Response to clobazam in continuous spike-wave during sleep

Abstract

Aim: To evaluate the efficacy of clobazam treatment in reducing epileptiform discharges and modifying neuropsychological function in continuous spike-wave during slow wave sleep. Method: We performed a prospective clinical trial in patients with continuous spike-wave during sleep aged 4 to 10 years. Patients underwent neuropsychological assessment and overnight electroencephalographic monitoring before treatment, and subsequent repeat assessment and overnight electroencephalographic monitoring 3 months after treatment. Treatment consisted of 1mg/kg clobazam up to a maximum dose of 30mg during the first night, followed by 0.5mg/kg nightly for 3 months. Results: Nine patients completed the study and had pre- and post-neuropsychological evaluation. There was a qualitative reduction in median (p25–p75) spike percentage after 3 months (72.2 [68.0–75.8] vs 32.7 [4.7–81.7]). There were no marked changes in median (p25–p75) IQ comparing pre- and post-clobazam treatment (80.0 [74.0–88.0] vs 80.0 [67.0–89.0]). There was a qualitative increase in Verbal IQ (83.0 [69.0–92.0] vs 95.0 [83.0–99.0]) and a qualitative decrease in Non-verbal IQ (84.0 [74.0–87.0] vs 71.0 [60.0–84.0]). Interpretation: Qualitative improvements in epileptiform activity and cognition occurred in patients treated with clobazam for 3 months and the relationship between epileptiform activity and cognitive outcome should be studied in larger studies. What this paper adds: Verbal IQ in patients with continuous spike-wave during sleep improved following short-term treatment with clobazam. Other neuropsychological improvements were observed, but varied by patient. Cognitive improvement was observed despite some worsening of epileptiform discharges.