Strokes and TIAs Flashcards
A 68-year-old right-handed woman is brought to the emergency department (ED) 30 minutes after suddenly developing speech difficulty and weakness of the right arm and leg.
Her family members report that she suddenly became mute and slumped down in her chair.
PMH: HTN,angina. Meds: atenolol and amlodipine.
Vitals: Temp is 36.6 °C (98 °F), HR 95 bpm, BP172/86 mm Hg.
Cardiovascular exam: No carotid bruit, + irregularly irregular pulse.
Neurologic exam: Lethargic but arousable patient who is able to follow some simple commands but has severe impairment of word fluency, naming, and repetition. She has a left lateral gaze deviation and right lower facial droop. There is total paralysis of the right upper extremity and, to a lesser degree, weakness of the right lower extremity. The left side displays full antigravity power without drift for 5 seconds.
-MCA stroke
cerebral ischemia
-Lack of blood flow -> neurons lack glucose -> neurologic symptoms develop -< if lasting for a few minutes can cause infarction (death of brain tissue)
-TIA: If brain flow is rapidly restored, there is no infarction, and symptoms lasts less than 24 hours
-Stroke: Neurological signs/symptoms > 24 hours and demonstrated infarction on imaging
cerebrovascular accident (CVA)
-stroke
-abrupt onset of neurologic deficit that is attributable to a focal vascular cause
-2 main types:
-!Ischemic(87%):Occlusion of artery to a region of the brain
-!2/3s are thrombotic
-!1/3s are embolic
-Hemorrhagic(13%) :Bloodvessel in the brainrupturesinto surrounding tissue
-Intracerebral hemorrhage (HTN, AVM) or SAH (aneurysm)
causes of stroke
-Thrombosis
-Narrowing of blood vessel due to atherosclerotic plaque -> ↓ blood flow
-Atherosclerotic fibrous cap damage -> platelet aggregation and clotting cascade -> thrombus formation w/ sudden blockage of blood flow
-Embolism
-Cardiac emboli: Afib, rheumatic heart dz, infective endocarditis, myxoma
-Arterial emboli: detachment of blood clot (atherosclerotic plaque) travels and lodges into smaller down stream artery
-Cardiac/aortic emboli: PFO, atheroma in aortic arch, atrial septal aneurysm, calcification of mitral valve annulus
-Cryptogenic: unknown origin
-Lacunar infarct: Narrowing of small blood vessels in the distal vertebral or basilar arteries
-Hypoperfusion: Heart failure with ↓ cardiac output, Watershed regions are the most vulnerable
-Vasculitis: Giant cell arteritis
-Moyamoya disease : Progressive stenosis of cerebral arteries -> ischemia
-Dissection of artery wall
CVA disease epidemiology
-Stroke is the 3rd leading cause of death worldwide, 5rd leading cause of death in the USA
-Leading cause of long-term disability
-Risk of first stroke is twice as high for black! > white
-Risk factors: !Age >55yo, HTN!, smoking!, afib!, male, obesity, DM, HLD, cerebral amyloid angiopathy, neoplastic disease, cerebral aneurysms, carotid bruits, drugs (cocaine, OCPs), previous strokes, migraines w/ aura, hematologic disorders (MM, SCD, PCV)
acute cerebrovascular syndromes
-stroke- symptoms with infarction
-TSI- transient symptoms with infarction
-TIA- transient ischemic attack WITHOUT infarction
stroke complications
-Hemorrhagic transformation
-After ischemic damage there is increased permeability of damaged blood vessels -> bleed
-High risk of transformation: tPA administration, massive stroke, hyperglycemia
-Cerebral edema
-Water accumulation occurs due to defective ATP pumps (sodium) and increased permeability of the blood brain barrier
-Can lead to ↑ ICP and herniation -> MCC DEATH
-Liquefactive necrosis can occur in 3-21 days
-Seizures- Brain injury ↑ irritability of nervous tissue neuronal discharges
-DVT due to immobilization
-Pneumonia due to impaired swallow mechanism / intubation
-Dysphagia occurs if there is damage to structures involving swallowing
-Dementia can occur due to brain damage
early recognition and intervention
-Rapid evaluation is essential
-Patients often do not realize something is wrong (anosognosia)
-It is important to teach family and friends about classic signs of a stroke
-TIME IS BRAIN
hemiparesis vs hemiplegia
-paresis- weakness
-plegia- paralysis
ataxia
-loss of full control of bodily movements
anosognosia
-lack of awareness of illness
ischemic penumbra
-Tissue surrounding the core region of infarction which is !ischemic but reversibly dysfunctional!
