Marijuana and Hemorrhagic Stroke: Does a Risk Exist?

Objective: To investigate the relationship between tetrahydrocannabinol (THC) exposure and hemorrhagic stroke. Background: Exposure to THC, a main psychoactive active ingredient in marijuana, is becoming more common and suspected to increase the risk of ischemic stroke. However, outcomes of hemorrhagic stroke are less interrogated. Design/Methods: Following the Preferred Items for Systematic Reviews and Meta-Analaysis guidelines, we searched PubMed and 6 other databases for studies reporting neurologic complication in patients with THC use. Quality appraisal will be formally conducted by the time of study presentation. Results: Of 3164 citations screened, 6 studies met inclusion criteria (median publication year=2016). Three studies had outcomes regarding subarachnoid hemorrhage (one case series, one retrospective cohort, and one case-control study) and 3 studies regarding intraparenchymal hemorrhage (all retrospective cohort). 5131 patients had THC use (n=3340 males, median age 40 years [range 23–47 years]). Of these, 4738 patients had both THC exposure and a hemorrhagic stroke. 2601 patients had intraparenchymal hemorrhage (IPH) and 2137 had a subarachnoid hemorrhage (SAH). In these patients, hypertension (54%), vasoactive substance use (71.3%), and tobacco abuse (51.2%) were the most prevalent comorbidities, with diabetes mellitus (8.8%), obesity (5.1%) and hyperlipidemia (4.6%) present but less common. Median mortality was 16% following stroke ([range 15–26%]). Conclusions: Few studies consider the impact of THC on cerebrovascular health, and even fewer the risk of hemorrhagic stroke. Given the changing sociolegal landscape surrounding marijuana use in the United States, there is a need to rigorously evaluate the effect of marijuana, cannabidiol, and THC on cerebrovascular outcomes. Reports of IPH and SAH following THC are concerning, but the literature is exceptionally sparse and wide-ranging in methods and reported outcomes. Large and more rigorous studies surrounding this relationship are necessary. Disclosure: Dr. Swetlik has nothing to disclose. Dr. Migdady has nothing to disclose. Dr. Hasan has nothing to disclose. Dr. Price has nothing to disclose. Dr. Cho has nothing to disclose.