Chart — Critical Care
Seizure Type Comparison Chart
Focal and generalized seizure types compared side-by-side — onset, consciousness, motor features, duration, postictal state, and clinical pearls.
Educational use only. Seizure classification and management require clinical assessment and physician-directed care. Follow institutional protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Seizure Classification Overview
| Category | Types | Key Feature |
|---|---|---|
| Focal onset | Aware (simple partial), Impaired awareness (complex partial), Focal to bilateral tonic-clonic | Starts in one brain region; may or may not spread |
| Generalized onset | Tonic-clonic, Absence, Myoclonic, Atonic, Tonic, Clonic | Both hemispheres involved simultaneously from onset |
| Unknown onset | Cannot classify based on available information | Requires EEG or additional clinical data to classify |
Seizure Type Detail Comparison
Focal onset aware (simple partial)
Onset
Focal — one hemisphere region
Consciousness
Preserved
Duration
Seconds to 2 minutes
Motor Features
Focal motor (twitching), sensory, autonomic, or psychic symptoms
Postictal
Minimal or none
Clinical Pearl
Patient is aware but may not be able to respond. Todd's paralysis possible after motor involvement.
Focal onset impaired awareness (complex partial)
Onset
Focal — spreads to impair awareness
Consciousness
Impaired
Duration
1–3 minutes
Motor Features
Automatisms: lip smacking, hand picking, repetitive movements, wandering
Postictal
Confusion for minutes to hours
Clinical Pearl
Patient appears conscious but cannot follow commands or respond meaningfully. Most common seizure type in adults.
Focal to bilateral tonic-clonic
Onset
Focal start, spreads bilaterally
Consciousness
Lost as it generalizes
Duration
1–3 minutes (full bilateral phase)
Motor Features
Focal onset → tonic stiffening → bilateral clonic jerking
Postictal
Prolonged confusion, fatigue (30 min–2+ hours)
Clinical Pearl
Focal onset distinguishes from primary generalized — lateralizing signs early may help localize the epileptic focus.
Generalized tonic-clonic (GTC)
Onset
Bilateral onset simultaneously
Consciousness
Immediate loss
Duration
1–3 minutes
Motor Features
Tonic phase (stiffening, cry, apnea) → clonic phase (rhythmic bilateral jerking)
Postictal
Deep confusion, fatigue, headache — 30 min to hours
Clinical Pearl
Classic 'grand mal.' Tongue biting, incontinence, post-event confusion are common. Cyanosis possible during tonic phase.
Generalized absence
Onset
Bilateral; abrupt onset
Consciousness
Brief impairment (stare)
Duration
5–30 seconds
Motor Features
None or subtle eye blinking; no falling
Postictal
None — abrupt return to activity
Clinical Pearl
Can be mistaken for daydreaming. 3 Hz spike-wave on EEG. Most common in children. Hyperventilation can provoke.
Myoclonic
Onset
Bilateral; usually morning
Consciousness
Usually preserved
Duration
Milliseconds to seconds
Motor Features
Brief sudden bilateral muscle jerks — may drop objects
Postictal
Minimal or none
Clinical Pearl
Classic in juvenile myoclonic epilepsy. May appear as 'clumsiness.' Can precede a GTC in the same morning.
Atonic (drop attack)
Onset
Bilateral; sudden
Consciousness
Briefly impaired
Duration
Seconds
Motor Features
Sudden loss of postural muscle tone — fall without warning
Postictal
Minimal; patient often immediately alert after fall
Clinical Pearl
High injury risk from falls — protective helmet considered in patients with frequent atonic seizures.
Status Epilepticus Threshold
Any seizure ≥5 minutes = Status Epilepticus
Also: two or more seizures without return to baseline between them. Treat at the 5-minute mark — do not wait. Non-convulsive SE may have no visible motor activity and requires EEG for diagnosis.
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Society of Critical Care Medicine (SCCM) · Surviving Sepsis Campaign · American Association of Critical-Care Nurses (AACN). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →