Small Vessel Ischemic Disease

Small vessel ischemic disease is also known as microvascular Ischemic or lacunar infarcts disease.

The condition describes disorders affecting the small vessels of the brain. Small vessel ischemic disease entails a situation where injuries to arterioles and capillaries are predominant, resulting in reduced and interrupted brain perfusion.

The brain is primarily affected by this disease, but the disease has been associated with other vital organs in a few cases.

Medical specialists employ the term microvascular ischemic disease to refer to tiny changes or complications that are observed in the walls of the blood vessels of the brain or other affected organs.

Most conditions that affect these micro-vessels can damage the brain’s white matter (the white matter contains nerve fibers that send interactive signals within the brain).

Due to the low mortality of small vessel ischemic disease (SVID) and barely accurate postmortem evidence, the current body of knowledge and understanding of small vessel ischemic disease is still immature.

However, traces of facts that seem to describe a condition similar to small vessel ischemic disease were found in literature dating back to the late nineteenth century.

It was not till the late twentieth century that doctors and medical researchers began to examine the pathophysiology and clinical manifestations of cerebral ischemic disease (SVID).

Small vessel ischemic disease is a persistent neurological disease in older individuals. It can cause stroke, dementia, mood disturbance (old-people-sickness), and gait problems without prompt treatment.

Approximately, the disease accounts for 45% of dementia cases, about 20% of all strokes worldwide, and 25% of Ischemic or lacunar strokes. Also, most frequently presented by people with Small vessel ischemic disease include cognitive impairment and depression.

Some persons refer to this disease as a “silent disease”, because most people do not experience any warning signals or noticeable symptoms.

However, medical specialists can investigate signs of small vessel ischemic disease using magnetic resonance imaging brain scans.

Table of Contents

Causes

The exact etiology of small vessel ischemic disease has not been comprehended yet; however, many factors have been closely associated with changes and damages to the brain’s blood vessels.

The first factor is the piling up of plaque, scar tissues, or fatty tissues inside these small arterioles; this can wholly or partially restrict blood flow to and in the brain.

When blood flow to the brain is cut-off or reduced, certain parts of the brain may not receive enough oxygen, leading to brain tissue damage and subsequently an ischemic stroke.

Secondly, a factor that can result in small vessel ischemic disease is that blood vessels can become hard and brittle.

A hardened artery can develop bulges called aneurysms, which can leak or burst, resulting in bleeding in the brain.

These events lead to a condition referred to as a hemorrhagic stroke.   

Risk Factors

One of the critical risk factors of small vessel ischemic disease (SVID) is age. According to a published review in 2009, just 5% of people at least 50 years are affected by SVID, but nearly 98% of individuals over the age of 90.

Some other risk factors of SVID include:

  • High blood cholesterol
  • Hypertension
  • Personal history of stroke and other cardiovascular diseases
  • Smoking
  • Diabetes
  • Autoimmune disorders
  • Inflammation of blood vessels due to infection
  • Radiation exposure
  • Atrial fibrillation

Symptoms

Small vessel ischemic disease can present itself in mild, moderate, or severe forms. Most older adults, particularly those with a mild form of the disease, are asymptomatic; that is, they show no symptoms of the disease even when there are visible damage areas (through MRI scan) in the brain; hence, the name is a silent disease.

According to recent research on small vessel ischemic disease, about 20% of healthy elderly individuals had silent damage in their brains, most of which resulted from small vessel disease. The reason for this manifestation is unknown.

Although asymptomatic, patients may present subtle changes in their cognitive and physical abilities.

Severe forms of small vessel ischemic disease can show symptoms such as:

  • Cognitive impairment (loss of thinking abilities)
  • Dementia (short term memory loss)
  • Problems with walking and balance
  • Depression

When small vessel ischemic disease results in stroke (a stroke is an emergency that requires prompt treatment to stop disease progression and increase chances of reversing the condition), symptoms presented include:

  • Sudden confusion
  • Numbness and weakness especially observed on one side of the body.
  • Difficulty in speaking and understanding.
  • Dizziness
  • Loss of vision
  • Loss of coordination
  • Frequent severe headaches

Diagnosis

The first line of laboratory tests used to diagnose small vessel ischemic disease is magnetic resonance imaging (MRI).

This imaging test uses strong magnets and high-frequency radio waves to create detailed images of the body’s internal structures, but in this case, the brain.

Small vessel ischemic disease can be observed on an MRI in various ways:

  • As small visible strokes (these are called lacunar infarcts)
  • Cerebral microbleeds (bleeding from small blood vessels in the brain)
  • White matter lesions that show up as bright on the scan (white matter hyperintensities)

Differential Diagnosis

The differential diagnosis varies widely and includes multiple disorders involving the white matter of the brain.

Other conditions that may present similar symptoms as small vessel ischemic disease (SVID) include:

  • Primary angiitis of the CNS (Central Nervous System)
  • CADASIL
  • Cerebral amyloid angiopathy

Treatment

Small vessel ischemic disease affects tiny vessels that transport blood, less than 0.5 mm in diameter.

This size makes the condition challenging to identify and treat surgically. Generally, treatments recommended by doctors are treatments to manage risk factors and symptoms.

Doctors’ choice of management may depend on the patient’s symptoms and risk factors best suiting a patient of small vessel ischemic disease.

Treatment approaches may include lifestyle changes and medications to reduce the risk of stroke, physical disability, and cognitive decline.

Treatment such as:

  • Reducing blood cholesterol level with diet, exercise, and statin drugs if required.
  • Reducing blood pressure with exercises and medications. The goal for a person 60 years and above; is systolic blood pressure below 150.
  • Asprin medications and blood-thinning drugs to prevent strokes.
  • Regular intake of B vitamins to lower homocysteine levels. High levels of homocysteine have been linked to atherosclerosis and blood clots.
  • Stop smoking.

Prevention

To reduce the risk of developing small vessel ischemic in the future and prevent the outcome of strokes, follow these tips:

  • If a person is overweight, they should work with a doctor and a dietitian to bring the weight back to a healthy range.
  • Healthy diet plans should be followed, such as DASH or Mediterranean diet, which are high in nutrition and low in saturated fat, sugar, and sodium.
  • Persons at risk should follow counseling advice from therapists regarding quitting smoking; alternatives such as nicotine replacement products and medications can reduce the urge to smoke.
  • An individual should be aware of his blood pressure, cholesterol, and blood sugar levels. These levels should always be in their normal range. If any deviation, corrective measures to adjust these levels should be taken.  
  • Limit or avoid alcohol.
  • Exercise at least 30mins a week.

Summary

Small vessel ischemic disease is not a condition to be overlooked as it can be severe, resulting in a stroke, dementia, and even death if not treated. The disease is the cause of 45% of dementia cases and 20% of stroke cases. A reasonable way to prevent these complications is first to avoid small vessel ischemic damage. Follow healthy diets, regular exercises, and follow medication prescribed by doctors.

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