I watched an emergency surgical procedure on an ER program one night – a real one. A man had suffered a closed skull injury to his brain, which had begun to swell. If it swelled too far, it would cut off its own circulation and die, so the surgeon opened a 2 or 3 inch hole in his skull to relieve this pressure.
The brain promptly bulged through the opening and the surgeon stated that there was nothing more he could do, that the man was going to die – and did. The swelling was too great for the hole.
My question is this. Would it not have been possible excise the scalp – it’s done all of the time – from the skull, take a bone saw and cut the top of the cranium all of the way around? Then section it into 4 pieces, loosely replace the scalp and bandage it? Then the brain could swell beyond the confines of the skull without crushing itself and, in time, return to normal?
Looking down on the skull, the operation would look like an oval with an X in it. Think of the loose plates as expansion joints. The scalp could be cut also, secured in place with long, loose stitches to allow it to slide as the plates shifted. Then the brain could swell upward and out. Presumably, within 24 to 48 hours, it would return to normal and the scalp sewn back securely and the ‘plates’ allowed to heal together.
First of all, if you do what you suggest, the patient has about a 100% chance of contracting an infection in his brain. His chances of dying from that are probably very high as well.
Second, the brain is surrounded in your skull with cranial fluids and such stuff. Without this, the brain would probably suffer severe damage. You can still keep the brain moist with a small hole, but with a whole side exposed?
Thirdly (and most significantly), when the brain swells, it doesn’t just swell “up” (superiorly) but also to the sides (laterally). You might relieve some of the pressure from the superior swelling, but some portions of the brain would still be severly compressed and be damaged.
(N.B. I am not a doctor (although I was an EMT) and could well be wrong on any of these issues).
The problem with the brain swelling is that it pushes the brain stem (the part at the bottom connected to the spinal cord) into the foramen magnum (“big hole”). The problem with this is that although the lower part of the brain stem fits perfectly well into the foramen magnum (which is where it is under normal conditions) the upper part of the brain stem has a larger diameter so that when it is pushed down into the foramen magnum it gets squeezed. When it is squeezed parts of it (such as the the part that controls breathing) stop working. If those parts die, that’s it.
I am not a neurosurgeon and didn’t see the TV show but I suspect that when the surgeon saw how much the brain was bulging he concluded that it must have so severely damaged that recovery was impossible.
Larger holes in the brain can be made, and the rate of infection in these situations is well below 100%, but the poster who made the note about the brain swelling in all directions is correct. To treat swelling of this magnitude with decompression, the whole brain would have to be removed from the brainpan. (I love that word, brainpan!) Another option is to give drugs to reduce swelling, such as urea. During my residency at 3 am, we even made up a song about urea (sung to the tune of “maria” from west side story):
Urea! We’ve got to start pushing Urea!
Or suddenly his brain will never be the same again!
Urea! Push it too slow and he’ll be dying!
Push it faster and at least we’ll be trying!
Urea! We’ve got to keep pushing urea!
You get the idea. It gets a little whack at 3 am in the ICU.
And no, I’m not a neurosurgeon, but I did spend a month on the neurosurgery unit during my residency training.
Seriously, lots of things can cause your brain to swell, but if I remember that episode, it was a traumatic injury to the head - he’d fallen off a scafflod or got whonked in the melon or something.
Presumably the patient would have suffered some intracranial bleeding which caused compression, including compression of the blood vessels that perfuse the brain. Hence, supply of oxygen and nutrient to the brain cells would have been restricted. Unlike muscular and other tissues, nervous tissue does not have the ability to “store” oxygen or glucose.
Once deprived of adequate oxygen, cells are not able to properly metabolise glucose, which they need to do in order to create enough energy to power all their internal workings. One of the vital functions that fail are the sodium/potassium pumps in the cellular membrane, which constantly exchange these ions against the concentration gradient.
The environment outside cells is rich in sodium, whereas the inside of cells is rich in potassium. When cells depolarise (trigger and/or conduct an electrical impulse) sodium and potassium rush across the membrane causing a reversal of polarity. The repolarisation process “resets” the cell by pumping out the sodium and bringing the potassium back in.
When the cell is deprived of oxygen or glucose, the Na+/K+ pump fails as there is insufficient energy to drive it. Hence sodium remains within the cell, and attracts in chlorine ions, which combine to form salt. Osmotic pressure then pulls water into the cell to dilute the high salinity, hence the cell swells. If hypoxia is prolonged the cell will die.
Hopefully that answers your question.
Incidentally, I am not a brain surgeon, but I am an ALS ambulance officer who is required to know this stuff as part of the EMST curriculum.
and when the brainstem is compressed through the Foramen; it can also compress veins and arteries. Without O2, as DVous Means said, your Na+/K+ pump fails. If just the veins are compressed, you cannot get rid of CO2…and when that happens, the body converts CO2 into Carbonic Acid, which upsets the pH balance in a big way, unless Sodium Bicarbonate is introduced to reverse it.
yes…me too…what caused the swelling? Without a full history (ie: was it caused by trauma? major infection etc) it’s a bit hard to determine a full regime of treatment.
