Epilepsy

What happens in a seizure

The brain's nerve cells communicate with electrical signals. A seizure occurs when a large group of neurons fires in an abnormal, synchronized burst. What the person experiences depends on where in the brain this happens and how far it spreads. Most seizures last from a few seconds to 2 minutes.

A single seizure does not mean epilepsy. Seizures can be provoked by low blood sugar, alcohol withdrawal, high fever in young children, or certain drugs. Epilepsy means the brain has an ongoing tendency to generate unprovoked seizures.

Types of seizures

The ILAE classifies seizures by where they start:

Focal seizures

Start in one area of one side of the brain.

• Focal aware: the person stays aware. They may feel a rising sensation in the stomach, déjà vu, fear, an odd smell or taste, tingling, or jerking of one limb. These are sometimes called auras.
• Focal impaired awareness: the person becomes confused or unresponsive, often staring, lip-smacking, fumbling with hands or wandering, with no memory of it afterward.
• Focal to bilateral tonic-clonic: a focal seizure spreads to both sides, causing a convulsion.

Generalized seizures

Involve both sides of the brain from the start.

• Tonic-clonic: stiffening (tonic), then rhythmic jerking (clonic), loss of consciousness, sometimes tongue biting and incontinence, followed by confusion and tiredness.
• Absence: brief staring spells of a few seconds, often many times a day, mainly in children. The person stops, then carries on as if nothing happened.
• Myoclonic: sudden, brief jerks, often in the morning.
• Atonic: sudden loss of muscle tone, causing falls ("drop attacks").
• Tonic: sudden stiffening.

Causes

• Genetic: many generalized epilepsies, including childhood absence epilepsy and juvenile myoclonic epilepsy, have a genetic basis.
• Structural: stroke (the commonest cause in older adults), head injury (post-traumatic seizures), brain tumors, malformations of brain development, hippocampal sclerosis.
• Infectious: meningitis, encephalitis, neurocysticercosis, HIV.
• Metabolic and immune: rare metabolic disorders and autoimmune encephalitis.
• Developmental conditions: such as cerebral palsy and autism.
• Unknown: in about half of cases, no cause is found.

Seizure triggers

In people with epilepsy, seizures are more likely with missed medicine, lack of sleep, alcohol, illness and fever, stress, menstrual hormone changes and, in some people, flashing lights (photosensitive epilepsy, a minority).

Conditions that can look like epilepsy

• fainting (syncope): brief loss of consciousness, often with a few jerks, quick recovery
• functional (psychogenic nonepileptic) seizures
• migraine with aura
• transient ischemic attacks
• sleep disorders and panic attacks

An accurate eyewitness account, or a video of an episode on a phone, is very helpful in telling these apart.

Diagnosis

• Detailed history from the person and witnesses.
• EEG (electroencephalogram): records brain electrical activity and may show epileptic patterns. A normal EEG does not rule out epilepsy. Sleep-deprived or prolonged video EEG may be used.
• MRI of the brain: looks for structural causes.
• Blood tests: glucose, electrolytes, and others to exclude provoked seizures.
• ECG: to rule out heart rhythm causes of collapse.
• Genetic testing in some children and adults.

Treatment

Anti-seizure medicines

Most people start one medicine, chosen according to seizure type, age, sex, other conditions and side effects. Common options include levetiracetam, lamotrigine, carbamazepine, oxcarbazepine, lacosamide, valproate, topiramate and zonisamide.

• About 2 in 3 people become seizure-free with medicines, usually with the first or second drug tried.
• Valproate is highly effective for generalized epilepsy but causes birth defects and developmental problems, so it is avoided in women and girls who could become pregnant unless no other option works.
• Take medicines at the same times daily and never stop suddenly, which can trigger severe seizures.

Drug-resistant epilepsy

When two appropriate medicines have failed, a specialist epilepsy center can assess:

• epilepsy surgery: removing or disconnecting the seizure focus, which can stop seizures entirely in suitable people, such as those with temporal lobe epilepsy
• laser ablation: a minimally invasive alternative for some focal epilepsies
• neurostimulation: vagus nerve stimulation (VNS), responsive neurostimulation (RNS) and deep brain stimulation (DBS)
• dietary therapy: ketogenic or modified Atkins diets, especially in children

Seizure first aid

For a tonic-clonic seizure:

1. Stay calm and time it.
2. Keep the person safe: move hard or sharp objects away, cushion their head.
3. Do not hold them down and do not put anything in their mouth.
4. When jerking stops, roll them onto their side to keep the airway clear.
5. Stay with them until they are fully awake, and speak calmly.
6. Call 911 if it lasts more than 5 minutes, another seizure follows, they are injured, pregnant, in water, have trouble breathing, or it is their first seizure.

For focal impaired awareness seizures, gently guide the person away from danger and stay with them until they are fully aware.

Living with epilepsy

• Driving: most US states require a seizure-free period, often 3 to 12 months, before driving. Check your state's rules.
• Safety: shower rather than bathe, swim only with supervision, and use caution with heights and heat.
• Sleep, alcohol and stress: regular sleep and limited alcohol reduce seizures.
• Pregnancy: plan with your neurologist; take folic acid; some medicines need dose changes.
• Mental health: depression and anxiety are more common in people with epilepsy and should be treated.
• SUDEP: sudden unexpected death in epilepsy is rare but is the most common epilepsy-related cause of death. The risk is highest with frequent uncontrolled tonic-clonic seizures, especially at night. Good seizure control lowers it.

Outlook

Many children outgrow certain epilepsies. Adults who are seizure-free for 2 years or more may, with their neurologist, consider slowly stopping medicine, though seizures return in some. With treatment, most people with epilepsy work, drive, have families and lead full lives.

Frequently asked questions

What is epilepsy?

Epilepsy is a brain condition that causes repeated, unprovoked seizures due to abnormal electrical activity. It is usually diagnosed after two unprovoked seizures, or one seizure with a high risk of more. It can begin at any age.

What are the first signs of epilepsy?

First signs vary: a convulsion, staring spells, brief jerks, sudden falls, déjà vu or odd smells, or episodes of confusion with memory gaps. Any first seizure needs urgent medical assessment.

What causes epilepsy?

Causes include genetic factors, stroke, head injury, brain infections, tumors and differences in brain development. In about half of people, no specific cause is found.

Can epilepsy be cured?

Some people become permanently seizure-free, including many children who outgrow their epilepsy and some adults after epilepsy surgery. For most, medicines control seizures rather than cure the underlying condition.

What should you do if someone has a seizure?

Stay calm, time the seizure, move dangerous objects away, cushion the head, and do not restrain them or put anything in their mouth. Turn them on their side after jerking stops. Call 911 if it lasts over 5 minutes or another seizure follows.

Can you drive with epilepsy?

Usually yes, once seizures are controlled. Most US states require a seizure-free period, commonly 3 to 12 months, before driving. Rules vary by state and for commercial licenses, so check with your neurologist and local licensing agency.