Some REAL expert reading!

Here’s a reference to an excellent and VERY recent (May 29th issue) review of the what, how, and why of traumatic intracranial hypertension. Online it’s subscribers only, but if this is a subject that interests you, it’s worth trying to get a copy of the article.

Traumatic Intracranial Hypertension

Stocchetti N, Maas A

New England Journal of Medicine, 2014: 370(22); 2121-2130

Oh and if management of near-lethal trauma interests you (I’ll get into some of this in future posts), then check this article in today’s New York Times out:

http://www.nytimes.com/2014/06/10/health/a-chilling-medical-trial.html?hpw&rref=health

 

A brief announcement

I’ve decided that I’m going to stop writing about Michael Schumacher, about his accident, and about what his situation may or may not be.

There’s not much more really to say. It leaves me with a leaden feeling in my gut that Michael is in his sickbed, and that more words aren’t going to help anybody with anything. And in terms of my blog, I think I’ve pretty much covered it all.

I’ll read all your comments as I’ve always done. Forgive the odd deletion – the criteria are fluid, and are highly dependent on whether they’re the first comments I read upon awakening, or rather in the near-euphoria of returning home after a long day at the hospital! Bear with me about that, and if a given deletion SEEMS illogical, trust me, it is. I in no way intend disrespect for your thoughts and for the fact that you actually WRITE stuff here. It still blows me away. But I’ll try to maintain a bit of decorum (totally arbitrary I know) in the comments, and will rely mostly on YOU to keep things civil. Or at least make the incivility so good that we all are dying to use it somewhere else. THAT would be worth it. And no, I’m not going to have an incivility contest. Hmm…

My interest in head injury, and in concussion in particular, remains, and will be a source of posts. The POTUS just had people to the White House to discuss this issue – there is a HUGE, almost evidence-based cultural tsunami going on, and its ramifications are enormous.

Anyway, see all of you soon.

Some important science on disorders of consciousness – part 2

Image

An MRI scanner

Imagine this: You’ve volunteered for a brain imaging experiment to help study consciousness. You come to the MRI suite, and lie down. The researchers put an IV drip in place, and then infuse a form of glucose that “lights up” the brain areas that are activated at any given moment. So far so good.

You’re told to close your eyes and imagine hitting a tennis ball back and forth with a partner. Sure enough, this consistently activates an area related to preparing the brain for motor activity (called the Supplementary Motor Area, SMA, in yellow below). Then you’re asked to imagine walking around your house, and to visualise all the things you’d see as you navigated like this. And once again, the corresponding area, called the Parahippocampal Gyrus, (PG, in green below) lights up. Here’s roughly what the images look like:

Image

Nothing unusual or unexpected here. But now let’s go a bit further with the technique.

Let’s now take a series of patients (54 to be exact) who have been diagnosed with either vegetative state (remember – that’s eye opening without any signs of conscious interaction with the environment) or a minimally conscious state (awake, but with fluctuating but consistent signs of consciousness), and let’s try the same experiment.

Incredibly, FIVE of these patients  (10%!) could manipulate brain activity in response to the researchers’ requests. These people were, in fact, obeying commands (“think about tennis”, “think about navigating”), but their response wasn’t behavioural, it was . . . metabolic; what’s crucial is that they clearly showed signs of consciousness.

This was an amazing finding, but the investigators took the work further still, and, using a very ingenious trick, what they revealed shocked the world of medicine.

Let’s quickly put you back into the fMRI machine. This time, here’s what I’m going to do. I’m going to ask you a simple, unambiguous question (like, do you have a brother?). I’m going to tell you to think “tennis” for YES, think “navigation” for NO. (Rather like using fMRI activation as a “blink once for yes, twice for no” kind of communication tool.) Turns out this works fine, with 100% accuracy with normal subjects.

I guess you see where I’m going with this. Let’s take one of the patients diagnosed as vegetative but who has shown the ability to “light up” his or her supplemental motor area or parahippocampal gyrus on demand. Let’s do the same thing with him. Let’s ask him or her questions – tennis if yes, navigation if no. What happens? Let me quote the researchers: “. . . for those five questions, the pattern (of activation) produced ALWAYS matched the factually correct answer.” 

I’ll let that soak in for a moment.

These scientists just took a patient who’d been diagnosed as vegetative (and again, I’ll insist that this means NO CONSCIOUSNESS) and not only TALKED TO HIM, but actually got answers!

What are the implications? First of all, this study shows how hard it actually is to make a proper diagnosis of the vegetative state. Until now, this diagnosis relied on confidently stating that there is evidence of absence of consciousness, based on detailed and lengthy observation of the patient’s behavioural responses. But remember, these patients have severely damaged brains; the behavioural repertory of responses that they can show may often be so limited that none will be found. But this study emphasises that absence of (behavioural) evidence is NOT necessarily evidence of absence (of consciousness). The infinitely more sensitive “behavioural” response of metabolic brain activation could allow, in the future, clinicians to make this diagnosis with much more confidence. This obviously has enormous implications in terms of medical and ethical decision-making as concerns any given patient.

More importantly for us, this tool would appear to open up the possibility of actually communicating with some of these patients (a small minority at best, but still . . .). The current procedure is much too cumbersome, difficult, and expensive to use routinely, but it’s not too much of a stretch to imagine a future where helmet-sized mini-MRI machines are placed on the heads of patients with prolonged disorders of consciousness to allow their care team and loved ones to communicate with them.

There is a huge amount of fascinating and useful research being done on consciousness – both normal and disordered. Functional imaging is one of the most powerful tools in this quest for knowledge. As they say, watch this space.

