Tags:  Medical cannabis; Stroke; Neurology; Cerebrovascular Disease.

 

The problem: Worldwide consumption of cannabis has surged in the past few years, mostly because of the ongoing changes regarding cannabis legislation. This has led to the increasing popularity of cannabis among young adults. However, several short and long term effects of cannabis use have not been studied adequately.

 

Why do this study? Previous studies have identified a potential relationship between cannabis consumption and stroke. This study aims to explore the current trends in young-onset stroke (YOS) related hospital admissions and examine any potential variations among self-reported cannabis users and non-users.

 

The study: This was a retrospective analysis using the National Inpatient Sample dataset from 2007-2014). All stroke-related hospitalizations for young adults (ages 18-49) with a current or past history of cannabis consumption were identified, using the relevant ICD-9 CM (International Classification of Disease, Clinical Modification, 9th edition) codes. Admissions with any relationship to cocaine or amphetamine use (known risk factors for stroke) were excluded from the analysis. The primary outcomes examined included trends and odds in cannabis-associated stroke-related admissions as well as inpatient mortality. Secondary study endpoints included racial disparities, hospitalization charges and length of stay.

 

A total of 34,857 admissions met the inclusion/exclusion criteria. A statistically significant increase in YOS admissions among cannabis consumers was identified, as the total number of admissions increased from 553 (2007) to 630 (2014). Odds of developing any stroke (OR: 1.16, 95% CI: 1.31-1.51) or acute ischemic stroke (OR: 1.41, 95% CI: 1.31-1.51) were higher in cannabis consumers when compared to non cannabis consumers. Analysis by gender revealed a  significant increasing trend in males only. Sub analysis by race revealed a substantial increase in the African American population (relative change 34.05% from 2007 to 2014, and a less marked yet significant trend among the white population (relative change 2.24% from 2007 to 2014) Mean length of stay and hospital charges increased (14.34% and 90.98% respectively) in patients who reported cannabis consumption.

 

Conclusions:  The main conclusion drawn from this study is the significant association between cannabis consumption and the risk of stroke, as there is a 16% increase in the risk of all subtypes of stroke and a 41% increase for acute ischemic stroke.

 

What does this study add? As the consumption of cannabis continues to increase, more information is needed regarding the potential side-effects. There is a great amount of literature that highlights potential associations of cannabis use, both good and bad. This study further elucidates the relationship between cannabis and the risk of stroke.

 

However, this study does have some limitations which could bring into question the validity of the results. Even though the perception and legal status of cannabis are changing, there is still a significant stigma associated with this use. Therefore, cannabis use can often be underreported by users. Similarly, cannabis use is associated with a higher rate of cocaine use, which is a known risk factor for the development of stroke. This study tries to diminish this effect by excluding patients with a history of cocaine or amphetamine use, but many instances often go underreported. Additional studies are needed to further clarify this association.

 

Funder:  The author(s) received no financial support for the research, authorship, and/or publication of this article.

 

Author conflicts: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Hemant Goyal has stock holdings in Rimrock Gold Corp., Tauriga Sciences and SinglePoint Inc.

 

Commentary: (David Casarett MD). This is a complex study that relies on existing medical records—always a challenge to interpret.  One problem in particular is what’s called ascertainment bias:  the chance that physicians, when they see a young patient with a stroke (a rare event) are going to be more likely to ask about use of cannabis and other drugs.  So is this a real association or just a byproduct of more aggressive questioning?  Until we know for sure, though, these results are worrisome enough that we should at least consider the possibility that cannabis could increase the risk of strokes in young adults.