While working in a brain injury unit, I noticed that some providers used the term severe brain injury when referring patients to neurology or neuropsychiatry, and this communicates something very specific that they may not realize they are communicating. Those of us seeing a patient after a brain injury may not know the specific terminology to use, so this episode is meant to help the listener understand how brain injury experts classify these injuries.

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References and readings (when available) are posted at the end of each episode transcript, located at psydactic.buzzsprout.com. All opinions expressed in this podcast are exclusively those of the person speaking and should not be confused with the opinions of anyone else. We reserve the right to be wrong. Nothing in this podcast should be treated as individual medical advice.

Transcript

Welcome to PsyDactic- Residency Edition.  Today is Tuesday, Oct 17, 2023.  It has been some weeks since I was able to produce another episode, and I apologize for my absence.   By apologizing, I am assuming that you care.  You probably don’t.  By the way, I am a 4th year psychiatry resident in the national capital region.  This is a podcast about psychiatry, psychology, and neuroscience that I do for my own benefit, and I hope it helps others, especially other psychiatry residents.   I produce this podcast alone in my home office, so you as the listener should be aware that I have no fact checkers or editors that are smarter than me to moderate my content.  That means that what I say here is entirely my own opinion, so take that for what it is worth.  Let me start by disclosing something about myself.

I remember starting full tackle football in Oklahoma when I was in the 4th grade.  I may be giving away my age here, and if you want to guess, go to PsyDactic.Com and fill out the form there guessing my age. My younger brother started playing in the 3rd grade because, well, he asked. It was a badge of pride to hurl your body at another person and in a tangled pile of flesh, tumble to the ground and mostly get back up again.  If I can quote a historical saying without being roasted on social media, “Flag football is for wusses.”  But in the past couple of decades, the glory that was once reserved for tough guys, has favored the wusses, because the quote wusses unquote were far less likely to end up frequently impaired in their ability to do things later in life like finding and maintaining employment.

The National Football league has served our country well as an experiment in what happens when adults repeatedly and with the weight of a professional contract hurl their body at someone else over and over and over and over again for a decade or more.  The result is something that is not unique to the NFL, but brilliantly shines the light on something called Chronic Traumatic Encephalopathy.

Impacts shake, bruise, and disrupt the brain.  When this happens over and over and over again, it results in something resembling dementia.  Some researchers have proposed that CTE results in an almost prion-like effect, where the misfolded proteins that accumulate in the brain of frequently concussed persons cause even more proteins to misfold and accelerates a progression to dementia.  There is no consensus as to what exactly causes it, but what we do know is that injuring the brain over and over and over again should be avoided.

I am going to disappoint you right now by NOT talking about CTE.  Instead, I am going to talk about something far more common that is likely to present itself to a physician: a single brain injury.  My even more limited focus is going to be on how to classify the severity of a single brain injury.  While working in a brain injury unit, I noticed that some providers who end up referring patients to neurology or neuropsychiatry after a brain injury used the word severe when describing the brain injury, and this communicates something very specific that they may not realize they are communicating. Those of us seeing a patient after a brain injury may not know the specific terminology to use, so this episode is meant to help the listener understand how brain injury experts classify these injuries.

Let’s start with a case.  Adriane had a car accident 4 months ago during which they lost consciousness briefly.  They don’t remember all the details, but they do remember what happened just prior to the accident.  They were on a country road, looking at a text on their phone and the car in front of them stopped suddenly.  When Adriane noticed, they swerved into the ditch and hit the side of a hill.  The airbag deployed and Adriane remembers waking up a few moments later somewhat disoriented.  Someone was tapping on the window.  The details are fuzzy, but they remember waiting for emergency responders and a tow truck and being taken to an emergency room for evaluation because they told EMS that they lost consciousness.

At the ED, Adriane had a CT scan that was negative for a bleed in their head or injury to their neck.  Their brief neurological exam was normal and they were discharged home a few hours later.  Their spouse drove them home.  They noted some neck stiffness, headaches, fatigue and sensitivity to light that seemed to improve over the next few days.  Adriane took 4 days off work and then returned and was able to perform well, but needed some extra breaks to go to a quiet, dark room occasionally because of headaches.

