Abstract
BACKGROUND AND OBJECTIVE: CDKL5 deficiency disorder presents as a challenging condition with early-onset refractory seizures, severe developmental delays, and a range of other neurological symptoms. Our study aimed to explore the benefits and side effects of anti-seizure medications (ASMs) in managing seizures among individuals with CDKL5 deficiency disorder, drawing on data from the International CDKL5 Disorder Database. METHODS: Data for this retrospective cohort study were obtained from the International CDKL5 Disorder Database, which contains responses from a baseline questionnaire administered between 2012 and 2022 and a follow-up questionnaire administered between 2018 and 2019. Families of eligible individuals were asked to provide information on ASMs that were previously and currently taken, the dose prescribed, the age at starting the medications, and the age at discontinuation for past medications. The outcome variables of interest were perceived seizure-related benefits for the current and past use of ASMs and caregiver-reported side effects. Rescue medications and infrequently used ASMs were excluded from the analysis. Descriptive statistics were used to summarise the characteristics of the study population. RESULTS: The study included 399 children and adults with CDKL5 deficiency disorder, descriptively analysing the perceived benefits and side effects of 23 unique ASMs based on caregiver reports. The study identified levetiracetam, topiramate, sodium valproate, vigabatrin, phenobarbital and clobazam as the most used ASMs. Notably, cannabidiol showed highly beneficial outcomes with few side effects, whereas levetiracetam and phenobarbital exhibited less favourable benefit-to-side-effect ratios. Dual therapy involving sodium valproate and levetiracetam was only used a small number (n = 5) of times but appeared effective in reducing seizure activity with relatively few side effects. Compared with monotherapy, polytherapy had a relatively higher likelihood of reported side effects than benefits. CONCLUSIONS: The study, leveraging a large sample size that exceeds that of previous research, emphasises the complex nature of seizure management in CDKL5 deficiency disorder. Our findings underscore the necessity of ongoing research to optimise treatment strategies, considering both the efficacy of seizure control and the potential for adverse effects. The study also points to the need for future investigations into the therapeutic potential of emerging treatments such as ganaxolone and the unresolved efficacy of cannabis products in seizure management.