Which EEG pattern is characteristic of infantile spasms?

• A. Hypsarrhythmia
• B. Normal EEG
• C. Focal discharges
• D. Burst-suppression

Answer: (A)

Infantile spasms are classically linked to hypsarrhythmia on EEG. This pattern is highly chaotic and disorganized, with very high-amplitude slow waves interwoven with multifocal spikes that occur asynchronously across different brain regions. It often shows up prominently during sleep and reflects widespread, irregular cerebral activity typical of West syndrome. This stands in contrast to a normal EEG, which would show no epileptiform abnormalities; focal discharges would imply a localized seizure focus rather than the diffuse, disorganized pattern seen here; burst-suppression describes alternating periods of low activity and bursts of spikes, a pattern more typical of severe encephalopathy or deep anesthesia, not the characteristic EEG finding in infantile spasms.