An estimated 70% of people with epilepsy can expect to become seizure-free with optimised anti-epileptic therapy. Conversely, a sizeable minority of patients will continue to experience break-through seizures. Although these are bound to be a frightening experience for the patient and their family, many seizures are self-limiting within a short time, without the need for rescue medication.

A prolonged acute convulsive seizure is defined as a seizure lasting more than 5 min, or two or more seizures occurring within 30 min without the complete recovery of consciousness in between. In contrast to brief seizures, a seizure lasting more than 5min is far less likely to be self-terminating, and may often progress to Status Epilepticus if untreated.

Status Epilepticus (SE) is defined as a seizure lasting more than 30 min, and may be associated with significant morbidity. Common sequelae include learning difficulties, memory deficits, and the ongoing risk of subsequent prolonged seizure activity. Alongside the underlying cause, seizure duration is a primary determinant of prognosis.

SE also carries a significant risk of death. Mortality in the paediatric population is estimated at up to 5%, and this figure rises exponentially in refractory cases.