The UK Infantile Spasms Multicenter Study previously showed that seizure control after 14 days and development at 14 months are better following hormonal treatments (prednisolone or tetracosactide depot) than following vigabatrin . At 4-year follow-up, 9 of 107 enrolled infants had died and 77 were tested for level of development, using the Vineland Adaptive Behavior Scales (VABS), and for seizure control by questionnaire. The median VABS scores were 60 for 39 children allocated hormonal treatment and 50 for 38 allocated vigabatrin (p=0.91). For children with spasms with no identified etiology, VABS scores were 96 for 21 allocated hormonal treatment, and 63 for the 16 allocated vigabatrin (p=0.033). For all 77 infants, development and epilepsy outcomes were not significantly different between the two treatment groups at 4-year follow-up. In patients with no identifiable etiology, development was better at both 14 months and 4 years in those allocated hormonal treatment. 
COMMENT. A review of the earlier report of the UKISS with a primary outcome of cessation of spasms on days 13 and 14  found the minimum doses used were vigabatrin 100 mg/kg/daily (n=52), oral prednisolone 40 mg day (n=30) or intramuscular tetracosactide depot 0.5 mg (40 IU) (n=25) on alternate days. Complete seizure control was obtained in 40 (73%) on hormonal treatments (prednisolone 21 (70%), tetracosactide 19 (76%)) and 28 (54%) on vigabatrin (p=0.043). Adverse events were reported in 30 (55%) of 55 infants on hormonal treatments and 28 (54%) of 52 on vigabatrin. Cessation of spasms occurred more often in infants on hormonal treatment than those given vigabatrin. Adverse events were common with both treatments. The subsequent studies show that hormonal treatment and vigabatrin are equally effective in control of infantile spasms with proven etiology, but for spasms with no identifiable cause, hormonal treatment is preferred.