Original Research

Cannabis Use and Stroke: Does a Risk Exist?

Swetlik, Carol MD, MS; Migdady, Ibrahim MD; Hasan, Leen Z. MD; Buletko, Andrew Blake MD; Price, Carrie MLS; Cho, Sung-Min DO, MHS

Author Information

Department of Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH (CS, IM, ABB), Department of Medicine, University of Connecticut School of Medicine, Hartford, CT (LZH), Welch Medical Library, Johns Hopkins University, Baltimore, MD (CP), Division of Neuroscience Critical Care, Departments of Neurology, Neurosurgery, Anesthesiology, and Critical Care Medicine, Johns Hopkins University, Baltimore, MD (MC).

Send correspondence to Sung-Min Cho, DO, MHS, Departments of Neurology, Neurosurgery, Anesthesiology, and Critical Care Medicine, Division of NCCU, Johns Hopkins Medical Institutions, 600 N. Wolfe Street, Phipps 455, Baltimore, MD 21287. E-mail: [email protected].

Received 9 January, 2021

Accepted 6 April, 2021

The authors report no conflicts of interest.

Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.journaladdictionmedicine.com).

Journal of Addiction Medicine 16(2):p 208-215, March/April 2022. | DOI: 10.1097/ADM.0000000000000870

Abstract

Aims:

Cannabis use has been reported as a risk factor for stroke. We systematically review the prevalence and outcomes of stroke in people with cannabis use.

Methods:

We searched MEDLINE and 6 other databases from inception to January 2020 for studies on the relationship between cannabis use and stroke. We followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) recommendations. Two independent reviewers extracted the data. Study quality was assessed by the Newcastle-Ottawa Scale for cohort and case-control studies.

Results:

Seventeen studies involving 3,185,560 people with cannabis use were included. Descriptive statistics demonstrated 18,676 (median 1.1%, interquartile range [IQR] 0.3%–1.3%) experienced stroke compared with 0.8% of those without use (Odds Ratio 1.17, 95% CI 1.10–1.25). Among people with cannabis use, median age was 26.2 years (IQR 25.2–34.3 years) and mostly male (median 57.8%). Of stroke subtypes, ischemic stroke was most prevalent (median 1.2%, IQR 0.4%–1.9%), followed by undefined stroke subtype (median 1.2%, IQR 1.1%–1.2%) and hemorrhagic stroke (median 0.3%, IQR 0.1%–0.6%). The majority of people with cannabis use who experienced stroke survived (median: 85.1%, IQR 83%–87.5%) and 64.0% of people experienced a good neurologic outcome, defined as modified Rankin Scale of 0 to 3. Few studies included outcomes of vasospasm or seizure.

Conclusions:

In people with cannabis use, the prevalence of ischemic stroke and hemorrhagic stroke was 1.2% and 0.3%, respectively, higher than the prevalence of people without use (0.8% and 0.2%). There is insufficient information on timing, exposure, duration, and dose-responsive relationship.