Tagged: neuroscience

HDIB? Neuroscience Grand Rounds II: Thoracic Outlet Syndrome

For the 2013 St Louis Cardinals, there will be a mainstay of the pitching staff conspicuously missing from spring training, with news that starter Chris Carpenter will miss most, if not all, of the season, due to continued issues stemming from thoracic outlet syndrome. Symptoms such as numbness, tingling, and discoloration of his pitching hand arose during a brief pitching session, and prompted shutting him down to prevent further injury; less than a year removed from surgery, Carpenter’s return and recovery look to be a little more complicated and lengthier than what was originally hoped.

So what is this condition that limited Carpenter to 30.2 innings of regular and postseason baseball in 2012, and why does it threaten his 2013?

Well, as we have done once before, it’s time to pick up our lab coats out from the dry cleaners, and dust off our medical kits, and get down to brass tacks. For those curious, here’s my medical kit:

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Top of the line stuff, no doubt.

For a pitcher, thoracic outlet syndrome (TOS) can be a devastating diagnosis, as it arises from a very complicated area of the body anatomically. Let’s take a somewhat simplified look at the area we’re talking about:

Picture-1

Broadly, the thoracic outlet is simply the area between the ribcage and collarbone, also known as the clavicle. As you can tell from the picture, this area is chock a block full of important things; muscles, arteries, veins, and important neural elements that comprise the brachial plexus, which is a complex of nerves that originate from the spinal cord. The nerves responsible for arm, forearm, and hand movement all arise from the brachial plexus; as you can tell, this is a very busy and crucial piece of anatomical and physiological real estate.

It is also a very small, crowded piece of real estate, which substantiates many of the problems encountered by those who suffer with TOS.

Let’s talk about those symptoms, and some possible causes shall we? Yes, we shall.

Much like our good friend Brandon McCarthy and his hematoma, folks who suffer from TOS do so at the hands of very particular process, seen across many different medical disciplines and disorders.

Smooshing. TOS is a transient smooshing disorder.

McCarthy’s smooshing was a bit more dangerous, since it arose from his brain swelling and smooshing into his cranium, a part of the anatomy without much give, shall we say. TOS is nonetheless a dangerous situation, as the pressure and swelling that arises from the initial injury or insult can cause smooshing, displacement, and compression of a number of critical structures in the already cramped thoracic outlet (the superior thoracic outlet, more specifically).

OK, so we have lots of anatomy, small space, smooshing- let’s dig a little deeper.

There is an initial insult – that’s fancy talk for a cause – that sparks the swelling and compression. Let’s talk about those for a second, kind and gentle readers impromptu medical residents.

You, with the Hello Kitty stethoscope, can you name some causes of TOS?

Nice list – yes, common causes of TOS include trauma arising from a car accident, a specific type of lung tumor called a Pancoast tumor, and any work that creates a repetitive motion and strain on the area, say, like pitching, swimming, or any other sort of over the head motions. Know it all medical residents who raise their hand over and over to answer questions are at risk of suffering from TOS. Not sayin’, just sayin’.

Also, people born with an extra cervical rib can have a predilection towards TOS, as the additional skeletal anatomy provides less of an outlet and square footage for the nerves and vasculature to course through.

We have cause… how about effect?

Symptomatically, TOS arises from what structure the smooshing affects, and can broken down into 3 categories: neurogenic, arterial, and venous. Regardless of the structures involved, pain is the most prominent symptom. From there, we can also see symptoms such as the ones Carpenter complained of, such as numbness and tingling, arising from nerve compression, skin that is discolored and cold to the touch, arising from poor circulation due to compressed arteries and veins, and muscle weakness.

OK, so let’s take these symptoms, and confirm that it truly is TOS – how would we do that?

Aside from your usual suspects, in the form of  imaging – x-rays, CT scan, or even a MRI – we can perform a costoclavicular maneuver, or be on the look out for Adson’s sign before we subject the patient to any undue insurance copays. However, these two methods aren’t very specific or sensitive, so some sort of x-ray, scan or even an electromyography (EMG) exam should be performed to confirm a diagnosis of TOS.

So our hypothetical diagnostic studies are back, and it’s TOS. Young residents, what do we do to treat it?

You, wearing glasses with no lenses with them, whatcha gonna do?

Start with physical therapy, then consider a surgical procedure called a first rib resection/scalenectomy, where a surgeon goes in, removes a rib, the scalene muscles, and any scar tissue that could be the compressive culprit, thereby, opening up the superior thoracic outlet, creating more space, and less smooshing opportunities?

In the immortal words of FP Santangelo – abso-LUTELY!

Let it also be known that cortisone and botox injections are other treatments that are less invasive, but may not completely resolve the underlying issue, but can give the patient a modicum of relief, enough to allow them to pursue physical therapy.

