ICU · Neurocritical care / monitoring

Continuous EEG & Non-Convulsive Status Epilepticus

Also known as Continuous EEG · cEEG · Non-convulsive status epilepticus · NCSE · Salzburg criteria · PLEDs · Periodic lateralised epileptiform discharges · Ictal-interictal continuum · Status epilepticus · LPDs / GPDs / LRDA / GRDA · SIRPIDs · Burst suppression · Quantitative EEG

Continuous EEG (cEEG) monitoring in the ICU detects the non-convulsive status epilepticus (NCSE) — a continuous or recurring epileptiform activity on the EEG without the clinical motor convulsions, producing a persistent impaired consciousness. NCSE is common in the comatose ICU patient (10-30 per cent of the comatose patients, especially after a convulsive SE, a TBI, a SAH, or a cardiac arrest) and is detected only by the EEG — the clinical examination cannot distinguish it from the metabolic encephalopathy. The Salzburg criteria diagnose the NCSE (the epileptiform activity plus a response to the IV antiepileptic), and the ACNS terminology standardises the description of the ICU EEG patterns (LPDs, GPDs, LRDA, GRDA, SIRPIDs). cEEG is also the tool for the post-arrest prognostication (background reactivity, malignant patterns), for the seizure monitoring during the status epilepticus treatment, and for the burst-suppression verification during the anaesthetic coma. The treatment: 1st line IV benzodiazepine, 2nd line levetiracetam or valproate or fosphenytoin, 3rd line a continuous infusion (midazolam or propofol) for the refractory. Untreated, the NCSE worsens the neurological outcome.