Infantile Spasms and Trisomy 21: Unfavorable Outcomes with First-line Vigabatrin Therapy

Abstract

Introduction: Among children with infantile spasms (ISs), those with trisomy 21 (T21) and those with normal development at onset and no identifiable etiology (previously referred to as “idiopathic”) are expected to have relatively favorable outcomes. The study objective is to determine if differences exist in treatment response, relapse, and subsequent epilepsy between these two groups when vigabatrin is used as first-line treatment. Methods: In this retrospective study, patients were classified into the following groups and clinical features were compared: T21 (n = 24) and IS with normal development at onset and no identified etiology (n = 40; control group). Results: There was no significant difference in the age of IS onset, sex distribution, or treatment lag between the groups. The T21 compared to the control group required a higher mean number of anti-seizure therapies (3.6 vs. 1.9, p < 0.001), had more relapses [10 (42%) vs. 4 (10%), p < 0.005)], and had higher risk of subsequent epilepsy [11 (46%) vs. 8 (20%), p < 0.003]. Relapses were often delayed in the T21 group, with a mean of 8 months after IS cessation. Conclusion: Our results differ from most studies using steroids as first-line treatment where the groups were shown to have similar treatment response and T21 patients had a low risk of relapse and subsequent epilepsy. Therefore, our results suggest that vigabatrin as first-line treatment in T21 with IS may be less favorable than steroids.

Response to treatment and outcomes of infantile spasms in Down syndrome

“…This is comparable to the results of Armstrong et al (n=20) and the ICISS Down syndrome subgroup analysis (n=37), with rates of 60% and 54% respectively. 17,18 Vigabatrin was the second most common first-line agent, with cessation of spasms in 28% (5 out of 18), similar to the 21% (5 out of 24) success rate reported by Datta et al 19 Our findings are also in agreement with the ICISS cohort, who reported the addition of vigabatrin was beneficial in only 1 out of 7 who did not respond to first-line prednisolone. 17,18 Only six children had both combination prednisolone and vigabatrin as first-line treatment in our cohort, with an 80% response although three out of six developed side effects, including one who required admission to an intensive care unit.…”

Children With Trisomy 21 and Lennox-Gastaut Syndrome With Predominant Myoclonic Seizures

“…In the literature, there appears to be a marginally more favorable outcome with the use of hormonal therapy first-line for epileptic spasms in trisomy 21. 22 -24 However, no large trials have been performed. It is known that children with trisomy 21, and those with normal development at onset and no identifiable etiology (previously referred to as “idiopathic”), are expected to have relatively favorable outcomes.…”