Download Ischemic_stroke

Diagnosis and Management
of acute ischemic stroke
Stroke-Definition
• Acute loss of vascular perfusion to a region of
the brain resulting in ischemia and loss of
neurologic function and/or tissue destruction
• Can be hemorrhagic or ischemic in etiology
Stroke definition continued
• Neurologic dysfunction can take the form of a
deficit in any neurologic domain including
motor, sensory or cognitive.
• Typical symptoms can include weakness,
incoordination, visual loss, language (production
or comprehension).
Stroke pathophysiology
• Ischemic: embolic, thrombotic, vasculitic or
hypoperfusion, arterial dissection.
• Hemorrhagic: intraparenchymal or
subarachnoid.
Epidemiology
• In U.S. 795,000 strokes per year, 625,000 are
ischemic
• There are currently 4.4 million stroke survivors
in the U.S.
• 3rd leading cause of death in U.S. and in other
industrialized countries.
Epidemiology continued
• Number one cause of disability in the U.S.
-26% will need assistance with ADLs.
-30% will need walking assistance
-26% will require admission to long term care
facility
Epidemiology
• Stroke occurs in all age groups including
children
• 75% of all stroke occur in the age 65 and older
group
• The age adjusted risk of death due to stroke in
blacks is 1.49 compared with whites.
Clinical presentation
• Acute neurologic deficit
• Sudden hemiparesis/hemiplegia, loss of
language function (receptive or expressive),
dysarthria, loss of vision in one or both eyes,
sudden ataxia, hemibody numbness, vertigo,
diplopia, clumsiness, sudden onset headache
(thunderclap)
Important history to obtain
HPI:
• Absolute onset of symptoms
• Presence of progressing or “stuttering
symptoms”
• Attempt to localize with questions to isolate
particular vascular territory: Anterior versus
posterior, left or right
Pertinent PMH
• Assessment of risk factors: DM, HTN, HLP,
coagulopathies, A-fib, CHF, previous stroke,
cardiac arrhythmias, cancer, pregnancy, recent
surgeries, recent TIA, migraine or other HA hx
• Medications: anticoagulants, antihypertensives,
antiplatelet agents.
• SHx: tobacco, ETOH, drug use, supplements
Pertinent family history
• Stroke, coagulopathies, DM, rheumatologic
conditions (young patients).
Ischemic Stroke classification
• Anatomic: Anterior (carotid) versus posterior
(vertebrobasilar) circulation, and dominent
versus non-dominant hemisphere.
• Large vessel versus small vessel (lacunar)
• Embolic versus thrombotic.
MCA infarct
Lacunar strokes
Anatomy of a stroke
Anterior circulation
Anterior circulation symptoms
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Monocular visual loss (Amaurosis fugax)
Language dysfunction: aphasia
Hemimotor: Face/arm>leg, leg>face/arm
Hemisensory symptoms
Apraxia
Hemivisual symptoms (also posterior
circulation)
Localizing anterior circulation
strokes
Posterior circulation symptoms
• Vertigo
• Ataxia
• Isolated Hemimotor dysfunction:
Arm=leg=face (Pontine stroke).
• Diplopia
• Dysarthria
• Hiccups
• Hearing loss
Diagnosis
• Based on history of acute onset neurologic
deficit in localizable vascular territory
• Associated objective clinical neurologic exam
findings
• Supported with specific neuro-imaging CT and
MRI findings
Diagnosis
Must localize process before creating
differential diagnosis and ordering
imaging
Important neurologic exam findings
• Level of consciousness, orientation **Usually
preserved with most focal strokes**
• Higher cortical functions: Language
comprehension and fluency, naming, praxis, leftright orientation, calculation,
neglect
Neurologic findings
• Cranial nerves: Pupils and extraocular
movements: affected by brainstem involvement
• Vision: Monocular versus binocular, visual field
testing.
• Facial movement: upper versus lower face
involvement: important in differentiating
brainstem (nuclear 7th) versus central 7th palsy
• Swallowing/gag
Neurologic Exam findings
• Motor: weakness-pyramidal pattern
tone: increased or decreased
posturing, pronator drift
• Sensory: negative sensory symptoms-central
pattern
• Reflexes: hyper-reflexia, Babinksi sign
• Gait: hemiparetic, apraxic or ataxic
Initial management
• ABCs
• O2
• IV fluids
Initial Diagnostic testing
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Vital signs including temperature
Labs: Glucose, coags, chemistry, CBC
EKG
Non contrast Head CT
Cardiac enzymes
Head CT pros and cons
Pros
• Can be obtained quickly
• Sensitive to identifying intracranial acute blood
Cons
• Ischemic changes may not show for 6+ hours
• Less sensitive to processes in posterior fossa
Ischemic stroke management
• Determine level of impairment, NIH stroke
scale can be helpful
• Antiplatelet therapy or tPA
• Blood pressure management, maintain MAP
100-130, SBP <220, DBP<120
use labetalol IVP, enalaprilat IVP or
Nitroprusside gtt if needed.
Ischemic stroke management
• Determine appropriateness for IV tPA or
intravascular intervention (IA tPA, mechanical
clot removal)
• Recent recommendations made for expanding
IV tPA window to 4.5 hours but tPA should still
be administered ideally within 1 hour of patient
presentation.
Additional stroke management
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Admission to telemetry bed
Continued IV hydration
DVT prevention
NPO until speech pathology eval if indicated.
Evaluate for signs of co-existent infection
Statin therapy?
Additional Evaluations
• MRI brain with DWI, MR angiography
• Carotid duplex neck for anterior circulation
strokes
• MRA neck for posterior circulation strokes
• CT angiography- sometimes indicated
• Echocardiogram +/- bubble study (in young)
• Conventional angiography rarely indicated
MRI-DWI
MRI-DWI
DWI and PWI (perfusion weighted)
Additional evaluations
• RPR, homocysteine, fasting lipid profile,
lipoprotein a, ESR or CRP
• Rheumatologic studies and hypercoagulation
panel if indicated (stroke in young)
Stroke complications
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Aspiration/pneumonia
DVTs
Falls
Depression
Secondary hemorrhage
Increased intracranial pressure
Stroke prognosis
• In Framingham and Rochester studies the 30
day mortality after stroke was 19%. The one year
survival rate was 77%
• In the Framingham heart study, 31% of stroke
survivors needed help caring for themselves,
20% needed help ambulating and 71% had some
impairment in vocational capacity.
What about TIAs
• These represent transient focal interruptions in
cerebral blood flow and can be embolic or
thrombotic.
• TIAs confer a 10% risk of stroke in 30 days.
• Half of all strokes that follow a TIA occur
within the first 48 hours.
Work-up of TIAs
• The diagnosis of a TIA often rests on a clinical
history of a localizable focal vascular event in
the context of known stroke risk factors.
• These should be evaluated aggressively with
hospital admission, telemetry, and a search for a
embolic source or other predisposition for an
ischemic stroke.
Questions?