A 6-year-old child with childhood absence epilepsy (CAE) has been having multiple absence seizures per day. First-line treatment is started. Which EEG pattern is pathognomonic of CAE, and which drug combination is currently considered MOST effective based on the 2010 NIH-funded CHILDHOOD ABSENCE EPILEPSY study?

• A Hypsarrhythmia; ACTH (tetracosactide) is the drug of choice
• B Focal temporal sharp waves; carbamazepine monotherapy is first-line
• C 3 Hz spike-wave discharges; lamotrigine monotherapy is first-line with lowest side effect profile
• D 3 Hz generalized spike-and-slow-wave discharges; ethosuximide or valproate as first-line, ethosuximide shown to be superior in attentional outcomes ✓

Explanation

Childhood absence epilepsy (CAE) is characterized pathognomically by 3 Hz generalized spike-and-slow-wave discharges on EEG, typically lasting 4–20 seconds and precipitated by hyperventilation. The NIH Childhood Absence Epilepsy study (Glauser et al. 2010, NEJM) compared ethosuximide, valproate, and lamotrigine: ethosuximide and valproate were significantly more effective than lamotrigine. Importantly, ethosuximide had superior attentional function compared to valproate at 12 months. Hypsarrhythmia is the EEG hallmark of infantile spasms (West syndrome), treated with ACTH or vigabatrin.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.