CNS Hemorrhagic stroke and Ischemia Flashcards
What’s up with an epidural hematoma?
- Occurs between the skull and dura
- TYPICALLY the middle meningeal artery (classic presentation)
- Collect in a convex, or lemon/lens shaped hematoma (on imaging)
What is up with hemorrhagic transformation
- An an ischemic stroke bed, you can get a large vessel to bust and “tranform” into a hemorrhage
- Mostly with large vessel cortical strokes
What is meant by intra-parenchymal hemorrhages?
- Formed blood clots which dissect into the brain
* Can be anywhere and have lots of causes
What are subarachnoid hemorrhages?
- Right next to brain, underneath arachnoid layer
- Trauma is most common cause
- Can be AVM (aneurisms) can be a non-traumatic cause
- RARE - cortical subarachnoid hemorrhage can show up with vasospasm, migraine, ischemia or without obvious cause
What’s up with a subdural hemorrhage?
- Between dura and thin arachnoid covering brain
- Typically from torn or ruptured bridging vein between dura and cortex
- Layers like a banana (on imaging)
What is usually the cause of intraperenchymal hemorrhages?
- HTN and age
- Usually occur in the basal ganglia (putamen), thalamus, pons and cerebellar deep grey matter
- If you see a hemorrhage in one of these areas in a HTN patient, no need to look further
What’s up with amyloid angiopathy?
- A specific entity in which patients get recurrent lobar hemorrhages that lead to progressive dementia and disability
- Amyloid deposition is found in the vessels (intramural)
- Different from systemic amyloidosis or to alzheimer’s amyolid plaques
- Can be found, however, in conjunction with alzheimers
Is a subdural hemorrhage usually trauma related?
- Not like the epidural ones
- In older patients brain atrophy makes it easier to tear bridging veins
- They can happen and not present clinically at all
Where do non-traumatic subarachnoid hemorrhages come from?
- 80% aneurysmal rupture
- 15% ateriovenous malformation
- Remember the rare occurance of the cortical SAH, which is more “leaky” than an arterial rupture and bleed
What is the typical presentation of hemorrhage?
- Think of what mass effect and herniation might entail
- Usually sudden onstet of neurological deficiets
- Typically have associated headache, nausea, vomiting along with depressed level of consciousness
What is the typical presentation of hemorrhage?
- Think of what mass effect and herniation might entail
- Usually sudden onstet of neurological deficiets
- Typically have associated headache, nausea, vomiting along with depressed level of consciousness
What type of hemorrhage is HTN NOT a risk factor for?
• Subarachnoid hemorrhage (SAH)
What might be the patients complaint in the situation of non-traumatic subarachnoid hemorrhage?
- Onset is “cataclysmic”
- “firecracker” or explosion in the head
- (very sincere headage)
- Sudden death in 1/3 from either acute hydrocephalus OR from sympathetic surge and cardiac arrhythia
- CNIII palsy can be a presenting sign
What is the hunt and hess classification of subarachnoid hemorrhage
- Grade 1 - asymptomatic or minimal headache; slight nuchal rigidity
- Grade 2 - moderate to severe headache, nuchal rigidity, no neurological deficit (apart from cranial nerve palsy)
- Grade 3 - drowsiness, confusion, or mild focal deficit
- Grade 4 - stupor, moderate to severe hemiparesis, possible early decerebrate posturing
- Grade 5 - deep coma, decerebrate posturing moribund
What is the course of an intraparenchymal hematoma?
- Begin with a mild headache, deficit, nausea
- Progress over a few minutes to hours into decreased levels of consciousness
- Often can look like a hemiparesis steadily progressing into hemiplagia
- Remember this problem is seen more with increased age and HTN
If you see amyloid crystals with a birefringence lens what CNS hemorrhagic disease are you looking at?
- Cerebral amyloid angiopathy
- Disease of the aged characterized by recurrent lobar hemorrhages that are often curiously well tolerated
- No primary therapy
Why would platelet and anti-coag theraphy help with future hemorrhage after an initial ischemic event?
- Ischemia can end up resulting in hemorrhagic transformation
- Thus, if you can prevent the ischemia (by thomboses) then you can prevent the transformation and hemorrhage
- Important in smoking patients
How does intracranial hemorrhage cause damage to the brain?
