About Seizure Emergencies

Seizure clusters and status epilepticus are common in LGS and are seizure emergencies.

What is a Seizure Cluster?

The definition of a seizure cluster varies from one individual to another, but in general, the term refers to a group of seizures occurring over a number of hours in a way that differs from an individual’s usual seizure pattern. For one patient, having three seizures over the course of two hours may represent a seizure cluster, while for another, a seizure cluster may be dozens of seizures over a few minutes. Adverse effects of seizure clusters include risk of injury from the seizures themselves, prolonged recovery time after seizures, and missed work, school, or social activities. Seizure clusters may progress into status epilepticus.

What is a Status Epilepticus?

The official definition of status epilepticus has evolved over time, but the term generally refers to a prolonged seizure that may not stop on its own without intervention. The most recent definition presented by the International League Against Epilepsy identifies generalized convulsive (tonic-clonic) status epilepticus as a seizure lasting longer than five minutes, with an increased risk of brain injury if the seizure continues for too long. For other seizure types, such as focal or absence seizures, these time points may be more prolonged.

The majority of seizures in individuals with LGS are short and terminate on their own in less than two to three minutes. However, if status epilepticus occurs, it is a medical emergency that may result in severe consequences if not treated rapidly.

What is a Non-Convulsive Status Epilepticus?

Non-convulsive status epilepticus (NCSE) is a prolonged seizure that looks like an altered mental state as opposed to the dramatic convulsions seen in generalized tonic-clonic status epilepticus. There are 2 main types of NCSE.

In the first type of NCSE, patients are confused or behaving abnormally and appear to be having a non-stop absence (petit mal) seizure or a non-stop focal impaired awareness (complex partial) seizure.

The second type of NCSE is subtle and occurs after a long generalized tonic-clonic seizure. The person will have continuous subtle motor jerks, especially of the face or hands, and this persists over time. Brain damage can occur if not treated in a timely manner.

What Causes Seizure Clusters and Status Epilepticus?

People with intractable epilepsy (seizures that are not controlled by medication) are at higher risk for having seizure clusters or status epilepticus, but these episodes may also occur in people whose seizures are usually well controlled.

Some common triggers for seizure clusters or status epilepticus include:

Illness
Missed antiseizure medication doses
Sleep deprivation
Stress
Having a Developmental and Epileptic Encephalopathy (DEE), such as LGS
Menstrual cycle

Seizure clusters or status epilepticus may also occur without an apparent trigger.

Keeping a seizure diary may be helpful in identifying seizure patterns triggers.