It has been suggested that there may be more than one subtype of lacunar stroke. One hypothesis is that in some patients it is caused by atheroma in the small perforating vessels within the brain while in others it is caused by a diffuse arteriopathy (called lipohyalinosis) associated with hypertension. MRI scans of all cases have been reviewed and we are examining the risk factor profiles of different subtypes of lacunar stroke.
CADASIL is the most common monogenic form of stroke. Fabry disease has been suggested to be an under diagnosed cause of stroke and can cause white matter hyperintensities in small vessel disease. We are screening for NOTCH3 mutations causing CADASIL and Fabry mutations in the cases. The Fabry study has been supported by an unrestricted educational grant from Shire.
A genome-wide association study (GWAS) is being performed in the cases and 1,000 controls. This is being funded by a project grant from the Stroke Association. We anticipate combining this data with data from other groups around the world to look for genetic variants associated with small vessel stroke.