Do white matter hyperintensities on MRI matter clinically?

Small vessel disease in the brain is one of the most common of all neurological disorders.1 It is often present even in young otherwise healthy people,2 and it leads to neurodegeneration, vascular cognitive disorder, and disability.3 As yet, small vessel disease cannot be directly measured. However, a specific clinical syndrome or white matter lesions identified on imaging (such as white matter hyperintensities on magnetic resonance imaging) can be used as surrogate markers of small vessel disease. In the linked systematic review (doi:10.1136/bmj.c3666), Debette and Markus assess the association between white matter hyperintensities and the risk of stroke, cognitive decline, dementia, and death.4

Small vessel disease comprises different pathological processes mainly affecting arterioles that supply the deep part of the brain. The lack of anastomoses in the vascular architecture of the deep part of the brain makes tissue more susceptible to disease and easily compromised during haemodynamically unfavourable conditions.5

The most common small vessel disease in the brain …