absence (petit-mal) seizure

Epidemiology

• age 3-15 years
• uncommon in adults (not in adults)

Pathology

• generalized seizure

Clinical manifestations

• sudden loss of consciousness
• motionless stare
• automatisms
  • rhythmic eye blinking
  • lip smacking
  • chewing
  • swallowing
  • hand movements
• brief, 30 seconds; < 5 seconds; many per day
  • typically last < 20 seconds
• seizure ends suddenly with the patient fully alert
• no postictal state

* memory problems, confusion, falls, dizziness, numbness (presumptively absence seizure)

Laboratory

• electroencephalogram (EEG) shows 3 Hz spike wave complexes

Differential diagnosis

• focal seizure
• both absence seizure & focal seizure may begin as staring spells
  • focal seizures with impaired awareness have longer duration 15-60 vs < 20 seconds, lower frequency (not many/day) & presence of aura & post-ictal state
• non-convulsive status epilepticus in older adults

Management

• ethosuximide (Zarontin) agent of choice
• alternative agents
  • valproate (Depakote)
  • clonazepam (Klonopin)
  • lamotrigine (Lamictal)
  • topiramate (Topamax)
• pregnancy:
  • if not taking anticonvulsant, & no seizures in 18 months, observe

More general terms

• primary generalized seizure