[01] Samir Patel, Department of Neurology, Sir Ganga Ram Hospital, New Delhi, India. [02] Anuradha Batra, Department of Neurology, Sir Ganga Ram Hospital, New Delhi, India. [03] Ish Anand, Department of Neurology, Sir Ganga Ram Hospital, New Delhi, India. [04] P. K. Sethi, Department of Neurology, Sir Ganga Ram Hospital, New Delhi, India. [05] Davinder Singh Rana, Department of Neurology, Sir Ganga Ram Hospital, New Delhi, India.

Air pollution is potential environmental risk factors for stroke. There is strong association between short term exposure to air pollution and admission to hospital for stroke and mortality from stroke. These associations were strongest in low and middle income countries, suggesting the need for policy changes to reduce personal exposure to air pollutants. Ambient sulfur dioxide (SO2) is considered a risk factor for ischemic stroke and seizure. We are reporting a case of young male without identifiable risk factors presented with posterior circulation ischemic stroke, which occurred after an accidental SO2 exposure. Endothelial dysfunction and inflammation are the possible underlying pathophysiology for development of stroke. Understanding the mechanism between SO2 exposure and the onset of brain ischemia would be helpful in preventing devastating health hazard.

Stroke, Posterior Circulation, Sulfur Dioxide

[01] Johnston SC, Mendis S, Mathers CD. Global variation in stroke burden and mortality: estimates from monitoring, surveillance, and modelling. Lancet Neurol. 2009;8:345–354 [02] Lim SS, Vos T, Flaxman AD, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet2012;380:2224–60 [03] Shah ASV, Lee KK, McAllister DA, Hunter A, Nair H, Whiteley W et al. Short term exposure to air pollutuion and stroke: systemic review and meta-analsis BMJ 2015;350:h1295 [04] Brook RD, Rajagopalan S, Pope CA III, Brook JR, Bhatnagar A, Diez Roux AV, et al.; American Heart Association Council on Epidemiologyand Prevention, Council on the Kidney in Cardiovascular Disease, and Council on Nutrition, Physical Activity and Metabolism. Particulate matter air pollution and cardiovascular disease: An update to the scientific statement from the American Heart Association. Circulation.2010; 121: 2331–2378. [05] J. Schwartz, “Daily deaths are associated with combustion particles rather than SO2in Philadelphia,”Occupational and Environmental Medicine, vol. 57, no. 10, pp. 692–697, 2000. [06] N. Sang, Y. Yun, H. Li, L. Hou, M. Han, G. Li. SO2 Inhalation contributes to the development and progression of ischemic stroke in the brain. Toxicological Sciences 2010; 114: 226–236. [07] Mateen FJ, Brook RD. Air pollution as an emerging global risk factor for stroke. JAMA 2011; 305: 1240–1. [08] World Health Organization. WHO air quality guidelines - global update. Bonn: WHO; 2005. [09] Leung JWC, Chung SSM, Chung SK. Endothelial endothelin-1 over-expression using receptor tyrosine kinase tie-1 promoter leads to more severe vascular permeability and blood brain barrier breakdown after transient middle cerebral artery occlusion. Brain Res. 2009;1266: 121-129. [10] Szyszkowicz M, Porada E, Tremblay N, et al. Sulfur dioxide and emergency department visits for stroke and seizure. Stroke Res Treat 2012;2012:824724