Hemorrhagic Stroke (2) Flashcards
What two types of hemorrhagic strokes exist?
- Parenchymal or intracerebral
2. Subarachnoid
What percent of all strokes do hemorrhagic strokes represent?
20%
What are the four types of cerebral hemorrhage?
- Subarachnoid hemorrhage
- Intracerebral hemorrhage
- Epidural hemorrhage
- Subdural hemorrhage
What is the MCC of a subarachnoid hemorrhage?
Rupture of a saccular (berry) hemorrhage
At what size do saccular (berry) hemorrhages need to be surgically treated due to high risk for bleed?
5 mm or greater –>(rupture and bleed at a rate of 1-3% per year)
*less than 2 mm aneurysms rarely bleed
In general, where are berry aneurysms likely to occur? Where specifically is the most common site?
At bifurcations in the circle of Willis
- bifurcation of the anterior communicating artery is most common site; also occur at bifurcation of the posterior communicating fairly commonly
- *vast majority occur in the anterior circulation
What are 6 risk factors for subarachnoid hemorrhage, other than genetic diseases?
- Tobacco use
- EtOH use
- HTN
- Oral contraceptives
- Stimulant drugs
- LOW cholesterol
What are 3 genetic diseases that are risk factors for subarachnoid hemorrhage?
- Polycystic kidney disease
- Marfan’s syndrome
- Ehlers-Danlos syndrome
What percent of pts with ruptured aneurysm causing subarachnoid bleed died before getting to ER? What percent die in next 3 months? What percent of those surviving initial bleed will have neurologic sequelae?
10-15% die before getting to ER
25% die within 3 months–> so overall mortality ~40%
~40% of those surviving initial bleed have neurological sequelae
What are 4 symptoms of a ruptured berry aneurysm/ subarachnoid hemorrhage?
- Sudden, severe headache–> “Worst headache of my life”
- Rapid loss of consciousness (some, not all pts)
- Meningeal signs- neck stiffness, photo/phonophobia
- Nausea/ Vomiting
What kind of focal neurological signs are seen with a subarachnoid bleed?
They are frequently minimal or absent altogether
What causes the headache and loss of consciousness in subarachnoid bleed?
Large pulse pressure change to brainstem as a result of arterial blood entering the subarachnoid space
What causes the neck pain, photophobia and phonophobia? Time frame?
Meningeal irritation secondary to the breakdown products of RBCs lying in the CSF (called meningismus)
- may not occur until a few hours after rupture of aneurysm/bleed; takes the RBCs a bit to get in CSF and then lyse
What other two signs can products of RBC breakdown cause in subarachnoid hemorrhage?
Abnormal vital signs–> elevated BP and cardiac arrythmias, due to irritation of brainstem centers regulating heart rate
What sign seen in subarachnoid hemorrhage may be seen with an eye exam?
Retinal hemorrhages
Although variably present, what focal neurological deficit may be seen in subarachnoid hemorrhage due to rupture of an aneurysm at the junction b/n internal carotid and posterior communicating artery?
CN III paresis–> dilated pupil and opthalmoparesis
What focal neurological signs may be present due to ruptured aneurysm in the anterior cerebral artery? (In a subarachnoid hemorrhage)
Paraparesis (paresis, esp of lower limb)
What focal neurological sign may be present in subarachnoid hemorrhage due to rupture of middle cerebral artery aneurysm?
Hemiparesis
What difference in presentation may help distinguish strokes due to subarachnoid hemorrhage from an ischemic stroke?
The absence of focal neurological signs–> although they may be present at times, they frequently are not; the fact that they may be there is what makes it hard to distinguish based on clinical presentation alone
What is the most important diagnostic test to identify a subarachnoid hemorrhage?
Non-contrast CT–> helps determine the amount of blood, locTion and the likelihood of a delayed complication=vasospasm
What is the only method to 100% rule out a subarachnoid hemorrhage?
Lumbar puncture–> should have blood in it; a some CT scans wil be false negative, particularly if the bleed is small or it is a day or two after the rupture
What must a lumbar puncture (which MUST be done in cases of suspected subarachnoid hemorrhage along w/ non-contrast CT) be delayed for 3-4 hours after onset of symptoms?
Have to give RBCs time to lyse and release Hgb into the CSF–> otherwise, blood seen in the CSF drawn could be from nicking a vein while performing the lumbar puncture
*centrifuge the CSF IMMEDIATELY= this will cause the intact RBCs from any blood due to a nicked vein to be spun down
What will centrifuged CSF look like if the blood is actually from an accidental venous nick? What if it’s from an actual subarachnoid bleed?
CSF will be clear after centrifuge if from an accidental source; will be red if from a subarachnoid bleed which has had time for RBCs to lyse in the CSF ad and release Hgb
What is Kerning’s sign? What does it indicate?
Resistance to full extension of the knee when the hip is flexed–> is a sign of meningeal irritation
What is the Brudzinski sign? What does it indicate?
Flexion of both hips and knees when the head is flexed forward–> also a sign of meningeal irritation
What is xanthochromia?
Yellow discoloration of CSF due to break down of Hgb–> takes a day or two to develop, so not seen at first in an acute presentation
Once a subarachnoid bleed is confirmed via CT/ lumbar puncture, what is the gold standard for identifying the location of the bleed?
4-vessel digital subtraction arteriography (should demonstrate one or more aneurysms)
*MRI also works pretty well, esp if the aneurysms are large
What is the definitive tx for a berry aneurysm (subarachnoid hemorrhage)?
Placement of coils with intra-arterial catheter (causes aneurysm to clot and seal itself)
OR surgical placement of a clip at the neck of the aneurysm (or combo of the two)
What are three common causes of parenchymal brain hemorrhage in order of frequency?
- Head trauma
- Hypertension
- Arterio-venous malformations
What kind of specific microaneurysms does hypertension cause?
Charcot Bouchard aneurysms
What four places in the brain do hypertensive bleeds most commonly occur? **
- Basal ganglia (30%)
- Thalamus (20%)
- Cerebellum (10%)
- Pons (5%)
Bleeds in these locations due to HTN, so commonly if not always caused by Charcot Bouchard aneurysms; is b/c these areas have small penetrating arterioles that are dilated in these aneurysms
What test is needed to identify an arteriovenous malformation that may be the cause of a parenchymal hemorrhage?
CT WITH contrast
W/o contrast, hard to see the malformations, which exist below the arachnoid mater
What are 3 goals of treatment for hypertensive/ traumatic parenchymal hemorrhages?
- Correct any bleeding problems (Give Vit K, fresh frozen plasma, rFVIIa, Prothrombin complex concentrate as needed)
- Reduce BP to less than 160/100 or MAP to less than 130 mmHg
- Monitor for and treat elevated intracranial pressure
Other than neuroSx, what are 2 ways to treat elevated intracranial pressure? Desired range of ICP?
- Hyperventilate
- Diuretics (osmotic)
*maintain CPP between 60-80 mmHg
What is tx for arteriovenous malformation?
Coils, sx removal, or obliteration with gamma knife x-ray device
