Infantile spasms and developmental epileptic encephalopathy — clinical case

Case summary

This six-month-old boy presents with the classic onset of West syndrome: two weeks of clustered flexor spasms on waking, captured on video, alongside developmental regression, a hypsarrhythmic EEG and a focal cortical dysplasia on MRI. He meets the ILAE 2022 definition of infantile epileptic spasms syndrome through the full classic triad, and the immediate priority is prompt first-line therapy, because the lag from spasm onset to treatment is a modifiable risk factor for developmental outcome. The focal cortical dysplasia on MRI and the absence of hypomelanotic macules together tell me this is a structural, non-TSC cause, which sets the first-line drug. [1] [11]

Key clinical issues

The first issue is confirming the diagnosis and the syndrome. The clustered flexor spasms, the loss of social smiling and babbling, and the chaotic, high-voltage hypsarrhythmic EEG together constitute West syndrome, and the EEG distinguishes true spasms from non-epileptic mimics such as Sandifer syndrome or benign myoclonus, both of which have a normal interictal EEG. This is a developmental and epileptic encephalopathy in which the ongoing epileptiform activity disrupts synaptogenesis in the immature brain, so the seizures are an active cause of developmental harm rather than merely a symptom. [7] [9]

The second issue is the aetiology and what it means for treatment. The focal cortical dysplasia is a structural cause, and the absence of hypomelanotic macules on Wood's lamp examination makes tuberous sclerosis unlikely. This is important because the first-line therapy turns on the TSC question: vigabatrin is first-line for TSC-associated spasms and hormonal therapy is first-line for every other cause. The focal lesion also raises the question of epilepsy surgery, because a resectable focal cortical dysplasia can be cured by early resection, so this child needs urgent referral to a paediatric epilepsy surgery centre for presurgical evaluation alongside first-line medical therapy. [5]

Investigations and management

The diagnosis is already secure from the triad and the EEG. I would complete the aetiology workup with chromosomal microarray and an epilepsy gene panel to exclude a coincident genetic cause, and I would arrange a formal baseline developmental assessment to benchmark the response to therapy. The first-line management is hormonal therapy, because the cause is structural and non-TSC: high-dose ACTH 150 IU per square metre per day by intramuscular injection, or oral prednisolone 40 to 60 mg per day, with blood-pressure and glucose monitoring, gastric protection, and vigilance for infection. Given the ICISS evidence that adding vigabatrin to hormonal therapy improves short-term spasm cessation, I would discuss combination therapy with the family while weighing the visual-field risk. [3] [4]

The long-term plan has three strands. First, confirm spasm cessation with a repeat EEG, because clinical cessation with a persistent hypsarrhythmia is an incomplete response that predicts relapse. Second, proceed urgently with epilepsy surgery evaluation for the resectable focal cortical dysplasia, because the window for developmental benefit closes with ongoing seizures. Third, build the developmental surveillance programme with early intervention services, physiotherapy, occupational and speech therapy, and psychology, because intellectual disability and autism are common long-term comorbidities and neurocognitive outcome dominates quality of life. [5] [11]

Discussion points

This case tests whether the candidate can integrate the diagnostic triad, the aetiology-driven first-line decision, and the time-to-treatment effect on outcome. The triad and the EEG confirm the syndrome, the focal cortical dysplasia and the negative Wood's lamp examination set hormonal therapy first-line and trigger epilepsy surgery referral, and the two-week history frames the conversation around urgency. The candidate who frames the spasms as a neurodevelopmental emergency, who reads the focal MRI lesion as a surgically curable substrate, and who closes with the family on realistic developmental expectations demonstrates the fellowship standard. [2] [9]