The role of cannabis in epilepsy illustrated by two case reports

Cannabis use is increasingly prevalent among individuals with epilepsy, yet its impact on seizure control remains poorly understood. While cannabidiol (CBD) has demonstrated antiseizure properties and gained FDA approval for specific epileptic syndromes, tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis, may alter neuronal excitability and potentially exacerbate seizure activity. We present two illustrative case reports of male patients with focal epilepsy and chronic cannabis use who underwent treatment with antiseizure medications and responsive neurostimulation (RNS). In both cases, cannabis use was temporally associated with breakthrough seizures and poor seizure control. These cases highlight the complex and multifactorial relationship between cannabis use and seizure outcomes, including potential pharmacokinetic interactions with antiseizure medications (ASM) and the possibility that cannabis may blunt the neuromodulation effects of RNS. Given the retrospective data and limited detail on cannabis use, these findings should be interpreted with caution. As cannabis use rises among individuals with epilepsy, further research is needed to clarify its potential effects on seizures and treatment response, including neuromodulation.