Status epilepticus (SE) is a very severe type of seizure.

For someone who has seizures, they’re normally similar in length each time they occur and typically stop once that time period has passed. SE is the name given to seizures that don’t stop, or when one seizure comes after another without the person having time to recover.

SE may be regarded as the most extreme form of epilepsy, or it may be a feature of a serious brain disorder. Such disorders include a stroke or inflammation of the brain tissue.

According to a 2012 review, SE happens to up to 41 per 100,000 people per year.

SE was given a new definition in 2015 as part of a revision of the classification of seizures. This is to help make diagnosing and managing seizures easier.

Previous definitions didn’t provide specific time points for when to treat SE or when long-term side effects or complications were likely to begin.

The proposed new definition of SE, published in the journal Epliepsia, is “a condition resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms, which lead to abnormally, prolonged seizures (after time point t1). It is a condition, which can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures.”

Time point t1 is the point at which treatment should begin. Time point t2 is the point at which long-term consequences may develop.

The time points differ depend on whether the person has convulsive or nonconvulsive SE.

Convulsive SE is the more common type of SE. It occurs when a person has prolonged or repeated tonic-clonic seizures.

This is an intense epileptic seizure and can cause:

  • sudden unconsciousness
  • muscle stiffening
  • rapid jerking of the arms or legs
  • loss of bladder control
  • tongue biting

Convulsive SE occurs when:

  • the tonic-clonic seizure lasts five minutes or longer
  • a person goes into a second seizure before recovering from the first one
  • a person has repeated seizures for 30 minutes or longer

For the new proposed definition of SE, time point t1 is five minutes, and time point t2 is 30 minutes.

Nonconvulsive SE occurs when:

  • a person has long or repeated absence or focal impaired awareness (also called complex partial) seizures
  • a person may be confused or unaware of what’s going on, but isn’t unconscious

Nonconvulsive SE symptoms are harder to recognize than convulsive SE symptoms. The medical community doesn’t yet have specific time points for when to treat or when long-term consequences are likely to begin.

Only about 25 percent of people who have seizures or SE have epilepsy, according to the Epilepsy Foundation. But 15 percent of people with epilepsy will have an SE episode at some point. It mostly happens when the condition isn’t well-managed with medications.

Most cases of SE happen to children under 15, especially in young children who have a high fever, and to adults over 40, with stroke leading to SE late in life.

Other possible causes of SE include:

  • low blood sugar
  • HIV
  • head trauma
  • heavy alcohol or drug use
  • kidney or liver failure

Doctors may order the following to diagnose SE:

Other possible tests include:

It can be difficult to diagnose nonconvulsive SE because the condition may be mistaken for other conditions, such as psychosis and drug intoxication.

Treatment for SE depends on whether the person is treated at home or in a hospital.

First-line treatment at home

If you’re treating a person having seizures at home, you must:

  • Ensure the person’s head is protected.
  • Move the person away from any danger.
  • Resuscitate as required.
  • Give emergency medication if trained to do so, such as midazolam (applied inside the person’s cheek or nose, using a dropper) or diazepam (injected in gel form into the person’s rectum).

Call an ambulance for a person who has any type of seizure if:

  • It’s their first seizure.
  • It lasts longer than five minutes (unless this is their usual).
  • More than one tonic-clonic seizure happens in quick succession without recovery in between.
  • The person suffered an injury.
  • You think urgent medical care is needed for any other reason.

Treatment in the hospital

First-line treatment in the hospital is likely to consist of:

  • high-concentration oxygen followed by intubation
  • assessment of cardiac and respiratory function
  • intravenous (IV) diazepam or lorazepam to suppress seizure activity

IV phenobarbital or phenytoin may be given to suppress electrical activity in the brain and nervous system if IV lorazepam doesn’t work.

Hospital staff will also carry out any necessary emergency investigations, such as blood gases, renal function, liver function, AED levels, and calcium and magnesium.

People with SE have an increased risk of permanent brain damage and death. People with epilepsy also have a small risk of sudden unexpected death in epilepsy (SUDEP). According to the Mayo Clinic, about 1 percent of adults with epilepsy die from SUDEP each year.

SE is considered to be a medical emergency and should be treated by medical professionals. But anyone can give emergency medications if they’re properly trained.

All people with epilepsy should have an individual care plan with a section on emergency medication. This should state:

  • when medication is used
  • how much should be given
  • what steps should be taken afterward

The person with epilepsy should write the care plan with their doctor or nurse. This lets them give their informed consent to emergency treatment.

No action may be required if a person’s seizures always last for a little longer than five minutes and end by themselves. An emergency care plan is vital if the person has previously had longer seizures that required emergency medications.