Lacunar Infarct
Risk Factors
The small, deep arteries involved in a lacunar infarct are uniquely vulnerable. Most arteries throughout the body will gradually taper into a smaller size, however, the arteries involved in a lacunar infarct branch directly off a large, high pressure main artery. Since these arteries do not gradually taper down, high blood pressure (hypertension) can directly damage these arteries. Hypertension can also cause atherosclerosis, a condition characterized by fatty deposit build up along the walls of blood vessels. When atherosclerosis is present, a clot (thrombus) may form within one of these small arteries. Potentially, the small thrombus can become disloged by the pounding pulse characteristic of high blood pressure, blocking flow further along the artery. Lacunar strokes are rarely caused by a thrombus that forms elsewhere in the body. Once a thrombus begins to travel in the blood stream it is termed an embolus. It is for an embolus to make its way into the small arteries that can cause a lacunar infarct. Initially studies indicated that almost all patients who experience lacunar infarcts have hypertension. However, later studies found hypertension to only account for 44-75% of patients (Agranoff, 2011).
Diabetes mellitus is a well known instigator for the development of small vessel disease throughout the entire body, this includes the small, deep arteries involved in a lacunar infarct.
Smoking is also an established risk factor.
Atrial fibrillation has a stronger association with nonlacunar infarcts (Agranoff, 2011).
Current data is less clear regarding a strong association between other risk factors as they relate to lacunar infarcts, including alcohol consumption, elevated cholesterol, and previous history of stroke (Agranoff, 2011).