[0:04]With vascular dementia, vascular refers to the blood flow to the brain, and dementia refers to problems like poor memory, difficulty communicating, and difficulty learning new information.
[0:15]Vascular dementia is also known as multi-infarct dementia, and it's a progressive loss of brain function caused by long-term poor blood flow to the brain, typically because of a series of strokes.
[0:29]Okay, let's start with some basic brain anatomy.
[0:32]The brain has a few regions. The most obvious is the cerebrum, which is divided into two cerebral hemispheres, each of which is divided into four lobes: the frontal, parietal, temporal, and occipital lobe.
[0:44]The frontal lobe controls movement and our personalities.
[0:48]It also handles our ability to count and spell and make decisions.
[0:53]The parietal lobe processes sensory information, which lets us locate exactly where we are physically and guides movements in a three-dimensional space.
[1:03]The temporal lobe plays a role in hearing, smell, and memory, as well as visual recognition of faces and languages.
[1:11]Finally, there's the occipital lobe, which is primarily responsible for processing visual information.
[1:19]All the cells in the body need oxygen, but that's particularly relevant for neurons, which can only function in aerobic conditions, meaning with a constant supply of oxygen.
[1:28]Neurons also don't have long-term energy stores, so they need a constant supply of glucose to keep working.
[1:33]Each time the heart beats, about a quarter of the blood pumped out goes directly to your brain via the internal carotid arteries and the vertebral arteries in the neck.
[1:43]Once they reach the base of the brain, these arteries join to form a ring called the Circle of Willis, which then branches off into smaller and smaller arteries, the smallest being the perforating arteries that eventually supply the entire brain with oxygen and glucose.
[2:02]Vascular dementia develops in some individuals when atherosclerosis starts to form in the arteries.
[2:07]That's when there's a buildup of plaque that thickens and hardens the artery wall.
[2:12]When this process affects the arteries supplying the brain, like the carotid arteries, it leads to a gradual decrease in blood flow to the brain, which is called chronic ischemia.
[2:22]Sometimes, small parts of the plaques can break away, and these bits can drift up towards the brain and can then eventually block a smaller artery, completely stopping the blood supply to the part of the brain that's supplied by that artery.
[2:35]Other times, tiny perforating arteries are affected by atherosclerosis and can get completely blocked off by plaque growing within them.
[2:44]Regardless of the cause, once blood supply to the brain falls below the demands of the tissue, it's considered an ischemic stroke.
[2:51]The tissue damage from an ischemic stroke is usually permanent because the tissue gets damaged and the dead tissue liquefies in a process called liquefactive necrosis.
[3:02]Brain tissue necrosis leads to a loss of mental functions governed by that area.
[3:07]If another stroke happens later on, more brain tissue might die off, and over time this damage gets worse and worse.
[3:14]The final result is dementia, a persistent loss of mental functions that is severe enough to affect a person's daily functioning.
[3:25]Symptoms of vascular dementia vary depending on which region of the brain is damaged.
[3:29]For example, if someone has strokes in the temporal lobe, it might be difficult for them to remember things or make new memories.
[3:36]Someone with a stroke in the left parietal lobe might lose the ability to speak, which is called aphasia.
[3:42]But then if they get another stroke in the frontal lobe, their personality might begin to change.
[3:47]One thing that's constant is that the symptoms of dementia appear suddenly, and brain function decreases with each stroke.
[3:56]Neuropsychological tests, like the mini-mental state exam, can be used to confirm that there is a loss of brain function.
[4:03]The vascular cause can be diagnosed using brain imaging, most commonly CT or MRI, which will show multiple cortical and subcortical infarcts, and changes like atrophy of the brain cortex, confirming the ischemia.
[4:19]Currently, there's no cure or medication to help specifically with vascular dementia.
[4:23]Treatment focuses on reducing the risk of repeated strokes.
[4:28]This means treating conditions like high blood pressure, high cholesterol, and reducing smoking.
[4:34]All right, as a quick recap.
[4:37]Vascular dementia is a progressive loss of brain function caused by multiple strokes or infarcts, which in turn are caused by atherosclerosis of the vessels supplying the brain.
[4:48]The signs and symptoms depend on where the strokes develop, and they usually appear one at a time.
[4:53]Treatment currently focuses on treating underlying conditions, which may prevent further strokes from happening.
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