What is epilepsy?
Epilepsy is a tendency to have repeated seizures. Your brain controls everything your body does (even when you’re asleep). Different parts of the body are controlled by the electrical activity coming from different parts of the brain.
An epileptic seizure happens because of a disruption of the electrical activity in the brain and seizures can vary enormously one from another because the brain does such a huge range of jobs. What happens in the seizure depends on where in the brain this unusual burst of electrical activity happens.
Different types of seizures
Everyone’s epilepsy is unique to them. (Since there are over 40 different types of seizures, that’s not surprising.) But the types of seizure are of two main sorts. We call one group ‘generalised seizures’ and the other
focal (or partial) seizures.
In this type, the whole brain is affected by the abnormal electrical disturbance (think brain storm and you’re about there) and the person becomes unconscious of their surroundings.
Focal (partial) seizures
Focal (from the word for a fixed point) means the seizure comes from one particular part of the brain. What the seizure looks like depends on where exactly in the brain it stems from, and what that bit of the brain does. With these seizures the person can become confused and disorientated, but will not lose consciousness.
Bilateral convulsive seizure
A bilateral convulsive seizure is when a focal seizure progresses and turns into a generalised seizure.
Tonic clonic seizures
These seizures can start with a cry as air is forced out of the lungs. The person then becomes stiff and falls to the ground unconscious. The
tonic (or stiff) phase then leads to a
clonic (or jerking) phase. After the seizure (usually around 1 - 3 minutes), the person may be confused and need to sleep.
These seizures may happen many times a day and put the person in a brief trance-like state. They’ll stare blankly into space and be unresponsive – usually for about 5-10 seconds. Then they’ll snap back, so these episodes may not even be noticed. (And that’s why, before the person has been diagnosed as having these sorts of seizures, their lack of response when being spoken to has often led to them being told off for not paying attention).
These seizures are quite dramatic. The muscles stiffen and, if standing up, the person will fall heavily to the floor, usually backwards. There is no jerking.
These can also be quite dramatic because muscle tone is lost, causing the person to go all floppy and fall to the ground. That’s why they are often called
drop attacks. (Another name is
During myoclonic seizures, the muscles jerk rather as if the person has had some sort of electric shock. Seizures often happen just after waking, or when the person is tired, before going to bed. There is a loss of consciousness, but it’s hardly noticeable because it lasts such a short time. Sometimes these seizures happen in
clusters (that means you get a string of them one after another).
Focal (partial) seizures
We said that ‘focal’ means the seizure comes from just one part of the brain. So what the seizure is like will depend on exactly where in the brain it comes from, and what that bit of the brain is supposed to do. (See below) Consciousness may be disturbed or impaired.
Temporal lobe epilepsy
Lobe simply means rounded or sticky out bit - think of your ear lobe. And ‘temporal’ comes from the Latin for time, because a man’s hair goes grey first on his temples and this bit of the brain is under there).
This is the most common type of epilepsy to cause focal seizures. The temporal lobes are responsible for, language, feelings, emotions and memory. So there may suddenly be a most strange mix of feelings, emotions, or thoughts. These might appear either very, very familiar, or perhaps very odd. This can be really unsettling, since we’re used to being able to make sense of our feelings and thoughts. It may feel as if part of your brain is being stirred with an invisible spoon, making the oddest things float to the top. Other symptoms may include fumbling or plucking at clothes, or wandering off in a confused state. Unusual speech can also occur.
Frontal lobe epilepsy
Seizures coming from the frontal lobe will vary, depending on which part is involved. They usually that start suddenly and end just as quickly. They may produce weakness in certain muscles, including those used to speak. Seizures usually happen during sleep, and they can look very strange and dramatic with all sorts of head turning, thrashing around or cycling movements of the legs.
Occipital lobe epilepsy
Seizures occurring in the occipital (it means
back of the head) lobe show up as odd things to do with your sight. So symptoms might include things like rapid eye blinking, or seeing patterns, flashing lights or colours.
Parietal lobe epilepsy
This word parietal comes from the Latin word for wall, so think of it as meaning the side walls to the brain. Seizures coming from the parietal area usually result in strange sensations and are also know as sensory (feelings) seizures. This might be a tingling, or warmness, and they often happen only down one side of the body. Some people say their arms and legs might feel bigger, or smaller, than usual, and bits of the body might go numb, all of which can feel really odd