Friday, November 4, 2011

Evaluating Spinal Cord Injury

This is part of a series of entries I should probably entitle something along the lines of "WTF does a PM&R doctor do?" If people like this entry, I could do more. I guess.

One of the main ways to evaluate a spinal cord injured patient is something called an ASIA exam. Contrary to popular misconception, this test was NOT developed in Asia. ASIA stands for American Spinal Injury Association. Why isn’t it called American Spinal Cord Injury Association? Because then it would be ASCIA. And that’s just ridiculous.

We do this exam on every spinal cord injured patient both on admission and on discharge and then a few times in between. I hate this exam with passion. When you’re first starting out, it seems kind of interesting, but eventually every resident grows to hate it. First, because it takes for freaking ever to do. Second, because it ends with a rectal exam. Nothing good ends with a rectal exam.

The point of the exam is to determine the patient’s level of injury. This has implications both for function and prognosis. We assign the patients a spinal cord level (C2 through S2) above which “everything works” and call them either complete (A) or incomplete (B through E). Complete means nothing works below the level of the injury and incomplete means some things work below the level of the injury. So if a patient is C6 ASIA A, it means everything works at and above the C6-innervated myotome, meaning they have full biceps strength, wrist extension at least against gravity, and no triceps, finger movement, or leg movement. The fact that it’s a complete injury (A) basically means no rectal voluntary tone or sensation.

The strength exam involves testing "key muscle groups" in the arms and legs. You want to find out the patient has full strength (5), less than full strength (4), strength against gravity only (3), strength with gravity eliminated (2), or just a muscle twitch (1).

The sensation exam is the most agonizing part. We have to go through every dermatome from C2 through S5 and test it both with a cue tip and a safety pin. This is why every PM&R resident has safety pins hanging off their ID badge, not because they are cloth-diapering babies between patients. If the patient has a complete injury where their spinal cord is just totally severed, there’s usually a line above which they feel everything and below which they feel nothing, so it’s pretty easy. However, if sensation is partially preserved, you may have to test the dermatome several times before the patient can give you an answer of whether sensation is normal (2), partial (1), or absent (0). For pinprick, it is truly agonizing, because they have to distinguish between sharp and dull 8 out of 10 times. If they can’t feel it at all, it’s easy. But for an incomplete injury, this can really take forever. Especially if the patient is intubated, which they often are.

Then comes the rectal exam. You’re checking if there’s any sensation in the rectal area or if they can voluntarily contract. I love this part (not really). But it’s probably the most important part for prognosis, because if they have any sensation or contraction, there’s a good chance for improvement of function. If the patient has no sensation or contraction whatsoever, there’s only like a 10% chance of improvement.

There's also a really complicated-looking form:

(Don't you love the picture of the guy bending over with his butt pointing at you?)

OK, example: if a patient is T4 ASIA B, that means that they have completely intact movement in their arms and completely intact sensation above the nipples. Since their score is B, that means they have some sensation in the rectal area and possibly other places. OK, I’ve said “rectal” way too many times.

This system is nice because when you hear a patient’s score, you should have a good idea of what their function is and what their spinal cord injury-related medical issues should be. Like can they use a manual wheelchair or a powerchair, can they live independently, can they breathe on their own, are they continent, etc. In a way, there’s something very analytical about it.

All right, I think I'm done boring you all to tears. Fin.


  1. I'm glad to hear that I'm not the only person who abhors sensory exams. It was the only thing I didn't like about my recent Neurology rotation. (Well, that and tPA cases coming in at 1 am when I was on call.)

  2. That counts as revision. Time for a break now I think.

  3. Hi Dr. Fizzy! I've been reading your blog for a while and I love it! I'd also love to see more entries like this. It was quite interesting and entertaining.

  4. That exam sounds like a Verizon commercial o.o

    "can you feel it now? good"

  5. As a first year med student, i really appreciate posts like these :) Thanks!

  6. i vote for more posts like this, but i'm biased.

  7. Actually, I'm going to let my good friend, the PM&R program director know about your blog - good publicity in general, for a much misunderstood specialty (says she who works in geriatrics, and feels just as misunderstood!)

  8. this is actually really helpful and not boring. thank you.

  9. Thank you! I really benefited from this post. I feel like I only have a vague understanding of PM&R so this helps a ton.