clinical overview of stroke

Question 1

what are the two types of stroke

Answer 1

infarct/ischemic stroke
haemorrhagic stroke

Question 2

what are the risk factors for stroke and which two are the important ones

Answer 2

-hypertension (Important)
-age (important)
-diabetes
-cholesterol
-lifestyle habits
-ethnicity/gender
-smoking
-heart disease

Question 3

describe what an infarct stroke is. What usually causes this disruption and what can happen due to this disruption. what symptoms can arise

Answer 3

It is also known as ischemic stroke. This happens when the blood flow is cut off or significantly reduced to parts of the brain, meaning there is disruption to blood flow, impacting the adequate levels of oxygen and nutrients required for brain cells and tissue to function properly.

this can be due to blood clots causing these blockage in blood vessels, which prohibit adequate blood flow to the brain. When the brain doesn’t get enough oxygen and nutrients, it will start to die within minutes.
The effects of an ischemic stroke depend on where in the brain the blockage occurs and how much of the brain is affected.

symptoms include: difficulty speaking, paralysis on one side of the body, weakness, confusion, visual problems, severe headaches, and facial droop

Question 4

describe what a hemorrhagic stroke is. What usually causes this disruption and what can happen due to this disruption? what symptoms can arise

Answer 4

its when blood vessel in the brain leaks or bursts, causing bleeding inside your brain. It can happen due to high blood pressure weakening the blood vessel wall over time or aneurysm (a weak spot in a blood vessel wall) bursts.

This can then cause increased pressure inside the skull, damaging brain cells and even disrupting adequate blood flow to parts of the brain by reducing the amount of oxygenated blood reaching those brain tissues for normal function.

symptoms include: difficulty speaking, confusion, weakness, loss of muscle coordination and balance, loss of consciousness or seizures, and a and a severe headache.

Question 5

Describe the vascular anatomy of the brain and its relation to the clinical features of stroke

Answer 5

it’s made of four major arteries: two carotid arteries that supply anterior part of brain and two vertebral arteries that join together to form basilar artery, which supplies the posterior part of brain.

The vascular anatomy of the brain is comprised of two vertebral arteries that join together to form the basilar artery and branches to form the superior cerebral artery and posterior cerebral artery, then form a circle of willis, which is comprised of the posterior communicating artery, the two internal carotid arteries, the anterior communicating artery and the anterior cerebral artery.

How this relates to strokes and their symptoms:

-Anterior circulation: the carotid arteries supply the front part of the brain; they branch into the middle cerebral artery and the anterior cerebral artery.
Blockage in this region may affect the leg more than the arm, difficulty speaking, confusion.

-posterior circulation: the vertebral arteries supply the back part of the brain, including cerebellum and brainstem, after forming basilar artery.
Blockage in these arteries can lead to dizziness, loss of balance and coordination, difficulty swallowing, and double vision.

Question 6

general summary of Ischemic and Hemorrhagic strokes

Answer 6

Ischemic Stroke: Happens when a blood vessel supplying the brain gets blocked, usually by a clot, leading to a lack of oxygen and nutrients in that area.
Hemorrhagic Stroke: Occurs when a blood vessel bursts, causing bleeding in the surrounding brain tissue and damage due to increased pressure.

Question 7

why can the brain still live for a while (mins-hrs) after blood vessel supplying this region gets occluded

Answer 7

some people may have good collateral circulation and it might buy you a few hours whilst other may not and their brain will die quicker. The brain’s collateral circulation is made up of other, less direct arterial pathways that might be able to bring blood to a part of the brain that is not getting it normally because an artery is blocked.

Question 8

how does smoking increase risk of stroke

Answer 8

Smoking can narrow blood vessel, increasing susceptibility to blood clots.

Question 9

what is atrial fibrillation and ventricular fibrillation and what stroke can atrial fibrillation cause

Answer 9

Atrial fibrillation (AFib)/ arrhythmia- irregular and often very rapid heart rhythm, the artia (Upper chambers) part of the heart doesn’t work properly and contract rapidly in an uncoordinated manner. Ventricular fibrillation leads to inefficient blood flow to the rest of the body.

