The difference between concussion and mild traumatic brain injury

Follow these links for more writing (and thinking) about concussion vs. traumatic brain injury, including the reasons why I believe concussion and brain injury are two separate parts of an ongoing process. I also believe we should stop calling the whole process “concussion” and refer to it as Concussive Brain Injury, or CBI.

I’ve been reading up on University at Buffalo’s work with concussion rehabilitation, using regulated exercise to deal with post-concussive syndrome (or post-concussion syndrome).

I have to say, it’s probably the most exciting news I’ve come across in a while. With all the talk about the NFL’s new post-concussion guidelines (which may or may not make a difference), and the increasing awareness about head injuries, expecially mild traumatic brain injuries (MTBI), it gets a little depressing, thinking about all the people who are getting hit in the head and suffering for years as a result.

A lot of folks are talking about it being an epidemic, that concussions are no joking matter, and lots of people are getting on the helmet bandwagon (especially since Natasha Richardson died from a brain injury while skiing). Prevention is great. But concussion is all but unavoidable in sports — especially student athletics. It happens. All the time. Yet nobody seems to have come up with a reliable way of addressing it when it does happen. Aside from bed rest and taking it easy, suggests for howto deal with concussions/brain injury are few and far between.

We know concussions happen. We know head injuries are common. We know they can have serious long-term consequences. You can try to prevent them, but you can’t be successful 100% of the time. And if you do have a head injury, you have to be sidelined from your life/sport, with no guarantee that the “treatment” will actually work.

I was starting to get seriously depressed.

Then, suddenly, I was looking around the other day and I found that the University at Buffalo has been working with regulated exercise to treat — even heal — the after-effects of concussion. Post-concussive syndrome is, according to the definitions of Willer and Leddy (at UB),  “persistent symptoms of concussion past the period when the individual should have recovered (3 weeks)”. According to them, post-concussive syndrome “qualifies as mTBI.”

This is interesting. I have heard a lot of people say that concussion is an mTBI, and the two are interchangeable. I am not a doctor, and I don’t have medical training, so I can’t throw my hat in the ring on that debate. But it is interesting to me, that people distinguish between the two.

At the UB web page on concussion research, there are some interesting papers, and they do talk about the difference between concussion and mild TBI.

Here’s what they have to say in the paper Retest Reliability in Adolescents of a Computerized Neuropsychological Battery used to Assess Recovery from Concussion (bold is mine)

A recent review … of concussion and post concussion  syndrome provided a model for distinguishing concussion from mild traumatic brain injury (mTBI) and post concussion syndrome (PCS). The model uses the most commonly accepted definition of mTBI and the one proposed by the American Congress of Rehabilitation Medicine and the Centers for Disease Control: loss of consciousness for no more than 30 minutes or amnesia as a result of a mechanical force to the head, and a Glasgow Coma Score (GCS) of 13 to 15 …. The model also uses the most commonly accepted definition of concussion as established by the American Academy of Neurology (AAN): a trauma induced alteration of mental status that may or may not involve loss of consciousness …. Although not explicitly stated in the AAN definition, concussion is generally viewed as a transient state from which the individual will recover fully in a relatively short period of time …. In contrast, mTBI is viewed as a permanent alteration of brain function even though the individual with mTBI may appear asymptomatic. Post concussion syndrome was defined in the Willer and Leddy … model as persistent symptoms of concussion past the period when the individual should have recovered (3 weeks) and therefore qualifies as mTBI. Neuropsychological testing is often used to describe the impairment associated with mTBI and PCS and have done so with relative success ….