Here’s a link to the original NY Times article about this research. The second contains a video by Liege’s own Steve Laureys (the lead researcher), explaining the technique. And the third is to a pdf of the original article, published in the New England Journal of Medicine.

http://www.nytimes.com/2010/02/04/health/04brain.html

http://thelede.blogs.nytimes.com/2010/02/04/doctor-demonstrates-method-of-speaking-with-vegetative-patients/?_php=true&_type=blogs&action=click&module=Search&region=searchResults&mabReward=csesort%3As&url=http%3A%2F%2Fquery.nytimes.com%2Fsearch%2Fsitesearch%2F%3Faction%3Dclick%26region%3DMasthead%26pgtype%3DHomepage%26module%3DSearchSubmit%26contentCollection%3DHomepage%26t%3Dqry575%23%2Flaureys&_r=0

http://www.nejm.org/doi/pdf/10.1056/NEJMoa0905370

We really need to have a word about baseline concussion testing

It’s funny, but I’d been feeling like writing about concussion (or MTBI, mild traumatic brain injury) for a few days now. Mr. Keselowski’s comments have given me a reason to.

As an emergency physician I see lots of concussions. This is a pathology that interests me personally, because it has long been underdiagnosed, undertreated, and, well, minimised. So from now on, I want you to promise me that when you read “mIld traumatic brain injury“,  you’ll see it like this:

xxxx traumatic FREAKIN’ BRAIN INJURY!!!! 

(and i want you to see it with the exclamation points)

There’s nothing mild about interacting with someone who’s concussed. Thought power reduced dramatically, asking the same question over and over again. The blank stare. The nausea. The vomiting. The total inability to string together a rational train of thought. Not sure that one needs to be a doctor (even a race-ignorant one!) to want to know, despite SUBJECTIVE denials (yes you racers SURE do want to get back into your cars), if this brain is still capable of information processing at over 200 mph. If I was sitting in the stands, I’d like to figure SOMEONE would take you out of your car if you couldn’t remember anything that happened a few minutes ago.

It doesn’t stop there actually. Yeah, this is regularly followed by days, or more typically weeks, of altered sleep-wake cycles. Not ideal for students, or pretty much anyone intent on any kind of productive life. Emotional lability. Head splitting headaches. Inappropriate laughter, or crying. Atypical morosity, or euphoria. Difficulty concentrating on anything, and in retaining information for any period of time.

I suppose it’s not surprising. With 100 TRILLION synapses, the brain is functioning at a rather sophisticated level of integration. Go ahead and kick a coke machine, Mr. Keselowski, and then see if it works. Not surprising it doesn’t, at least not how it did before, right? How about your brains inside your helmet after hitting the wall? Get the picture?

Funny thing is, until that brain, that kicked-100-trillion-synapse-coke-machine inside your helmet gets better (and remember how easy it is to deny symptoms), it’s exquisitely sensitive to a second concussion. Do you REALLY think Dale Jr.’s second concussion was a coincidence? And it’s even scarier. We know from other sports that when that still-recovering brain gets a mild hit, it can sometimes, and unpredictably, swell. This causes a coma, and is often, all too often, associated with a persistent vegetative state, or even death. We call it the second impact syndrome. Ever hear about it? It’s why we like to diagnose concussions, and then make sure they’re GONE before letting you guys back in the cockpit. Better for everybody.

I don’t resent being told, generically, that “doctors don’t understand our sport”. But let me tell you something. Very very clearly. READ THE ABOVE MR. KESELOWSKI. That’s medicine, and it’s sport, and it’s people getting their heads knocked. Do people in YOUR sport get their heads knocked Mr. Keselowski? See? We’re starting to understand each other.

We really do understand concussion, or at least how to do the best we can with concussed patients in 2013.

I’ll suppose, Mr. Keselowski, that you’re too . . . busy . . . to be following all the stories in the lay press about the epidemic of chronic traumatic encephalopathy (CTE). Anyway, I’m sure I’ve no need to remind you Brad (can I call you Brad?, you can call me Gary), CTE is caused by numerous episodes of, yes you guessed it (you’re a SHARPIE!) concussion. And with CTE, the terrible, treatment-resistant depression. The almost constant descent into alcohol and/or drug dependency. The dementia. The death in the late 40s or early 50s. The ruined families that started with such promise.

You say you racers are risk takers. That’s certainly true. I’ve known my share.  They, however, would appear not to be willing to risk CTE. I’m pretty sure no one would blame them.

ImPACT, the test NASCAR is going to use, uses OBJECTIVE criteria. That’s what makes it beautiful. Compared to baseline, it allows the clinician to judge the severity of cognitive dysfunction . . . OBJECTIVELY. Beyond a well described, objective threshold, a concussion is present. Until those scores are back to baseline, the concussion isn’t healed. This is one more, objective, tool (and not the only tool) in the arsenal of the physician taking care of you guys.

Just when we’re making into inroads on getting concussion taken seriously, in high schools, in colleges, and pretty much everywhere people are getting them, you come along and discredit what is virtually a major public health initiative. Dude, you’re a risk taker? Go bungee jumping. But when you’re behind the wheel of that car, you’re a sportsman, and you’re doing it in front of thousands of people sitting there. And for millions sitting in front of their TV sets. You can hurt the ones at the track. Kill them even. Getting behind the wheel when you’re concussed puts them at risk. Do you REALLY want to criticise a tool that can prevent that from happening?

Read a bit, DM me, we’ll talk. I want you to understand why we do this. It’s really not to bother you guys, just to make it all safer.