Adriane decides to go to their psychiatrist who treats them for anxiety.  Adriane reports that they now have a stutter.  The stutter embarrasses them and is getting worse. They are more irritable, have lost their temper with their spouse (which is out of character), and they have more difficulty falling asleep and now wake up frequently during the night or very early in the morning which is a change from the past.  They feel unfocused, and fatigued during the day. For the first time in their life, they have had thoughts that life is not worth living, but have no suicidal thoughts or plans.  After sharing this, their psychiatrist writes prescriptions for tylenol for headaches, mirtazapine for sleep, increases their Zoloft, orders an MRI and refers them to neurology, with the statement “severe brain injury please evaluate and treat.”

Let’s stop there for a moment.  The first thing we need to do at this point is determine the medical severity of the brain injury.  This is different from the gestalt that a patient presents with a week or two after the injury.  Adriane had a brief loss of consciousness at the time of injury and some confusion afterward with difficulty recalling details of events following the crash.  Their structural imaging was normal.  One detail that I didn’t include was the Glascow Coma Scale score when the emergency technicians arrived. Adriane was conscious, with eyes open, appeared oriented to the situation and could tell the paramedic where the pain in their face and neck was.  Their score was 15, the maximum possible.  All of this is to say that the brain injury was initially determined to be mild.  Adriane was likely concussed from the accident, but not severely damaged according to most of the criteria out there.

We should back-up here and define some terms.  I said that Adriane’s brain injury was mild, but the psychiatrist described the injury as severe because Adriane is now presenting with quite a few new symptoms.

There is not one universally accepted criterion for what is a brain injury and how to classify its severity.  The Department of Defense and Veterans administration have produced criteria that are similar to many others and come from examining a population with high rates of TBI.  Military members are frequent in motor vehicle crashes and roll-over, are exposed to blast injuries, shrapnel, bullets, falls, etc.  I should mention that I do not speak for the DoD or the VA even as I summarize their guidelines after this.  This podcast is only my opinion and an interpretation of the work of others.  I am a psychiatry resident, NOT a brain injury expert.

Here is a summary of the DoD/VA definition of a TBI:

A traumatically induced structural injury and/or physiological disruption of brain function as a result of an external force that is indicated by new onset or worsening of at least one of the following clinical signs, immediately following the event:

□ Any period of loss of or a decreased level of consciousness;

□ Any loss of memory for events immediately before or after the injury;

□ Any alteration in mental state at the time of the injury (confusion, disorientation,

slowed thinking, etc.);

□ Neurological deficits (weakness, loss of balance, change in vision, praxis,

paresis/plegia, sensory loss, aphasia, etc.) that may or may not be transient;

□ or an Intracranial lesion

https://www.cdc.gov/nchs/data/icd/sep08tbi.pdf 

Classifying the severity of brain injuries is more tricky than simply defining it.

The first thing to consider is imaging.  In a mild TBI, imaging (usually a CT or MRI) is normal.   It doesn’t have to be abnormal in moderate or severe injuries.  It can be normal in all classes of injury, so the only help imaging gives us for classification is to rule out a mild injury.  Anyone with abnormal imaging, like a bleed, or stroke, or brain swelling has at the very least a moderate injury.  Whether the injury is severe depends on other factors.

Loss of consciousness is another measure.  For mild injuries, LOC is less than 30 minutes. For moderate injuries it is greater than 30 minutes but less than 24 hours.  Severe injuries are any LOC greater than 24 hours.  So using only these two criteria, we can have a severe TBI in a patient with normal imaging who is continuously unconscious for more than 24 hours following the injury.  I am not sure if this would include patients who are medically sedated, but I imagine any injury that would require the patient to be sedated is a severe injury using common sense.

Somewhat less than LOC is an altered level of consciousness.  They are not entirely unconscious, but something is obviously off.  An altered level of consciousness is harder to define than a loss of consciousness, but clinically is often manifested by difficulty in becoming fully responsive to the external or internal environment.  There is some response, but it is diminished.  A person may be somnolent, hard to arouse, but able to respond briefly with some mumbling.  They may be obtunded where they seem conscious but disconnected from the environment or very slow to respond to pain. We can use words like Confused, Delirious, Somnolent, Obtunded, or Stuporous.  Mild AOC occurs at the time of injury up to 24 hrs.  Moderate or Severe AOC is persistence after 24 hours.

For determining brain injury severity at the time of injury, AOC is most often captured by the Glasgow Coma Scale and this scale can also be used after 24 hours as an objective measure of AOC.  This scale measures 3 factors: Eye opening, verbal response, and motor response.  You can google it to view how it is scored.  In general scores of 13-15 indicate a mild injury, 9-12 a moderate injury, and 3-8 is a severe injury.  The lowest possible score is 3.  This scale is especially important for first responders and emergency and trauma physicians.  They will laugh at you if you say the score is 0, because this is not on the scale.

