Does smoking marijuana cause stroke?
January 26, 2013, 10:05 pm
Cannabis-related Stroke: Myth or Reality? Wolff V et al. Stroke 2013 Feb;44(2):558-63. doi: 10.1161/STROKEAHA.112.671347. Epub 2012 Dec 27.
There have been scattered reports in the literature claiming an association between the use of cannabis and ischemia and/or hemorrhagic stroke. Although no convincing mechanism has been postulated, some suggest that use of marijuana or hashish and the occurrence of stroke may stem from the ability of cannabis to cause orthostatic hypotension, or possibly vasoconstriction.
If such an association is real, it must be exceedingly rare. The purpose of this paper, from the University of Strasbourg in France, was to “analyze the different aspects of neurovascular complications in cannabis users as described in the literature”. This stated purpose is so vague as to be useless, and, in fact, the entire paper is a mess.
The authors searched PubMed for articles association stroke OR ischemic stroke with cannabis OR marijuana. The say they identified 59 cases. But how were these chosen? What was the case definition? Did the case descriptions rule out other known causes of stroke, such as cocaine or amphetamine use? The authors don’t bother to discuss this. I do agree with their recommendation that young patients with unexplained stroke by asked in detail about their drug consumption.