Risk factors as possible targets for prevention of small vessel disease

Introduction: Lacunar infarcts, white matter lesions (WMLs), deep intracerebral hemorrhages (ICHs), and microbleeds are now considered various manifestations of age- and vascular risk factor-related cerebral small vessel disease (SVD). As a whole, these lesions are associated with a plethora of disabilities commonly seen in elderly persons. These may include cognitive impairment, dementia, depression, motor and gait disturbances, urinary symptoms, functional impairment, and stroke. More importantly, presence of these lesions increases mortality [1, 2]. Given the close association of WMLs with vascular risk factors, morbidity and mortality associated with these lesions are likely preventable. This chapter reviews the risk factors for the presence and progression of each of these manifestations. Knowledge of such risk factors generates hypotheses regarding possible targets for prevention. Lacunar infarcts: Background: Understanding the pathogenesis of lacunar infarcts provides an important link to potential risk factors. The term “lacune” originated in the neuropathologic literature to describe a small cavity that remained in the brain tissue after the necrotic parenchyma of a small deep infarction had cleared [3, 4]. Dechambre was credited for using the term in 1838, and Durand-Fardel provided a treatise on the topic in 1843 [3]. According to Durand-Fardel, an associated term, “état criblé” (i.e., tissue riddled with holes or a sieve-like state) referred to dilated perivascular spaces and “atrophie interstitielle du cerveau” to rarefaction of the nervous system, viewed as being tantamount to leukoaraiosis [4]. Pierre Marie has been recognized for finding lacunes in 45 of 50 brains at necropsy and linked the healed area to obliteration or rupture of a perforating artery or its branches due to local arteriosclerosis [3].