-Maintained by collaterals
-Can be salvaged if re-perfused in time!
-Primary goal of revascularization therapies
common causes of ischemic stroke
-Thrombosis:
-Lacunar stroke (small vessel)
-Large-vessel thrombosis
-Dehydration
-Embolic occlusion:
-Artery-to-artery:
-Carotid bifurcation
-Aortic arch
-Arterial dissection
-Cardioembolic:
-Atrial fibrillation
-Mural thrombus
-Myocardial infarction
-Dilated cardiomyopathy
-Valvular lesions
-Mitral stenosis
-Mechanical valve
-Bacterial endocarditis
-Paradoxical embolus:
-Atrial septal defect
-Patent foramen ovale
-Atrial septal aneurysm
-Spontaneous echo contrast
-Stimulant drugs: cocaine, amphetamine
uncommon causes of ischemic stroke (dont need to know)
-Hypercoagulable disorders:
-Protein C deficiencya
-Protein S deficiencya
-Antithrombin III deficiencya
-Antiphospholipid syndrome
-Factor V Leiden mutationa
-Prothrombin G20210 mutationa
-Systemic malignancy
-Sickle cell anemia
-β Thalassemia
-Polycythemia vera
-Systemic lupus erythematosus
-Homocysteinemia
-Thrombotic thrombocytopenic purpura
-Disseminated intravascular coagulation
-Dysproteinemiasa
-Nephrotic syndromea
-Inflammatory bowel diseasea
-Oral contraceptives
-COVID-19 infection
-Venous sinus thrombosis
-Fibromuscular dysplasia
-Vasculitis:
-Systemic vasculitis (PAN, granulomatosis with polyangiitis [Wegener’s], Takayasu’s, giant cell arteritis)
-Primary CNS vasculitis
-Meningitis (syphilis, tuberculosis, fungal, bacterial, zoster)
-Noninflammatory vasculopathy
-Reversible vasoconstriction syndrome
-Fabry’s disease
-Angiocentric lymphoma
-Cardiogenic
-Mitral valve calcification
-Atrial myxoma
-Intracardiac tumor
-Marantic endocarditis
-Libman-Sacks endocarditis
-Subarachnoid hemorrhage vasospasm
-Moyamoya disease
-Eclampsia
TOAST classification
-Large artery atherosclerosis
-Cardioembolism
-Small-vessel occlusion
-Stroke of other determine etiology
-Stroke of undetermined etiology
-flow reducing carotid stenosis -> if narrow vessel and patient becomes hypotensive -> pressure is not enough to perfuse brain
cardioembolic strokes
-~20% of all ischemic strokes are cardioembolic in nature
-Thrombi that detach from heart walls or left sided valves
-Thrombi can fragment or lyse quickly, producing a TIA
-!!Sudden maximum neurologic deficient at onset
-MC blockage in the intracranial carotid artery, MCA, PCA or their branches (less often ACA)
-MCC: Atrial fibrillation!
-Other causes: MI, prosthetic valves, rheumatic heart disease, ischemic cardiomyopathy
-Rare paradoxical embolization can occur when venous thrombi migrate to the arterial circulation
-Patent foramen ovale (PFO)
-Atrial septal defect
-Right-to-left shunting can be demonstrated with bubble-contrast echocardiography !
