Vascular Dementia

Vascular dementia refers to a decline in cognitive abilities caused by conditions that obstruct or reduce blood flow to different areas of the brain, leading to a deprivation of oxygen and nutrients.

About

Inadequate blood flow can harm and ultimately destroy cells throughout the body, but the brain is particularly vulnerable. In vascular dementia, changes in cognitive function can occur suddenly after a stroke, which blocks major blood vessels in the brain. Alternatively, cognitive difficulties may start as mild changes that gradually worsen due to multiple minor strokes or another condition affecting smaller blood vessels, resulting in widespread damage. Some experts prefer the term “vascular cognitive impairment” (VCI) over “vascular dementia” because it better encompasses the concept that vascular-related cognitive changes can range from mild to severe. Vascular brain changes often coexist with changes associated with other forms of dementia, such as Alzheimer’s disease and dementia with Lewy bodies. Studies have shown that vascular changes and other brain abnormalities may interact, increasing the likelihood of a dementia diagnosis. Vascular dementia alone is present in approximately 5% to 10% of people with dementia, but it is more commonly seen as part of mixed dementia. However, vascular dementia remains underdiagnosed, similar to Alzheimer’s disease, despite being recognized as common.

Symptoms

The impact of vascular conditions on cognitive abilities varies depending on the severity of blood vessel damage and the affected brain regions. Memory loss may or may not be a prominent symptom, depending on the specific areas of reduced blood flow in the brain. Vascular damage that initially affects brain regions involved in memory storage and retrieval can lead to memory loss resembling that of Alzheimer’s disease.

Symptoms may be most noticeable soon after a major stroke, and they can include sudden confusion, disorientation, speech difficulties, physical stroke symptoms, difficulties with walking and balance, and numbness or paralysis on one side of the face or body. Multiple small strokes or other conditions affecting blood vessels and nerve fibers deep within the brain can cause more gradual cognitive changes as damage accumulates. Early signs of widespread small vessel disease include impaired planning and judgment, uncontrolled emotional responses (such as laughing or crying), decreased attention span, impaired social functioning, and difficulty finding the right words.

Causes and Risk Factors

Any condition that damages blood vessels in the body can lead to brain changes associated with vascular dementia. Advancing age is a major risk factor, similar to Alzheimer’s disease. Additional risk factors for vascular dementia overlap with those for heart disease, stroke, and other vascular conditions. Many of these factors are also linked to an increased risk of Alzheimer’s. Strategies to reduce the risk of vascular-related diseases and protect the brain include not smoking, maintaining healthy blood pressure, cholesterol, and blood sugar levels, following a balanced diet, engaging in regular exercise, maintaining a healthy weight, and limiting alcohol consumption.

Diagnosis

The diagnostic criteria for vascular dementia have varied, but in 2011, the American Heart Association and American Stroke Association issued a joint scientific statement on the vascular contributions to mild cognitive impairment (MCI) and dementia. According to this statement, a diagnosis of vascular-related cognitive impairment or dementia is more likely if neurocognitive testing confirms the presence of cognitive decline, brain imaging shows evidence of recent stroke or other vascular brain changes consistent with the cognitive test results, and there is no indication that nonvascular factors contribute to the cognitive decline. The statement also highlights variations in the criteria that may suggest the possibility, rather than the likelihood, of cognitive change being due to vascular factors.

Since vascular dementia often goes unrecognized, experts recommend professional cognitive screening for individuals at high risk, including those who have had a stroke or transient ischemic attack (TIA), commonly known as a ministroke, or who have risk factors for heart or blood vessel disease. Screening for depression is also advised, as it frequently coexists with brain vascular disease and can contribute to cognitive impairment.

Outcomes and Treatment

The FDA has not approved any drugs specifically for treating vascular dementia symptoms. However, clinical trials have shown that drugs approved for treating Alzheimer’s symptoms may provide modest benefits for people with vascular dementia. Treatment primarily focuses on preventing the worsening of vascular dementia by addressing the underlying conditions that cause it, such as hypertension, hyperlipidemia, or diabetes mellitus.

Controlling risk factors that may further damage the brain’s blood vessels is an important treatment strategy. There is substantial evidence that treating these risk factors can improve outcomes and help delay or prevent further cognitive decline.

Vascular dementia, like other forms of dementia, shortens life span. Some data suggest that individuals who develop dementia after a stroke have an average survival time of three years. However, cognitive changes may improve during the recovery and rehabilitation phase after a stroke as the brain generates new blood vessels and other regions of the brain take on new functions.