While time will tell whether Carpenter can overcome the nagging effects arising from his thoracic outlet syndrome, the prognosis looks fairly encouraging, as the vast majority of those who elect to get surgery enjoy symptom free lives post-operatively. However, there does exist a small population around 5% – who remain symptomatic after surgery, and require further interventions, be it additional surgery, or other non surgical options.

For those so inclined, you can read more about TOS here and here; it’s a small sample of what’s out there, but hey, Google is your friend.

As for our Cardinal friends, 2013 still looks to be a promising year, even without their pitching and emotional leader toeing the rubber. While it remains to be seen if this is the last of Carpenter’s career, let it be known that this Redbird’s wing is well on the mend.

Chris  Carpenter

HDIB? Neuroscience Grand Rounds: Epidural Hematoma

So by now many/most of you have seen the Brandon McCarthy incident that occurred during Wednesday’s game against the Los Angeles Angels of Anaheim, the Inland Empire, Barstow, and High Desert of Kern and LA Counties, and parts of San Diego. Scary stuff, life threatening stuff. Stuff of nightmares, and stuff that conjures up flashbacks to Juan Nicasio, even Ray Chapman.

As a neuroscientist by trade, I feel compelled to have a teaching moment, and hopefully shed some light on the medical aspects of the incident, in hopes of arming folks with a little extra knowledge of this type of injury, and perhaps add some additional gravity to the situation, while also alleviating some of the mystery, and concern over the epidural hematoma Brandon sustained.

Excuse me while I change into my white coat — mine’s flannel lined, and super comfy.

Ahh, that’s better; gotta love the LL Bean Health Care catalog.

While he didn’t quite dodge the ball coming off of Erick Aybar‘s bat, McCarthy did dodge a huge bullet in terms of his long-term health; he was quickly seen, and the physicians involved with his initial care did him a great service by getting a CT scan of his head. With the help of my crack staff of interns here at HDIB?, here’s a ‘nice’ CT image of what an epidural hematoma looks like:

Guhhhh

See the bright white crescent on the left? That’s the hematoma, which is simply an area of blood that has pooled outside of blood vessels due to trauma. As you can image, a baseball to the noggin at over 120 miles per hour will create enough trauma for the tiny capillaries and vessels of the head to get a little leaky, shall we say. For this type of injury, the blood pools between the tough, layered outer covering of the brain – collectively called the dura – and the skull. As more blood seeps out of blood vessels, the greater the pooling between the dura, and skull. More pooling, more intracranial pressure – the skull doesn’t have much ‘give’, as you can imagine, to flex against the swelling – which in turn, pushes the hematoma into the brain.

From here, the brain gets smooshed (medical term there, folks), and depending upon which part of the brain gets smooshed the most, you can see a number of symptoms, arising from what that smooshed brain area is responsible for – language, vision, movement, what have you. More severe hematomas can smoosh all the way down to more basic areas of brain that are responsible for things like, say, breathing. This can happen over a matter of hours, or a matter of days, which is why the CT scan, as well as keeping a person with this in the hospital for observation, is a crucial aspect of diagnosis, and treatment of this injury.

OK, my impromptu neurosurgery residents, what do we need to do, and how do we do it. Yes, you with all of the tattoos, playing Fruit Ninja on your phone – whatcha got?

…reduce intracranial pressure is the first step? Excellent! What’s a quick, and mildly barbaric way to do that?

You, the one with the bowtie, picking your earwax and smelling it, you’re up.

… a craniotomy? What you lack in social skills, you add in sheer neuroscience genius. While you are correct in wanting to do this, there are other methods of reducing the pressure from the hematoma, but the craniotomy is arguably the quickest, and most thorough way to get this resolved.

OK, so off we go to the OR to drill a hole in poor Brandon’s skull, to ‘evacuate’ the hematoma, and reduce that brain smooshing. You can find more in-depth information about the procedure here.

There we have it, in a nutshell – for those scoring at home, it’s a Brazil nut. While a somewhat common injury, especially in falls, and car accidents, it’s exceedingly rare within the realm of baseball injuries. McCarthy’s prognosis is quite good, given the speed in which the medical staff treated this, from the team trainer, down to the neurosurgeon.

Isn’t neuroscience great?

The answer is yes. Yes it is.

…and even more awesome is that Brandon is going to be OK, and hopefully back on the mound soon, albeit not this season, I would imagine.

I hope you enjoyed my teaching moment, and that it adds to your enjoyment of the game, and to your amazement of the human body, at rest, and in motion.

Is Brandon McCarthy awesome?

Yes. Yes he is. And with the help of modern medicine, he will continue to be.