Seizures: Definition, Types & Clinical Presentation

A seizure is a transient occurrence of signs/symptoms due to abnormal excessive or synchronous neuronal activity in the brain. It is a symptom, not a diagnosis.

Classification (ILAE 2017)

• Focal Onset: Originates in one hemisphere.
  • Aware (consciousness intact)
  • Impaired awareness
  • Motor (automatisms, tonic, clonic, myoclonic)
  • Non-motor (sensory, autonomic, emotional, cognitive)
• Generalized Onset: Bilateral networks from onset.
  • Motor: Tonic-clonic (grand mal), tonic, clonic, myoclonic, atonic (drop attacks).
  • Non-motor (absence): Typical, atypical, myoclonic, eyelid myoclonia.
• Unknown Onset: Insufficient data.
• Unclassified.

Example Clinical Scenario

"The patient experienced a sudden generalized tonic-clonic seizure: abrupt loss of consciousness, fall, body stiffening (tonic phase, 10–30 sec), then rhythmic jerking (clonic phase, 1–2 min), followed by postictal confusion, fatigue, and amnesia. Tongue biting and urinary incontinence occurred."

Key Phases

• Prodrome: Hours/days before (mood change, headache, "feeling off").
• Aura: Focal aware seizure (warning): déjà vu, epigastric rising, visual/sensory changes.
• Ictal: Seizure activity itself.
• Postictal: Confusion, drowsiness, headache, Todd's paralysis (transient weakness).

First Aid

• Stay calm; time the seizure.
• Protect from injury (move objects, cushion head).
• Do NOT restrain, put anything in mouth, give water/meds.
• Roll to recovery position after jerking stops.
• Call 911 if: >5 min, recurrent without recovery, first seizure, injury, pregnancy, diabetes, water.

Epilepsy vs. Seizure

Epilepsy = ≥2 unprovoked seizures >24h apart, or 1 unprovoked + high recurrence risk (e.g., abnormal EEG/MRI), or epilepsy syndrome diagnosis.