-Bacterial endocarditis! give rise to septic emboli!, suspect this is multifocal stroke symptoms
artery to artery embolic stroke
-Thrombus formations on atherosclerotic plaques can embolize
-MC cause of large vessel occlusion
-Any diseased vessel can be a source:
-Aortic arch
-Common carotid bifurcation
-Internal carotid
-Vertebral artery
-Basilar artery
-cervical artery dissection
artery to artery embolic stroke: cervical artery dissection
-cervical artery dissection of the internal carotid or vertebral arteries:
-Artery-to-artery embolic stroke in young patients (<60yo)
-2% of all ischemic strokes
-!Painful dissection preceding stroke by hours/days
-back, back of neck, if carotid -> anterior neck or ipsilateral eye
-High risk: Ehlers-Danlos, Marfans disease, cystic medial necrosis, fibromuscular dysplasia , PCKD
-Trauma (MVA, sports) can cause carotid or vertebral artery dissections
-Spinal manipulative therapy is associated with vertebral artery dissection and stroke
signs and symptoms of strokes
-can be obvious or subtle, they include:
-Sudden weakness or numbness to the face, arm, leg. Especially on one side of the body
-Trouble speaking or understanding
-Sudden trouble seeing in one or both eyes
-Sudden trouble walking
-Dizziness or loss of balance or coordination
-Sudden severe headache with no known cause
-Sudden confusion
-Symptoms begin abruptly and correlate with affected brain area
-Symptoms last > 24 hrs
-Symptoms of an ischemic attack are always negative and simultaneous
-Hemiparesis or hemisensory deficits are common -> Contralateral to brain injury
-Thrombotic strokes tend to be gradual ± stepwise, embolic strokes tend to be more abrupt
-Often awake from sleep with neurologic deficits
-May have preceding TIAs
-Embolic strokes occur abruptly over seconds without warning
-Worst deficits present at onset
-MC from heart (embolization), internal carotid, aorta
thrombotic strokes
-atherosclerotic plaque rupture
(most common)
-Hypertension
-High cholesterol
-Diabetes
-Blood clotting disorders
-Smoking
-Recreational drug use
-Vessel trauma
-Can be large vessel occlusion!
(LVO) or small vessel occlusion
cardioembolic strokes
-~20% of all ischemic strokes are cardioembolic in nature
-Thrombi that detach from heart walls or left sided valves
-Thrombi can fragment or lyse quickly, producing a TIA
-!!Sudden maximum neurologic deficient at onset
-Often embolize into the intracranial carotid artery, MCA, PCA or
their branches (less often ACA)
-MC cause of thrombi: Atrial fibrillation!
-Other causes: MI, prosthetic valves, rheumatic heart disease, ischemic
cardiomyopathy
-Rare paradoxical embolization can occur when venous thrombi
migrate to the arterial circulation
-Patent foramen ovale (PFO)
-Atrial septal defect
-Right-to-left shunting can be demonstrated with bubble-contrast
echocardiography!!!
-Bacterial endocarditis give rise to septic emboli, suspect this
is multifocal stroke symptoms
ACA syndrome
-<3% off all strokes are due to ACA occlusion
-ACA supplies:
-Medial and superior frontal and parietal lobes
-Corpus callosum (partial)
-Basal ganglia (partial)
-ACA stroke syndrome:
-!Contralateral hemiplegia- Worse in the legs > arms/hands/face
-Contralateral sensory loss (usually minimal)
-Urinary incontinence
-Frontal lobe dysfunction- personality changes
-Gait apraxia
-Abulia- Absence of willpower or the ability to act decisively, may have a delay in verbal and motor responses
MCA syndrome
-MC artery causing stroke
-Proximal MCA = M1 segment
-M1 segment occlusion (total MCA):
-!Contralateral hemiplegia (face/arm > leg)
-!Contralateral hemisensory loss
-Contralateral hemianopsia- blind on the side opposite of the lesion
-Gaze preference to ipsilateral side (towards lesions)
-Dysarthria (d/t face weakness)
-LEFT / Dominant hemisphere: Global aphasia!
-RIGHT: Non-dominant hemisphere: Anosognosia- neglect things they cant see, !constructional apraxia- cant copy drawings, and neglect!
MCA syndromes: Gerstmann syndrome
-AFFECTS: Parietal lobe of the dominant side (usually left) ANGULAR GYRUS
-Cause: Stroke (MC), TBI, Tumor
-Signs and symptoms
-Left-right disorientation- cant tell which is which
-Agraphia: Inability to write when you could previously
-Acalculia: Inability to calculate numbers
-Alexia: Inability to read/recognize words you once could read
-Finger agnosia: Impairment in recognizing and naming their own fingers
ICA syndrome
-MCA and ACA combined
-Internal carotid artery occlusion
may be asymptomatic
-Symptomatic occlusion similar to
mainstem MCA stroke
-Often preceded by TIAs or
transient monocular blindness due
to ophthalmic artery branch
-amourax fugax
vertebral artery syndrome
-symptoms of occlusion are variable
-have plenty of collateral supply
-dissection denoted by pain
Which of the following signs and symptoms would commonly be seen after occlusion of the MCA stem in the left hemisphere (assume that the left hemisphere is dominant for language in this patient). IndicateALLcorrect answers.
