Absence Seizures (Petit Mal): Symptoms, Diagnosis & Treatment
Absence seizures (formerly petit mal) are generalized non-motor seizures with brief (4–20 sec) impaired awareness. Onset 4–12 years; often outgrown by adolescence.
Clinical Features
- Sudden behavioral arrest: blank stare, unresponsive.
- Automatisms: lip smacking, eyelid flutter (3 Hz), hand fumbling.
- No postictal confusion — immediate resumption.
- Can occur dozens/hundreds daily; mistaken for daydreaming/ADHD.
- Provoked by hyperventilation (90% trigger).
EEG Hallmark
Generalized 3 Hz spike-and-wave discharges (frontally predominant). Activated by hyperventilation, photic stimulation.
Differential
- Focal impaired awareness seizures (longer, postictal, focal EEG).
- Daydreaming/ADHD (interruptible, no EEG correlate).
- Juvenile absence epilepsy (onset 10–17, may have GTCS).
Treatment
| First-Line | Alternative/Adjunct | Avoid (Worsen) |
|---|---|---|
| Ethosuximide (most specific) | Valproate (if also GTCS; teratogen) | Carbamazepine, oxcarbazepine, phenytoin, gabapentin, pregabalin, vigabatrin |
| Lamotrigine (slower titration) | Levetiracetam, zonisamide |