Frequent cannabis use linked to seizure burden in epilepsy

A small study of adults with drug-resistant epilepsy found that frequent cannabis users had more severe seizure markers than nonusers, including a higher rate of focal-to-bilateral tonic-clonic seizures and a greater average number of antiseizure medications. The researchers stressed that the findings show an association, not that cannabis caused the differences. The retrospective study examined medical records for 64 adults admitted to an epilepsy monitoring unit: 22 people who used cannabis on at least 20 days a month and 42 who did not use it. Patients who used cannabis less frequently were excluded from the comparison. The study was published in Epilepsia. Focal-to-bilateral tonic-clonic seizures were recorded in 90.9% of frequent users, compared with 57.1% of nonusers. The annualized frequency of those seizures averaged 3.00 among frequent users and 1.32 among nonusers. Frequent users also took an average of 3.05 antiseizure medications, compared with 2.21 for nonusers. The groups differed in how soon they reached specialized monitoring. The mean interval from epilepsy onset to admission was 5.0 years for frequent users and 18.1 years for nonusers.