Some strokes happen on a very small scale. A lacunar stroke, also known as a lacunar infarct, occurs when a blood clot blocks a tiny artery deep in the brain, damaging or killing brain cells in only a small area—typically less than 15 to 20 millimeters. These strokes are quite common, accounting for upwards of 20 percent of all strokes. Some lacunar strokes result in noticeable symptoms—more on those below—while others are asymptomatic and go unnoticed. But despite their tiny size and whether or not they produce symptoms, lacunar strokes can have major life consequences. Bottom Line Health asked Cleveland Clinic neurologist Maria Sokola, MD, what people need to know about lacunar strokes.
Lacunar stroke symptoms
When a lacunar stroke is symptomatic, the symptoms often—though not always—fall into one of five distinct syndromes.
- Pure motor hemiparesis involves weakness or even paralysis in the arm, leg, and facial muscles on one side of the body. This is the most common lacunar stroke syndrome.
- Pure sensory stroke involves abnormal or impaired sensation in part of the body. This could be a sudden numbness, but some people instead experience pain, unusual temperatures or pressure, or other odd sensory alterations.
- Ataxic hemiparesis most noticeably results in clumsiness, but along with this loss of coordination, there’s a degree of weakness in the muscles of the face, arm, and leg on one side of the body.
- Dysarthria or clumsy hand syndrome causes slurred or slowed speech, a consequence of weakness in the muscles that are used to talk. Meanwhile, one arm experiences some loss of coordination, which might make it difficult to perform tasks requiring precise movements, such as tying shoelaces or writing.
- Sensorimotor stroke combines the sensory effects of a pure sensory stroke, described above, with weakness or paralysis in one arm and leg.
In a minority of patients, lacunar stroke symptoms increase in severity during the hours or days following those symptoms’ onset.
It’s no coincidence that many of these potential lacunar stroke symptoms are related to bodily movement and sensation. Lacunar strokes often occur in parts of the brain involved with these functions, such as the thalamus, basal ganglia, internal capsule, corona radiate, or pons. The severity of lacunar stroke symptoms varies widely, as does patients’ ability to recover from them. Some will recover fully while others experience permanent disability.
Symptomless stroke
It’s worth noting that many lacunar strokes do not result in any of the five syndromes listed above, or, indeed, in any noticeable symptoms at all. When the MRIs of seemingly healthy elderly people are examined, 20 percent of them show evidence of asymptomatic lacunar strokes, according to a systematic review published in The Lancet. Other studies have hinted that the percentage of elderly people who have had “silent” lacunar strokes could be even higher. But lacunar strokes can have major long-term health consequences even for patients who don’t experience stroke symptoms and who don’t even realize they’ve had strokes. Whether lacunar strokes are symptomatic or asymptomatic, having them significantly increases the risk that someone will experience cognitive decline, dementia, and/or further strokes.
Lacunar stroke risk factors and prevention strategies
The two risk factors that most significantly increase the odds that a patient will have lacunar strokes are high blood pressure and diabetes. Other potential risk factors include sleep apnea, smoking, high cholesterol, and atherosclerosis. Certain genetic disorders can predispose people for lacunar strokes as well—even among patients who lack other risk factors—though, fortunately, these disorders are relatively rare. Most lacunar strokes occur in people ages 55 and older, though there are exceptions, especially when genetic disorders are involved.
The good news is that patients have some control over many, though not all, lacunar stroke risk factors:
- Blood pressure and cholesterol levels can be kept under control, if necessary, with the help of medications.
- Smokers can quit the habit.
- Diabetics can keep their blood sugar levels under control, and people at risk of developing diabetes can live a more active lifestyle and lose weight.
- Adopting a heart-healthy diet can be very beneficial. Mediterranean Diet that features lots of whole grains, fruits, vegetables, nuts, and healthy fats like olive oil is a particularly good option. Helpful: learn more about the Mediterranean diet here.
Lacunar stroke diagnosis
If you suspect you or a loved one might be experiencing a lacunar stroke, do what you would do if you suspected any other sort of stroke: Call for an ambulance immediately. Time is of the essence with strokes. The sooner treatment is received, the greater the range of available treatment options and the better the odds of recovery.
The emergency room staff likely will have a computed tomography (CT) scan taken of the patient’s brain and probably a CT angiogram of his or her head and neck as well. A CT angiogram involves the injection of contrast dye into the patient’s circulatory system to make issues such as blockages more visible. These scans might identify evidence of the lacunar stroke—or they might not. Lacunar strokes are so small that they don’t always show up on CT scans.
An MRI of the brain is significantly more sensitive and would identify a higher percentage of lacunar strokes and related issues, but MRIs tend to take more time than CT scans and they’re not readily available in many ERs, so ER physicians often cannot wait for an MRI scan to be available before beginning treatment.
Additional tests will be done as well. A blood pressure reading certainly will be taken, and a range of lab tests probably will be ordered, too. These are likely to include a cholesterol level test and a blood sugar level test for diabetes and prediabetes. As noted above, high blood pressure, diabetes, and high cholesterol are potential risk factors for lacunar strokes. An ultrasound of the heart also might be done. This could provide evidence that the patient has had high blood pressure for an extended period of time.
Treatment options
How a lacunar stroke will be treated depends on several factors including the severity of symptoms and amount of time that’s passed since those symptoms began. The most common treatment options are intravenous thrombolysis, which involves the injection of a medication that dissolves blood clots, or dual antiplatelet therapy, which involves taking both aspirin and a P2Y12 inhibitor, both of which reduce the odds of further blood clots. Intravenous thrombolysis can only be administered if treatment is received within 4 ½ hours of the initial onset of stroke symptoms, however. Important: A study recently published in the Journal of the American Medical Association concluded that dual antiplatelet therapy was as effective as intravenous thrombolysis for patients with minor, non-disabling lacunar strokes.
A patient who had a lacunar stroke might be prescribed an anti-clotting medication, and/or medications to help control any underlying lacunar-stroke risk factors, such as high blood pressure.
Depending on the stroke’s symptoms, physical therapy, occupational therapy, and/or speech therapy might be beneficial as well.
