Your Brain On... Vascular Dementia

Dr. Ayesha Sherzai (0:00)

Most people think dementia starts with memory loss, but for many people it actually starts decades earlier in the blood vessels. Long before someone forgets a name or miss an appointment, the brain is being quietly hurt by things like high blood pressure, high cholesterol, glucose imbalance, poor sleep, inflammation, and chronic stress. Not once, not twice, but all the time, day after day, year after year. This kind of damage doesn't look dramatic. There's no big stroke, no clear warning sign. It happens slowly and silently. And that's why it's so often missed. We usually speak about dementia as something mysterious or inevitable, or as a disease that just shows up late in life. But when doctors look closely at brain scans and research, a different picture shows up. Alzheimer's disease almost never comes by itself. In most people with memory or thinking problems, there's already damage to the brain's blood vessels, narrowed vessels, injured white matter, and brain networks that aren't getting enough blood. Vascular dementia is one of the most common causes of cognitive decline around the world. And when you include mixed dementia and early vascular brain injury, which we'll talk about, blood vessel disease plays a very important role in most cases of dementia that we see. This episode is about the kind of brain damage that hides for years, and sometimes even decades, before anyone finally calls it dementia. This is Your Brain On Vascular Dementia.

So Dean, we, you and I have seen a lot of cases of vascular dementia in our clinic, and you specifically, I remember you sending them to me after diagnosis, because as a vascular neurologist, it was my job to address the risk factors. I think it would be really great if we could start with a definition of what vascular dementia is, and what vascular cognitive impairment is, and the difference between the two.

Dr. Dean Sherzai (1:56)

So vascular dementia by DSM standard is when you're having vascular diseases, such as strokes or microvascular disease that really occupies most of the brain, or a significant part of the brain, you also have cognitive decline to the extent that it's affecting your activities of daily living, and it's not delirium. Delirium is a momentary change or alteration in mental state. It could be from things that are transient. So it's not a transient state. That's just a blunt definition of vascular dementia. But vascular dementia in reality is one of the most common types of dementia that's understated. And we really need to start thinking about this because it's also one of the most preventable causes of cognitive decline.

Dr. Ayesha Sherzai (2:40)

Absolutely. So according to the DSM criteria, like you said, DSM-5, there should be some evidence of vascular damage in the brain. So when they do scans, whether it's a CT scan or an MRI, there should be some evidence of a tiny stroke or damage to the blood vessels in the brain. And like you said, there should be some cognitive decline that interferes with daily life. So anything that prevents people from managing their activities of daily living that could be driving, managing finances, taking care of their hygiene, fixing a meal for themselves, kind of taking care of their household. Why is it that they excluded delirium? Is it because delirium is seen in multiple different conditions?

Dr. Dean Sherzai (3:19)

Because delirium is something that is seen in many conditions. Medications can cause delirium. Depression can cause delirium. Lack of sleep can cause delirium. Post-surgery anesthesia can cause delirium. So many other things that can cause delirium, which is an altered mental state that is transient.

Dr. Ayesha Sherzai (3:34)

Absolutely.

Dr. Dean Sherzai (3:34)

And it's not related to underlying pathologies, such as vascular disease or neurodegenerative disease for that matter. And my interest and your interest is in VCI in particular, because we can make such a difference in that stage. But in reality, it's the stage that's also not diagnosed. Nobody talks about it because there's no diagnosis, at least clinical diagnosis where somebody could actually get evaluation for it. Vascular cognitive impairment is basically everything I defined, but the daily activities are still fine. They're able to do their daily activities, but maybe a little slower, maybe at a rate that was different from the past. So most people don't make much of this because they think it's just part of aging, but it's not part of aging.

It's the beginnings of a decline that can actually lead to dementia.

Dr. Ayesha Sherzai (4:20)

Would VCI be equivalent to MCI for Alzheimer's disease? I don't know if I said it properly, but you know what I'm saying? MCI is pre-Alzheimer's. Is VCI pre-vascular dementia?