Marijuana use in adults admitted to a Canadian epilepsy monitoring unit

- A high percentage of patients with uncontrolled epilepsy self-medicate with marijuana.
- 84% of patients with epilepsy perceived seizure improvement with marijuana use.
- The perception of benefit was the same among patients with psychogenic nonepileptic seizures.
- Correlation was found between stress decline and perception of seizure improvement.
- Cannabinoids might exert an antiseizure influence through stress reduction.

ObjectivesEpidemiologic evidence supporting antiseizure properties of cannabis is limited and controversial. We determined the prevalence of marijuana use and its perceived effects in patients with and without epilepsy.MethodsInformation was collected over 14 months from consecutive adult patients admitted to an epilepsy monitoring unit using a 27-item anonymous questionnaire. Patients with cognitive impairment unable to understand the questions or give informed consent and readmissions were not recruited. Subjects were divided into 4 groups, those with epileptic seizures, those with psychogenic nonepileptic seizures (PNES), those with both epileptic and PNES, and those with other nonepileptic events. Patients with exclusively epileptic seizures were compared with those with exclusively PNES.ResultsFrom 310 patients, 18 undiagnosed cases were excluded leaving a cohort of 292 patients with median age 35 (range: 27-49) years; 57.2% female. Epilepsy was documented in 190 (65.1%), PNES in 64 (21.9%), and both types of seizures in 26 (8.9%). Median duration of seizure disorder was longer (2 [1-9] vs. 13 [5.7-25] years; p < 0.001) and seizure frequency lower (daily or weekly in 62.3% vs. 44.9%; p = 0.03) in patients with epilepsy compared with those in patients with PNES. Overall, 166 (57%) had tried marijuana, and 36.2% used it over the past year. Utilization was 57.1% in sole epilepsy and 64.1% in sole PNES, but daily use was more likely in epilepsy (59% vs. 33.3%). Estimated mean dose was 1 g/day. Marijuana use was associated with tobacco smoking (p < 0.001) but not alcohol use. Eight patients used other street drugs. Improvement in seizures was perceived by 84% in those with epilepsy and 72.7% in those with PNES. In the 2 groups, stress was decreased in 84.9% and 88%, sleep improved in 77.3% and 88%, and memory/concentration was better in 32% and 28%, respectively. Antiepileptic drug side effects were decreased in 53.2% of marijuana users. Perceived effect on epileptic seizures correlated with effect on stress (r = 0.35, p = 0.004). Adverse effects of marijuana were mild and reported in 30.7% but included possible seizure precipitation in 5 patients with epilepsy.SignificancePatients with uncontrolled epilepsy or nonepileptic events had a high rate of marijuana use with associated perceived improvements in seizure control, stress, sleep, and drug side effects. Stress reduction may contribute to the perceived impact of marijuana on seizures and nonepileptic events in adults.