Being able to use the GCS lets other physicians know that objective criteria were applied.  Another important note is that penetrating brain injuries where the dura mater (that thick outer layer of the brain) is breached preclude the use of the GCS at 24 hours because of the work that is required to repair these injuries.  These injuries generally require multiple surgeries or other procedures, so the picture gets messy.  How these injuries are understood is more dependent on the course of their recovery than the criteria I am talking about here.  The criteria presented here are most applicable to closed head injuries.

Another criteria that can differentiate between mild, moderate and severe TBI is post traumatic amnesia.  It is common for patient’s to have amnesia after the event.  Amnesia is not altered consciousness.  It is an altered memory.  They may have retrograde amnesia (for events prior to the TBI, especially for the same day).  It is less common for them to have retrograde amnesia for distant events, but this is possible. I may be wrong, but from what I read, the term “post traumatic amnesia” is specifically a problem with memory consolidation, which means that it refers to events during and following the traumatic event.  Mild TBIs are expected to have PTA of less than a day, moderate TBIs for 1 to 7 days, and severe TBIs for >7 days.  However, it would be notable if a patient had significant amnesia for more distant events or familiar facts, like they couldn’t remember where they lived or what the names of their children are.

Let me stop right here and ask a different question.  What do I know about Adriane? Adriane had a brief loss of consciousness at the time of injury which is considered mild. There was some brief confusion afterward with difficulty recalling details of events following the crash but no post traumatic amnesia after 24 hours.  That meets mild criteria.  Their structural imaging was normal, which is not all that helpful.  Their AOC, determined by the GCS was 15, which is consistent with a mild injury.  Had any of those criteria been moderate or severe, Adriane that would increase their classification, but that was not the case.

So, when the psychiatrist wrote the word “severe” in their referral, they were communicating something different than was being understood by the neurologist.  The neurologist may be expecting someone with imaging findings or extended LOC or AOC or significant amnesia.  It is not uncommon for patients after TBI to report worsening of psychiatric symptoms or new onset symptoms.  A TBI is a physically and psychologically traumatic event.  In the case of Adriane, it is reasonable to consult a neurologist who is an expert on finding neurological signs and symptoms of a brain injury that might have been missed.

One thing that I have not touched on here is that the psychiatrist ordered an MRI.  When protocoling an MRI for brain injury, there is a specific TBI protocol that can look for changes that are not apparent on a CT scan or an MRI at the time of injury.  For the psychiatry residents or attendings out there, it is good to know this, because it may be best to defer this decision to someone else.

In this episode, I have distracted psychiatry residents and attendings in the audience with descriptions of stuttering, headaches, and sleep disturbances, while at the same time I tried to focus our attention on how to describe and classify a traumatic brain injury.  Often, having more information can result in suboptimal decisions.  Sending Adriane to a neurologist or neuropsychiatrist is reasonable.  Describing his brain injury as “severe” is more reflective of our own immediate reaction to a lot of new information than it is an understanding of it.

One thing that I do know is that when a patient like this presents and we are referring to them, we also need to explain why in both words and behaviors.  If we seem overwhelmed by their reports and desperate to get someone else to weigh in, we might communicate that to the patient through our actions and make them less confident in our care in the future.  If we are able to explain to them our motives, then trust can be maintained.  For example, I might say something like, 

“You experience a traumatic event.  Post traumatic headaches are common and expected.  Often people who have mild brain injuries report headaches, concentration and attention issues in addition to headaches.  I am concerned about your stutter, but I also know that new stuttering is not usually a sign of permanent brain injury.  It is most frequently a sign that your brain is trying to make sense of the distress that you are experiencing and it will improve over time.  I expect your stutter to get better over the next few weeks.  I am going to refer to a neurologist, who will be able to test whether there are any signs of permanent brain injury.  With a single traumatic brain injury, we expect that you will make a full recovery within a few weeks.  This evaluation will help us to decide whether we need to do anything more to support you through this. In the meantime, avoid doing any activities that might result in falls or hitting your head again, because your brain needs time to heal.  Do you participate in any sports?“

As psychiatrists, we know that there will be patients who will google or ChatGPT or use some other service that may give them information to feed their fears. That is a separate issue and one that will be more relevant in the near future.  What we can do now it instill confidence in a our patients because we are at the very least confident to be able to tell them that their TBI was mild.

I am Doctor O and this has been an episode of PsyDactic Residency Edition.