Status epilepticus is one of the true neurological emergencies, and it features in the Neurology SCE, the Acute Medicine SCE and MRCP. This overview covers what it is, why it matters and the concepts physicians are expected to understand.

Definition

Older definitions used a duration of 30 minutes. In current practice, a tonic-clonic seizure lasting five minutes or more, or repeated seizures without recovery of consciousness in between, is treated as status epilepticus. The change reflects evidence that seizures become harder to stop the longer they continue.

Why time matters

Prolonged seizures are associated with neuronal injury, systemic complications such as hypoxia, aspiration, rhabdomyolysis and cardiac arrhythmia, and higher mortality. For this reason hospitals follow a time-based protocol, and exams test whether candidates understand the principle of escalating care promptly.

Types

  • Convulsive status epilepticus, with ongoing tonic-clonic activity.
  • Focal status epilepticus, which may affect one limb or one side of the body.
  • Non-convulsive status epilepticus, in which a patient remains confused or drowsy without obvious jerking. It is easily missed and is confirmed with EEG.

Causes

Status epilepticus is often the presentation of another problem. In people with known epilepsy, missed medication or a recent change in treatment is common. Other causes include alcohol withdrawal, low blood glucose, low sodium or calcium, infection including encephalitis and meningitis, stroke, brain tumour, head injury and drug toxicity.

Recognising mimics

Not every prolonged episode is epileptic. Functional (dissociative) seizures, syncope with brief jerking and movement disorders can all be mistaken for status. Features such as eyes closed during the event and fluctuating movements suggest a functional cause, but the distinction can be difficult and specialist assessment is important.

How to revise

Focus on the definition, the types, the causes and the importance of time. Exam questions often present a drowsy patient after a seizure and expect you to consider non-convulsive status, or present a first episode and expect you to search for an underlying cause.