Ambulatory Local Field Potential Recordings from the Thalamus in Epilepsy: A Feasibility Study.

INTRODUCTION: Stimulation of the thalamus is gaining favor in the treatment of medically refractory multifocal and generalized epilepsy. Implanted brain stimulators capable of recording ambulatory local field potentials (LFPs) have recently been introduced, but there is little information to guide their use in thalamic stimulation for epilepsy. This study sought to assess the feasibility of chronically recording ambulatory interictal LFP from the thalamus in patients with epilepsy. METHODS: In this pilot study, ambulatory LFP was recorded from patients who underwent sensing-enabled deep brain stimulation (DBS, 2 participants) or responsive neurostimulation (RNS, 3 participants) targeting the anterior nucleus of the thalamus (ANT, 2 electrodes), centromedian nucleus (CM, 7 electrodes), or medial pulvinar (PuM, 1 electrode) for multifocal or generalized epilepsy. Time-domain and frequency-domain LFP was investigated for epileptiform discharges, spectral peaks, circadian variation, and peri-ictal patterns. RESULTS: Thalamic interictal discharges were visible on ambulatory recordings from both DBS and RNS. At-home interictal frequency-domain data could be extracted from both devices. Spectral peaks were noted at 10-15 Hz in CM, 6-11 Hz in ANT, and 19-24 Hz in PuM but varied in prominence and were not visible in all electrodes. In CM, 10-15 Hz power exhibited circadian variation and was attenuated by eye opening. CONCLUSION: Chronic ambulatory recording of thalamic LFP is feasible. Common spectral peaks can be observed but vary between electrodes and across neural states. DBS and RNS devices provide a wealth of complementary data that have the potential to better inform thalamic stimulation for epilepsy.

Efficacy of artisanal preparations of cannabidiol for the treatment of epilepsy: Practical experiences in a tertiary medical center.

Medically refractory epilepsy continues to be a challenge worldwide, and despite an increasing number of medical therapies, approximately 1 in 3 patients continues to have seizures. Cannabidiol (CBD), one of many constituents of the Cannabis sativa or marijuana plant, has received renewed interest in the treatment of epilepsy. While highly purified CBD awaits Food and Drug Administration (FDA) approval, artisanal formulations of CBD are readily available and are seeing increased use in our patient population. Although randomized controlled trials of CBD are ongoing and promising, data regarding artisanal formulations of CBD are minimal and largely anecdotal. Here, we report a retrospective study to define the efficacy of artisanal CBD preparations in children with epilepsy. Given the known interaction between CBD and clobazam, we also conducted a subgroup comparison to determine if clobazam use was related to any beneficial effects of CBD. Additionally, we compared response rates with CBD and with clobazam alone within an overlapping patient cohort. A pediatric cohort with epilepsy of 108 patients was identified through a medical record search for patients using CBD oil. The addition of CBD resulted in 39% of patients having a >50% reduction in seizures, with 10% becoming seizure-free. The responder rate for clobazam was similar. No patients achieved CBD monotherapy, although the weaning of other antiepileptic drugs (AEDs) became possible in 22% of patients. A comparable proportion had AED additions during CBD therapy. With concomitant use of clobazam, 44% of patients had a 50% reduction in seizures upon addition of CBD compared with 33% in the population not taking clobazam; this difference was not statistically significant. The most common reported side effect of CBD was sedation in less than 4% of patients, all of whom were also taking clobazam. Increased alertness and improved verbal interactions were reported in 14% of patients in the CBD group and 8% of patients in the CBD and clobazam group. Benefits were more marked in the CBD alone group, in contrast to the CBD and clobazam group, but this difference was not statistically significant. In summary, these findings support efficacy of artisanal CBD preparations in seizure reduction with few significant side effects. The response to CBD was independent of concurrent clobazam use, although clobazam may contribute to the sedation seen with concurrent CBD use.