Objective: There is accumulating evidence for Cannabidiol (CBD) therapy in refractory epilepsy. This study utilized prolonged Video-EEG (vEEG) to evaluate the effect of add-on CBD in patients with refractory epilepsy. Methods: Children with refractory epilepsy of varied aetiologies enrolled in a CBD (Epidiolex®, GW Pharmaceuticals) Compassionate Access Scheme (2017 to 2019) were included. 24-hr inpatient vEEG was obtained prior to CBD commencement and at 3 months. Seizure types were assessed on EEG review, with video features scrutinized as required. Data was retrospectively and independently reviewed by two EEG specialists, blinded to pre- or post-status of vEEG, with differences resolved by consensus. Clinical data available included carer assessed Global Impression of change (GIC). Wilcoxon signed rank test was performed to compare seizure types pre and post, and data analysed using R statistical software. Results: 47 patients completed both vEEG studies. 12186 seizures were agreed on across all studies. Highest counts were spasms (4430 events) and tonic seizures (3644 events). Across the entire cohort, there was no significant difference in total seizures (by seizure type) post-treatment. However, those patients reporting most significant improvement in GIC had statistically significant seizure counts following treatment (p=0.004) Conclusions: In the largest cohort of CBD-treated patients studied by vEEG, no differences in seizure frequency were noted across the entire cohort, although those with highest GIC had significant seizure improvements, indicating a positive effect of CBD for some patients. Our findings may be limited by cohort size and influenced by seizure severity in this highly select group.

Stephen Malone
Queensland Children's Hospital
Australia

Yeeshu Singh
Gold Coast Hospital
Australia

Sandra Gurr
Queensland Children's Hospital
Australia

Kylie Hale
Queensland Children's Hospital
Australia

Vishal Kapoor
Queensland Children's Hospital
Australia

Geoff Wallace
Queensland Children's Hospital
Australia