Cannabidiol‐enriched oil for adult patients with drug‐resistant epilepsy: Prospective clinical and electrophysiological study

Abstract

AbstractObjectiveCannabidiol‐enriched oil (CBDO) is being used increasingly to improve seizure control in adult patients with drug‐resistant epilepsy (DRE), despite the lack of large‐scale studies supporting its efficacy in this patient population. We aimed to assess the effects of add‐on CBDO on seizure frequency as well as on gait, cognitive, affective, and sleep‐quality metrics, and to explore the electrophysiological changes in responder and non‐responder DRE patients treated with add‐on CBDO.MethodsWe prospectively recruited adult DRE patients who were treated with add‐on CBDO. Patients were evaluated prior to treatment and following 4 weeks of a maintenance daily dose of ≈260 mg CBD and ≈12 mg Δ9‐tetrahydrocannabinol (THC). The outcome measures included seizure response to CBDO (defined as ≥50% decrease in seizures compared to pre‐CBDO baseline), gait testing, Montreal Cognitive Assessment (MoCA), Hospital Anxiety and Depression Scale (HADS), and sleep‐quality questionnaire assessments. Patients underwent electroencephalography (EEG) recording during rest as well as event‐related potentials (ERPs) during visual Go/NoGo task while sitting and while walking.ResultsNineteen patients were recruited, of which 16 finished pre‐ and post‐CBDO assessments. Seven patients (43.75%) were responders demonstrating an average reduction of 82.4% in seizures, and nine patients (56.25%) were non‐responders with an average seizure increase of 30.1%. No differences in demographics and clinical parameters were found between responders and non‐responders at baseline. However, responders demonstrated better performance in the dual‐task walking post‐treatment (p = .015), and correlation between increase in MoCA and seizure reduction (r = .810, p = .027). Post‐CBDO P300 amplitude was lower during No/Go‐sitting in non‐responders (p = .028) and during No/Go‐walking in responders (p = .068).SignificanceCBDO treatment can reduce seizures in a subset of patients with DRE, but could aggravate seizure control in a minority of patients; yet we found no specific baseline clinical or electrophysiological characteristics that are associated with response to CBDO. However, changes in ERPs in response to treatment could be a promising direction to better identify patients who could benefit from CBDO treatment.