Path II final Vascular diseases Flashcards
Brain receives what percent of cardiac output and oxygen in body?
15% CO
20% O2
Cerebrovascular Disease Classification
1) Parenchymal Diseases
2) Infarcts due to local vascular obstruction
3) Hemorrhages within the brain parenchyma of subarachnoid space
parenchymal injuries
One of three major types of Cerebrovascular Disease (5% of them)
Associated with GENERALIZED REDUCTION IN BLOOD FLOW
Example: Global Hypoxic-Ischemic Encephalopathy
infarcts due to local vascular obstruction
One of three major types of Cerebrovascular Disease (80%)
AKA Stroke (Ischemic Stroke)
Hemorrhages within the Brain Parenchyma
One of three major types of Cerebrovascular Disease (15% of CVD)
AKA Stroke (Hemorrhagic Stroke)
CVD stroke
AKA Ischemic Stroke
Due to LONG TERM hypertension ->Hyaline Arteriosclerosis (causes obstruction of vessels less than 300 microns)
Blood can’t flow to tissue so it undergoes ischemia
People have neurological deficits due to lack of blood flow
IRREVERSIBLE
cause of ischemic stroke?
LONG TERM hypertension which leads to Hyaline Arteriosclerosis
What type of sclerosis is associated with Ischemic Stroke?
hyaline arteriosclerosis
is ischemic stroke damage reversible?
No; irreversible
what is the general cause of a stroke?
atherosclerosis
Mechanism of a stroke
Atherosclerosis->platelet activation-> thrombi formation
thrombi can obstruct blood vessels and the brain
what is the most common location of thrombi formation?
bifurcation of the common carotid artery and Birfurcation of the internal carotid artery
what artery is the most common location of an ischemic stroke?
middle cerebral artery
what test do you perform to identify ischemic stroke?
geroge’s test
most common cause of ischemic stroke?
thrombosis!!
stroke in internal carotid requires what?
operation
Lacunar Area
Found in the mid-brain
Full necrosis and atrophy occurs here if there is a lack of blood flow
Most common infarction is associated with atherosclerosis (Followed by platelet formation and thrombosis leading to complete obstruction of blood flow)
Can also occur with a thrombi-embolism
Where is the Lacunar Area?
In the mid-brain
source of thrombosis/emboli
The HEART
1) Mitral Stenosis (reduced BF)
2) Artificial Valves
mitral stenosis and thrombosis/emboli
Mitral Stenosis causes reduced blood flow
Thrombi are loose and can go into circulation -> Brain
Example: Bacterial Endocarditis can lead to ischemic hemorrhagic stroke (mechanical obstruction of the lumen -> Bacteria released into the parenchyme)
bacterial endocarditis and thrombosis/emboli
Bacterial Endocarditis can lead to ischemic hemorrhagic stroke (mechanical obstruction of the lumen -> Bacteria released into the parenchyme)
Artificial Valves and thrombosis/emboli
Artificial valves used when there is valvular insufficiency
Can promote thrombosis that can go into circulation (Thrombocytes develop)
Must take anti-coagulants for rest of life
Hemorrhagic stroke is ___% of Cerebrovascular disease
15%
Hemorrhagic stroke: 2 types
1) Intercerebral/Parenchymal
2) Subarachnoid Hemorrhagic Stroke
Intercerebral/Parenchymal Stroke
A type of Hemorrhagic Stroke
Due to LONG TERM hypertension
Deposition of hyaline-like substances in the vascular wall -> Increased pressure causes rupture of these vessels and leakage into the brain
Vascular cell is more brittle from hypertension -> Rupture of the vessel wall
Brain is soft/gel-like and easily damaged
Blood can cause atrophy of the tissues and acts like a toxin to the tissues it contacts
Intercerebral/Parenchymal Stroke is due to what?
LONG TERM hypertension
Vessels become brittle and rupture, leaking blood into the brain
Problems with High Blood Pressure and Hemorrhagic Stroke
Causes rupture of hyalinized blood vessels
Sudden increase in BP causes rupture
Mechanical damage leads to degradation of the artery
Brain tissue is soft and like gel -> Blood causes atrophy of the tissue (like a toxin) when in contact with brain outside of vessel
Usually happens in people under 50
subarachnoid Hemorrhagic stroke
occurs around the brain, not in it
subarachnoid Hemorrhagic stroke
Usually occurs when aneurysms that are at the bifurcation rupture
subarachnoid Hemorrhagic stroke
Rupture of the blood vessels of the subsrachnoid space (Generally cerebral arteries that are part of the Circle of Willis)
subarachnoid Hemorrhagic stroke
What vessels are typically involved in Subarachnoid Hemorrhagic Stroke?
Cerebral Arteries that are part of the Circle of Willis
2main types of aneurysms
1) Beri (Sacular; less than 1cm diameter)
2) Giant (Up to 5cm diameter)
Size of Beri Aneurysm
4-7mm diameter
No more than 1cm diameter
death of beri aneurysm
People die at age 48-50
signs/symptoms of beri Aneurysm
Vague signs and symptoms that usually only appear when rupture develops
Giant aneurysm size
Can be up to 5cm (pin-pong ball)
Manifestation of giant cell aneurysm
similar to brain tumor
headache, nausea, vomiting, papilledema
What resolves a TIA?
Fibrinolytic activity of blood
How long does it take a TIA to resolve?
They resolve within 24 hours
Manifestations of TIA
1) Amaurosis Fugax (Unilateral vision loss)
Amourosis fugax
Occurs with TIA
Painless, temporary unilateral loss of vision
Due to temporary thrombosis of the Opthalmic Artery
Causes ischemia to retina
Emboli can obstruct blood flow (most commonly due to an emboli from a stenosed carotid artery)
Vision loss lasts for the period of time that the clot obstructs the flow
Has similar symptoms to Amaurosis Fugax
temporal arteritis
Most common sources of emboli in Amaurosis Fugax
Plaque or clot from stenosed carotid artery
Other sources are heart or heart valves and arterial spasms
How long does vision lost las with Amaurosis Fugax?
Only for as long as the obstruction prevents blood flow
how to handle a TIA
Sit down and call 911
Give anti-coagulants which can prevent future TIA’s
