Vessel/lacunar strokes

Small vessel/lacunar strokes have better short- and long-term (1-year) survival as compared to other stroke subtypes. In the NINDS trial of rt-PA within 3 hours of onset, patients classified as small vessel stroke on the basis of their clinical syndrome had a 50% chance of a normal NIHSS score at 3 months if they received placebo, increasing to 70% in the treatment group. In the Lausanne cohort, 95% were independent after their first event, as opposed to only 65% of the cardioembolic strokes and 49% with large vessel atherothrombotic infarctions. Eighty-two percent of patients with small vessel stroke were independent at 1 year. Even at the time of maximal deficit, between 38% and 64% of small vessel/lacunar patients were independent, with motor impairment and extent of white matter disease adversely affecting outcomes. " In TOAST, small vessel/lacunar stroke was the only subtype associated with a favorable outcome, independent of the NIHSS score. ... 

It may be especially difficult to confidently establish the diagnosis of the most benign subtype of stroke, small vessel/lacunar stroke, accounting for 10-29% of all... 

Nadeau SE, Jordan JE, Mishra SK, Haerer AE. Stroke rates in patients with lacunar and large vessel cerebral infarction. J Neurol Sci 1993 114 128-137. 

Subcortical white matter infarcts may mimic a superficial MCA infarct causing a partial anterior circulation syndrome or present as a lacunar syndrome (pure motor, ataxic hemiparesis or sensori motor stroke). Superficial perforating artery infarcts (medullary branches) are often accompanied by cortical spotty lesions. Borderzone and white matter medullary branches infarctions are usually caused by hypoperfusion due lo large vessel occlusion or stenosis (Bogousslavsky 1993 Donnan and Yasaka 1998), but white matter medullary branches infarction can also be caused by cardioembolism (Lee et al. 2003). 

Stroke localization using clinical data is not infallible in about one-quarter of cases where a recent lesion is visible on brain imaging, it is not in the expected place (Mead et al. 1999). For example, although most pure motor strokes are caused by a lacunar infarct as a result of small vessel disease, in a few cases the CT or MR scan shows striatocapsular infarction caused by middle cerebral artery occlusion with good cortical collaterals... 

Cerebrovascular disease is a consequence of hypertension. A neurologic assessment can detect either gross neurologic deficits or a slight hemiparesis with some incoordination and hyperreflexia that are indicative of cerebrovascular disease. Stroke can result from lacunar infarcts caused by thrombotic occlusion of small vessels or intracerebral hemorrhage resulting from ruptured microaneurysms. Transient ischemic attacks secondary to atherosclerotic disease in the carotid arteries are common in hypertensive individuals. 

In some cases, showers of small emboli cause penetrator strokes as well as cortical strokes. Small emboli may also reach these vessels. Chroiuc meningitis due to tuberculosis or syphilis commonly causes stroke in the penetrator territory due to inflammation around the parent vessel at the base of the brain with occlusion of the thin penetrators exiting through the inflammatory reaction (Table 2.4 lists the causes of lacunar infarcts) [69]. 

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