Flashcards in Hemorrhagic Stroke Deck (24)
The incidence of cerebral hemorrhage is roughly equally divided between....
- Bleeding around the brain
- Subarachnoid hemorrhage
- Bleeding into the brain, parenchymal, or intracerebellar
80% of Subarachnoid Hemorrhages are caused by
Berry Aneurysm rupture.
Berry Aneurysms of what size tend to rupture?
Over 20% of the population has an aneurysm measuring less than 2mm in diameter. These rarely rupture
Risk factors for SAH
- oral contraceptives
- low cholesterol
- Genetics (polycystic kidney disease, marfan
Symptoms of SAH
- sudden severe headache, worst of my life
- rapid loss of consciousness
- neck stiffness, pain, photophobia
- Focal neurologic signs frequntly absent
What helps to differentiate SAH from ischemic stroke?
Lack of neurologic symptoms...This is because there is no injury inside the brain parenchyma at this point.
Other signs of SAH
- Abnormal vital signs like high BP or arrhythmias (due to breakdown products from RBCs that irritate the brainstem centers for regulating heart rate)
- Subtle neuro signs like CN III paresis
- Paraparesis (bilateral leg weakness) suggests potential aneurysm of anterior cerebral
- Hemiparesis (weakness on one side of body) suggests potential MCA aneurysm
Most important diagnostic test to reveal SAH
When may a CT scan be negative in a pt with an SAH
- When the bleeding is slight or the scan is delayed for several days.
If the CT is negative and you still suspect SAH, whats next
What is the only method to 100% rule out a subarachnoid bleed
Lumbar puncture in SAH technique? KNOW!!!
Must delay the onset of the lumbar puncture 4 hours after the headache starts. THis will allow time for some of the RBS's to lyse and release their contents (hemoglobin). THis will help you differentiate between blood cells that entered the CSF when you nicked a vein performing the spinal tap versus blood from an aneurysm. Must centrifuge the blood immediately because blood from a nicked vein will centrifuge to the bottom and leave the supernatant clear.
How do you tell where the aneurysm is?
MRI will revela aneurysms over 5mm.
- GOLD STANDARD: 4 vessel digital subtraction arteriogram.
Treatment for SAH
Definitive therapy for Berry aneurysm is the placement of small coils within the aneurysm through an intrarterial catheter. to cause the aneurysm to clot and itself
Most common cause for parenchymal hemorrhage?
-trauma is most common
What kind of aneurysms does HTN lead to
Charcot Bouchard aneurysms that eventually rupture.
Where do Charcot Bouchard aneurysms usually arise
Hypertensive bleeds generally occur where?
- Basal Ganglia
AVM (arteriovenous malformation) hemorrhage treatment
- Intravascular occlusion of AVM with coils followed by surgical removal or obliteration of AVM
50% of cerebral hemorrhages are
subarachnoid in nature....the other 50 are parenchymal
Regarding subarachnoid hemorrhages, CNIII paresis (down and out eye) with pupil dilation and ptosis (lid lag) usually means what
You have a berry aneurysm at the junction of the PCOM and Internal carotid. Lies right on top of the optic tract.
Regarding subarachnoid hemorrhages, Paraparesis (bilateral leg weakness) means what
aneurysm of the anterior cerebral artery
Whereas hemiparesis generally means middle cerebral artery aneurysm
yellow discoloration of spinal fluid that becomes present a couple days after a subarachnoid hemorrhage due to breakdown of hemoglobin/