Haem. stroke & Aneurysms Flashcards
Causes of Aneurysms
- weakness in BV present at birth
- HP in weak BV
- previous aneurysm
- Race( African Americans are more likely to have a SA hemorrhage)
- fatty plaques which cause BV weakness
- inherited disease that weaken BV
- gender( woman more likely to dev a brain aneurysm/suffer a SA hemorrhage)
- trauma
- STIS like syphilis
- PCKD
- infection
- unknown
3 main locations of an aneurysm
- cerebral 2. thoracic aortic 2. abdominal aortic
symptoms of a ruptured vs unruptured cerebral anuerysm
unraptured tend to have no related symptoms but ruptured include severe headaches with rapid onset, neck pain and stiffness, increasing drowsiness, paralysis, impaired speech and visual problems
the symptoms of a cerebral ruptured aneurysm are associated with…
location of the bleed
most common type of anneurysm is
saccular and this accounts for 80-90% intracranial aneurysm
4 main types of cerebral aneurysm
- saccular 2.fusiform 3.giant 4.dissecting
Ruptured brain aneurysms are fatal in…. Of the people that do survive how many suffer permanent neuro deficit
40%, 66%
saccular aneurysms are the most common…
cerebral aneurysm(80-90%)
Fusiform aneurysms
- less common type - an outpoching of an arterial wall on both sides and dont have neck or stem
Giant aneurysm size and risk
>2.5cm and have a high and can be diff to treat
percentage of saccular aneurysms that dont rupture
50-80%
define
size of most saccular aneurysms
0.5 to 2cm
saccular aneurysm size and lcoation
tend to be rounded lobulated focal outpoucgings which usually arise at the arterial bifurcation and may arise from the lateral wall
define
Dissecting aneurysm
creates a false lumen and tends to be the most damaging type of aneurysm as it thins the vessel wall and can usually end up being quite large
T/F
The prevalnce of AA increases with age
true
T/F
Rupture of aa is associated with 70% mortality
false, it is 80%
T/F
surgical repair of ruptured AA has a 50% mortality
true
As a consequence of increased mortality associated with AA and ruptured aa…
screening men over 65 reduced aneurysm related mortality
Patients diagnosed eith small AA should have…
ongoin surveillance with ultrasound and CV risk factor modif
Things to consider when treating an unruptured Aneurysm
- risk of hemorrhage/ rupture probabbility
- size and location
- age and health of patient family history
- aneurysm ruptured? recurring storke?
- surgical risks
Treatment for an unruptured aneurysm
- Surgical clipping
- Endovascular coiling
Surgical Clipping
The neurosurgeon removes a section of skull to access the aneurysm and locate the BV that feeds it. They place a small clip on the neck of the aneurysm to stop BF
Endovascular coiling
can reach via a stent to enter the vessel then the coil enters the space to increase the structural integrity of the vessel and prevent rupture
2 types of Haemorhaggic stroke
Intracerebral and Subarachnoid
Percentage breakdown of each type of stroke and frequency
embolic- 25%
thrombotic - 60%
subarachnoid- 5%
intracerebral-10%
Pharmacological agents for HS
We can use osmotic agents to reduce edema and IC pressure following a HS. e.g mannitol infusion
Mannitol infusion
used to raise serum osmolarity as it is a high sucrose solution thus pulling fluid from tissue to blood
Adverse events of using mannitol for ruptured aneurysm
- 10% of patients will develop edema because the BBB tends to become leaky post-stroke thus the gradient may not be ensured
- can be very dangerous depending on site of the brain
surgical treatment for HS or ruptured aneurysm
- surgical clipping
- depends on where and how bad the damage is
- endovascular coiling
- filling and natural clotting can still plug the ruptured aneurysm
- surgical repair(aortic aneurysm)
- 50% effective
4 types of ischaemic stroke models
- middle cerebral artery occlusion
- photothrombotic stroke
- endothelin-1 stroke
- embolic stroke
Haemorrhagic stroke model
- autologous blood injection
- t-PA induced stroke
- endovascular puncture
Middle Cerebral Artery Occlusion advantages
- mimics human stroke as most common human stroke is MCAO
- reperfusion and duration is controlled
- BF is measured
- Most common model
Cons of MCAO
- Variable infarct damage
- invasive surgery
- animals cant be studied longterm
Photothromotic Stroke Pros
- induces a thrombus
- minimal surgical intervention
- popular with the animal ethics people
- highly reproducible infarct damage
- can control where to induce the stroke well
Photothrombotic stroke Cons
- little or no pneumbra
- unable to measure BF
Endothelin Model Pros
- Conscious model of stroke
- repro infarct damage
- low mortality
Endothelin Model Cons
- induces astrocytosis and facilitates axonal sprouting
- unable to measure BF
- lacks a BBB breakdown
Endovasc model Pros
- closely mimics SAH in clinic
- BF can be measured with laser dopler
Autologous blood injection model Pros
- Blood is injected into the striatum to establish a hematoma
- widely used model for HS as it has good repro and is relevant to ICH patients
Autologous blood injection model Cons
- Does not simulate BV rupture as there is no constant Blood supply
Endovasc puncture model cons
invasive surgery
