Seizures

Overview

A seizure happens when a group of brain cells fire abnormal electrical signals all at once. Depending on which part of the brain is involved, this can cause jerking movements, stiffening, staring spells, unusual sensations, confusion, or loss of awareness. A seizure is an event, not a disease by itself.

Having one seizure does not always mean a person has epilepsy. A single seizure can be triggered by a temporary problem such as fever, low blood sugar, alcohol withdrawal, or a head injury. Epilepsy is the term used when a person has a lasting tendency to have repeated, unprovoked seizures. Most seizures stop on their own within a couple of minutes.

Symptoms

Seizures look very different from person to person. Signs depend on the type of seizure and which part of the brain is affected.

• Generalized tonic-clonic seizure: loss of consciousness, body stiffening, then rhythmic jerking of the arms and legs
• Absence seizure: brief staring spells with a blank look, common in children
• Focal seizure: twitching, tingling, strange smells or tastes, fear, or repeated movements such as lip-smacking, sometimes with altered awareness
• Temporary confusion, a dazed feeling, or trouble speaking
• Loss of bladder or bowel control during the event

Many people feel tired, sore, or confused for minutes to hours afterward. This recovery period is called the postictal phase. Some people notice a warning feeling before a seizure, known as an aura, which can include a strange smell, a rising sensation in the stomach, or a sense of fear or familiarity. Recognizing an aura can sometimes give a person a few moments to get to a safe place.

Causes

Seizures can be provoked by a wide range of conditions that disturb normal brain activity:

• Epilepsy and other long-standing seizure disorders
• High fever, especially in young children (febrile seizures)
• Very low blood sugar or low sodium levels
• Head injury, stroke, or brain infection such as meningitis
• Alcohol or drug withdrawal, or drug overdose
• Lack of oxygen to the brain
• Brain tumors or birth-related brain differences

In many people, especially those with epilepsy, no single cause is found.

Risk Factors

• A personal or family history of epilepsy
• Previous head injury or stroke
• Brain infections or developmental brain conditions
• Sleep deprivation
• Heavy alcohol use or sudden withdrawal
• Certain medications or recreational drugs

Diagnosis

Because the seizure itself is often over before a doctor sees the person, diagnosis relies heavily on the description of what happened.

• History: a detailed account from the person and any witnesses, including what happened before, during, and after
• EEG (electroencephalogram): records the brain's electrical activity to look for patterns linked to seizures
• Brain imaging: MRI or CT scans to look for structural causes such as injury, stroke, or tumor
• Blood tests: to check for low blood sugar, electrolyte problems, infection, or drug effects

Treatment

Treatment depends on the cause and on whether seizures are likely to recur.

• Anti-seizure medications: the mainstay of treatment for epilepsy; the goal is to control seizures with as few side effects as possible
• Treating the trigger: correcting low blood sugar or sodium, treating infection, managing fever, or stopping an offending drug
• Other options: for hard-to-control epilepsy, doctors may consider special diets, nerve stimulation devices, or surgery

Seizure first aid: keep the person safe, ease them to the floor, turn them onto their side, cushion the head, remove nearby hazards, and do not put anything in their mouth or hold them down. Stay until they are fully alert, and time how long the seizure lasts so you can tell medical staff. Loosen anything tight around the neck and speak calmly and reassuringly as the person recovers, since they may be confused or frightened.

Prevention

• Take anti-seizure medication exactly as prescribed and do not stop suddenly
• Get regular, adequate sleep
• Limit or avoid alcohol and recreational drugs
• Manage fevers promptly in young children
• Identify and avoid personal seizure triggers, such as flashing lights for some people

When to See a Doctor

See a doctor after any first-time seizure to find the cause. Call emergency services right away if:

• A seizure lasts longer than 5 minutes
• The person does not wake up or has trouble breathing after the seizure stops
• Another seizure begins before the person fully recovers
• The seizure happens in water, during pregnancy, or with diabetes, injury, or high fever
• It is the person's first known seizure

Related Topics

Frequently Asked Questions

References

1. National Institute of Neurological Disorders and Stroke (NINDS). Epilepsy and Seizures.
2. Mayo Clinic. Seizures - Symptoms and causes.
3. Centers for Disease Control and Prevention (CDC). Epilepsy.
4. MedlinePlus, U.S. National Library of Medicine. Seizures.