Epilepsy

What is epilepsy?

Epilepsy is a neurological condition that causes a tendency to have repeated seizures, which happen when the brain's normal electrical activity is temporarily disrupted. It's usually diagnosed after you've had more than one seizure, since a single seizure doesn't necessarily mean you have epilepsy.

Symptoms of epilepsy

The main symptom of epilepsy is having seizures. These can look very different from person to person, though most people have a similar pattern each time. A seizure usually lasts a few seconds or minutes and stops by itself.

Seizures can include:

• your body becoming stiff or floppy, or suddenly falling to the floor
• jerking or twitching movements
• losing awareness of your surroundings, staring into space, or not being able to respond normally
• unusual feelings or sensations, such as strange smells or tastes, tingling, numbness, changes in your vision, or a sudden feeling of fear or déjà vu
• unusual behaviour, such as fidgeting, wandering around, or repetitive movements like lip-smacking
• unintentionally losing control of your bladder.

You might be aware of having a seizure and remember it afterwards, or you might not. Epilepsy can start at any age, though it most often begins in young children or in people over 50.

Causes and risk factors

Epilepsy happens when the brain's normal electrical activity is disrupted, though the exact cause often isn't clear. No cause is found in around half of cases. 

When a cause can be identified, it's usually genetic (a tendency inherited from one or both parents, or a new change in your own genes), a structural change in the brain (such as the brain not developing typically, or damage from a head injury, stroke or brain bleed), or an infection affecting the brain, such as meningitis or encephalitis. Less commonly, it's linked to a rare metabolic or immune condition, or a genetic condition associated with brain changes, such as tuberous sclerosis.

Everyone has some natural resistance to seizures, sometimes called your 'seizure threshold', and this is partly genetic. This may help explain why some people develop epilepsy after a brain injury while others with a similar injury don't; it can reflect both the injury itself and a person's underlying tendency to have seizures.

You may be more likely to develop epilepsy if you:

• have a close relative with epilepsy, particularly if theirs affects the whole brain rather than one area
• have had a stroke, a brain infection, or a serious head injury
• have a brain tumour or dementia
• had complications before or during birth, such as being born early or not getting enough oxygen
• had seizures with a high fever (febrile seizures) as a young child.

Are there different types of epilepsy and seizure?

Epilepsy can be described in two ways: by the type of seizure someone has, or by the underlying type of epilepsy, which reflects what's causing the seizures and which part of the brain is involved; for example, temporal lobe epilepsy is named after the part of the brain affected.

Seizures are broadly divided into generalised seizures, which involve both sides of the brain from the start, and focal seizures, which begin in one area and may or may not spread further; sometimes it isn't clear which of these applies, known as an unknown-onset seizure. Within these broad groups, recognised patterns include:

• tonic-clonic seizures, where you become unconscious, your muscles stiffen and your body jerks and shakes
• tonic seizures, where your muscles suddenly stiffen and you may fall, then recover quickly
• atonic seizures, where your muscles suddenly go floppy and you may fall, then recover quickly
• absence seizures, where you briefly lose awareness of what's going on around you
• focal seizures, where you have unusual feelings, sensations or movements, with or without losing awareness
• myoclonic seizures, where your muscles briefly jerk.

You may have only one of these seizure types, or more than one.

How is epilepsy diagnosed?

Having one seizure doesn't necessarily mean you have epilepsy, since seizures can have other causes. You'll usually be diagnosed with epilepsy if you've had more than one seizure more than 24 hours apart, or if you've had one seizure and tests suggest you're at high risk of having more.

If you have a seizure, you'll usually be referred to a specialist doctor (a neurologist). They'll ask in detail about what happened before, during and after your seizure, so it can help to bring along anyone who witnessed it, or a description or video if possible, since many people don't remember their own seizure.

Tests you might have include an electroencephalogram (EEG) to check your brain's electrical activity, an electrocardiogram (ECG) to check your heart, blood tests, and brain scans such as an MRI or CT scan. These support a diagnosis or help rule out other causes, but a normal result doesn't necessarily rule out epilepsy. Your specialist will look at your test results alongside your symptoms and history together.

How is epilepsy treated?

There's no cure for epilepsy, but treatment can often help you manage it well.

Medicine

The main treatment is medicine to prevent seizures, called anti-epileptic or anti-seizure medicine, taken regularly rather than to stop a seizure once it's started. Up to 70% of people with epilepsy could become seizure-free with the right medicine, though it can take time, and sometimes a trial of more than one medicine, to find what works best for you. Which medicine suits you depends on your seizure type and factors such as your age and any other health conditions.

If you're at risk of a seizure lasting longer than usual, you may also be given emergency medicine for a family member or carer to use.

If you take epilepsy medicine and there's a chance you could become pregnant, or your partner takes epilepsy medicine, it's important to discuss this with your specialist. Some epilepsy medicines can affect a developing baby, or, in men, affect sperm, so you may need to review your treatment or use contraception.

If you haven't had a seizure for two years, your specialist may discuss gradually reducing your dose, though you should never change or stop your medicine without their guidance.

Other treatments

If medicine doesn't control your seizures well enough, other options may be considered. These include surgery to remove the part of the brain where seizures start, or, when that area is too important or extensive to safely remove, a procedure that interrupts the nerve pathways that let seizures spread instead. 

Vagus nerve stimulation uses a small device placed under the skin of your chest to send mild electrical pulses to a nerve in your neck, usually alongside medicine. For some children, and occasionally adults, a specially supervised ketogenic diet can also help reduce seizures.

When should I get help?

If you think someone is having a seizure, stay calm, cushion their head with something soft, and clear away anything they could be hurt by. Don't hold them down or put anything in their mouth. If they're jerking or shaking, gently turn them onto their side once the jerking stops, to help them breathe.

Call 999 if it's the first time it's happened, it lasts longer than 5 minutes or longer than usual for them, they don't recover as usual afterwards, they have another seizure without recovering in between, or they've had 3 or more seizures in 24 hours. If you've had a seizure for the first time but didn't go to hospital, or you have a seizure after a long gap without one, contact your GP urgently or call NHS 111.