A 4-month-old male presents with clusters of brief flexion spasms of the trunk and limbs occurring predominantly upon waking, with developmental regression over 2 weeks. His mother reports capturing video of the episodes. EEG shows the pattern marked **D** in the diagram — hypsarrhythmia with a modified variant showing focal lateralization and increased posterior synchrony. Examination reveals ash-leaf macules on the trunk under Wood lamp. Which of the following represents the most evidence-based first-line management approach for this condition?

Explanation

## Why High-dose ACTH or prednisolone combined with vigabatrin is correct The clinical presentation describes infantile spasms (West syndrome) with the EEG pattern marked **D** — hypsarrhythmia with modified variant features (focal lateralization, posterior synchrony) consistent with a structural etiology. The ash-leaf macules under Wood lamp examination are pathognomonic for tuberous sclerosis complex (TSC), a leading identifiable cause of infantile spasms. According to Nelson 21e and Harrison 21e Ch 422, the evidence-based first-line approach combines: (1) ACTH or high-dose prednisolone for 2 weeks with taper (standard hormonal therapy for infantile spasms); (2) vigabatrin as first-line for TSC-associated infantile spasms (superior efficacy in TSC); (3) baseline ERG and visual field assessment before vigabatrin initiation to establish baseline vision and monitor for the known adverse effect of irreversible visual field constriction (30–40% incidence). The ICISS trial demonstrated that combined hormonal + vigabatrin therapy yields superior seizure control and developmental outcomes compared to monotherapy. Early treatment (within 2 weeks of spasm onset) significantly improves long-term neurodevelopmental prognosis. ## Why each distractor is wrong - **Vigabatrin monotherapy with monthly visual field monitoring**: While vigabatrin is first-line for TSC-associated infantile spasms, monotherapy is inferior to combined hormonal + vigabatrin (ICISS trial evidence). Additionally, visual field monitoring should occur *before* initiation (baseline ERG/VF) and during therapy, not monthly alone; baseline assessment is mandatory. - **Levetiracetam as first-line agent with standard dosing**: Levetiracetam is not established as first-line for infantile spasms. ACTH, prednisolone, and vigabatrin (especially in TSC) are the evidence-based first-line agents. Levetiracetam may be considered as adjunctive or second-line therapy but lacks the robust trial evidence supporting hormonal therapy and vigabatrin in this context. - **Phenobarbital with phenytoin combination therapy**: Phenobarbital and phenytoin are older anticonvulsants with limited efficacy in infantile spasms and are not recommended as first-line. They lack the evidence base of ACTH, prednisolone, and vigabatrin, and their use delays definitive treatment, worsening developmental outcomes. **High-Yield:** In infantile spasms with ash-leaf macules (TSC), combine ACTH/prednisolone + vigabatrin with baseline ERG/visual field assessment; early treatment (within 2 weeks) is critical for neurodevelopmental prognosis. [cite: Nelson 21e; Harrison 21e Ch 422; ICISS trial evidence on combined hormonal + vigabatrin superiority]