Cerebral Venous Thrombosis and Nitrous Oxide Intoxication: Report of Two Cases and Review of the Literature

Abstract

Background: Cerebral venous thrombosis (CVT) has various risk factors, including contraception, pregnancy, neoplasia, and thrombophilia. Nitrous oxide (N₂O), historically used as an anesthetic and more recently as a recreational drug, has been associated with neurological complications such as myeloneuropathy and thromboembolic events. Here, we report two cases of CVT associated with N₂O use and provide a review of the literature on this association.

Methods: We describe two local cases of CVT associated with N₂O use and 10 additional cases identified by literature review.

Results: Among the 12 patients, seven had co-existing CVT risk factors. Most patients reported chronic N₂O use. Hyperhomocysteinemia was reported in nine patients. Management included anticoagulation, vitamin supplementation, cessation of N₂O use, and support for addiction or psychiatric care. The outcome was generally favorable, although one local case experienced CVT recurrence following a relapse in N₂O use.

Conclusions: These cases highlight an emerging association between CVT and N₂O use. Prompt recognition of this link is critical to recommend cessation of N₂O use, alongside anticoagulation therapy and consideration of vitamin supplementation to prevent complications and recurrence.

Keywords: cerebral venous thrombosis; drug; homocysteine; nitrous oxide; vitamin B12.

FIGURE 1

Brain MRI showing left lateral sinus thrombosis. (A) Axial T2* scan showing hypointensity in the left lateral sinus indicating the thrombus. (B) T1 with gadolinium showing an endoluminal defect in the left lateral sinus indicating thrombosis.

FIGURE 2

Brain MRI showing left sigmoid sinus thrombosis. (A) Axial T1 scan showing spontaneous hyperintensity in the left sigmoid sinus indicating the thrombus. (B) Axial T1 scan after gadolinium injection showing an endoluminal defect in the left sigmoid sinus indicating thrombosis.