So, basically,

  • mTBI = a loss of consciousness for no more than 30 minutes or amnesia as a result of a mechanical force to the head, and a Glasgow Coma Score (GCS) of 13 to 15
  • Concussion = a trauma induced alteration of mental status that may or may not involve loss of consciousness; it’s a transient state from which the individual will recover fully in a relatively short period of time
  • Post concussion syndrome (PCS) = persistent symptoms of concussion past the period when the individual should have recovered (3 weeks)
  • PCS, due to its enduring nature, qualifies as mTBI

(Note: I think someone needs to fill in the gap about how PCS satisfies the criteria for mTBI,  if they require that there be some loss of consciousness or amnesia involved. How lasting effects qualifies based on these criteria puzzles me. But for the purposes of this discussion, I’ll let this slide.)

I find this really compelling information, and it helps me make more sense of the whole “concussion thing”. I know I’ve sustained a bunch of concussions in the course of my life, and I also know that I have been diagnosed with “Late effect of intracranial injury.” But I could never really distinguish between the mTBI vs. concussion. I actually thought — and had been told — that they’re the same thing.

But that never made much sense to me, because when I look around at me, and I read that “An estimated ten percent of all athletes participating in contact sports suffer a concussion each season” And that’s just athletes. Plenty of people fall down, too, or are in car accidents. I’m not entirely sure what to make of it. Apparently, hundreds of thousands of people sustain concussions each year, yet the general population doesn’t appear to be completely crippled by TBI (though some people I know would debate that 😉 ) How is it possible, that so many people are sustaining concussions, especially in their youth and/or in sports, yet we’re not all running around impaired?

Making the distinction between a concussion that is transient, and a concussion that turns into an mTBI makes all the sense in the world to me. It makes it possible distinguish between someone who’s experiencing short-term issues, and someone who needs to deal with a broader-spectrum and deeper set of challenges. And in doing so, it de-stigmatizes concussion (at least in my mind), by steering clear of the “concussion = brain injury = brain damage” concept, which could be quite debilitating to a youth who has hit their head while playing a sport they love.

There are tons of potential ramifications and implications from being able to state that concussion is not necessarily an enduring brain injury. I may write more about this later, but it requires more thought.

The other very hopeful piece of this is that, by saying concussion is not always followed by brain injury, you’re opening a window to addressing concussions promptly so they do not turn into mild traumatic brain injuries. This, to me, is key. It not only makes sense of the two different kinds of injuries, but it also establishes that it may in fact be possible to treat the concussion to prevent it from becoming a more serious, long-term injury — the “gift” that keeps on giving. And by understanding concussion and brain injury this way, you also up the ante and really infuse the topic of prompt treatment with urgency. If acting promptly to address concussion makes it possible to avoid a lasting brain injury, then it’s in everyone’s best interest to become familiar with and properly trained in the recognition and treatment of concussion.

In this case, if mTBI is only present if concussion symptoms persist, and there’s no guarantee that concussion will result in a lasting brain injury, then prompt recognition and action may save the day.

Now, I’m still noodling over the idea that subconcussive impacts can seriously affect the brain over the long term, which Malcom Gladwell talked about in his article “Offensive Play“. But I am still hopeful. Because while subconcussive impacts may affect the brain, it could be that the damage takes place when no action is taken to address the injuries when they happen. Again, I’m not a doctor or a qualified medical professional, but it seems to me that if actively treating concussion helps with the really obvious issues — as the University at Buffalo has shown it does (albeit on a fairly limited scale) — then it might just help repair lesser damage done.

It might. I only wish I had the medical and scientific background and credentials to be able to speak as an expert on this. But apparently expertise is no guarantee of being able to help out, when it comes to TBI. The vast majority of experts haven’t had the wherewithall to state definitively what can actually be done about brain injuries, let alone recommend specific action that works, and there are thousands upon thousands, if not millions, of people suffering, day in and day out (along with their loved ones and co-workers) with the after-effects of concussion and mild traumatic brain injury.

So, somebody’s got to take the lead in finding a solution… Or at the very least think about finding one. The folks in Buffalo are up to wonderful work, and I can only hope that more folks have the gumption to take their lead and do something about this wretched hidden epidemic of ours.

Now, I’m off to address my own issues of the day.