Definition

Status epilepticus refers to a prolonged seizure of any type. It is a neurological emergency that requires prompt assessment and treatment to avoid severe complications or death. [1] SE is far more common in adults than children.

Whilst most presentations are clinically obvious, typically with tonic-clonic seizures affecting all four limbs, some seizures may be far more subtle and require a high index of suspicion for diagnosis.

Rapid diagnosis and emergent treatment is essential to terminate the seizure and to minimise the risk of any long term neurological damage. Various treatment strategies are available but the mainstays of treatment are benzodiazepines.

Traditional definitions of SE refer to either:

• A single seizure persisting for more than 30 minutes
• Multiple seizures of shorter duration without a full neurological recovery in between seizures

Revised definition of SE refers to seizures that persist for more than five minutes without intervention or recurrent seizure activity without recovery between episodes. [1-6]

This relates to evidence demonstrating that:

• A significant proportion of seizures that continue for five minutes will persist for longer than 30 minutes
• The average seizure duration in adults is less than one minute

Hence, seizures that persist beyond five minutes represent a significant deviation from the norm.

Further to this, there is evidence that neuronal injury can result after just five minutes of seizure activity.

Established SE refers to clinical or electrographic seizures that persist for 30 minutes or longer without full neurological recovery in between.

Refractory SE is defined as the persistence of convulsions despite adequate doses of two intravenous anticonvulsant agents.

SE may be subdivided into convulsive and non-convulsive forms. These will be discussed in greater detail.