Probably a very stupid question but I can’t wrap my head around it. For instance if someone had head trauma, why can they not wake up after a few days or so? What is it that keeps them unconscious for such a duration of time with nothing to wake them?
Edit: i’m confused why this got so many upvotes but thanks😁
In: 5318
[removed]
[removed]
A coma is a state of minimal brain function, it’s not like being awake or asleep. Neurons that should be firing and signals that should be transmitted aren’t, during a coma. This is usually due to some sort of damage.
We use the Glasgow Coma Scale to judge whether someone is in a coma. It measures things like responses to pain and whether someone can open their eyes. A score of 8 or lower indicates someone is officially “in a coma”, though the typical “laying in bed totally non responsive” imagery of a coma is usually indicative of a very low score on the Glasgow Coma Scale.
To sum up, a coma is when the brain can’t function properly due to damage. This damage can have effects that cause them to not respond to their senses, and unconsciousness.
The key is the Reticular Activating System in the brain, a web site is here to explain.
https://bodytomy.com/reticular-activating-system
What I find interesting is that they vary depending on the animal. In dogs, for instant, when awoken by a threshold stimulus they are fully alert and off like a rocket. With humans, not so much. Probably due to operant conditioning.
There are lots of reasons to be in a coma. Direct brain injury from trauma is only one. The first step in managing coma is finding out the cause, reversing it if possible, and managing complications that happen when someone cannot care for their body.
For direct brain injuries we talk about primary and secondary injury everything we do in the hospital as neurosurgeons is trying to protect the healthy brain from the injured brain which swells.
[removed]
This stuff is complicated, I’ll make it as simple as I can but I’m sorry in advance for any inaccuracies made for the sake of explanation
You have basic brain functions that are the most important things your brain does to keep you alive and you do those unconsciously. Like keeping your heart beating or keep your lungs breathing. You might lose some of these functions or maybe they’re a lot weaker than before the coma and need help to keep you alive, like from a ventilator (a machine that breathes for you). It varies from injury to injury.
You also have higher, more complicated, brain functions like consciousness and thought.
These are controlled by different areas of your brain. The complicated stuff is mostly in the main brain 🧠 and the simpler stuff is mostly in the base of the brain.
Knocking out the complicated stuff is much easier than knocking out the simple dumb stuff. And when you just knock out the higher functions you get a coma.
Now why can’t you wake up? Well first, you’re not asleep. You just don’t have consciousness. The car doesn’t have a working engine to get moving but the battery is still working so the lights still turn on.
Sometimes the damage can heal but it’s a very complicated and finicky process. And you will slowly regain consciousness. Sometimes it doesn’t and you’re just left with the base, unconscious functions.
There’s a part of the brain called the “reticular activating system” (RAS), which is located in the brainstem. There are a bunch of connections from it all throughout the rest of the brain. Although this is a simplification, basically this system being turned “on” makes us conscious, and it being turned “off” makes us unconscious. How to define consciousness is really, really hard and almost more philosophy than science, but one way to understand it is to think about whether or not we are able to perceive and react to our environment.
We naturally go through cycles of this system turning on and off as we sleep and wake up. However, if this system gets hurt from a stroke, physical brain damage or swelling, or some kind of toxins causing the nerve cells to not work well, it will make you unconscious–even if most of the rest of the brain is in decent shape! Of course, big damage to the rest of the brain can also cause a coma, but usually it has to be *really* big damage to both the left and right halves of the brain to cause that if the RAS isn’t touched by itself.
A coma that lasts for a long time is usually a pretty bad sign in terms of predicting if someone will recover. Although there are a lot of different factors, if someone is in a coma for more than 3 days their chances of recovery are usually less than 1 in 10. If someone is in a coma for more than 2 weeks, the odds of recovering are more like 1 in 50.
Some people may have enough healing of the rest of their brain so that some basic functions like the sleeping/waking cycle, opening their eyes, and some spontaneous movements start to come back, but they will remain completely not able to respond to anything in their environment and its believed they have no actual consciousness/thought–this is called a “persistent vegetative state.”
The opposite to this is if the connections between the brain and the rest of the body get destroyed but the RAS doesn’t get hurt. This is called a “locked-in” syndrome, and results in being completely conscious but unable to move any part of your body except your eyes.
I similarly often wonder what makes us alive, what suddenly changes when we die that is so irreversible that we can’t replicate it even with all the 21st century advanced medical technology.
Living organisms have so many specialized things working in unison, that when one crucial part fails, everything quickly falls apart, often irreversibly.
Movies make coma out to be some kinda of hibernate computer mode for your brain that you keep trying to restart and it wont boot until one time it does. It’s much more like joint injury though. Takes a long time to heal, not all parts heal at the same speed, some parts never heal, return t function is variable depending on severity and parts injured. Consciousness may never return but other parts might go back to full function. The brain is a crazy thing.
Latest Answers