A blockage in one of the small arteries deep in the brain can cause a lacunar stroke. This is a common type of ischemic stroke.

Typically, ischemic strokes occur when the blood supply to the brain does not flow properly due to blockage. Blood clots or other particles may cause these blockages. A person can also develop serious health implications due to these events.

Lacunar strokes make up about 1 in 4 of all ischemic strokes. They tend to occur in older adults, and doctors associate them with hypertension — or high blood pressure — and diabetes mellitus.

Sometimes doctors may refer to this condition as a lacunar infarct.

Keep reading to learn more about lacunar strokes, including details about their risk factors, treatment options, and outlook.

A lacunar stroke is an ischemic stroke. It is usually not too physically disabling, but if it affects memory or decision-making capabilities, a person may not be able to live as independently as they would like.

Ischemic strokes happen when the blood flow to the brain is blocked. The blockage stops oxygen and nutrients from reaching the brain cells, and as a result, the cells die.

Some small lacunar strokes lead to lacunar stroke syndrome. This generally refers to a set of symptoms that people with the condition may experience.

A person can sometimes have multiple lacunar strokes at the same time, leading to various physical or cognitive issues.

Lacunar stroke syndrome

Doctors have identified over 20 lacunar syndromes, but the most common include:

  • pure motor hemiparesis or weakness in the arm and leg on one side
  • sensorimotor stroke or paralysis and loss of sensation on one side of the body
  • ataxic hemiparesis or issues with balance and coordination
  • dysarthria-clumsy hand syndrome or difficulty speaking and writing
  • pure sensory stroke or when there is loss of, or abnormal sensation, to one side of the face or body, or one side of both the face and body

A blockage in one of the small arteries deep in the brain can cause a lacunar stroke. This area of the brain contains structures like the thalamus and basal ganglia.

It often happens when the arteries are narrowed, making them more likely to become blocked. A lacunar stroke can occur due to the thickening of the arteries and obstruction of the arteries from plaque formation. Plaques refer to deposits of fat and other substances that can build up in the arteries.

Certain risk factors or other medical conditions can increase the likelihood of developing a lacunar stroke.

Several risk factors make lacunar strokes more likely, including:

  • Hypertension: High blood pressure can put a strain on the inner lining of the arteries and cause damage as blood presses against it with force.
  • Atherosclerosis: Atherosclerosis refers to the buildup of cholesterol and other fatty materials on the artery walls.
  • Diabetes mellitus: This condition increases the risk of lacunar stroke by damaging blood vessels and increasing the risk of high blood pressure.
  • Smoking: Smoking tobacco damages the arteries and may even lead to plaque forming in the arteries. Plaques can block blood flow.
  • Hyperlipidemia: High levels of fats in the blood can damage and narrow the blood vessels. Also, a buildup of cholesterol and other fatty materials on the artery walls causes them to become hard and narrow.
  • Age: Experiencing a lacunar stroke at an older age is associated with long-term disability.
  • Genetic factors: Certain genes and genetic conditions can significantly increase a person’s risk of stroke. These can include:
    • carriers of a gene called APOe4, which is linked to Alzheimer’s disease
    • cerebral autosomal dominant arteriopathy with subcortical infarct leukoencephalopathy or CADASIL, which affects blood flow in vessels of the brain

According to research, such as the Northern Manhattan Study published in 2020, Black people are more likely to experience a lacunar stroke than white people.

A person may have no symptoms as lacunar strokes are small. However, sometimes symptoms, including the following, can occur:

How much a lacunar stroke affects a person depends on the impact it has on the brain.

Anyone with sudden onset neurological symptoms requires emergency diagnosis and treatment.

Doctors may use the following to help them diagnose lacunar stroke:

  • CT scan: These images can help rule out life threatening conditions, such as bleeding on the brain. However, because of the small size of these strokes, doctors also require other tests to support their diagnosis.
  • Magnetic resonance imaging, or MRI: MRI images are more detailed and can help doctors confirm lacunar stroke.
  • CT angiogram: This test uses a CT scan and dye injected into the arteries to help doctors see if there is any blockage or narrowing.

Doctors may also perform other tests to assess blood and circulatory health.

Doctors typically treat lacunar strokes in the same way as other types of ischemic stroke.

Emergency treatment focuses on restoring blood flow to the brain as quickly as possible. Doctors use “clot-busting” medications — also called thrombolytics — to break up the clot and improve blood flow. They can deliver the medications through a vein or directly into the brain.

If these medications do not help, a neurosurgeon can remove the blockage in a procedure called a mechanical thrombectomy.

Rehabilitation can help people recover as much function as possible after a stroke. Some forms include:

  • Physical therapy: helps people relearn skills such as sitting up, walking, and lying down
  • Occupational therapy: helps people relearn skills they would use daily, such as eating and drinking
  • Speech therapy: helps people relearn how to communicate with others

Doctors also treat the underlying conditions that increase the risk of lacunar strokes, such as hypertension, diabetes, and atherosclerosis. Treating these conditions can help prevent a lacunar stroke from happening again.

Lacunar strokes are small, but they can still cause serious neurological symptoms. Having a lacunar stroke is a major risk factor for future strokes.

Studies suggested that 23–41% of people have some level of neurological deterioration after their stroke begins.

Can people recover?

People who receive emergency treatment for lacunar stroke may recover fully and the outlook for these strokes is better than others. Research shows that lacunar strokes have a case fatality of 0–3% within the first month and 3–9% within the first year. With other strokes, these figures are 14% and 28%, respectively.

However, in some cases, stroke can lead to long-term disability.

Doctors think that lacunar strokes are a leading cause of vascular dementia and cognitive impairment.

If an individual experiences several of these strokes, it can lead to other complications, including:

Lacunar strokes occur when a small blood vessel deep in the brain becomes blocked. Although small, they can cause significant neurological damage.

Risk factors for lacunar stroke include underlying medical conditions, such as hypertension, diabetes, and atherosclerosis as well as age and lifestyle factors, such as smoking.

People who receive emergency treatment for lacunar stroke often make a full recovery, but they may have an increased risk of future strokes.