Which of the following disorders involves sudden or gradual onset of loss of language skills and is characterized by nocturnal multifocal spikes and spike-wave discharge?

• A. Temporal lobe epilepsy
• B. Lennox-Gastaut syndrome
• C. Landau-Kleffner syndrome
• D. Dementia with Lewy bodies

Answer: (C)

Language regression with sleep-related epileptiform activity points to Landau-Kleffner syndrome. In this condition, a child who develops normally may suddenly or gradually lose language skills, sometimes accompanied by seizures. The hallmark EEG finding is nocturnal, sleep-activated multifocal spikes and spike-wave discharges, reflecting epileptiform activity that disrupts language processing during sleep. This combination—regression of language paired with sleep-activated epileptiform activity—is what distinguishes Landau-Kleffner syndrome from other epilepsy or cognitive disorders.