Dementia after stroke is fairly common. Within 1 year, 18.4% of people who have had a stroke experience dementia. A stroke can damage the brain, leading to a type of dementia known as vascular dementia.

The above information comes from a 2021 study in the Journal of Neurology, Neurosurgery & Psychiatry.

Vascular dementia is the second most common type of dementia behind Alzheimer’s disease. It happens when the brain suffers an injury due to decreased blood flow.

There are no approved medications for post-stroke dementia. Instead, doctors may recommend drugs used to treat other types of dementia. While there is no cure, preventing additional strokes may slow or stop cognitive decline. Rehabilitative treatments may help some people.

Read on to learn more about dementia after a stroke.

An older man with dementia after a stroke, looking in the mirror on front of a wardrobe.Share on Pinterest
Yasser Chalid/Getty Images

A stroke deprives the brain of blood and oxygen. This can damage various parts of the brain. If the damage is severe, a person may develop dementia.

It is common for people to have impairments after a stroke. Sometimes these impairments get better with treatment or time. However, post-stroke dementia can be a progressive disease that does not improve.

A 2021 systematic review and meta-analysis reports that, at any given time after a stroke, 16.5% of people experience dementia. At 1 year after a stroke, the figure rises to 18.4%. These figures exclude people who had dementia prior to the stroke.

The symptoms of dementia after a stroke are similar to the symptoms of other types of dementia. However, in the early days following a stroke, it can be difficult to distinguish dementia from the symptoms of the stroke itself.

A doctor may recommend brain imaging and neurocognitive testing. Neurocognitive testing refers to a group of brain function tests that assess for signs of brain damage and decline.

Some symptoms of dementia after a stroke include:

  • new or worsening memory impairments, such as trouble remembering names or recent events
  • problems with decision-making, such as the inability to make good decisions or follow directions
  • confusion, such as frequently getting lost
  • problems with self-care, such as difficulty bathing or getting dressed
  • speech issues such as difficulty speaking or understanding speech
  • changes in mood or personality, such as depression, aggression, or anxiety

A person’s abilities following a stroke sometimes improve with rehabilitation, but there is no cure for stroke-related dementia.

Preventing future strokes may slow or stop the progression of dementia, and it can prolong a person’s life. However, this will not reverse the disease. Factors that may help reduce the risk of another stroke include:

  • quitting smoking
  • maintaining a moderate weight
  • lowering blood pressure
  • getting more exercise
  • eating a healthy diet

Dementia is an unpredictable disease, and no two people experience the exact same progression. Statistics on average progression do not predict how dementia will progress for each individual. Some people remain stable for long periods. In others, the disease progresses rapidly or suddenly gets worse.

Progression depends on many factors, including:

  • the degree of damage to the brain
  • whether a person has another stroke or cardiovascular episode
  • the quality of care and treatment

The 5-year survival rate among people with vascular dementia following a stroke is 39%.

In people who already have dementia, a stroke often makes symptoms worse. This is because a stroke can cause additional damage to brain regions previously unaffected by dementia.

For example, a person who previously showed only memory problems may begin to have difficulties with speech or mobility after a stroke. Having dementia prior to a stroke may also increase the risk of worsened dementia and brain damage after a stroke.

New or worsened symptoms may have a significant effect on a person’s independence and self-care abilities. If this happens, continuing rehabilitation and getting support with hygiene and nutrition is important to maintain health.

A stroke is a medical emergency. Prompt treatment may prevent damage and potentially prevent dementia. A person should go to the hospital or call 911 for stroke symptoms such as:

  • sudden weakness or numbness, especially if it affects just one side of the body
  • confusion
  • speaking difficulties
  • trouble moving one side of the body
  • trouble seeing or hearing
  • drooping on one side of the face when a person tries to smile
  • inability to raise both arms to the same level without one arm drifting down

After a stroke, a person should see a doctor if:

  • impairments persist or get worse
  • they develop new or worsening impairments
  • stroke or dementia treatment does not work or causes unpleasant side effects

There is no cure for vascular dementia. As with other forms of dementia, it is progressive and gets worse with time.

As dementia after a stroke means that a person already has vascular disease, their life expectancy is short relative to the general population. It may also be shorter than that of people with other types of dementia.

People with vascular dementia who have had a stroke have a 5-year survival rate of 39%. They are more vulnerable to death from cardiovascular diseases, including stroke.

Managing underlying cardiovascular risk factors may help a person live longer.

A stroke can cause significant brain damage, which can lead to vascular dementia. Stroke can also worsen dementia for people who already have the condition.

It is important for people with vascular disease to talk with a doctor about strategies to reduce their risk of having a stroke. A person who thinks they are having a stroke should seek emergency medical care. Prompt intervention may reduce the risk of long-term complications, including dementia.