Stroke Flashcards
Expressive Aphasia
Damage to Broca’s area in frontal cortex
Able to understand speech but left with limited language
Receptive Aphasia
Damage to Wernicke’s area in temporal lobe
Impaired language comprehension
Two major classifications of stroke
Ischemic and Hemorrhagic
Stroke definition
Acute neurologic deficit due to impaired blood flow to an area of the brain resulting in tissue injury
Subclassifications of ischemic stroke
embolic and thrombotic
Subclassifications of hemorrhagic stroke
aneurysm, AV malformation, HTN
What percent of cardiac output does the brain receive?
15-20%
What arteries perfuse the anterior portion of the brain?
R+L internal carotid arteries
What does a transient ischemic attack precede?
Thrombotic/ischemic stroke
What arteries perfuse the posterior portion of the brain?
R+L vertebral arteries
When assessing patient to see if they have had a TIA in the past, what symptoms should you ask about?
- dim/impaired vision
- weakness, numbness, tingling
- headache
- vertigo
- speech problems
What 2 things can cause a TIA?
- microemboli that temporarily block blood flow
- carotid stenosis
What the penumbra?
Area surrounding infarcted zone where neurons are minimally perfused but still viable
Describe the Cincinnati Pre-Hospital Stroke Scale
- presence/absense of facial palsy
- unilateral arm weakness
- speech: you can’t teach an old dog new tricks
What 3 things does the Canadian Neurological Scale assess?
- mentation
- motor function
- motor response
4 Clinical Manifestations of a Stroke
- Numbness/weakness of face and arms
- difficulty with balance and speech
- unilateral loss of vision
- contralateral hemiparesis
Symptoms indicative of a left-sided stroke
- right sided hemiplegia
- impaired speech/language
- impaired right sided discrimination
- slow, cautious performance
- aware of deficits
- impaired language/math comprehension
Symptoms indicative of a right-sided stroke
- left side hemiplegia
- left side neglect
- spatial/perceptual problems
- denies/minimizes problems
- rapid performance
- short attention span
- impulse/safety problems
- impaired judgment/concept of time
8 Key Points of Assessment of a Post Stroke patient
- General appearance
- Behaviour
- LOC/GCS
- PERRLA
- Dizziness, vision, tremors
- Body position, posture, gait
- Pain/headache
- MSK (sensation and strength)
Gold standard diagnostic procedure for stroke
CT
What 3 things does GCS assess?
- spontaneous eye opening
- appropriate verbal response
- follows motor commands
Why is PTT/INR important to assess post stroke?
Patients on anticoagulant therapy post stroke are at increased risk of bleed
What can a CBC show post stroke?
- Increased RBC/HgB = polycythemia = increased risk for thrombotic event
- decreased platelets; patients on thrombolytic therapy post stroke at increased risk of bleed
Why is creatinine/BUN assessed post stroke?
May show increased levels
> Mild to moderate renal dysfunction is an independant risk factor for ischemic stroke
> May be associated with poor prognosis in patients with ischemic stroke
Why is a pregnancy test given to women of child bearing age in assessment of stroke?
tPa is harmful to fetus
Why is a lipid profile ran for stroke patients?
Increased LDL and triglycerides increase risk of thromboembolic event
Why is an electrolyte panel ran on stroke patients?
Increased/decreased levels of sodium, potassium, or calcium may mimic symptoms
> dehydration causes altered LOC
Why are blood glucose levels assessed for a stroke patient?
Hyperglycemia is associated with a poor prognosis
Hypoglycemia can mimic stroke symptoms
The brain needs a very constant supply of glucose to function properly
Following an acute stroke, why would blood glucose be slightly elevated?
1/3 of stroke patients have diabetes
Stress hyperglycaemia mediated by release of cortisol and norepinephrine
Purpose of transesophageal echocardiography for stroke
Will be ordered if concerned about embolic event; can look into right atrium to see clotting
Usual source of embolus causing stroke is dysrhythmia, murmur, HTN
Why is a lumbar puncture performed for stroke patients?
When CT is clear but still suspicious something is going on
> r/o meningitis and subarachnoid hemorrhage
4 Priorities for Stroke
- Inadequate perfusion r/t interruption of arterial blood flow to brain
- Decreased mobility r/t impaired cognition/neuromuscular changes
- Sensory perception deficits r/t altered neurological changes
- Aphasia or dysarthria r/t decreased circulation or muscle weakness
10 Important Things to Monitor Post Stroke
- Oxygenation
- Glucose
- BP
- Fever
- ECG
- Seizure
- ABG
- Sats
- LOC
- Bloodwork
Why monitor oxygenation post stroke?
The brain is highly sensitive to oxygen change and cerebral hypoxia can mimic symptoms of stroke
The brain cannot store oxygen or glucose and thus need a ready supply
Impaired swallowing/gag reflex increases risk for aspiration pneumonia which can lead to poor oxygenation
Why monitor serum glucose post stroke?
Hyperglycemia secondary to metabolic stress r/t cortisol and catecholamine release. Increased blood sugars can cause further damage in brain (edema, bleeding rx)
Hypoglycemia can mimic symptoms of stroke
Why monitor BP post stroke?
- cerebral blood flow regulation (need adequate perfusion)
- identification of hemorrhage
- uncontrolled BP can exacerbate edema causing secondary injury
Why monitor fever post stroke?
Fever increases oxygen needs of brain
Can indicate inflammation/infection
Why monitor ECG post stroke?
- patients post stroke are at increased risk for cardiac complications
- arrhythmias are source of embolic stroke (stroke reoccurence)
- Stroke can affect the autonomic nervous system and lead to changes in heart rate and blood pressure. These changes may result in cardiac ischemia (insufficient blood flow to the heart muscle). Monitoring the ECG can help identify ischemic changes
Why monitor for seizure activity post stroke?
Early detection because patients are at increased risk for post-stroke/late-onset seizures
When must tPA be started and why?
Within 4.5hr of onset of symptoms; outside of this outcomes get worse and risks increase
What symptoms would cause you to stop a tPA infusion?
Nausea, vomiting, headache, acute hypertension
When should patients with acute ischemic stroke/TIA start aspirin?
Within 48 hours of onset
What are patients on tPA at increased risk for?
bleedings
What are contraindications for aspirin?
allergy, GI bleed
Besides aspirin, what other anti-platelets may a stroke patient be on?
- Plavix
- Apixaban
- Rivaroxaban
What must be avoided for 24 hours after tPA treatment?
Anticoagulants
What 3 surgeries could stroke patients undergo?
- cerebral angioplasty with stent placement
- carotid endarterectomy
- aneurym clipping or coiling
