Lacunar stroke is a small (<20 mm axial diameter), subcortical infarct or hemorrhage in the deep white matter, internal capsule, thalamus or ventral pons, in the territory of supply of an intracerebral small penetrating / perforating artery.1 Lacunar strokes are most commonly ischemic (ie, infarcts) and are caused by disease of intracerebral small (40–200 μm diameter) penetrating arteries.2 Intracerebral small artery diseases causing lacunar ischemic stroke include intrinsic cerebral arteriolar occlusive disease (eg, arteriolosclerosis, lipihyalinosis, fibrinoid necrosis, and arteritis) and, in a small minority (10%) of cases, occlusion by embolism from a proximal source. Intracerebral small artery diseases causing lacunar hemorrhagic stroke include amyloid angiopathy, fibrinoid necrosis, and arteritis. The pathogenesis of intracerebral small vessel disease is largely unknown and may primarily reflect endothelial dysfunction and failure.2 However, the pathological processes leading to the arteriolar disease are associated with prolonged exposure to vascular risk factors, particularly hypertension.2 Hence, tight control of vascular risk factors such as hypertension underpins the management of the ≈25% of patients (varying 10% to 40% in different populations) with ischemic stroke who have lacunar stroke attributable to intracerebral small vessel disease as the underlying cause.3–8 A meta-analysis of 45 randomized controlled trials (RCTs) of blood pressure (BP)–lowering drugs found that reducing mean BP by 10 mm Hg systolic, or 5 mm Hg diastolic, reduced the risk of stroke by ≈40% (relative risk reduction [RRR] 41%; 95% confidence intervals [CI, 33–48]).9 The strength of association was slightly less extreme in the 13 trials that based their recruitment on a history of stroke (RRR, 34%; 95% CI [21–44]) compared with the 25 trials that solely recruited participants with no history of vascular disease (RRR, 46%; 95% CI [35–55]).9,10 There was also evidence of modification by age in …