From the Guidelines
Vigabatrin remains the drug of choice for infantile spasms, particularly in patients with tuberous sclerosis, and should be used at 50-150 mg/kg/day divided twice daily 1. Infantile spasms are a severe form of epilepsy that typically begins in the first year of life, characterized by sudden, brief muscle contractions involving the neck, trunk, and extremities. The treatment of infantile spasms should begin immediately upon diagnosis as delays can worsen developmental outcomes. Some key points to consider in the management of infantile spasms include:
- An EEG showing hypsarrhythmia is crucial for diagnosis, and video EEG monitoring helps confirm the characteristic spasms.
- The underlying mechanism involves abnormal brain development or injury leading to chaotic electrical activity.
- Parents should be educated about monitoring for side effects including hypertension, immunosuppression, and visual field defects with vigabatrin.
- Regular follow-up with a pediatric neurologist is essential to assess treatment response, typically within 2 weeks of initiation, with the goal of complete cessation of spasms and resolution of hypsarrhythmia on EEG.
- According to the guidelines for managing cardio-facio-cutaneous syndrome, which is associated with infantile spasms, referral to a neurologist for a baseline evaluation and accurate seizure classification with clinical history and EEG are crucial for guiding medical management 1.
- Additionally, consideration of the risk of cardiomyopathy with steroid management in children with infantile spasms is important, and consultation with a cardiologist may be necessary 1.
From the FDA Drug Label
The safety and effectiveness of vigabatrin as monotherapy for pediatric patients with infantile spasms (1 month to 2 years of age) have been established [see Dosage and Administration (2.3), Clinical Studies (14. 2)] . In a randomized, placebo-controlled IS study with a 5 day double-blind treatment phase (n=40), the adverse reactions that occurred in >5% of patients receiving vigabatrin and that occurred more frequently than in placebo patients were somnolence (vigabatrin 45%, placebo 30%), bronchitis (vigabatrin 30%, placebo 15%), ear infection (vigabatrin 10%, placebo 5%), and acute otitis media (vigabatrin 10%, placebo 0%).
Vigabatrin is effective for the treatment of infantile spasms in pediatric patients from 1 month to 2 years of age.
- The most common adverse reactions in this population are somnolence, bronchitis, ear infection, and acute otitis media.
- The duration of therapy for infantile spasms was evaluated in a post hoc analysis, suggesting that a total duration of 6 months of vigabatrin therapy is adequate for the treatment of infantile spasms 2.
From the Research
Definition and Treatment of Infantile Spasms
- Infantile spasms are a rare, catastrophic, age-specific seizure disorder of infancy, often associated with developmental delay 3.
- The mainstay of treatment for infantile spasms is adrenocorticotropic hormone (ACTH), but vigabatrin has been used as an alternative, especially for infantile spasms related to tuberous sclerosis complex 4, 3, 5.
Efficacy of Vigabatrin
- Vigabatrin has been shown to be effective in decreasing the frequency of infantile spasms, particularly in cases related to tuberous sclerosis complex 3, 5.
- A retrospective study found that 30% of infants with infantile spasms not related to tuberous sclerosis complex responded to vigabatrin therapy within 4 weeks, with 27% remaining free of all clinical seizure types at final follow-up 4.
Side Effects and Limitations
- Vigabatrin is associated with a serious adverse effect, permanent visual field constriction, which may affect 6-7% of exposed infants 5.
- The use of vigabatrin is limited by its potential side effects, and treatment choices must balance the risks against the potential benefits of controlling the spasms 5.
Current Treatment Options
- Current first-line treatments for infantile spasms include ACTH, oral corticosteroids, and vigabatrin, with other antiepileptic drugs and novel therapies being explored 6, 7.
- The choice of treatment depends on the underlying cause of the infantile spasms and the individual patient's needs and circumstances 4, 3, 5, 6, 7.