EEG response to high dose nocturnal diazepam in children with developmental/epileptic encephalopathy with spike-and-wave activation in sleep (DEE/EE-SWAS)

OBJECTIVE: To assess the response to high-dose daily nocturnal diazepam (HDD) in children with developmental and or epileptic encephalopathy with spike-wave activation in sleep (DEE/EE-SWAS) METHODS: A prospective cohort of patients (4-12 years), newly diagnosed with DEE/EE-SWAS and initiated on the first course of HDD therapy, was followed for one year. Sleep EEG scores (SES) pre and post-HDD were evaluated every three months for 12 months to monitor treatment response. Spike-wave index (SWI) was calculated using the percentage of 1-second bins containing at least one spike. An EEG grading system based on both sleep SW index (sSWI) (Grade: 1-4) and background distribution of epileptiform discharges (Grade: 0-4) was used and summed to yield an aggregate SES (ASES) (Grade: 1-8). RESULTS: Eighteen eligible children (M:F 12:6; median age, 7.6 years; range, 4.4-11.6 years) were initiated on the first course HDD (median, 0.5 mg/kg/d; range, 0.3-0.6 mg/kg/d). sSWI decreased significantly from 85.7 % (mean, SD 13.9) to 32.6 % (mean, SD 37.1) at subsequent EEG follow-up (95 % CI = -70.60, -35.62; p < 0.001). ASES decreased from 6.5 (SD 1.3) to 3.1 (SD 1.9) (95 % CI = -4.17, -2.60; p < 0.001). EEG relapse after a period of improvement after HDD initiation occurred in 10 children. Minimal response to HDD occurred in 2 children. Five patients manifested mild side effects, including altered behaviour (2), hyperactivity (2), and lethargy (1). CONCLUSION: We demonstrate that using a structured EEG scoring system in DEE/EE-SWAS, combining the SWI and its distribution HDD safely and significantly reduces both sSWI and ASES. However, high rates of EEG relapse were recorded.