- Mass effect
- Focal and secondary ischemia (shutting off cerebral vasculature because of such a high pressure)
- Effects of irritating blood (induction of vasospasm)
What is the formula for cerebral perfusion pressure?
- CPP = MAP - ICP
* Systolic BP above 160 is associated with a higher risk of recurrent hemorrhage
What is the treatment paradigm of SAH in terms of blood pressure?
- SAH = subarachnoid hemorrhage
- These problems are often surgically treated, so part of medical management is preparation for surgery
- Benefit by sedation and relative hypotension reduces the risk of re-bleeding before surgical intervention
- Treatment with nimodipine and statins help reduce the amount of ischemic damage from vasospasm
- After surgery, you really need to keep the BP normal or even higher than normal to reduce vasospasm
What can Nimodipine and Statin pharmacologic therapy be helpful with?
- Subarachnoid hemorrhage
- Can reduce amount of ischemic damage from vasospasm
- Caused by irritation of blood vessels by the blood in the subarachnoid space
- After surgery, you really need to keep the BP normal or even higher than normal to reduce vasospasm
What diagnostic procedure must be done in the case of SAH?
- Subarachnoid hemorrhage requires an angiogram to determine the cause of the bleeding
- Can also determine potential efficacy of surgery or if surgery is even indicated
In general, what does stroke or cerebrovascular disease mean?
- Any vascular injury to the brain
* Hemorrhage or ischemic
What is meant by transient Ischemic Attack?
- Aka - TIA
- Ischemic neurological deficits that have completely resolved by 24 hours regardless of their severity or relative duration
- Depth and duration of ischemia can vary so there is no exact time agreed upon as “transient”
What is the overall general clinical presentation of a stroke?
- The severity of the stroke will depend on the size of the vessel (and thus the area of ischemia) involved
- Focal neurological deficits come on rapidly with no warning
- Headache
- Rapid change in consciousness
- Onset is most severe with farily quick improvement over seconds, minutes, hours, days, weeks
What is the overall general clinical presentation of a stroke?
- The severity of the stroke will depend on the size of the vessel (and thus the area of ischemia) involved
- Focal neurological deficits come on rapidly with no warning
- Headache
- Rapid change in consciousness
- Onset is most severe with farily quick improvement over seconds, minutes, hours, days, weeks
What will a typical patient with a large vessel (middle cerebral artery) stroke present with?
- Hemiparesis,
- hemi-sensory loss
- Homonymous hemi-anopsia (lack of sight) contralateral to the ischemic side of the brain
- To get this you need a large vessel stroke mechanism or major artery occlusion
Compare and contrast a large vessel and small vessel stroke.
• Large vessel, large area of dysfunction, many actions and sensory deficits
○ Can look like a full hemiparesis
• Small vessel, isolated motor or isolated sensory deficit on one side of the body
○ Caused by occlusion of the small penetrating vessels that arise from larger arteries deep in the brain
○ Produce lacunar infarctions
○ Can contribute to multi-infarct dementia from multiple lacunar strokes that can accumulate over many years
What are the risk factors associated with atherosclerosis and why does this matter for ischemic stroke?
- Matters because atherosclerotic plaques can break off and occlude cerebral arteries
- Internal carotid can be occluded like coronary arteries
- Age
- Men
- Race
- Hypertension
- Lipid disorders
- Insulin resistance
- Homocysteine elevation
- Smoking
- Obesity
- Physical inactivity
- Diabetes
- Alcohol abuse
What’s the confusing thing about alcohol being an atherosclerosis risk factor?
- 1-2 drinks a day can decrease your risk, but once you get into 6-pack a day or just plain alcoholic, it increases your risk
- Both of these risks are evidence supported
What can happen in the heart that could cause an ischemic stroke?
- Atrial fibrillation, congestive heart failure and valvular disorders
- Rarely, atrial septal defect
- These structural problems allow for clots to form and emboli to be ejected into blood stream
- Emboli can occlude major or minor cerebral vasculature
An IV drug user would be at higher risk for what specific type of stroke?
• Infected embolic stroke
• Can also create a mycotic aneurysm
○ Infected aneurysm, or seat of infection on a vessel that destroys the wall
○ The loss of structural integrity might lead to dissection, or just a base for throwing extra small clots into the brain
What neoplastic condition (and it’s relation to stroke) seems to be over-represented on board exams?
