Why is a MTBI called a Mild Traumatic Brain Injury?
The classification of traumatic brain injuries as Mild, Moderate, and Severe was originally developed for rescue personnel to quickly communicate the severity of the initial physical trauma when a patient was being transported to the hospital.
Used in emergent care the designations make sense. They are a way of letting the hospital know the level of immediate care the patient will need.
Mild vs Moderate & Severe TBI
The classification system of Mild, Moderate, and Severe traumatic brain injury is based on three factors – all of which relate to the condition of the patient immediately after the injury.
Measuring a patient’s motor response, verbal response and eye opening response, the Glasgow Coma Scale (GCS) is based on a 15 point scale. A Mild Traumatic Brain Injury (MTBI) would have a rating of 13 – 15.
The amount of time a person is unconscious is called Loss of Consciousness (LOC). For a MTBI classification a person would have had no loss of consciousness at all or less than 30 minutes.
The amount of time you cannot remember is called Post Traumatic Amnesia (PTA). It is pretty common to not be able to remember an accident itself nor to retain a clear memory of immediately after. For a brain injury to be considered mild the amnesia should be one day or less.
Why is Mild the Wrong Terminology for a MTBI?
Though the terms Mild, Moderate, and Severe traumatic brain injury make sense when used in emergency/acute care, they are also now used universally as a diagnostic level of traumatic brain injuries.
That doesn’t work for a few reasons.
1. Medical vs Common definition of the word Mild
Medical use of Mild as a severity measurement
Mild, Moderate, and Severe indicate the severity of the illness or injury on a continuum. This method of categorizing is used for everything from Incontinence to Alzheimer’s.
In medicine, the term Mild always has specific parameters that define what the word means for a specific ailment and in relation to what the words Moderate and Severe mean for the ailment.
Definition of Mild in general English use
In general use, the the term Mild has an entirely different meaning, which does not specifically relate to a moderate and severe continuum. Mild has the following meanings according to the Oxford English Dictionary:2
- gentle and not easily provoked.
- not keenly felt or seriously intended.
- (of an illness or pain) not serious or dangerous.
- (of weather) moderately warm, especially less cold than expected.
- (of a medicine or cosmetic) acting gently and without causing harm.
- (of food, drink, or tobacco) not sharp or strong in flavor.
Confusion between the medical and common definitions
The word Mild sounds about as serious as the common cold. A cold takes 8 days to get over. Therefore, shouldn’t you be over your mild brain injury in a few weeks?
No! Because a brain injury is simply never mild as the word mild is used by most people.
Calling a Brain Injury “Mild” is confusing because the patient (and their family and friends) think of the general meaning; not the medical meaning. People think a Mild Traumatic Brain Injury means it is not serious and therefore should not really be much of a problem.
Using the term Mild gives the wrong message to caregivers, the patient, and especially to friends, family, and coworkers who are not privy to discussions with the doctors and other medical staff.
2. MTBI Diagnosis Difficulties
Initial/Acute diagnosis of a MTBI is difficult
Because most injury to the brain in a MTBI is on the cellular level, the injury does not show up on conventional imaging techniques such as MRI and CT Scans.
To correctly diagnosis MTBI, all doctors have had in their diagnostic toolbox was the knowledge of the accident, the three scales mentioned above, and self-reported symptoms.
All of those are problematic.
First, patients are often unsure of and have difficulty describing what happened to their head during an accident. Second, in the three scales mentioned above the measurements for an MTBI are truly mild and often subtle. Third, symptoms of an MTBI often do not show up right away.
Therefore the diagnosis of MTBI is often delayed by days, weeks, or even months after the injury date.
MTBI or/and Post-Concussive Syndrome?
After the acute phase, things get murky.
Contrary to what many sites and information packets say, I question whether it is true that MTBI symptoms resolve within three months in the majority of cases. The initial symptoms may resolve fairly soon, but many of the more subtle and profound symptoms that appear over time do not resolve quite so quickly.
If you have symptoms that last more than 3 months, you may hear the term Post-Concussive Syndrome or you may be seeing a medical practitioner who continues to use the term MTBI. The terms are often used interchangeably.
Although no universally accepted definition of postconcussive syndrome exists, most of the literature defines the syndrome as the development of at least 3 of the following symptoms: headache, dizziness, fatigue, irritability, impaired memory and concentration, insomnia, and lowered tolerance for noise and light.
Confusion exists in the literature, with some authors defining it as symptoms of at least 3 months’ duration, while others define it as symptoms appearing within the first week.
Depending on the definition and the population examined, 29-90% of patients experience postconcussive symptoms shortly after the traumatic insult. 3
Call it what you will: MTBI or Post-Concussive Syndrome, but I have yet to meet an adult who says they had no lingering symptoms from a MTBI after three months! So I think the 90% number is likely the correct one.
3. MTBI symptoms are NOT Mild!
One of the big things people do not think about in regards to brain injuries is that the brain controls every single aspect of who we are.
Therefore, a MTBI can cause a huge number of problems. Many of the symptoms are subtle changes which are difficult to describe yet have a profound effect on how we operate in our life.
For example, here is an abbreviated list of Psychological Symptoms that can occur with a MTBI. 5
Often a MTBI patient will not observe a symptom until they go to use that part of the brain and find it “missing”. (See the blog post Gone Missing.) For example, you may not need to do addition and division until you are handed a bill when out to dinner with friends and expected to figure your share out.
Medical personal tend to measure a patient’s TBI severity based on only a small range of symptoms: headache, dizziness, fatigue, irritability, impaired memory and concentration, insomnia, and lowered tolerance for noise and light.
In reality a patient is usually reeling from a far broader range of problems, which are by no means Mild as a MTBI can be effecting most areas of his or her life.
- Department of Defense and Department of Veterans Affairs (2008). “Traumatic Brain Injury Task Force”. http://www.cdc.gov/nchs/data/icd9/Sep08TBI.pdf. (retrieved from Wikipedia: Traumatic Brian Injury Classification) ↩
- Oxford English Dictionaries: link words ↩
- Eric L Legome, MD, Postconcussive Syndrome Clinical Presentation Medscape:National Library of Medicine. Available from: http://emedicine.medscape.com/article/828904-clinical ↩
- Brain Injury Checklist from Brain Injury Resource Center http://www.headinjury.com/checktbi.htm ↩
- This symptom list is part of a much longer comprehensive Brain Injury Checklist from Brain Injury Resource Center list found at http://www.headinjury.com/checktbi.htm. Scroll down a bit on the page. The list is very useful to print out and take with you to a doctor’s appointment. ↩
- Kulbe, J.R., Geddes, J.W., Current status of fluid biomarkers in mild traumatic brain injury, Exp. Neurol. (2015), http:// dx.doi.org/10.1016/j.expneurol.2015.05.004 ↩
- Greenwald, B. D., Ambrose, A. F., and Armstrong, G. P. (2012). Mild brain injury. Rehabil. Res. Pract. 2012, 469–475 ↩