Clinical Features and Treatment Efficacy in Mutation-Related Epileptic Encephalopathy in the Infant

Abstract

Purpose Mutations in the cyclin-dependent kinase-like 5 (CDKL5) gene are associated with epileptic encephalopathy and severe cognitive impairment. We aim to characterize the association between this gene and treatment efficacy. Methods We retrospectively analyzed 10 patients who were treated at Severance Children's Hospital for epileptic encephalopathy who were subsequently diagnosed with a CDKL5 mutation using next-generation sequencing. Results Electroencephalography (EEG) results showed generalized pattern abnormalities in 60% (6/10) of patients with CDKL5 mutations. We analyzed the effects of three treatments, namely antiepileptic drugs (AEDs), ketogenic diet (KD), and steroids. A more than 50% reduction in seizures was observed in 12% (1/8) of patients treated with clobazam. KD treatment proved ineffective in most cases. In addition, a more than 50% reduction in seizures was observed in 57% (4/7) of patients treated with steroids. EEG analysis of patients treated effectively with steroids revealed that 75% (3/4) showed hypsarrhythmia and 25% (1/4) showed focal epileptiform. Conclusion In this study, as in other studies, AEDs and KD did not effectively control seizures in most patients with a CDKL5 mutation. However, steroid therapy reduced the frequency of seizures in patients who also exhibited hypsarrhythmia. This suggests that steroid treatment is helpful in cases of hypsarrhythmia with CDKL5 mutations.

Keywords

• spasms, infantile
• cdkl5 deficiency disorder
• epilepsy
• epileptic encephalopathy