- Atrial myxoma and other intravascular or cardiac tumors
- They can cause stroke as well
- Throw little tumor-bits that can end up occluding vessels
A young patient free of risk factors gets a stroke. Your differential changes to include what?
- Vasculopathies
- Hematological disorders
- Inflammatory mechansims
- Venous infarction
- Vasospasm
What are the particular vasculopathies we talked about that can increase the risk of “young stroke”?
• FMD = fibromuscular dysplasia
○ Mostly women, hypertrophy of arterial media, surgical dilatation is treatment
○ HSV-1 virus is candidate cause
• Moya-moya
○ Epstein barr virus is associated
○ Intimal hyperlasia and secular aneurysms and dissection
○ Children, more common in asian and african descent
• Spontaneous arterial dissection
○ Tear in endothelium, blood pooling between layers
○ Can throw clots, therapy is anticoag
○ HSV-1 also candidate
What hematological disorders should you be concerned about causing ischemic strokes?
- Familial/genetic disorders in preventing thrombosis
- Factor V leiden, prothrombin gene deletion, deficiencies in protein C, protein S, antithrombin
- If the body can’t bust up clots well AND there is a PFO or ASD…you could have paradoxical embolization
What is paradoxical embolization?
• A thrombosis of venous origin that somehow manages to cross through a cardiac defect to get into arterial circulation and cause problems
Why is Sickle Cell anemia a concern in ischemic strokes?
• Sickle cell crises can create thromboses that can occlude small and medium vessels in the brain
What does the state of malignancy have to do with ischemic strokes?
- Malignancies can cause a hypercoagulable state
* If there is stroke history and blood tests show coag, search for malignancy
What risk factor for ischemic stroke is present in menopausal women as well as young women?
- Oral contraceptive pill and hormonal therapy
- Implicated in stroke and venous thrombosis
- 25X increased risk if there is the triad of migrane-smoker-OCP
What autoantibodies, when present, can lead to spontaneous miscarriage AND risk of ischemic stroke?
- Antiphospholipid antibodies
* Therapies range but often look like antithrombotics or anticoag (warfarin)
Does a vasculitis have to be a systemic disease to affect the CNS?
- Nope. While the vasculidities CAN secondarily affect CNS
- There are cases of isolated CNS vasculitis
- Traditionally auto-immune, but infections causes are candidates now too
- VZV is increasingly a candidate
How can migraine and stroke be related?
- Migraine is common, the link to stoke is pretty uncommon
- Vasospasm (sterile serotonin mediated intramural inflammation)
- Increased platelet aggregation that clogs the microcirculation leading to permanent cellular injury
- Treatment is antiplatelet therapy
What venous stroke -related problems should you be aware of?
- Post partum sagittal sinus thrombosis (3-5 days)
- Non-traumatic venous infarction from dehydration, CNS infections and hypercoag states
- The most common cause is major head trauma
Sympathetic drugs, severe HTN and primary vessel irritation can all help cause what?
• Vasospasm. Can result in ischemic brain damage
What pharmacological agents are shown to reduce the long term risk of recurrent ischemic stroke?
- Aspirin
- Thienopyridines (clopidogrel, prasurgrel, ticlopidine)
- Anticoagulants
Should you use combo therapy for stroke risk reduction?
- It could help after catheter-invasive procedures or after a major ischemic event.
- HOWEVER, long term benefit??? Not really supported
- Common combos are aspirin and clopidogrel OR aspirin-warfarin
What are the aspirin recommendations for reducing stroke risk?
- Single coated aspirin a day either 81mg, or 325mg
- GI catastrophes do occur
- Cost of aspirin therapy can be increased if an H2 blocker or proton pump inhibitor is required on a regular basis (to block the GI complications)
Atrial fibrillation should be first treated with?
- Warfarin is highly effective in primary prevention of stroke in afib
- Relative risk of stroke is reduced by 70%
- The other situation for warfarin is mechanical heart valves
What are the class of newer, alternative oral anticoagulants called?
- DTIs or direct thrombin inhibitors
- Include dabigatran, rivaroxiban, apixaban
- Most of their benefits are in lower risk populations
- NOT mechanical valves situations
What are the hospital used injected/IV anticoags?
- Drug (target)
- Heparin (ATIII, thrombin)
- LMW heparins (ATIII, Thrombin, Xa)
- Argatroban (thrombin)
Whats the CHADS score?
