What Really Causes Epilepsy? A Trip to an Unknown Land
- Published27 Oct 2020
- Reviewed27 Oct 2020
- Source BrainFacts/SfN
More than 50 million people suffer from epilepsy, a neurological disorder where neurons malfunction and fire at the same time, triggering seizures.
This video is from the 2020 Brain Awareness Video Contest.
Created by Youssef and Yousra Ismail
CONTENT PROVIDED BY
Imagine you went for a walk inside your brain. You look to your right to see some nerve cells or neurons busy doing their work moving your arm. You look to your left and you see some other neurons thinking about what you’ll be having for dinner later tonight.
And all of a sudden you hear a loud noise
You turn your head to see some neurons arguing together, refusing to do their assigned tasks, and shouting loudly all at the same time.
That’s exactly what happens during an epileptic seizure. Epilepsy is a neurological disorder affecting more than 50 million people worldwide! And it’s defined as the occurrence of multiple seizures due to malfunction of some neurons in the brain causing them to fire synchronously.
But what’s a seizure?
Let’s go back to the basics. If we take a look at any neuron in the brain, we’ll find two types of neurons acting on it to control its function. The first one is called an excitatory neuron that, when fires, activates the neighboring nerve cells. While the second is called an inhibitory neuron, and when it fires, it stops those neurons from working. And these two different types of neurons work together in a balanced manner to coordinate the work of other nerve cells.
Neurons in the brain communicate with each other through chemicals known as neurotransmitters. And so, the excitatory neurons release excitatory neurotransmitters as glutamate, while the inhibitory neurons release inhibitory neurotransmitters as GABA.
So, what happens during a seizure is one of two things: either the excitatory neurons fire more than needed, or the inhibitory neurons fire less than usual. And both situations cause other neurons to fire more than they normally would.
And while the neuronal error is usually quite the same, the seizure itself can have multiple different presentations. For example, if the neurons malfunction and overfire in one localized area of the brain, the seizure appears on the body part controlled by it, like unintentional arm movement or even perception of a weird smell. And these would be called a focal seizure.
However, if the neuronal malfunction spreads across the brain or is already all over the brain from the start, the seizure shows all over the body. And this may present in multiple different ways. The most common is the Tonic Clonic seizure, also known as grand-mal, which presents as loss of consciousness and muscle tension followed by rhythmic muscle contractions all over the body.
But also, children sometimes present by what’s known as absence seizure, or petit-mal, where a child all of a sudden pauses then goes back to what they were doing without even remembering that a seizure happened.
There are multiple different causes of epilepsy from genetic disorders, to tumors, trauma, or even brain infection. Yet in most of the cases the cause remains unknown. And that’s why the treatment usually aims mainly at controlling the seizures, which is done primarily using medications known as antiepileptic drugs.
Antiepileptic drugs work in multiple different ways such as enhancing the function of inhibitory neurons by increasing the production of GABA and amplifying its action. While some other drugs suppress the action of excitatory neurons by blocking the glutamate receptors (or action site).
And both of these mechanisms prevent the neurons from rapid repetitive firing. However, epilepsy can also be treated surgically when a specific cause for the seizures has been identified, such as a tumor or when the seizures are of the focal type and the neurons causing the disease are located.
And finally, with recent technological advances, a device called Responsive Neuro-Stimulator has been used to treat patients with epilepsy not responding to drug treatment. The device is implanted within the brain and continuously monitors the activity of the neurons. And when it senses an increase of neuronal firing the device produces an electrical impulse resetting the neurons and preventing the seizure before it even happens.
Epilepsy is one of the most common neurological disorders and that’s why it’s important for all of us to know how to act if we see someone having a seizure. All you have to do is put that person in a recovery position and make sure to time the duration. And if it continues beyond five minutes quickly call an ambulance. Never put anything in their mouth and move any sharp object away. Stay calm till the seizure ends and reassure them that everything is going to be okay.