Is adjunctive Cannabidiol effective in controlling seizures for adult patients with Lennox-Gastaut Syndrome? – A single centre long term follow up study

Epileptic encephalopathies are a disabling and life-limiting cause of childhood-onset epilepsy. Lennox Gastaut syndrome (LGS) is a characteristic example. In spite of the development of multiple medical and surgical therapies, many patients with these conditions remain treatment refractory Cannabidiol was licenced by The National Institute for Health and Care Excellence (NICE) in December 2019 for the adjunctive treatment of seizures associated with Lennox Gastaut syndrome [TA 615]. As the largest complex epilepsy centre in the Midlands, we describe our findings from a single centre retrospective study in 50 adults (aged 16 and over) with LGS- associated epilepsy. Our outcome measure was the efficacy of Cannabidiol on seizures of differing types over a 6-24-month period. Patients were treated with adjunctive Cannabidiol (with Clobazam, as per NICE recommendations). Each patient’s usual anti-seizure medications (ASMs) were continued. Patients with a Vagal Nerve Stimulator (VNS) in situ remained on this treatment. Gradual titration of Cannabidiol from 1 mg/kg/day up to 10 mg/ kg/ day reduced the frequency of both focal and generalised seizures with ≥ 50 % seizure reduction in 76 % of the cohort. No patients became seizure free. Cannabidiol was well tolerated; 94 % of the cohort remained on the drug at last follow up.