V A S C U L A R Flashcards
What kind of sx do you expect in a patient with a stroke affecting the basilar artery?
Coma, “locked in” syndrome, cranial nerve palsies, apnea, visual sx, drop attacks, dysphagia, dysarthria, vertigo, “crossed” weakness and sensory loss affecting ipsilateral face and contralateral body
Immediate labs to get when pt presents with stroke
CBC with platelets, cardiac enzymes and troponin, electrolytes, BUN, creatinine, serum glucose, PTT, PT, INR, lipid profile, and O2 sat
Most sensitive modality for diagnosing acute ischemic infarct
Diffusion weighted MRI
If you suspect an embolic stroke, what tests should you order next
ECG, echo
Contraindications to tPA tx
SAMPLE STAGES Stroke or head trauma within last 3 most Anticoag with INR >1.7 or prolonged PTT MI (recent) Prior intracranial hemorrhage Low platelet count (185 OR diastolic>110 Surgery in the past 14 days TIA Age 400 mg/dL) or decreased (<50) blood glucose Seizures at onset of stroke
If anticoag is contraindicated in pt who just had a stroke, what meds can you give them instead?
ASA + clopidogrel.
Target INR for pts with prosthetic valve
3-4. OR you can add anti-platelet agent.
Thrombotic stroke is due to rupture of…?
Atherosclerotic plaque, which usually develops at branch points e.g. bifurcation of internal carotid and MCA in circle of Willis. It results in a PALE infarct at the periphery of the cortex.
Embolic stroke is due to …?
Thromboemboli, usually 2/2 afib. Usually involves MCA. Results in HEMORRHAGIC infarct at periphery of cortex.
Ischemic stroke – describe the pathology
Results in liquefactive necrosis*. Eosinophilic change in the cytoplasm of neurons (red neurons) is an early finding, 12 hours after. Necrosis occurs in 24, infiltration by neutrophils days 1-3, and microglial cells (days 4-7), and gloss (weeks 2-3) then ensue. This results in a formation of a fluid filled cystic space surrounded by gliosis.
Which cranial nerve is associated with berry aneurysms?
CN III palsy with pupillary involvement
What should you do if you suspect SAH but get a negative CT?
Immediate LP to look for RBCs, xanthochromia, increased protein (2/2 RBCs) and increased ICP. LP results can be falsely negative in first 6-12 hours bc xanthochromia not yet developed and after first 24-28 hours because its resolved.
7 conditions associated with berry aneurysms (aka SAH)
MAKE SAH. Marfans Aortic coarctation Kidney dz (ADPKD) Ehlers danlos Sickle cell anemia Atherosclerosis History (familial)
Additionally, being black has a higher risk.
Intracerebral hemorrhage is classically due to rupture of?
Charcot Bouchard micro aneurysms of lenticulostriate vessels. Usually in BASAL GANGLIA.
What feature of berry aneurysms make them more prone to rupture?
Lack of a media layer
Pt presents with intractable vomiting, FEVER, occipital headache, blepharospasm, severe dizziness and inability to walk. Muscle strength is preserved and no sensory abnormalities noted. What is the most likely etiology?
Cerebellar hemorrhage. Fever is common in any intracranial hemorrhage.
What kind of sx expected in MCA stroke
Aphasia if dominant (usually left) hemisphere or neglect if non dominant (right) hemisphere
CL paresis and sensory loss in face and arm
Gaze preference* toward side of lesion
Homonymous hemianopsia
What kind of sx expected in ACA stroke
C/L paresis and sensory loss in log
Cognitive or personality changes –abulia, emotional disturbance, etc.
Dyspraxia
Urinary incontinence
What kind of sx expected in PCA stroke
Homonymous hemianopsia Memory deficits Dyslexia/alexia Dysphagia Dysarthria
What kind of sx expected in posterior limb of internal capsule stroke
Unilateral motor impairment with no sensory or cortical deficits
No visual field abnormalities
Describe how homocysteinuria can cause CVA and what tx is.
CVA 2/2 pathologic changes in vessel walls and increased adhesiveness of the platelets usually involving cerebral vessels. Give Vit B6, folate, and B12 as well as anti-platelets or anti-coagulation. Don’t confuse with Marfans (same body habitus!)
4 causes of craniocervical dissection
Trauma
FMD
Inflammatory/infectious diseases
Marfans
Presentation of cingulate “subfalcine” herniation
Displacement of cingulate gyrus under fall cerebra; occurs 2/2 mass lesions of frontal lobes. Could compress ACA leading to infarction
Presentation of transtentorial herniation
Pushes midbrain inferiorly Presents with rapid change in mental status B/L small and reactive pupils Cheyne-Stokes respirations Flexor or extensor posturing
Presentation of uncal herniation
CN III becomes intrepid – leading to fixed and dilated IPSILATERAL pupil followed by eye that is deviated down and out.
Ipsilateral hemiparesis from compression of cerebral peduncle against tectorial edge
Compression of PCA
Rupture of paramedic artery leads to Duret (brainstem) hemorrhage
Cerebellar tonsillar herniation into foramen magnum - signs and sx
Tonsillar herniation – > medullary compression –> respiratory arrest. Usually rapidly fatal.
Which tracts affected in ASA stroke? Sx?
Infarct of paramedian branches of ASA and vertebral arteries (medial medullary syndrome): lateral corticospinal tract, medial lemniscus, caudal medulla –hypoglossal nerve.
Sx: contralateral hemiparesis of lower limbs, decreased contralateral proprioception, ipsilateral hypoglossal dysfunction (tongue deviates ipsilaterally).
Which tracts affected in PICA stroke? Sx?
Lateral medullary (Wallenbergs) syndrome: lateral medulla affecting vestibular nuclei (vertigo, nystagmus, vomiting); lateral spinothalamic tract (decreased pain and temp sensation to limbs); spinal trigeminal nucleus (decreased pain and temp sensation to face); nucleus ambiguus (dysphagia, hoarseness, decreased gag reflex); sympathetic fibers (ipsilateral Horners); inferior cerebellar peduncle (ataxia, dysmetria).
Which tracts affected n AICA syndrome? Sx?
Lateral pons–cranial nerve nuclei; vestibular nuclei (vomiting, vertigo, nystagmus); facial nucleus (paralysis of face, decreased lacrimation, salivation, decreased taste from anterior 2/3 of tongue, decreased corneal reflex); spinal trigeminal nucleus (Decreased pain and temp sensation); cochlear nuclei (ipsilateral decreased hearing); sympathetic fibers (ipsilateral Horners syndrome)
Besides the lateral pons, what else does AICA supply?
Inferior and middle cerebellar peduncles.
If a pt has a berry aneurysm with a CN III palsy, where is the lesion?
Posterior communicating artery
Which kind of hematoma crosses suture lines?
Subdural hematoma
Which kind of hematoma can cross falx, tentorium?
Epidural hematoma
When does irreversible damage begin to the brain in hypoxia?
5 minutes
4 most vulnerable areas of the brain to hypoxia
Hippocampus
Neocortex
Cerebellum
Watershed areas
