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 or days 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 represented by the occurrence of three seizures over the course of two days.
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. Of note, infantile spasms, a very common seizure type in babies with TSC, by nature occur in clusters and do not require rescue medication administration.