Abstracts

Rationale: Cannabidiol use among children with treatment-resistant epilepsy has escalated over the past four years in North America after initial anecdotal reports of potential benefits in children with Dravet syndrome and Lennox-Gastaut syndrome. We report here the correlation between the use of artisanal cannabinoid oil and clinical response among children with treatment-resistant epilepsy seen at the Children’s Comprehensive Epilepsy Centre at the Alberta Children’s Hospital in Calgary, Alberta, Canada. Methods: We conducted a retrospective study of children with treatment-resistant epilepsy who were administered artisanal cannabinoid (aCB) oil by their parents/guardians between Jan 1, 2016 and Dec 31, 2017 while being followed by the Pediatric Epilepsy Program at the Alberta Children Hospital. Commercially available aCB preparations likely had differing ratios of cannabidiol and tetrahydrocannabinol (THC) due to varying commercial suppliers. Seizure frequency scores before and after a minimum 6-month treatment period with aCB were analyzed. A significant positive response was defined as a greater than 50% reduction in reported seizure frequency during the treatment period compared to each person’s baseline seizure activity. We also collected data on seizure and epilepsy types in addition to previous use of anti-seizure medications and correlated these findings with outcome. Results: Twenty-six children (14 boys) with age range 2 – 18 years who were given aCB were identified.  Twenty-five children had been treated with multiple anti-seizure medications. Six children (23.1%) had at least a fifty percent reduction in the seizure frequency score. In the remaining twenty patients (76.9%), there was no reported benefit in terms of seizure reduction. Three (11.5%) children had serious side-effects consisting of severe encephalopathy attributed mainly to elevated serum levels of clobazam. In our experience, no patient became seizure free during treatment with aCB oil. Conclusions: Among children with treatment-resistant epilepsy in Southern Alberta, the use of aCB resulted in limited clinical benefits. Consistent with recently published reports, we had a small number of patients who exhibited serious side-effects. Only one four patients experienced significant seizure reduction, but one of ten children had a serious adverse effect leading to intensive care unit admission. No children became seizure-free with aCB treatment. These results are confounded, however, by the lack of information regarding the actual proportions of cannabidiol and THC in the artisanal forms of aCB administered by parents. Funding: None