Seizure clusters are typically defined as an increase in someone’s usual number of seizures over a specific time period. They are often described as three or more seizures in a 24-hour period.

People who experience a seizure cluster can be at risk for status epilepticus if the seizure cluster lasts longer in duration than it would normally. Status epilepticus is defined as seizure activity lasting over 5 minutes, or multiple seizures without recovery between each seizure. A person with a seizure cluster can also be at risk for status epilepticus if the clusters occur very close together in time, if the person is unable to recover between seizures, or if anti-seizure medications are unable to stop the seizures.

The definition of a seizure cluster can be vague. Some people use the term to describe periods of time when their seizure frequency is higher than normal. If you are experiencing more seizures than you typically do, it is important to let your doctor know right away, with detailed descriptions of your seizures. Having a seizure diary can help you document and remember specific details.

Seizure clusters need to be recognized early to prevent an emergency, get treated quickly, and improve the quality of life for the person living with epilepsy.

Are Certain Types of Epilepsy More Likely To Have Seizure Clusters?

Seizure clusters may be associated with focal (or localized) epilepsies, such as temporal lobe epilepsy. However, clusters can also occur in people living with generalized epilepsy. One small study surveyed people living with epilepsy and found that almost one-third of participants experienced seizure clusters. In this study, the most frequent type of epilepsy reported with seizure clusters was extratemporal lobe epilepsy, or epilepsy that originates in places other than the temporal lobe.

Another study looked at people with focal onset impaired awareness seizures (previously known as complex partial seizures) or partial seizures that progress into generalized seizures (previously known as secondarily generalized seizures). Of these people, approximately 66 percent displayed some type of seizure cluster.

Risk Factors for Seizure Clusters

Regardless of epilepsy type, cluster seizures are more likely to happen in people who have a hard time controlling their seizures or have refractory epilepsy. Refractory epilepsy, also called drug-resistant or intractable epilepsy, is defined as epilepsy that has not responded to two or more anti-seizure medications.

In one study of risk factors for seizure clusters, scientists found that seizure clusters were associated with:

• An earlier age of seizure onset
• Symptomatic generalized epilepsy
• Cortical dysplasia (when the top of the brain doesn’t form correctly)
• An infection of the central nervous system
• Having seizures at least once per year
• Refractory epilepsy
• Status epilepticus

Symptoms of Seizure Clusters

Seizure cluster symptoms will depend on the type of epilepsy a person has. In general, seizure clusters happen when a person has three or more seizures within 24 hours. Clusters have also been reported over periods of 4 hours.

General symptoms of seizures include:

• Confusion
• Uncontrollable jerking in the arms or legs
• Staring
• Loss of awareness or consciousness
• Anxiety, fear, or deja vu

Treating Seizure Clusters

Treating seizure clusters is critical. The earlier someone receives treatment for seizure clusters, the better their outcome will be.

Several medications can be used to treat cluster seizures outside of the hospital, including Nayzilam (midazolam nasal spray), Valtoco (diazepam nasal spray), and the rectal form of Diastat (diazepam). These medications may be difficult to give someone during a seizure emergency, but it’s important to have rescue medications on hand if you have epilepsy or take care of someone who does. You should also have a seizure action plan.

Other rescue medications are available in the hospital. The same types of medications used to treat regular seizures are used to treat cluster seizures. These drugs are known as antiepileptic drugs or anti-seizure medications. Benzodiazepines are the medication class of choice for controlling seizure activity.

You should notify your doctor as soon as possible if you have a seizure cluster, even if taking your rescue medication resolves it. If your epilepsy is complex, you may need to visit a hospital with a specialized epilepsy center for the most effective treatment.

Visit your nearest emergency room right away if you experience a seizure cluster and you do not have a rescue medication, if your medication is not working, or if you have continued seizures.

Building a Community

MyEpilepsyTeam is the social network for people with epilepsy and their loved ones. On MyEpilepsyTeam, members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.

Do you or a loved one experience seizure clusters? Have you made a seizure action plan? Share your experience in the comments below, or start a conversation by posting on MyEpilepsyTeam.