Cerebrovascular Disease Flashcards
(94 cards)
1
Q
Fifth leading cause of death in US and leading cause of disability
A
CVA
2
Q
What part of the US has the highest regional incidence and prevalence of stroke and higher stroke mortality than the rest of the country?
A
Southeastern US (the “stroke belt”)
B/c of higher risk factors (ie DM, HTN, diet)
3
Q
What is the difference in incidence between men and women when it comes to stroke/
A
Men have higher incidence than women at YOUNGER ages but not older
Incidence is reversed and higher for women by age 75
4
Q
Risk factors for stroke
A
Similar to those for CAD
HTN
DM
Smoking
Dyslipidemia
5
Q
A stroke is the acute neurologic injury that occurs as a result of one of these two pathologic processes…
A
Hemorrhage
Ischemia
6
Q
Hemorrhage is characterized by ….
A
Too much blood within the closed cranial cavity
7
Q
Ischemia is characterized by ….
A
Too little blood to supply an adequate amount of oxygen and nutrients to a part of the brain
8
Q
Ischemic strokes are due to…
A
Thrombosis
Embolism
Systemic hypoperfusion
9
Q
Local in situ Obstruction of an artery
A
Thrombosis
10
Q
Particles of debris originating elsewhere that block arterial access to a particular brain region
A
Embolism
11
Q
Major causes of embolism —> ischemic stroke
A
Atrial fibrillation (clots form in the heart b/c of stagnant blood flow then travel to the brain)
Carotid artery plaques rupturing
12
Q
General circulatory problem —> insufficient blood flow —> ischemic stroke
A
Hypoperfusion
13
Q
Ischemic strokes caused by hypoperfusion typically present a bit differently. Explain.
A
Typically diffuse and non focal compared to embolic/thrombotic events
Most affected patients have evidence of circulatory compromise with hypotension and may present with pallor, sweating, tachycardia, or severe bradycardia, kidney dysfunction etc
Neurologic signs are typically bilateral
14
Q
What is the mechanism for watershed infarcts?
A
Secondary to low flow states from vessel overlap or systemic hypotension
15
Q
Brain hemorrhage due to intracerebral hemorrhage or subarachnoid hemorrhage
A
Hemorrhagic stroke
16
Q
What are the types of hemorrhagic stroke?
A
Intracerebral hemorrhage (aka parenchymal) - bleeding directly into brain tissue
Subarachnoid hemorrhage - bleeding into the CSF that surrounds the brain and spinal cord
17
Q
Which type of CVA is more common?
A
Ischemic CVAs make up 87% of all strokes in the US
18
Q
What percentage of CVAs are hemorrhagic and of those, what percentage are intracerebral vs subarachnoid?
A
13% hemorrhagic
10% intracerebral
3% subarachnoid
19
Q
Why is it so important to know the difference between hemorrhagic vs ischemic CVA?
A
B/c they have the opposite treatments
If you want to differentiate - CT scan!
20
Q
What are the two categories of stroke syndromes?
A
Large vessel (stroke within a particular vessel)
Small vessel (disease of either vascular bed - a lacunar stroke)
21
Q
Anterior circulation strokes result from a defect in ______ supply
A
Carotid artery
Extracranial and intracranial carotid arteries, the middle and anterior cerebral artery branches
22
Q
Posterior circulation strokes result from a defect in _______
A
The vertebrobasilar system
Extracranial and intracranial vertebral arteries, basilar artery, and posterior cerebral arteries
23
Q
MOST COMMON TYPE OF CVA (looking for the specific vessel)
A
Middle Cerebral Artery (MCA)
24
Q
An MCA stroke affects the ______, ______, and ______ lobes
A
Frontal
Temporal
Parietal
25
SSx of an MCA stroke
Contralateral hemiplegia/hemianaesthesia (weakness/numbness) variably affecting the face and arm greater than the leg
Dominant hemisphere involved = global aphasia present
Non-dominant hemisphere affect = hemineglect is seen
26
What do we mean when we say a patient “looks to the lesion”?
