What Is Multi Infarct Dementia?

Overview 

Multi-infarct dementia, also known as vascular dementia, occurs when there is reduced blood flow to the brain which causes damage that impacts a person’s thoughts, feelings and behaviour over time. This can develop as a result of strokes. This is when the blood supply to the brain is temporarily blocked by a blood clot or a rupture in a blood vessel, preventing oxygen supply to areas of the brain. Multi-infarct refers to when the brain has been affected by multiple strokes, leading to tissue death in the affected areas. The loss of function in the infarcted regions of the brain can cause the onset of multi-infarct dementia. 

What are the signs and symptoms of multi infarct dementia? 

The severity and range of symptoms of multi-infarct dementia depends on the intensity of the damage and on the regions of the brain that have been affected. The main symptoms associated with multi-infarct dementia are as follows: 

• Difficulties with balance and movement
• Feeling confused 
• Issues with speaking or comprehending speech
• Headaches that come on suddenly 
• Being numb or paralysed on one side of the body 

If you or someone you know is experiencing any of the above signs or symptoms, it is important to speak to your healthcare provider as soon as possible to discuss any concerns. It can help to take someone you trust to support you in your visit to your healthcare provider. 

As multi-infarct dementia is a consequence of multiple strokes, it is important to identify when you or your loved one is experiencing a stroke. Symptoms of stroke are listed as follows: 

• Sudden numbness of the face, arm or leg on one side of the body
• Confusion 
• Difficulty speaking and understanding speech 
• Difficulty seeing in one or both eyes 
• Trouble with walking, dizziness or loss of balance
• A severe headache that comes on suddenly 

If you see someone with any of these symptoms, it is important to call for an ambulance as soon as possible to prevent complications and further strokes. 

However, not all strokes are visible and so a person may not even realise they are having one. These are known as silent strokes, which are small strokes that damage small regions of the brain and can recur over time. 

The infographic below shows the link between where the blood vessel damage occurs and which symptoms are present in multi-infarct Dementia:

Image source: Parr-Reid S. BioRender. 

What are the causes of multi infarct dementia? 

There are a range of genetic and environmental factors that increase a person’s risk of having a stroke and hence, multi-infarct dementia. The main risk factors are shown in the infographic below:^1,2

Image source: Parr-Reid S. Canva. 

Multi-infarct dementia is the second most common type of Dementia after Alzheimer’s Disease, accounting for 20% of all dementia cases.³ As mentioned in the infographic above, age itself is a risk factor for multi-infarct Dementia. Once a person reaches the age of 65, their risk of multi-infarct dementia doubles every five years. 

It is uncommon for someone under the age of 65 to be diagnosed with multi-infarct dementia. The condition is more common in those assigned male at birth than those assigned female at birth, which may be explained by differences in the amount of risk factors between the sexes.   

How is multi-infarct dementia diagnosed? 

Whilst there is no specific diagnostic test for multi-infarct dementia, multiple clinical tests can be performed to identify characteristic symptoms and signs of multi-infarct dementia: 

1. Your healthcare provider will look at your medical history to identify any risk factors or signs of multi-infarct dementia
2. Laboratory tests that measure your blood cholesterol and blood sugar levels may be performed. Certain blood tests may be requested to rule out vitamin deficiencies or thyroid disease
3. Your healthcare provider will assess your reflexes, muscle function, movement, sensation to touch, sight, and coordination, as these are all linked to your brain function
4. If your healthcare provider has spotted symptoms that are concerning, they may request a brain scan. The two most frequently used brain scans for diagnosing multi-infarct dementia are MRI and CT scans
5. Your healthcare provider may conduct neurological exams to test your speech, writing, language, arithmetic, memory, planning, and reasoning. It is important to know that these tests may obtain results for symptoms which overlap with other types of dementia, so presence of these symptoms alone cannot definitively tell you that you have multi-infarct dementia 

What is the outlook for patients with multi infarct dementia? 

The median survival time following diagnosis for multi-infarct Dementia is thought to be just under four years, compared with seven years for Alzheimer’s Disease and 5 years for mixed Dementia.⁴

How is multi infarct dementia treated? 

Whilst there is no cure for multi-infarct dementia, there are some key ways to manage multi-infarct dementia. There are three main categories of management, including lifestyle changes, medications and care plans. 

The infographic below shows some examples of these management methods:

Image source: Parr-Reid S. Canva. 

A doctor can prescribe some of the following medications to manage the conditions that increase your risk of experiencing more strokes, which can lead to complications and death if you already live with multi-infarct dementia.

Table 1: Medications used for the management of multi-infarct dementia 

Can you prevent multi infarct dementia? 

There are two key types of prevention strategies for multi-infarct dementia. The first type is primary prevention, which involves early detection and the treatment of risk factors.⁵ This involves targeting high-risk groups, such as the elderly, smokers, and those with high blood pressure, high cholesterol, diabetes, or heart disease. For example, a study of 7046 elderly patients found that the relative risk of multi-infarct dementia was more than a third lower in those being treated with medications for their high blood pressure than those who did not manage their blood pressure.⁶

The other main type of prevention is known as secondary prevention, which focuses specifically on preventing further strokes or providing timely intervention if a stroke does occur.^7,8

Supporting someone with multi infarct dementia 

As a friend or registered carer for someone with multi-infarct dementia, there are lots of ways in which you can support them. This may include helping them with everyday tasks, like grocery shopping, gardening or exercise. You may also need to support them when they are eating, drinking and going to the toilet. This is important as dehydration and poor toilet hygiene can lead to urinary tract infections, constipation, and headaches. However, a person’s dignity needs to be prioritised so it is important that you provide appropriate support. 

As a carer, it can be challenging caring for someone with multi-infarct dementia, so it is important to maintain your self-care. Reaching out to charities and support groups can be a step that you can take to improve your mental health and get advice on how to support a patient with multi-infarct dementia appropriately.  

Summary 

Multi-infarct dementia is the second most common type of dementia worldwide. It is normally diagnosed in those aged 65 and over. The condition results from multiple strokes, which effectively starve some brain areas of oxygen and lead to cognitive decline over time. The median life expectancy of someone with multi-infarct dementia is four years after diagnosis. Multi-infarct dementia cannot be cured but can be managed with lifestyle changes, medications, and personalised care plans, such as paying for a nursing home for longer-term support. As more research is conducted to understand multi-infarct dementia, more treatment and prevention options will become available to improve the quality of life and life expectancy of individuals living with this condition.