- A risk score grading atrial fribrillations as a risk for causing stroke
- Points for age, HTN, CHF, DM, previous stroke
- This is for weighing the risk of hemorrhage in geriatric population with benefit of stroke reduction
What is an endarterectomy?
• Carotidendarterectomy(CEA) is a surgical procedure used to reduce the risk of stroke, by correcting stenosis (narrowing) in the common carotid artery or internal carotid artery.Endarterectomyis the removal of material on the inside (end(o)-) of an artery.
When do you refer for an endarterectomy?
- 70-90% stenosis
* Not effective before that
Ischemic stroke resuscitation…can it be done?
- Yes, with TPA (tissue plasminogen activator)
- But it must be IV or IA and within 4.5 hours of stroke
- Keep fluids up, maximize cardiac output, don’t lower BP
The two most important/common mistakes you can make in stroke care that minimize long term outcome are…?
• Delaying the treatment of dehydration (by being afraid to administer saline b/c of CHF for example)
○ Do treat the dehydration
• Inducing hypotension (treating the HTN associated with stroke for about a week)
○ Resist lowering blood pressure
When do you use glucose supplementation in a stroke patient?
- In the RARE hypoglycemic stroke patient, glucose can really help with hemiplegic deficits (even abolish them)
- However, in non-hypoglycemic patients, glucose admin can really mess them up (through breaking of atherosclerotic plaque)
- The risk is too much in normal people so use glucose or insulin only in bad cases of hypoglycemia or unstable glucose
Can there be a stroke without a visualized problem by both MRI and CT?
• Clinical symptoms don’t lie, so yes, there are silent strokes (in terms of silent on imaging)
In what cases would a lumbar puncture be a particularly helpful diagnostic procedure?
• Exclude neurosyphilis
• Vasculitis
• Inflammatory conditions
• RARELY, stroke mimic
• Subarachnoid hemorrhage (when other imaging doesn’t find it)
○ been going on for a while before the CT that missed it
○ Spinal or brainstem source that is not in the region of scanning
○ See xanthochromia indicating blood staining the CSF in the recent weeks
What is the CHADS2 score?
- (points) letter- risk factor
- (1)C - congestive heart failure
- (1)H - HTM, consistently above 140/90 mmHg (or consistently treated with pharm.)
- (1)A - age (over 75 years)
- (1)D - diabetes melitus
- (2)S2 - prior stroke or TIA
What does the CHADS2 score mean?
- It tells you the evidence based risk of stroke given the score of the metric
- 0 - 1.9%
- 1 - 2.8%
- 2 - 4%
- 3 - 5.9%
- 4 - 8.5%
- 5 - 12.5%
- 6 - 18.2%
What is the general mode of treatment depending on CHADS2 score?
- 0 - aspirin if any coags and start them on daily aspirin
- 1 - can use warfarin or aspirin for anticoag, and start them on aspirin daily or raise INR to 2.0-3.0
- 2 or greater - warfarin is your anticoag and you raise INR to 2.0-3.0 (unless other contraindication)
Where are the common ICH locations?
- ICH - intracranial hemorrhage
- Cerebral lobes
- Basal ganglia
- Thalamus
- Pons
- cerebellum
Where in the cerebral vasculature do you more often see saccular (berry) aneurysms?
- 40% - anterior cerebral artery just before the anterior communicating artery shoots off
- 34% - middle cerebral artery
- 20% - internal carotid, before bifurcation into middle and anterior cerebral arteries
- 4% - basilar artery
There is a vessel malformation that is an important source of bleeds in colorado. What is it?
• Cavernous angioma
What does the presence of an acute hemorrhagic infarction imply?
- Reperfusion of dead tissue
- A clot is lodged proximally in the vessel (we were given a middle cerebral artery picture)
- As the clot busts (natural course or b/c of anti-coags) it showers other vessels with smaller chunks AND moves more distally in the vessel
- Reprofusion of the proximal offshoots is the result, which will leak out of the damaged vessels into surrounding parenchyma
Where will you see more reprofusion leakage, the grey or the white matter?
- Grey, which is more perfused with more vessels anywhay
* Therea re more small foci of hemorrhage in the necrotic gray matter than in white matter
How big is an infarction to be classified as a lacunar infarction?
- = 1cm
* Associated symptoms often hemiparesis or hemisensory loss
