Basic Guide to Epilepsy

About Epilepsy

Basic Guide
to Epilepsy

About epilepsy

Epilepsy is as common as diabetes and asthma. With as many as one in 103 people affected, epilepsy is the most common neurological disorder in the UK. Around 87 people are diagnosed with epilepsy every day.

Many of you reading this will have epilepsy yourselves, or will have family members, friends, work colleagues or neighbours who have epilepsy.

Q. Who has epilepsy?

Epilepsy can affect anyone at any time, although it is often diagnosed before the age of 20 or after 60. It can affect people of all ages, races, social classes and ability groups. Most people with epilepsy do not have the condition for the whole of their lives, particularly those whose epilepsy develops in childhood.

Unless someone experiences a seizure it is impossible to tell whether someone has epilepsy — unless you are told.

Q. What is epilepsy?

Epilepsy is the tendency to have recurrent seizures, which tend to recur spontaneously. These seizures occur when there is a temporary disturbance in the brain and the signals it sends to the body become mixed up, rather like an electrical storm in the brain. What happens during a seizure depends on which part of the brain the ‘storm’ is occurring. Different seizure types are outlined later in this section – people with epilepsy can have one type, or more than one type.

Up to 70% of people with epilepsy don’t have seizures – they are controlled through taking medication.

Q. What causes epilepsy?

For many people there is no proven cause for their epilepsy. This is classically referred to as “cryptogenic” epilepsy, or more recently “epilepsy of unknown cause”. For some the cause may be genetic, although this represents a minority of patients. In other people with epilepsy, the cause is more certain, and the condition develops as a result of damage to the brain, for example, from injury, birth trauma, or stroke. This is known as “symptomatic” epilepsy.

All our brains have the capacity to produce a seizure in certain circumstances. Most brains won’t do this unless encouraged, and so are said to have a ‘high seizure threshold’. Others have a low threshold and people with cryptogenic epilepsy have a lower resistance to seizures. In the case of epilepsy arising from injury or illness – symptomatic epilepsy – the existing seizure threshold may be lowered.

People are more than a medical condition – the seizures are epileptic, not the person.

Q. How is epilepsy diagnosed?

Diagnosis is based on events and there is no one medical test that can ‘prove’ that a person has epilepsy. Tests such as an EEG (electroencephalogram) can pick up on abnormal electrical activity in the brain, but an EEG is not usually grounds enough alone for a diagnosis. These tests can, though, help to find out the seizure type, identify any underlying cause and indicate appropriate treatment.

 Most cases of epilepsy are diagnosed through witnessed accounts of seizures and through descriptions of what happened before, during and after, by both the person suspected of having epilepsy, and the person who was with them at the time. To be diagnosed with having epilepsy, the person must usually have recurrent attacks – one is not enough to constitute a diagnosis.

Once diagnosis has been confirmed, the person will be offered antiepileptic medication which is designed to stop them from having seizures altogether, or reduce the amount of seizures they have.

One in 20 people has a seizure at some time in their lives.

Recognising seizures and epilepsy

There are many different types of seizures, and only some involve losing consciousness. Some seizures, known as generalised seizures, affect the whole brain, while others, called focal seizures (formerly partial seizures), affect only part of the brain.

Generalised seizures

In these types of seizure the whole brain is affected by an abnormal electrical disturbance and the person becomes unconscious of surroundings. The following are some examples of generalised seizures.

Tonic-clonic seizures

These used to be known as “grand mal” seizures. The seizure usually starts with a cry and a loss of consciousness with the person falling to the ground. A ‘tonic’ or stiff phase then leads to a ‘clonic’ or twitching phase.

Finally there may be confusion, often followed by sleep. In addition to the very obvious convulsive movements, an observer may see the lips turn blue and if the tongue has been bitten blood may trickle from the mouth with frothy saliva. It is possible, but by no means always the case, that the person could be incontinent of urine or in rare cases, doubly incontinent.

Tonic seizures

These seizures are quite dramatic. The muscles stiffen and, if standing up, the person will fall heavily to the floor, often receiving injury to the head. There is no jerking. 

Atonic seizures

The muscle tone is lost causing the person to flop and fall to the ground. Sometimes referred to as “Drop Attacks” or astatic seizures, these can also be quite dramatic. The person falls heavily to the ground and although recovery is swift the result is often head or facial injury.

Clonic seizures

In these seizures the muscles contract and relax continuously causing the person having the seizure to twitch and jerk repeatedly.

Myoclonic seizures

“Myo” means muscle and “clonic” means jerk. When myoclonic seizures occur the muscles jerk rather as if the person has had some sort of electric shock.

Seizures usually occur shortly after waking or before retiring to bed when the person is tired. There is a loss of consciousness but it is hardly noticeable because the period is so brief.

Absence seizures

These seizures are usually observed in children and are sometimes referred to as “petit mal”. They occur suddenly, provoking a brief trance-like state. Affected children stare blankly into space and their failure to respond when they are spoken to often results in them getting told off in school for not paying attention.

‘Simple’ focal (partial) seizures

These seizures are again subdivided into two main categories – focal motor seizures and focal sensory seizures. There is no impairment of consciousness.

Focal motor seizures

These cause movement of the limbs, head or neck and they originate in the frontal lobes of the brain. If the seizure is in the right frontal lobe then the seizure movement is produced on the left hand side of the body and vice versa. Seizures originating in the frontal lobe can also involve an interruption in speech. 

Focal sensory seizures

These seizures originate in the parietal lobes of the brain, producing physical sensations such as tingling or unnatural warmth. If the seizure is in the right parietal lobe of the brain it will produce a tingling or warmth on the left hand side of the body and vice versa.

‘Complex’ focal (partial) seizures

These seizures usually originate in the temporal lobes of the brain and are non-convulsive in nature. They differ from simple focal seizures because they produce impaired or altered consciousness.

The seizures often commence with a simple partial seizure (called an aura) in which those experiencing the seizure become disorientated but still aware of what is going on. They may then go on to unknowingly pluck at clothing or smack lips and perhaps wander about aimlessly. Their behaviour is seen to be out of character.

Secondarily Generalised Seizures

It is possible for someone who has had a partial seizure to then go straight into a generalised seizure. In these cases, the generalised seizure is known as a secondarily generalised seizure and it is usually atonic, tonic, clonic or tonic-clonic.

Status epilepticus

This phrase is used to describe a situation when a seizure is prolonged or when there is a series of seizures during which the person does not regain consciousness. It is a medical emergency which needs active treatment by a doctor in order to stimulate the brain back to normality.