Lacunar infarct.

The term lacuna, or cerebral infarct, refers to a well-defined, subcortical ischemic lesion at the level of a single perforating artery, determined by primary disease of the latter. The radiological image is that of a small, deep infarct. Arteries undergoing these alterations are deep or perforating arteries with a diameter ranging between 100 and 400 microm, numbering 6-12, that generally originate at right angles directly from the main arteries. The concept of lacunar syndrome was introduced in clinical practice to describe those clinical pictures that generally, although not always, have a cerebral infarct of lacunar type as the underlying mechanism. Classic clinical syndromes induced by lacunar infarcts are, in decreasing order of frequency, pure motor stroke, pure sensory stroke, sensorimotor stroke, ataxic hemiparesis, and dysarthria with motor disability of one hand, as well as a number of rare or incomplete syndromes. Small lacunar infarct that will then degenerate into a lacuna is caused by a reduction of blood flow to a perforating artery. In turn, this is the result of various arterial disorders, the most frequent of which include microatheroma, lipohyalinosis, fibrinoid necrosis, and Charcot-Bouchard aneurysm. Other forms of arteriopathy that can affect small vessels include amyloid angiopathy, and cerebral autosomic dominant arteriopathy with subcortical infarcts and leukoencephalopathy. Hemodynamic disorders also can be a cause of the disease. Diagnosis is made with 1,5 Tesla MRI and prognosis is generally good.