A. Inability to understand or carry out spoken or written commands!!
B. Inability to speak more than a few stereotyped words!!
C. Lack of response to threatening gestures (visual threat) when they are given on only the left side- neglect is only on right side
D. Paralysis of the right arm!!!
E. Paralysis of the right leg!! (less)
F. Paralysis of the left leg
PCA stroke syndrome
-Posterior cerebral artery supplies occipital lobes, inferior temporal lobes, thalamus, midbrain
-Either side:
-!!Contralateral homonymous hemianopia with macular
sparing (lateral geniculate nucleus)
-Contralateral sensory loss (thalamic involvement)
-Dominant side:
-!Alexia without agraphia: CANT read, CAN write -> Affected: Corpus callosum, occipital lobe (typically left)
-!Anomia: difficulty naming objects and colors
-!Visual agnosia: inability to describe what an object is used for
-Non-dominant side
-Prosopagnosia: inability to recognize faces
-Bilateral infarctions: Anton syndrome (cortical blindness)
-RARE
-Affected: bilateral occipital lobes (distal basilar artery or bilateral PCA involvement)
-Cortical blindness, are often unaware they are unable to see
Wallenberg syndrome
-lateral medullary infarct
-PICA (off the Vertebral artery)
-Dizziness, nystagmus, N/V, dysarthria,
dysphagia, diplopia, hiccoughs
-!!!!Mixed findings
-Ipsilateral facial numbness (CN V)
-Ipsilateral Horner’s syndrome
(sympathetic)
-Ipsilateral gait ataxia (cerebellum)
-Contralateral loss of pain & temperature
sensation in limbs (spinothalamic)
horner’s syndrome
-Damage to the oculosympathetic
pathway of one side of face
-Symptoms will be ipsilateral:
-Ptosis, miosis (small), anhidrosis
-Causes: Idiopathic, brainstem
stroke, carotid dissection,
neoplasm
-Any lesion along the 1st, 2nd, or 3rd
order nerve – there are so many!
-CT or MRI to find underlying
problem
lacunar strokes
-Small (2-15mm) non-cortical infarcts (subcortical) caused by occlusion of a single penetrating branch of a large cerebral artery
-Contralateral, mostly motor/sensory defects
-Pure motor stroke: internal capsule lesion- weak
-Pure sensory stroke: thalamic lacunar stroke - numb
-Ataxic hemiparesis
-Dysarthria-clumsy hand syndrome: speech, swallowing difficulties, facial weakness, hand weakness, clumsiness
-pure strokes are subcortical-> just this stuff listed
-dont need to know specifics
anterior vs posterior circulation
overview of strokes
cincinatti prehospital stroke scale (CPSS)
-Scoring tool forEMS in the pre-hospital setting
-3 physical examfindings:
-Facial droop
-Arm drift
-Abnormal speech
-<1 minute to perform
-Prescence of 1 finding = 72% chance of stroke
stroke flow chart
door to needle time of <= 60 min
-endovascular therapy (from onset for symtpoms)- up to 24 hours for large vessel occlusion -LVO
-admission to monitored bed - within 3 hours
-interfacility transfers- within 1 hour
national institutes of health stroke scale (NIHSS)
tPA for acute ischemic stroke
-Administration
-Ensure 2 peripheral IV lines
-rTPA: Administer 0.9 mg/kg IV (max 90mg)
-Give 10% of total dose by initial bolus, remaining 90% over 1 hour
-Frequent BP monitoring
-Avoid urethral catheterization ≥2 hours
-!No other anti-coagulants/platelet for 24 hours
-BP goals after starting: <180 SBP and <105 DBP
-Complications
-Bleeding!!!:
-If decline in neuro status, uncontrolled BP -> stop infusion, give plts/cryoprecipitate and reimage brain emergently
-Angioedema!!!- might need to intubate - famotidine, steroids, benedryl
who can and cant get TPA
adult stroke algorithm
-dont need to know?
transient ischemic stroke: risk stratification tool: ABCD2
-Predicts likelihood of subsequent stroke in 2 days
-ABCD2 score <4 –> ASA alone
-ABCD2 score≥ 4 –> (dual antiplatelet therapy) DAPT x 21 days
-Prevent strokesby aiming at the cause
-Non-cardioembolic stroke= dual-antiplatelet therapy
-ASA+clopidrogel or ASA+ticagrelor or ASA+dipyridamole (dont worry about the last one)
-Afib = LMWH
-Heart thrombus = DOAC
