Medical Mondays: Surviving a Shot to the Head

Boy, it's been a while since I did a Medical Mondays. I've been continuing to get medical questions from writers, but finally have a chance to breathe and blog about one of them. 

Here's one from a blogging friend many of you know, the talented Jessica Bell! Jessica is author to several books, including Bitter like Orange Peel and String Bridge, as well as the Writing in a Nutshell series, and is an editor of Vine Leaves Literary Journal. 

Jessica asks:

"One of my characters shoots himself in the head to commit suicide. Is there anywhere he can point the gun and still survive? I also need him to be in a coma for 8 months, (I can make it less if need be). Is it possible he could wake up from that and still have full brain function?"

Great question, Jessica (but a sad one!) A person can definitely suffer from a GSW to the head and survive, but the odds are generally slim. The majority of GSW to the head result in death (90% or so). So for this scenario to work, there are a few details that would have to happen.

1. Brain structures to hit and miss. The less brain tissue the bullet encounters, the less damage. There is some duplication between the left and right hemispheres of the brain, so ideally the bullet should not pass through both sides of the brain, only one side. Also, it would be important to miss certain structures, like the brainstem (responsible for your heart beating, breathing) and other central structures, like the basal ganglia and thalamus. The bullet should miss the ventricles, which are fluid-filled structures inside the brain. Damage to those might cause excessive fluid to build up in the brain. So, an ideal bullet trajectory in this scenario might be going from the left forehead through the top of the left skull, missing those important structures and "skimming" the top of only one hemisphere.

2. The bullet. It should be small caliber and have a low velocity. The more energy a bullet has, the more energy is imparted to the brain tissues as it passes through, causing more destruction. Smaller bullets and slower bullets cause less damage. So Jessica's character would need to be shot with a low caliber handgun as opposed to a high powered weapon. 

3. Complications. Since Jessica needs the patient to be in a coma for a long time, but have minimal long term damage to the brain, she may have to build in several complications to keep him sick in the neuro ICU.  Any GSW will cause brain swelling, so a coma makes sense for a while if there is a lot of swelling. Add in more problems, like a brain infection, or extra fluid building into the brain that needs a drain (ventricular drain, shunt, or temporary removal of a piece of skull), or a later brain bleed that needs an extra surgery to stop the bleeding. 

Below are several articles that highlight the issues that occur in head GWS, as well as info on those rare survivors. Sadly, this scenario was very much in the consciousness of Americans when Representative Gabrielle Giffords survived an assassination attempt. 

What does it take to survive a bullet to the brain? By LiveScience 
Surviving a gunshot wound to the head, by MedicineNet 
Q&A with a neurosurgeon on the status of Gabrielle Giffords 
Living Miracles: Survivors of Gunshots to the Head 

Thank you Jessica for a fascinating question. Good luck on your WIP (and good luck to your character!)