Episode 163: Vascular Dementia      

Future Dr. Ruby explains gives a definition of vascular dementia and concisely explains the pathophysiology and presentation of this disease. Dr. Arreaza reminds us of the importance of treating diabetes to prevent dementia.  

Written by Carmen Ruby, MSIV, Ross University School of Medicine. Editing and comments by Hector Arreaza, MD. 

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What is vascular dementia?

Vascular dementia is a condition that arises due to damage to blood vessels that reduce or block blood flow to the brain. A stroke can block an artery and result in various symptoms, such as changes in memory, thinking, or movement. Other conditions like high blood pressure or diabetes can also damage blood vessels and lead to memory or thinking problems over time.

Vascular dementia (VaD) is a type of dementia that slowly worsens cognitive functions and is thought to be caused by vascular disease within the brain. Patients with VaD often exhibit symptoms similar to Alzheimer's disease (AD) patients. However, the changes in the brain are not due to Alzheimer’s disease pathology (amyloid plaques and neurofibrillary tangles) but due to a chronic reduction in blood flow to the brain, eventually leading to dementia. 

Alzheimer’s disease pathophysiology is very complex, and studies have shown that patients with AD can experience simultaneously several vascular issues that can affect cognitive function. For example, patients with AD may experience mini-strokes and have a reduction of the flow of oxygen and nutrients to the brain tissue. So, AD can be worsened by vascular factors as well, but the vascular factors are not the main problem in AD.

Clinically, patients with VaD can appear very similar to those with AD, which makes it difficult to distinguish between the two diseases. Nevertheless, some clinical symptoms and brain imaging findings suggest that vascular disease is contributing to, if not entirely explaining, a patient's cognitive impairment.

Epidemiology.

In the US, VaD is the 2nd most common type of dementia (15-20% of cases). Prevalence increases with age (∼ 1–4% in patients ≥ 65 years.) People affected by vascular dementia typically start experiencing symptoms after age 65, although the risk is significantly higher for people in their 80s and 90s.

Etiology

VaD may occur as a result of prolonged and severe cerebral ischemia of any etiology, primarily:

• Large artery occlusion (usually cortical ischemia) *Acute*
• Lacunar stroke (small vessel occlusion resulting in subcortical ischemia) *Acute/Subacute*
• *Chronic* subcortical ischemia

Risk factors:

• Advanced age
• History of stroke
• Underlying conditions associated with cardiovascular disease:
  • Chronic hypertension
  • Diabetes
  • Dyslipidemia
  • Obesity
  • Smoking

Clinical Features:

Symptoms depend on the location of ischemic events and, therefore, vary widely amongst individuals, but a progressive impairment of daily life is common. Because of the diverse clinical picture, the term "vascular cognitive impairment" is gaining popularity over Vascular Dementia.

Dementia due to small vessel disease:

• Symptoms tend to progress gradually or in a stepwise fashion and comparatively slower than in multi-infarct dementia.
• Generally associated with signs of subcortical pathology:

Dementia due to large vessel disease 

• Usually, sudden onset
• Multi-infarct dementia: typically, stepwise deterioration 
• Generally associated with signs of cortical pathology:
  • Early symptoms
    • Reduced executive functioning
    • Loss of visuospatial abilities
    • Confusion 
    • Apathy
    • Motor disorders (e.g., gait disturbance, urinary incontinence)
  • Later symptoms
    • Impaired memory
    • Further cognitive decline: loss of judgment, disorientation
    • Mood disorders (e.g., euphoria, depression)
    • Behavioral changes (e.g., aggressiveness)
    • Advanced stages: further motor deterioration: dysphagia, dysarthria
• Dementia due to large vessel disease 
  • Usually, sudden onset
  • Multi-infarct dementia: typically, stepwise deterioration 
  • Generally associated with signs of cortical pathology:
  • Cognitive impairment in combination with asymmetric or focal deficits (e.g., unilateral visual field defects, hemiparesis, Babinski reflex present)

Overall, the symptoms vary depending on which areas of the brain are affected.

