Lacunar versus non-lacunar syndromes.

Small-vessel disease is the accepted most frequent cause of lacunar stroke. The main clinical features seen with lacunar infarcts are motor and/or sensitive deficit, ataxic sign, without cortical involvement. A lacunar syndrome is generally the result of a small deep infarct within the territory of a single perforating artery with the maximum diameter on imaging of 15 mm. Recent studies have demonstrated alternative causes of lacunar stroke other than small-vessel disease (e.g. cardio embolism, atherosclerosis or other causes), especially in large lacunae, with a potential relevance on functional outcome. These findings suggest that lacunar stroke is not always a benign disease. Moreover, clinical features may be significant in terms of disability in lacunae in close proximity to crucial anatomical site. The following chapter reports the classical lacunar syndrome and discusses the debated etiology of lacunar stroke.