Contralateral homonymous hemianopia, and a day or two of gaze preference to the ipsilateral side
27
Is an anterior cerebral artery stroke common?
Nope - only 3% of all cerebral infarcts
28
Anterior cerebral artery strokes affect the _______
Frontal pole/lobe
29
Contralateral hemiplegia/hemianaesthesia in the leg greater than the arm
Anterior cerebral artery stroke
Patient may present with profound abulia (delay in verbal and motor response) or perseverating speech
30
What is abulia?
A delay in verbal and motor response
Seen more with ACA strokes
31
Anterior communicating artery (AComm) strokes are characterized by...
Impingement of cranial nerves
VISUAL FIELD DEFICITS******
32
Posterior cerebral artery strokes affect the _______
Occipital cortex
33
Contralateral homonymous hemianopia, with significantly reduced light touch and pinprick sensation
Posterior cerebral artery stroke
34
PCA strokes may go unnoticed by patient because...
Motor involvement is usually minimal unless it is a large infarct
35
What is Wallenberg’s syndrome?
Lateral medullary syndrome - stroke in the Posterior Inferior Cerebellar Artery (PICA)
****Affects the lateral medulla —> ipsilateral loss of facial pain and temp sensation with contralateral loss of these senses over the body****
36
SSx of PICA stroke (Wallenberg’s syndrome)
```
Vertigo
Vomiting
Nystagmus
Ipsilateral ataxia
Hoarseness
Dysarthria
Dysphagia
Hiccups
Ipsilateral Horner’s Syndrome (typically incomplete - ptosis/miosis without anhidrosis)
```
37
“Locked-in syndrome” is the result of ...
Complete basilar artery occlusion affecting the pons —> quadriplegia and facial/mouth/tongue weakness but preserved consciousness and preservation of vertical eye movements/blinking
38
Why do you get such a diversity of symptoms with a basilar artery occlusion?
Because it supplies the brainstem, which contains many structures in close apposition
39
What is a lacunar stroke?
Occlusion of one of the small, penetrating branches of the Circle of Willis, middle cerebral artery stem, or vertebral and basilar arteries
Thrombosis of these vessels causes small infarcts that are referred to as lacunes
40
Lacunar strokes are commonly associated with...
Chronic HTN
Especially older patients with uncontrolled HTN
41
Whether the presumed stroke is ischemic or hemorrhagic, the initial assessment is the same and should include...
Airway
Breathing
Circulation
42
Why do you have to be so careful about airway/breathing with stroke patients?
Increased ICP can lead to a decreased respiratory drive
Depending on location/severity they may also have decreased level of consciousness
Intubation may be necessary to restore adequate ventilation and to protect the airway
43
Mean arterial blood pressure (MAP) is usually _______ in patients with an acute stroke
Elevated
May be due to chronic HTN, which is a major risk factor for the stroke
Often represents an appropriate response to maintain brain perfusion
44
The decision to treat elevated BP in a stroke patient requires a fine balance between...
The potential danger of severe increases in BP and a possible decline in neurologic functioning when BP is lowered
45
Most consensus guidelines agree that you should not start treating BP for ISCHEMIC stroke unless...
It is greater than 220/120 - the risk of further ischemia is too great otherwise
Exception is if you are treating with thrombolytics
46
Many guidelines suggest keeping BP _______ for hemorrhagic stroke to prevent increases in bleeding
<160/90
Keep in mind it is undesirable for the systolic BP to drop “too” low (<140) and cause ischemia in other areas
47
What is the most important initial question when taking history on a suspected stroke patient?
WHEN DID THE SYMPTOMS START?
Then consider DDx and evaluate for any focal neuro deficits that may point to the location of the problem
48
The first diagnostic test in the assessment of a stroke
NON CONTRAST CT scan of the brain
Why? R/o hemorrhage
49
Diagnostic imaging that is more sensitive for ischemia early in the course of a CVA but that is not widely available yet
STAT diffusion weighted MRI
50
In addition to CT, what dx tests do you need to do for your CVA patient?
```
ECG
CBC incl platelets
Serum glucose
PT/INR and PTT
Cardiac enzymes (troponin)
BMP
```
51
With a hemorrhagic CVA, your diagnosis is based on...
