The relationship between stroke and dementia can be underlined by looking at a condition called vascular dementia. Vascular dementia is the second most common form of dementia, and it’s a condition that is most commonly associated with the left side of the brain (the parts of the brain linked to memory, planning, reasoning, and other thought processes.)
Vascular dementia may occur in stroke patients that experience a stall in the blood flow directed to their brain. It won’t affect everyone, but there is a definite relationship between strokes (of specific impact and location) and dementia.
There are various types of dementia. And vascular dementia just so happens to be one of the most common classifications thereof. It’s a condition that is very closely linked to, as you can guess, the vascular systems of your body.
In this case, we’re looking at vascular dementia and how it relates to a stroke. We’ve already confirmed that yes, there is, in fact, a relationship, and that stroke can lead to an onset of vascular dementia. However, their link is a little more complicated than that implies.
To put things in perspective, in this study, conducted in 2012, a researcher reviewed the results of several older studies in order to come up with the following… “Out of the 5,514 people that were considered (both with pre- or post-stroke dementia); 9.6% to 14.4% experienced an onset of dementia after just one stroke.”
It was also discovered that the risk increased quite dramatically for those who suffer from recurrent strokes (up to at least 29.6% to 53.1% chance of onset of dementia.) All this, the researcher observed, pointed to a positive relationship between both factors, meaning, that stroke is a risk factor for dementia and vice versa.
Types of Vascular Dementia
There are actually four types of vascular dementia, only three of which are associated with strokes. As mentioned at the very beginning, vascular dementia is caused by damage inflicted in the left hemisphere of the brain. However, not everyone will experience it in the same way.
The types of vascular dementia are thus separated as a result of the type of damages accrued, and each can affect the patient differently and progress differently as well…
- Single-Infarct Dementia: This type of vascular dementia describes a condition that often occurs after a singular but powerful ischemic stroke that affects a single large portion of the brain
- Multi-Infarct Dementia: Opposite to the previous, multi-infarct dementia is a result of a series of transient ischemic attacks (mini-strokes) over a short period of time that causes widespread damage all over the brain.
- Subcortical dementia: This type of dementia is characterized by the onset of a lacunar stroke, which is a type of ischemic stroke that specifically affects the small arteries located deep in the brain.
- Mixed dementia: This is the type of vascular dementia that is characterized by occurring at the same time as Alzheimer’s Disease, and thus, is not technically associated with strokes.
What Causes Vascular Dementia?
One important thing of note is that the risk factor of vascular dementia directly correlates to the risk factors associated with a stroke (which is what causes the positive relationship we established previously.)
These risk factors include the following:
- History of smoking
- High blood pressure and cholesterol levels
- Age (most people who suffer from vascular dementia are 65 years of age, or older.)
- Atherosclerosis (the calcification of arteries that can lead to blockages that prevent blood flow)
When to See a Doctor
If you’re concerned about your risk for vascular dementia, and or stroke; then the best thing to do is to talk to your doctor. They’ll be able to diagnose any signs of onset dementia (although generally not the type of dementia) immediately.
Dementia has a tendency of worsening over time. And so it is even more important that you are diagnosed early; so that you can be provided treatment plans that suit your own specific condition.
The relationship between stroke and dementia has become more and more defined over the years. However, the complexity of both makes it difficult to provide one with a clear description of their connection.
The thing we know for certain is that stroke can cause dementia — broadly diagnosed as vascular dementia. We also know that there are different types of vascular dementia. And that how you experience it will be different based on the type of stroke(s) you suffered; as well as the damages accrued.
Finally, we know that the relationship goes both ways (your risk of a stroke increases if you have dementia, and your risk for dementia increases if you experience a stroke.) As to what else we can hope to learn in the future, only time will tell.
- Pendlebury, Sarah T. “Dementia in Patients Hospitalized with Stroke: Rates, Time Course, and Clinico-Pathologic Factors.” International Journal of Stroke, vol. 7, no. 7, Nov. 2012, pp. 570–581., doi:10.1111/j.1747-4949.2012.00837.x.