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Aug
13
2008

Last week’s Neurological Fun

PeterSo what was I up to at St. Mike’s for two other days of the week?

Well, one day I was in a study of head injury cases, as they try to find the commonalities of concussion, and recovery from such. Of course, they can’t get a baseline measurement (you can’t do a “before” measure if you don’t know who’s going to get bonked on the head!), so they do a series of measurements periodically afterwards. This is for two reasons: to try and get a general idea of the pattern of recovery, and also to use the data as a guideline in testing the severity of a head injuries in Emergency.

At the end of that session, I had a follow-up CAT scan for both the study doctor and the neurosurgeon who oversaw me when I was in the hospital in June (and who had been considering opening my skull during the most stressful moments).

On Thursday was my 8 a.m. visit with Dr. Cusimano, whose resident gave me a detailed physical to see if I had lost any function. The good surgeon came in a little early, so he took over the second half of my examination. On occasion, he was quite stern with the student, making sure he understood the precision of the tests and not to asking leading questions. Since I had majored in Brain & Behaviour Psychology at Queen’s 20 years ago, I found this vaguely familiar and fascinating, and occasionally added my observations to help where the examination was lacking precision.

Aside from getting fatigued easier (and that is dissipating), I have only one noticeable after-effect from the head injury: my sense of smell is on the blink. It isn’t entirely broken, but there is always a predominant smell, which changes depending on certain circumstances. If I’m lucky it will be like now: lemon, or some other acceptable food smell. I have caught some smells on the fly—we got stuck behind a garbage truck the other day, which definitely was not filled with lemons 😉 . And it does heavily affect my sense of taste in the extra dimensions that are provided by smell.

But the doctor was starting to wrap up the interview by then, so he interrupted the resident’s summary of my smell report with “Ah! Anosmia!”—which is the complete lack of smell, and not what I have. He started quizzing his student about the construction of the words “anosmia” and “ageusia”. He then proceeded to show me (and provide me a print-out of) my CAT scan the day of the accident, and then two months later.

So let’s take a look, shall we? Okay so a quick summary of the head. You got yer skull, and you got yer brain, which is wrapped in the protective cushion layers called the meninges. The inner surface of the skull isn’t a perfect negative of the brain’s sulci and gyri, due to the protective meningal layers, but it does have the general contours.

If you whack your head right (ahem, this is foreshadowing) you can get the brain to jerk inside its protective cave, causing the meningal layers and maybe a little bit of brain to get ripped on the inner skull. Then comes the blood, which drips into the frontal cortex, and a bit into the back of the right temporal cortex. (The CAT x-ray images are flipped left to right and show two different levels of my brain.) The white blotches are blood.

CAT scans of Peter's brain, hours after his fall

Those blood drops can screw up the neuronal activity something awful, and is the reason I don’t remember much of my next four days, including the devotion of my wife and parents through the many hours in emergency and my room (thank you folks, I’ll never be able to know what you went through), and have only patchy impressions of the visits of Reid and Andy. And remember, if I said anything stupid or embarrassing: remember, I call BRAIN INJURY!!!

Next up are shots from eight weeks later. They are rough approximations of the latitudes of the first two pics, but not exact by any means (the doc lined them up to print in about five seconds). Also, my conscious head is at a different horizontal angle than my unconscious head, so any major structural differences you think you see are not major damage. That said…there is subtle damage.

CAT scans of Peter's brain, 8 weeks after the fall

See that black shadowy powder where the blood splotches used to be? That’s glia scar tissue, reacting to the invading blood. (The glia cells are the subserviant cells to the brain cells (neurons), helping keep the chemical, oxygen and energy balance and generally being protective filler. In the brain they tend to inhibit the regrowth of severed neurons by forming scar tissue.)

So what does this damage mean? What have I lost? The doctor scoffed. “The brain is plastic, and with relatively light injury like this the functions remap within a week or two.” Since I’m not showing any of the known chronic signs of trouble: impulsive spending, bad memory, irritability, anger, depression, major bouts of crying, or trouble sleeping, and they can’t find any physiological trouble, things are pretty good, all things considered.

But then came the most negative comment by the doctor: My sense of smell. What’s the prognosis? “It could come back, but I wouldn’t bet on it.”

I will take this comment seriously, but with a grain of salt. He did tell his student that those nerves can regrow, but they are very fine. He didn’t quite have the right idea of how my sense of smell was affected. So remapping my sense of smell entirely may be quite difficult, or take a long time. But some of my reading on the subject suggests that this may not be neuronal at all, but due to sinus cavities issues like infections. Stay tuned.

And in the end, I’d rather the doctor be conservative in his predications, so I can exceed his hopes. And I’m sure Dr. Cusimano would be delighted to be wrong.

No comment yet

  1. bryanf says:

    My mom almost completely lost her sense of smell during her second heart valve replacement surgery. It might’ve been related to a large contusion on the back of her head that arrived during the procedure, or it could have been purely physical nasal trauma related to tubes up the nose going badly. In either case, she (and we all) figured it was a small price to pay for having a working heart.

  2. John Chew says:

    I had a friend who lost her sense of smell for five years, but it all came back. She lost it following a winter of really bad sinus infections. She got it back when a doctor friend of hers told her that vegans who want their nerves to regrow have to take vitamin B supplements.

  3. David "Abby Normal" Barker says:

    Now that’s a brain!

  4. Peter says:

    Thank you, both Bryan and John.

    Make no mistake: given that something like 20% of the side-effects of medium-to-severe concussions are vision related—blurred or doubled vision—I’d waaaay prefer a disturbance in the old olfactory centres. That said, my situation isn’t simple (maybe), because my sense of smell is not gone.

    It’s in the mushy middle: true, I don’t catch many odours of my general surroundings, but I do catch some, sometimes, and I’m always smelling something. It might be more in the region of phantosmia or parosmia, but I’m not entirely sure about those two either.

    The standard smell I’m catching medicinal/biological. I can’t quite put my finger on it, and it doesn’t make food attractive, but it isn’t the “rotting flesh” or “feces” that is commonly reported in phantosmia and parosmia. Also a strong input, like lemon or cinnamon may well be taken in short order and predominate for 24-72 hours.

    So is it the sensory equipment? or the neurons leading from it? or something interfering/physically blocking less powerful odours from the sensors (for instance, mucus)? I didn’t notice this immediately after the event, but a week or two later. That makes me wonder whether a sinus infection is involved, or even just plain old allergies (given that my nemesis ragweed is once again at large in the metropolis).

    I’m hoping my case is worth exploring a bit more. But I will put up with this long-term if need be.

    As for vitamin B, we’re talking B12, right? My diet before and after the accident has been moderately filled with meat, poultry and dairy, so even if my liver is for some reason not keeping the standard multi-year stockpile of B12, it should be getting a pretty constant supply. But I’ll check this up with my GP as I bury him with two months of news, discharge forms, and CAT scans next week!

    Thanks again.

  5. Peter says:

    Thank you David.

    I’m still working on my half of the “Puttin’ On the Ritz” number!

  6. aiabx says:

    Sorry buddy, that was a legal contract you signed, whether you remember it or not. See you on collection day!

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