The effect of lead time to treatment and of age of onset on developmental outcome at 4 years in infantile spasms: evidence from the United Kingdom Infantile Spasms Study.

PURPOSE: Infantile spasms is a severe infantile seizure disorder. Several factors affect developmental outcome, especially the underlying etiology of the spasms. Treatment also affects outcome. Both age at onset of spasms and lead time to treatment (the time from onset of spasms to start of treatment) may be important. We investigated these factors. METHODS: Developmental assessment using Vineland Adaptive Behaviour Scales (VABS) at 4 years of age in infants enrolled in the United Kingdom Infantile Spasms Study. Date of or age at onset of spasms was obtained prospectively. Lead time to treatment was then categorized into five categories. The effects of lead time to treatment, age of onset of spasms, etiology, and treatment on developmental outcome were investigated using multiple linear regression. KEY FINDINGS: Age of onset ranged (77 infants) from <1 to 10 months (mean 5.2, standard deviation 2.1). Lead time to treatment was 7 days or less in 11, 8-14 days in 16, 15 days to 1 month in 8, 1-2 months in 15, >2 months in 21 and not known in 6. Each month of reduction in age at onset of spasms was associated with a 3.1 [95% confidence interval (CI) 0.64-5.5, p = 0.03] decrease, and each increase in category of lead time duration associated with a 3.9 (95% CI 7.3-0.4, p = 0.014) decrease in VABS, respectively. There was a significant interaction between treatment allocation and etiology with the benefit in VABS in those allocated steroid therapy being in children with no identified etiology (coefficient 29.9, p=0.004). SIGNIFICANCE: Both prompt diagnosis and prompt treatment of infantile spasms may help prevent subsequent developmental delay. Younger infants may be more at risk from the epileptic encephalopathy than older infants.

Developmental and epilepsy outcomes at age 4 years in the UKISS trial comparing hormonal treatments to vigabatrin for infantile spasms: a multi-centre randomised trial.

BACKGROUND: Infantile spasms is the name given to a difficult to treat, severe infantile epilepsy with high morbidity. The United Kingdom Infantile Spasms Study (UKISS) showed that absence of spasms on days 13 and 14 after randomisation was more common in infants allocated hormonal treatments than vigabatrin. At 12-14 months, those with no identified aetiology allocated hormonal treatment had better development. However, epilepsy outcome was not affected by treatment allocated. It is not known if the difference in development persists as the infants grow. METHODS: Infants in UKISS were followed up blind to treatment allocation by telephone at a mean age of 4 years using the Vineland Adaptive Behaviour Scales (VABS) and an epilepsy questionnaire. FINDINGS: 9 of 107 enrolled infants had died. 77 were traced and consented to take part. The median (quartile) VABS scores were 60 (42, 97) for the 39 allocated hormonal treatment and 50 (36, 67) for the 38 allocated vigabatrin (Mann-Whitney U=575; p=0.091; median difference (95% CI): 8 (-1 to 19)). For those with no identified aetiology, VABS scores were 96 (52, 102) for the 21 allocated hormonal treatment and 63 (37, 92) for the 16 allocated vigabatrin (U=98.5; p=0.033; median difference (95% CI): 14 (1 to 42)).The proportions in each treatment group with epilepsy were similar. INTERPRETATION: For all 77 infants, development and epilepsy outcomes were not significantly different between the two treatment groups. The better development seen at 14 months in those with no identified aetiology allocated hormonal treatment was seen again at 4 years in this study.