Epilepsy explained: seizures, diagnosis and treatment

What epilepsy and seizures are

The brain works using tiny electrical signals passing between nerve cells. A seizure happens when there is a sudden burst of excessive electrical activity that disrupts how the brain normally works. Epilepsy is diagnosed when someone has a lasting tendency to have these seizures. Seizures are broadly divided into two groups. Focal seizures start in one part of the brain and may cause odd sensations, twitching, or altered awareness. Generalised seizures involve both sides of the brain and include the well-known convulsive type, with stiffening and jerking, as well as brief absences where a person appears to switch off. One seizure does not always mean epilepsy; doctors look at the pattern and cause.

What causes it

In many people, no clear cause is found, and the epilepsy is described as being of unknown cause. In others, it can be linked to a difference in how the brain has developed, a genetic tendency, a previous head injury, a stroke, a brain infection or a scar on the brain. Epilepsy can begin at any age, though it often starts in childhood or in older age. Certain things can make seizures more likely in someone who has epilepsy, such as missing medicine, lack of sleep, alcohol, stress or illness. For a small number of people, flashing lights can trigger seizures, but this is less common than many assume.

How it is diagnosed

Diagnosing epilepsy relies heavily on a detailed description of what happened before, during and after the episodes, so an account from someone who witnessed it is very valuable. You should be referred to a specialist, usually a neurologist. Tests help find the type and cause. An EEG records the brain’s electrical activity and can show patterns linked to epilepsy. Brain scans, usually an MRI, look for any underlying cause such as a scar or structural difference. Blood tests may rule out other conditions that can mimic seizures, such as faints or low blood sugar. Reaching the right diagnosis matters, because treatment and advice depend on the type of epilepsy.

Treatment on the NHS

Most people with epilepsy are treated with anti-seizure medicines, which reduce the tendency of the brain to have seizures. The aim is to prevent seizures with as few side effects as possible, usually starting with a single medicine chosen for your seizure type. Many people become seizure-free on treatment. If one medicine does not work, another may be tried, or occasionally a combination. Never stop epilepsy medicine suddenly, as this can trigger seizures. For a minority whose seizures are not controlled by medicines, other options such as surgery, special diets or nerve stimulation devices may be considered by specialists. Regular reviews help keep treatment right for you.

Seizure first aid and living safely

If you see someone having a convulsive seizure, stay calm, protect them from injury by cushioning their head and moving nearby objects, and time the seizure. Do not restrain them or put anything in their mouth. When the jerking stops, gently roll them onto their side and stay until they recover. Call 999 if the seizure lasts more than five minutes, if another follows quickly, if they are injured, or if it is their first seizure. Living with epilepsy also involves practical steps: taking medicine reliably, getting enough sleep, and following DVLA rules about driving, which usually requires a seizure-free period. Support is available from your epilepsy team.