Management and Treatment

There is hope when it comes to managing the symptoms of vascular dementia. Although there is no cure for the condition, there are medications available that can help make life easier for those living with it. Additionally, there are drugs commonly used to treat memory issues in Alzheimer's disease that may be effective for individuals with vascular dementia. Sometimes, people with vascular dementia may experience mood changes, such as depression or irritability. These changes can be managed with medications used for depression or anxiety.

Vascular risk modification: If your patient is experiencing cognitive impairment and has clinical or radiologic evidence of cerebrovascular pathology, getting screened for vascular risk factors, especially hypertension, is essential. Treatment can help prevent dementia, but it may not be as effective in reversing it. Statins are given after a stroke regardless of lipid levels.

Antithrombotic therapy: For patients with vascular dementia who have had a clinical ischemic stroke or transient ischemic attack, they must receive the appropriate antithrombotic therapy based on the specific stroke subtype to help prevent any future ischemic strokes.

When considering antiplatelet therapy for patients with vascular dementia who have not had a clinical ischemic stroke or TIA, it is important to make an individualized decision. For instance, we may prescribe aspirin at a dosage of 50-100 mg daily for patients with an infarction seen on brain imaging but not for those with only white matter lesions.

Cholinesterase inhibitor therapy: It is recommended to start cholinesterase inhibitor therapy, such as donepezil or galantamine, for patients with vascular dementia who have a gradual cognitive decline that is not a direct result of a stroke. The evidence suggests that this treatment may offer a small cognitive benefit, but the clinical significance is unclear. Experts do not recommend cholinesterase inhibitors for patients with dementia diagnosed after a stroke if there is no gradual cognitive decline.

Antipsychotics: We can briefly mention antipsychotics. They may be used but we have to remember they may increase mortality in the elderly, and the patient and family must be aware of this risk. Some examples are risperidone, quetiapine, and olanzapine, use them cautiously. Let’s talk beyond medications, what other treatments can we offer? 

Non-pharmacologic options: In addition to medications, there are various ways to help a person with vascular dementia. Research has shown that physical exercise, sleep hygiene, and maintaining a healthy weight can not only enhance brain health but also reduce the risk of heart problems, stroke, and other diseases that affect blood vessels. 

Patients must be encouraged to eat a balanced diet, get enough sleep,limit alcohol intake, and encouraged to quit smoking, as these are other crucial ways to promote good brain health and reduce the risk of heart disease. Additionally, comorbid conditions such as diabetes, high blood pressure, or high cholesterol, must be treated, because they affect brain function and quality of life overall.

It is essential to understand that emotional outbursts and personality changes can be caused by underlying brain disease and are not always intentional responses or reactions. When behavior problems overwhelm an individual, their family members, or friends, it is critical to seek support. Patient and caregiver support groups are helpful, offering a space to vent, grieve, and gain practical advice from others experiencing similar challenges. Exploring other sources of support, such as adult day programs, can also benefit caregivers and individuals affected by vascular dementia. 

Conclusion: Now we conclude episode number 163, “Vascular dementia basics.” Future Dr. Ruby explained that vascular dementia is mainly caused by an impaired circulation of blood and oxygen to certain areas in the brain. This can be a result of large or small vessel disease. Dr. Arreaza reminded us of the importance of treating diabetes as a way to prevent dementia. 

This week we thank Hector Arreaza and Carmen Ruby. Audio editing by Adrianne Silva.

Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at [email protected], or visit our website riobravofmrp.org/qweek. See you next week! 

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References:

1. Smith, MD EE, Wright, MD, MS CB. Treatment of Vascular Cognitive Impairment and Dementia. Wilterdink, MD JL, ed. UpToDate. Published online May 24, 2022. Accessed February 27, 2024. https://www.uptodate.com
2. Vascular Dementia. Memory and Aging Center. Published 2020. https://memory.ucsf.edu/dementia/vascular-dementia
3. Vascular dementia. AMBOSS. Published online June 29, 2023. Accessed February 28, 2024. https://www.amboss.com/us
4. What Happens to the Brain in Alzheimer's Disease? National Institute on Aging, https://www.nia.nih.gov/health/alzheimers-causes-and-risk-factors/what-happens-brain-alzheimers-disease. 
5. Royalty-free music used for this episode: Space Orbit by Scott Holmes, downloaded on July 20, 2022 from https://freemusicarchive.org/music/Scott_Holmes/.