The CT scan
Ct will show blood in the area of the brain that is suffering from stroke
52
With an ischemic CVA, how will the CT look?
May very likely be normal
Ischemia takes a certain length of time to be evident on CT
53
When will you need to diagnose a stroke clinically?
If symptoms have been present for <6 hours, the affected area is small or located in an area of the brain not well seen on CT (ie posterior fossa)
AND
The CVA is secondary to ischemia
54
Treatment for an acute CVA depends upon...
Whether the stroke is ischemic or hemorrhagic in nature
55
Early (~48 hours) initiation of ____ has shown benefit for the treatment of acute ISCHEMIC CVA
Aspirin
Short-term use of dual antiplatelet therapy (Clopidigrel) plus aspirin may be beneficial for patients with high-risk transient ischemic attack or minor stroke
56
If the brain CT shows no bleed, ______ should be given within 48 hours
Full dose aspirin
If patient is suffering from dysphasia, it should be given rectally to prevent aspiration
57
What is the most effective maneuver for salvaging ischemic brain tissue that is not already infarcted in an ischemic stroke?
Timely restoration of blood flow using thrombolytic therapy
Extremely disputed - because does it help if you convert their ischemic stroke into a hemorrhagic one?
58
Currently, tPA is not recommended beyond _______
4.5 hours of symptoms
59
What is the caveat for BP control if giving thrombolytic therapy?
Desired systolic CP ≤ 185 and diastolic BP ≤ 110 to reduce risk of hemorrhage
60
What is the timeline you should shoot for when evaluating and treating an ischemic stroke?
Eval by physician in first 10 min
Stroke team in first 15 min
Heat CT or MRI within 25 min
Interpretation of neuro scan within 45 min
Start of IV tPA if eligible within 60 min
61
As a general rule, CT scan must be _____ to consider tPA
Normal
If it shows blood —> hemorrhage, and tPA obviously out
If it shows ischemia (acute hypodensities) you known Sx have been going on too long for tPA to be considered safe
62
What is Intra-arterial thrombolysis?
Catheter-directed tPA
Smaller dose than peripheral IV tPA, can be done after peripheral IV tPA
NOT proven beneficial thus far but it’s a thing
63
What is mechanical thrombectomy?
Endovascular treatment with a stent retriever improves outcomes for patients with acute ischemic stroke caused by large artery occlusion in the proximal anterior circulation who can be treated within 6 hours of sx onset
64
What is the mainstay of therapy for hemorrhagic strokes?
All anticoagulant and antiplatelet drugs should be d/c immediately
Anticoagulant effect should be reversed immediately with appropriate agents
• Example - fresh frozen plasma, Vitamin K, possibly prothrombin complex concentrates (PCCs) to replenish clotting factors and reverse the effects of warfarin
65
Methods to lower ICP in patients with hemorrhagic stroke
Initially:
Elevate HOB to 30 degrees
Use analgesia/sedation
```
More aggressive therapies:
Osmotic diuretics (ie mannitol)
Ventricular catheter drainage of CSF (bolt)
Neuromuscular blockade
Hyperventilation (short term)
```
66
What is the BP goal for patients with hemorrhagic stroke?
160/90
Higher BPs can caused continued force for bleeding
Use antihypertensives to achieve - Nicardipine drip is common
67
Your patient with a hemorrhagic stroke may also need...
Antiepileptic treatment to quickly control any seizures they may have
68
Any brain hemorrhage warrants _______
Immediate neurosurgical consult - but many will not require operative intervention
69
Which types of hemorrhages will likely require surgical removal of the hemorrhage immediately?
