What are Lacunar Infarcts?

Lacunar infarcts, also known as lacunar strokes, are small areas of dead tissue deep within the brain usually caused by blockages or obstructions in the smaller branches of major arteries. Though typically small when compared to other types of strokes, lacunar infarcts account for approximately 20% of all strokes, especially in those with high blood pressure or diabetes. The smaller strokes associated with lacunar infarcts are typically not fatal; however, they often can result in brain damage and other associated disabilities similar to larger, life-threatening strokes.

The type of damage caused to a person by a lacunar infarct is typically classified as being one of five different classifications, called syndromes, each consisting of a specific set of symptoms. The most common syndrome is a pure motor stroke, which accounts for as much as 50% of all lacunar infarcts. Those afflicted with this syndrome experience a severe weakness or are paralyzed on one side of their body. They can also suffer from other symptoms, such as a difficulties swallowing and speaking.

The second most common syndrome is ataxic hemiparesis. This syndrome causes weakness and clumsiness on one side of the body, and is caused by a lack or reduction in motor control that can appear from hours to days after the lacunar infarct occurs. The third syndrome, dysarthria, is similar to antaxic hemiparesis and considered by some to be a variant of it. Patients with dysarthria typically experience a weakness or clumsiness in one hand also caused by a reduction in motor control.

The final two syndromes associated with lacunar infarcts are sensory related. Pure sensory stroke syndrome causes tingling, numbness, or other unusual sensations on the affected side of the body. Mixed sensory stroke syndrome usually involves either a weakness or paralyzed body part, as with a pure motor stroke, with the addition of the sensory symptoms associated with a pure sensory stroke. The sensory symptoms in both of these syndromes can either be continuous or come and go with varying levels of severity at unpredictable intervals.

There is no specific medical treatment for those who have experienced a lacunar infarct beyond physical rehabilitation and taking measures to prevent another occurrence. Lacunar infarct patients do, however, tend to recover faster and more completely than do those who have experienced other types of strokes. As many as 80% of those who suffer a lacunar infarct are able to function independently in one year, compared to about 50% of those afflicted with another form of stroke.