Atrial fibrillation (AFib) can lead to the formation of blood clots within the atria—the upper chambers of the heart. These clots can then travel through the bloodstream to the brain, where they can block blood flow, causing an ischemic stroke.

Question 10

whats the difference between thrombus and embolus

Answer 10

-Thrombus is formation of blood clot
-Embolism is when this breaks off and occlude vessel elsewhere, often getting trapped in small vessels in deep brain tissue

Question 11

does grey or white matter have more blood and why

Answer 11

grey matter has more blood (has a greater amount of small blood vessels) due to greater congitive process carried out, requiring energy to function adequately.

Question 12

is prevelence of embolism and thrombosis

Answer 12

E-80%
T-20%

Question 13

causes of ischemic stroke

Answer 13

-thrombosis (formation of blood clot within blood vessel in the brain, could be due to atherosclerosis; -plaque buildup; narrowing arteries)

-embolism
(blood clot or other debris circulating in blood, lodges in blood vessels, blocking it.

conditions like atrial fibrillation can increase the risk

Question 14

what are the 2 types of hemorrhagic stroke and their causes

Answer 14

• intracerebral haemorrhage
  (most common type). when an artery bursts in the brain, flooding surrounding tissue with blood. this could happen due to increased blood pressure leading to weakening of arterial wall over time, trauma and malformations)

-subarachnoid haemorrhage
(bleeding in subarachnoid space- the area between the brain and the tissue covering it.) often caused by the rupture of an aneurysm (a weakened spot in the blood vessel wall, that causes it to bulge outwards), this could also be caused by arteriovenous malformations, traumatic injury.

Question 15

what is arteriovenous malformations and typical medical intervention for this

Answer 15

In AVMs, the arteries and veins connect directly, without the usual network of tiny blood vessels in between. This can cause problems because the veins, which are not built to handle the high pressure and flow of arterial blood, may weaken and even rupture. AVMs can occur anywhere in the body but are commonly found in the brain and spinal cord.

Treatment options for AVMs may include medication, surgery, or embolisation, which is the blocking of the abnormal blood vessels.

Question 16

what is the torcula and what medical condition is it called when you get blockage in this region ad causes for this condition

Answer 16

The torcula, also known as the merging of sinuses, is a specific area in the brain where several dural sinuses merge together. It is located at the rear part of the brain, near the occipital bone. The dural sinuses are large veins that allow blood drainage from the brain, carrying deoxygenated blood back to the heart.

If the torcula or the dural sinuses get blocked, it can lead to a condition called venous sinus thrombosis. This occurs when a blood clot forms within the dural sinuses, obstructing the normal flow of blood. Venous sinus thrombosis can have various causes, including blood disorders, infections, head injuries, or certain medications. When a blockage occurs, blood cannot be properly drained from the brain, which can result in increased pressure within the skull.
This can lead to a range of symptoms, including severe headaches, blurred vision, seizures, nausea, vomiting, difficulty speaking or understanding speech, weakness, or numbness in certain body parts, and in severe cases, loss of consciousness. If left untreated, venous sinus thrombosis can be life-threatening.

Question 17

different symptoms of stroke

Answer 17

difficulty speaking
loss of coordination/balance
paralysis (one sided)
weakness
blurred vision
double vision (diplopia)
loss of consciousness
vomiting/nausea
difficulty swallowing
ataxia (poor muscle control, affecting different parts like speech and balance)
hemiparesis (one sided muscle weakness)
quadriparesis (affects all four limbs)
aphasia (inability to speak)
dysarthira (slurred speech)
amaurosis fugax (temporary loss of vision)
vertigo (sensation that world is spinning)

Question 18

what type of scan looks at capillaries/ arteries and veins

Answer 18

angiogram/angiography

inject contrast into arteires, visualise the lumen of blood vessels
(the greater the contrast/darker the greater the blood flow)

Question 19

what is small vessel disease

Answer 19

a condition where the small blood vessels in the brain get damaged.
Health conditions like high blood pressure, diabetes, high cholesterol, and smoking frequently cause this damage. All of these factors can harm the walls of your tiny blood vessels, making them thick, stiff, weaker or blocked.

if this occurs in the brain, it can lead to mini-strokes which may not cause immediate symptoms but can add up over time and disrupt cognitive process over time.