Cerebellar hemorrhages >3cm in diameter
Those who are deteriorating
Brainstem compression
Hydrocephalus due to ventricular obstruction
70
Secondary prevention for specifically for ISCHEMIC CVAs
Antiplatelet meds
Warfarin if afib or prosthetic heart valve
Carotid endarterectomy if justified
71
Secondary prevention for either type of CVA
Treatment of underlying condition (DM/HTM/HLD)
Cessation of smoking/heavy alcohol or illicit drug use
72
Transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction
Transient Ischemic Attack (TIA)
73
TIA was originally defined as a sudden onset of focal neurologic symptom and/or sign lasting _______ and caused by ________
<24 hours
Transient decrease in blood supply
Using 24 hours was an arbitrary cut-off and therefore lack of tissue damage regardless of the timing is more precise/adequate
74
The “classic” definition of TIA is inadequate b/c...
Even relatively brief ischemia can cause permanent brain injury
With diffusion weighted MRI becoming more prevalent, “Transient symptoms with infarction” has become its own category - the patient is clinically unharmed but the brain has still suffered injury
75
Why do we care about TIA?
The stroke risk in the first two days after TIA is ~4-10% and just under 30% over the following 5 years
Symptoms do NOT have to be focal either - even global sx such as numbness/tingling can be a TIA
76
Testing/therapy for TIA is based upon....
Lessening the risk for impending stroke
```
EKG - looking for afib
Carotid U/S - assess need for carotid endarterectomy
Lipid lowering meds
Anti-HTN meds
Diet/lifestyle mods
```
Start daily aspirin unless contraindicated
Some hospitals are even using CTA of the circle of Willis and carotids to assess for blockage/aneurysm
77
What is a “high risk” headache?
Severe HA w/o previous hx of HA
Sudden onset
Somnolence
Vomiting
78
Patients with high risk features to their HA need...
Urgent Non-contrast CT
If abnormal, you may likely have your diagnosis and can manage
79
If your urgent non-contrast CT of your patient with a sudden severe headache is normal, what do you do next?
LP to obtain CSF for analysis
80
The headache onset with subarachnoid hemorrhage is usually...
Sudden and sometimes described as “thunderclap”, WORST HEADACHE OF MY LIFE
81
Subarachnoid hemorrhages are most often caused by...
Ruptured secular aneurysms or trauma
82
Most aneurysmal SAH occur between ____ and _____ years of age
40 and 60
Slightly higher incidence in women too
83
Risk factors for SAH
```
Aneurysms in other blood vessels
Fibromuscular dysplasia or other connective tissue disorders
HTN/HLD
DM
Heart disease
Obesity
Hx of Polycystic kidney disease
Smoking/alcohol abuse
Family hx of SAH
```
84
What is the most common complication of SAH?
Rebleeding
Occurs more often within the first day
85
A common complication of SAH that causes symptomatic ischemia and infarction in approx 20-30% of patients with aneurysmal SAH
Vasospasm
86
Vasospasm complications of SAH typically begins __________ after hemorrhage
No earlier than day 3, reaching a peak at day 7
87
_______ and ________ are the leading causes of death and disability after aneurysm rupture in SAH
Vasospasm
Re-bleeding
88
How is SAH diagnosed?
Noncontrast CT —> blood in the subarachnoid space IF scan performed within 24 hours of bleed
If CT normal, LP looking for bleeding or infection
89
How to differentiate between SAH and traumatic tap following LP?
If traumatic tap (you hit a vessel as you were obtaining CSF), the RBC numbers tend to decrease from 1st tube to 4th tub
If SAH, the RBC numbers tend to stay the same
90
Most sensitive indicator of SAH on CSF analysis
Xanthochromia (pink or yellow tint of the CSF) - represents hemoglobin degradation products
91
How do you manage SAH patients?
Admit to ICU
Analgesia - can diminish hemodynamic fluctuations to help prevent re-bleeding
Control of ICP
Transcranial Doppler U/S to monitor for vasospasm
92
What do you do to prevent vasospasm in SAH patients?
IV fluids and nimodipine
93
Once admitted and diagnosed, how do you treat SAH patients?
Stop all blood thinners
Seizure prophylaxis
Nimodipine (start w/in 4 days and continue for 21 days)
Surgery (aneurysm clipping or endovascular coiling) to prevent re-bleeding and prevent another aneurysm
94
Are traumatic SAHs more or less serious than spontaneous SAH
Generally NOT as severe as spontaneous SAH
