And like what physically happens in the brain to cause it?
In: Biology
As another poster explained causes, I’ll address what actually happens.
When you move your arm, you are contracting one muscle and expanding another. Most muscles work in pairs, or paired groups like this. When you have a seizure, your brain, among other things, tells ALL of your muscles to contract at once. This results in your body violently vibrating or shaking since all those pairs are trying to do the same thing at once. They are also working as hard as they can the whole time. Some seizures are relatively short, and others can last much longer. Even if it only lasts for a few minutes, your muscles can all be sore for days afterwards, like you did the hardest, most complete workout youve ever done, for hours. You’ll probably also have some time missing as you black out while this is happening. You may bite your tongue, and potentially lose bladder control.
As a note, if you see someone having a seizure DO NOT PUT YOUR HAND IN TNEIR MOUTH. It is physically impossible to swallow your tongue. You do not need to try and prevent it. Doing so will only result in you getting bitten. Simply clear the area around them so they can’t hurt themselves and call an ambulance.
Your brain runs on electricity. Normally, that electricity operates in a certain way.
When someone’s brain has abnormal changes in how its electricity operates, we call it epilepsy.
But epilepsy isn’t one condition. It’s a bucket term used for a whole group of related conditions. So it has no one cause.
When you think of epilepsy, you are likely thinking of what are commonly called grand mal seizures, which are one of many types of seizures. Even that term is outdated and inaccurate. These seizures also have no one cause. They are characterized by abnormal, excessive, and synchronized electrical discharge in the brain, the source of that discharge could be a brain injury, a brain tumor, an underlying genetic condition, or several other causes as well.
So to recap:
– epilepsy isn’t one thing
– the thing people most commonly think of as epilepsy is just one tiny slice of it
– that tiny slice has no one cause
Source: I have epileptic seizures in my temporal lobe and frontal lobe, as a by product of some brain surgeries I had back in 2008.
Brains send signals in cycles. A neuron fires and that triggers anther neuron which triggers another neuron and so on until it gets back to the first neuron. Like, say you’re looking at something and trying to figure out what it is. Your optic nerve starts it off, and then your visual cortex tries to figure out where the lines are, what the shape is…and that triggers neurons in the memory part of your brain to see if it matches shapes you’ve seen before, which sends the signal back to the visual cortex to analyze part of it more closely, then back to memory to see if you recognize it…and so on.
Neurons don’t automatically fire, they *might* fire, or they might not. If more neurons are coming in, it increases the odds of that neuron firing. Too few, and the neuron doesn’t fire. As these signals propagate through your brain, when the signals are useful, they amplify and keep the signal going strong. If the signal isn’t useful – like, maybe that shape you’re looking at doesn’t match anything in your memory – the signal gets weaker and weaker and dies off.
For this reason, it’s very important that your neurons can turn *off* and allow the cycle to die when it’s supposed to. Even after you’ve recognized the shape, your brain needs to be done recognizing, right?
A seizure is when the signal doesn’t die off like it should. Some clump of neurons is too sensitive, or maybe the enzymes that help regulate and turn off neurons aren’t working correctly. Either way, the signal cycles through that part of the brain over and over and over again, getting stronger every time and going super fast. Instead of a signal sweeping through your brain like it should, it’s just looping in that one, broken part so fast that your neurons stop really doing their job. Eventually, the seizure stops when the neurons *can’t* fire anymore. They’ve exhausted all of their chemicals needed to do so, and the person is left weak and out of it as the neurons rebuild their supplies and start to function normally again.
If the seizure is really bad, that loop leaks out into other parts of the brain. Maybe they’re leaking into the parts that control your body and sending rapid but weak signals to clench the muscles, and you get the jerking, flailing, shaking of a grand mal seizure. Note, though, that grand mal seizures are rare – most seizures are limited to a small area of the brain and it can look as innocent as just kind of zoning out for a bit.
Lights and sounds can trigger seizures because they create rapid, strong, confusing signals to begin with. In a normal brain, the neurons have some built-in limits that say not to fire too often, so if the signal loops around too quickly (say, because the lights are blinking quickly), the neurons just kind of give up trying to keep up and nothing really happens.
Latest Answers