Tuesday, May 26, 2009

Fragmentation and Cavitation

A small caliber slug entered this patient's skull at the bridge of her nose. Surprisingly, she arrived alive (by EMS). The Xray also shows the Endotracheal Tube which saved her life (note the curved white line which traces from the opening of the mouth down the back of the throat... this is a radiopaque line on every tube to allow us to see it on Xrays). She walked out of the hospital about three weeks later.

Note the fragmentation of the slug caused by its impact with the skull, and note the remainder of the slug towards the back of the head. In other words you can see where it went by all the little white and grey dots which start at the bridge of the nose and end in the posterior aspect of the brain (inside the blue lines).

Because this small caliber slug carried a relatively small amount of energy it did not exit the brain. However, on its course through the brain it DID cavitate and cause much damage. Cavitation is caused by the shock wave of energy produced by the bullet, and an interesting though technical description of this type of wound and its management can be found here.



  1. That's incredible! Was there neurological damage from this injury?

  2. charles,
    for legal reasons i can not tell you exactly what her outcome was but not only did she walk out of the hospital, she seemed 'all there' mentally. this may be because the bullet tracked 'sub cortical' or deep in the brain and missed the part that makes us humans.

  3. Jeez,enough metal in her head for a Metallica album...and thats not counting those fillings...

  4. Fascinating stuff. I read the linked text; it seems to imply that so long as blood flow is not compromised the tissue can recovery. My (admittedly elementary) understanding of the delicacy of nerve tissue seems to contradict this - what kind of side effects/recovery can a patient who suffers this kind of injury expect? Is there likely to be permanent brain damage? I heard just recently that the traditional thinking (again, elementary school level education on this kind of topic) regarding the regeneration of nerves was completely wrong (that is, they do regenerate - well into advanced years).

    The text also mentions copper/lead poisoning due to bullet fragments contacting CSF - why wouldn't that be a factor in this case?

    The things you guys can do/learn are amazing.

    -Lowly business wonk.

  5. dear lowly business wonk,

    i would be way out of my area of expertise to comment on nerve regeneration and the latest research... perhaps etoteipi can comment. i can partially answer though, as we know from head injured and stroke patients that the brain, especially in a relatively young person, can do remarkable things in rerouting bad connections. as a general rule, one side of the brain can do most of what the entire brain can do, but 'plasticity' comes into play and some stroke patients never recover (head injured patients too) to the extent expected, while others recover more than we could have hoped.

    again, i can not comment on specifics of this case but given the apparently devastating injury the end result was not expected. a neurologist could probably tell you, with both an antero-posterior view and this lateral view, the likely damage and likely symptomatic results of this injury.

    oh by the way, i lost, long ago, the belief that we do anything other than our jobs and heartily wish, even in this economy, that i had gone to business school.

  6. 9-11 ,was this another UGA professor???


  7. 911doc,

    Thank you so very much for your response; it's really amazing to me that someone can take a good peppering of metal fragments right through the forebrain and survive, much less recover. I know a (very) little bit about the complexity of structures within the body, and the thought of the damage that can be caused by the forces involved (as you noted, cavitation, something I had never considered before) in addition to just the penetrative intrustion through the various tissus up to an including the brain. Wow. I don't stop in and comment this often enough but I appreciate the opportunity and insight to see information like this (we laity don't get tidbits like this often enough - and particularly with medical stuff I can understand, but as an avid techniphile it's much easier to get information about the particulars of a discovery/situation, whereas in medicine the Names Must be Changed to Protect the Innocent, as it were). Thank you for doing this, at little or no personal gain.


  8. Annonymous,
    don't you ever look at "The National Enquirer"?? They have a regular series of people who not only survive getting impaled in the grape with various sharp implements, but live productive lives with arrows, monkey wrenches, etc etc, sticking outta their heads...
    Seems like most of em' live in England...
    We only use about 2% of our Brains anyway...


  9. My mother is a neurophysiologist. For decades, she has been studying brain healing. Many of her experiments involve making an incision in the brain of a rat. She then lets it heal, and discovers that lost function returns, and new growth forms around the incision. It shows hope for those of us on the wrong end of the projectile.

    Doctor: Do you try to remove all of the metal and bone fragments, or just the ones that can be reached without too much further damage to the brain?

  10. dear matt m,
    better question for the neurosurgeon, but, as a rule, removing bullet fragments is for the pathologist at autopsy. but you have reminded me of one of the great hollywood western myths. it may be true that docs in the old west 'went digging' for bullets in their patients but we do not, with rare exception (spinal cord impingement). need a tox person to comment on the long term effects of lead shot embedded in the body but most bullets are not made of lead anymore.

  11. frank,
    maybe. but i know that auburn u. is doing a lot of research for the army on 'steerable bullets' which is damn cool.

  12. Vincent J. M. DiMaio's excellent book on gunshot wounds addresses this issue. According to him, lead poisoning due to retained bullet fragments is rare but can occur if the bullet is in a bone or adjacent to a joint. If you encounter it, write it up!

    Most commercially available bullets are lead cored but have a bonded copper jacket. However, the base is usually (but not always) exposed lead, so poisoning from a retained bullet is a remote possibility. Notable exceptions are the military's training ammunition, which is lead-free (primers and all!)

  13. Oh you people don't know shit!!! This is not a "small caliber" (it's a .45) it's a "slow velocity" handgun.
    It hit just above the glabela on the frontal boss the hardest part of the skull. The small fragments driven thru the base of the brain are small copper fragments and can stay where they are forever. They will not cause "lead poisoning"
    Someone was close to correct when they tried to describe the projectile. It is a copper coated lead bullet. The jacket came apart, the lead deformed on the skull, hence no penetration. Try to think of the middle of the horns on a Cape Buffalo. Just the hardest place on the skull of a semi-human who is stupid enough to get caught in any place this might happen.(think drug dealer not getting paid)
    I once got an EMS call with THREE VICTIMS,all gsw's to the head. I sent them all home.
    The trouble with drug homies is that they buy expensive guns but don't know what to feed them!!!
    Stupid POS's

  14. oldfart in the f***cking hizzie!

    oldfart, you get a 90% and the only reason you didn't get 100% is because of photoshop.

  15. I love that grumpy bastard.

  16. You don't tug on Superman's cape,
    You don't spit into the wind,
    You don't pull the mask off an ole' Lone Ranger,
    And you don't argue ballistics with Old Fart!
    (Haikus my butt)