Pre-existing Small Vessel Disease in Patients with Acute Stroke from the Middle East, Southeast Asia, and Philippines

Asymptomatic small vessel disease (SVD), including white matter hyperintensities (WMHIs), periventricular hyperintensities (PVHIs), silent stroke (SS), and cerebral microbleeds (CMBs), increases the risk of stroke. There are limited studies of SVD in subjects from the Middle East and Southeast Asia (SA). All patients admitted to stroke service between 2014 and 2015 were reviewed for presence of “pre-existing” SVD. Stroke mimics with no previous history of stroke were used as controls. There were 1727 patients admitted with stroke. Analysis was done on 988 subjects (914 strokes and 74 controls) who had MRI scan done. Pre-existing SVD was seen in 642 (64.9%) patients (WMHIs 19.6%, PVHIs 33.2%, SS 51.4%, and CMBs 22%). Silent strokes were significantly more common with ischemic stroke (IS) compared to intracranial hemorrhage (ICH) (62.0 vs 34.3%, p < 0.001). CMBs were more in ICH compared to IS (42.9 vs 23.1%, p < 0.001). The risk of developing CMBs among Far Eastern (FE) patients was 1.58 times more (p = 0.07), while 1.48 times more in Arabs (AR) (p = 0.026) compared to SA after adjusting for age. The risk of developing PVHIs was significantly higher in Arab compared to SA (odds ratio (OR) 1.43; p value = 0.021). Similarly, the risk of developing WMHIs was also significantly higher in AR patients (OR 1.6; p value = 0.009) compared to SA. The majority of ethnic AR, SA, and FE populations show pre-existing SVD on MRI. The advanced changes at a young age may be related to high prevalence of untreated risk factors and possibly as yet defined genetic and environmental factors.