Infantile Spasms (West Syndrome)

A 6-month-old boy presents with clusters of sudden flexion spasms of the head, trunk, and limbs occurring on awakening (salaam attacks). Development has plateaued over the past month and he no longer tracks his mother's face. Examination reveals hypotonia and hypopigmented ash-leaf macules on the trunk, suggesting tuberous sclerosis complex (TSC). An interictal EEG (marked **B**) demonstrates a chaotic, high-voltage (>200 microvolts), disorganized background with multifocal spikes and slow waves with complete loss of normal architecture—hypsarrhythmia. Which of the following is the most appropriate first-line therapy for this patient?