Disclosures: The study and editorial authors report no relevant financial disclosures.

January 06, 2022
2 min read

Recent marijuana use linked to risk for complication from subarachnoid hemorrhage

Disclosures: The study and editorial authors report no relevant financial disclosures.

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Among patients with aneurysmal subarachnoid hemorrhage, those with recent cannabis use were more likely to have delayed cerebral ischemia than those without recent use, researchers reported.

Michael T. Lawton

“We’re all vulnerable to a bleeding stroke or a ruptured aneurysm; however, if you’re a routine marijuana user, you may be predisposed to a worse outcome from a stroke after the rupture of that aneurysm,” Michael T. Lawton, MD, president and CEO of Barrow Neurological Institute in Phoenix, said in a press release.

Graphical depiction of data presented in article
Data were derived from Catapano JS, et al. Stroke. 2022;doi:10.1161/STROKEAHA.121.035650.

Lawton and colleagues analyzed 1,014 patients treated for aneurysmal subarachnoid hemorrhage from August 2007 to July 2019, of whom 4.5% tested positive for cannabis on routine urine toxicology screening (users: mean age, 47 years; 41% women; nonusers: mean age, 56 years; 71% women).

Among the cohort, 36.2% developed delayed cerebral ischemia; 50.2% had a poor functional outcome, defined as modified Rankin Scale score of greater than 2; and 13.5% died.

Cannabis and delayed cerebral ischemia

Delayed cerebral ischemia was more common in patients who tested positive for cannabis than in those who did not (52.2% vs. 35.4%; P = .03), but there was no relationship between delayed cerebral ischemia and testing positive for cocaine, methamphetamine or tobacco (P .29), Lawton and colleagues found.

Radiographic vasospasm was also more common in patients who tested positive for cannabis than in those who did not (88.9% vs. 70.5%; P = .008), and among those with radiographic vasospasm, 50% of cannabis users had delayed cerebral ischemia compared with 39% of nonusers (P = .17), according to the researchers.

In a propensity score-adjusted analysis, cannabis use was associated with delayed cerebral ischemia in the patient population (OR = 2.7; 95% CI, 1.4-5.2; P = .003).

“When people come in with ruptured aneurysms, and they have a history of cannabis use or are positive on a toxicology screen, it should raise a red flag to the treating team that they are at higher risk of vasospasm and ischemic complication,” Lawton said in the release. “Of all the substances detected in the toxicology screen, only cannabis raised the risk of delayed cerebral ischemia. Cocaine and meth are hypertensive drugs, so they are likely related to the actual rupture but not expected to have an impact on vasospasm.”

‘An open question’

In a related editorial, Feras Akbik, MD, PhD, and Ofer Sadan, MD, PhD, both assistant professors of neurology and neurosurgery at Emory University School of Medicine, wrote: “Ultimately, given the prior mixed results regarding the association of marijuana with cardiovascular complications, ischemic stroke or hemorrhagic stroke, it remains an open

question whether cannabis precipitates cerebral ischemia via cerebral vasospasm and delayed cerebral ischemia. Future studies should attempt to better quantify the cannabis exposure in terms of chronicity, dose and temporal relationship between the cannabis use and the aneurysm rupture event, in order to better understand whether indeed marijuana can precipitate cerebral ischemia.”