Synopsis
Apply the 2025 ILAE seizure classes and supported consciousness and manifestation descriptors, avoid inferring a Generalized seizure from bilateral convulsions alone, and use classification to select safe investigations and syndrome-appropriate treatment.
- Use the 2025 ILAE main classes—Focal, Generalized, Unknown whether focal or generalized, and Unclassified—then apply supported classifiers and descriptors: consciousness where assessable, observable or non-observable manifestations, and the chronological evolution of the event.
- A Focal seizure begins in a network limited to one hemisphere. When assessable, classify consciousness as preserved or impaired—using both awareness and responsiveness—then describe observable and non-observable manifestations in the order they occurred.
- A focal to bilateral tonic-clonic seizure may look fully generalised once convulsions spread, so the aura, first head or eye deviation and initial unilateral movement are disproportionately informative.
Investigation priorities
Identify the earliest manifestation, consciousness and sequence needed to assign a seizure class and supported descriptors.
Management branches
A suspected epileptic event is being classified after immediate safety needs are met.
- 1. Ask what the person experienced first, including sensory, emotional, cognitive, autonomic or motor symptoms before awareness changed.
- 2. Ask witnesses about responsiveness, eye and head direction, first moving body part, symmetry, sequence, duration and post-event behaviour without offering diagnostic labels.
Key medicines
Lamotrigine or levetiracetam for focal seizuresNICE advises either as first-line monotherapy; dosing is titrated from the current BNF and product guidance, with lamotrigine increased particularly slowly and according to interacting medicines.
Ethosuximide for isolated absence seizuresNICE recommends ethosuximide first line for absence seizures without other seizure types; start and titrate using age, weight, current formulary and specialist instructions.