Cerebrovascular Disease Flashcards
Risk factors for stroke
Similar to those for CAD (HTN, DM, smoking, dyslipidemia)
Men higher incidence at younger ages and higher for women by age 75
What causes a CVA?
Acute neurologic injury occurring due to hemorrhage or ischemia
Causes of ischemic stroke
Thrombosis (in situ obstruction of artery)
Embolism (a fib sends from somewhere else in body)
Hypoperfusion (circulatory problem)
Presentation of ischemic stroke due to hypoperfusion
Pts have evidence of circulatory compromise with hypotension and may have pallor, sweating, tachycardia/bradycardia, kidney dysfunction
Neuro signs are usually more bilateral (more uniform sxs)–sxs of brain dysfunction more diffuse and nonfocal
What are watershed infarcts?
Susceptible to strokes and ischemia secondary to low flow states from vessel overlap or systemic hypotension (some arteries will do a little perfusion into an area that another artery usually does)
What can cause a hemorrhagic stroke?
Intracerebral hemorrhage (parenchymal)- bleeding directly into tissue (more common type here) Subarachnoid hemorrhage-bleeding into CSF
Most common type of CVA
Ischemic!!
Why do you need to differentiate ischemic and hemorrhagic stroke?
For tx!! (do by a CT)
How is ischemia shown on CT?
Hypodense (darker) area of brain tissue
How to divide stroke syndromes
Large vessel: within anterior or posterior circulation
Small vessel: disease of either vascular bed (lacunar stroke)
Stroke syndrome due to large vessel in anterior circulation
(carotid artery supply)
Extracranial and intracranial carotid arteries, middle and anterior cerebral artery branches (middle/anterior cerebral artery, anterior communicating)
Stroke syndrome due to large vessel in posterior circulation
(vertebrobasilar system)
Extracranial and intracranial vertebral arteries, basilar artery and posterior cerebral arteries
CVA most commonly due to which artery
Middle cerebral artery
What does a stroke in middle cerebral artery affect?
Frontal, temporal and parietal lobes
Presentation of stroke syndrome due to middle cerebral artery (anterior)
Contralateral hemiplegia/hemianesthesia (weakness/numbess) variably affecting FACE and ARM greater than leg
Can see contralateral homonymous hemianopia and a day or two of gaze preference to ipsilateral side can be seen
Different presentations of stroke due to middle cerebral artery for dominant or nondominant hemisphere
Dominant: global aphasia (trouble talking)
Non dominant: hemineglect (half of world means nothing)
Presentation of stroke due to anterior cerebral artery
(frontal pole/lobe)
Contralateral hemiplegia/hemianesthesia (weakness/numbess) in the LEG greater than the arm
May have profound abulia (delay in verbal and motor response) or perseverating speech
Presentation of stroke due to anterior communicating artery
Impingement of cranial nerves so visual field deficits
Presentation of stroke due to posterior cerebral artery
(occipital cortex)
Contralateral homonymous hemianopia
Light touch and pinprick sensation may be reduced
-stroke may go unnoticed by pt b/c motor involvement is usually minimal unless large infarct
What presentation is seen with stroke due to posterior inferior cerebellar artery (PICA)?
Wallenbergs syndrome (lateral medullary syndrome)
What is Wallenbergs syndrome?
Ipsilateral loss of facial pain and temp sensation with contralateral loss of these senses over body
VERTIGO, VOMITING, nystagmus, ipsilateral ataxia, hoarseness, dysarthria, dysphasia, hiccups, ipsilateral Horners syndrome
(PICA)
What is Horners syndrome?
Typically incomplete ptosis and miosis without anhidrosis
Presentation of stroke due to basilar artery
Complete occlusion affects pons and produces LOCKED IN SYNDROME
What is the locked in syndrome?
Quadriplegia and facial/mouth/tongue weakness
Preserved consciousness (reticular formation spared)
Preservation of vertical eye movements and blinking
(basilar)
What is a lacunar stroke?
Occlusion of one of small, penetrating branches of circle of willis, middle cerebral artery stem or vertebral and basilar arteries
Thrombosis causes small infarcts called lacunes
What is a lacunar stroke associated with?
Chronic untreated HTN
Initial assessment for all kinds of strokes
Airway
Breathing
Circulation
What to remember with stroke pts and airway
They can have increased ICP which can lead to a decreased respiratory drive (may need to intubate, also if don’t have good level of consciousness)
What tends to be elevated in pt with acute stroke?
Mean arterial pressure (maybe due to HTN which is risk factor for stroke)
*appropriate response to maintain brain perfusion
BP control for ischemic stroke
DO NOT START treating BP unless greater than 220/120 (b/c risk of further ischemia)