Efficacy, safety and tolerability of Gabapentin as monotherapy for dystonic cerebral palsy

Objectives: To study the effectiveness of Gabapentin as monotherapy in dystonic cerebral palsy compared to accepted conventional therapy and understand its safety and tolerability.

Methods: A prospective, double-blind, randomised controlled trial was conducted in children with predominantly dystonic cerebral palsy. They were scaled for motor severity by Gross Motor Functional Classification system(GMFCS), quality of life by PedsQL Cerebral Palsy Module, dystonia by Barry-Albright Dystonia Scale(BADS) and Movement Disorder Childhood Rating Scale(MD-CRS) and randomised for treatment with gabapentin or trihexyphenidyl. The scales were administered on first visit, first followup(week 12) and second followup(week 24).

Results: 28 children were enrolled, mean age 4.4 years, M:F ratio 1.5:1. Dose of gabapentin ranged 23.0-50 mg/kg/day, reduction needed in 10%, trihexyphenidyl ranged 0.1-0.8 mg/kg/day, dose reduction needed in 37.5%. Significant difference observed in scores at 12 weeks and 24 weeks from baseline, for both drugs. No significant difference was observed in change in scores of both groups at 12 and 24 weeks: p-value for BADS, MD-CRS and PedsQL not significant. Change of atleast 2 points in dystonia scales was reported higher in gabapentin group: BADS(70% vs 50%), MDCRS-1(80% vs 37.5%), MDCRS-2(50% vs 37.5%), however not statistically significant. Improvement in PedsQL reported almost equal in both groups(75% vs 70%). Incidence of side effect was comparable in both groups. Most common side effect with gabapentin- drowsiness, increased urinary frequency; with trihexyphenidyl- drowsiness, hypotonia.

Conclusion: This study gives evidence that Gabapentin is as efficacious as conventional drug therapy for dystonic cerebral palsy with good tolerability.