U of U PA School Stroke and TIAs

What is a stroke?

Neurologic deficiency attributed to an acute focal injury of the CNS by a vascular cause

Includes

-Cerebral infarct

-Intracranial hemorrhage

-Subarachnoid hemorrhage

Where do strokes occur?

Any portion of the brain

Retina

Spinal cord

What are the cortical signs of a stroke? (5)

Localize to specific lobe of the brain

-Speech/language

-Cognitive function

-Spatial orientation

-Vision

-Eye gaze deviation

What are the non cortical signs of a stroke? (4)

Weakness

CN deficits

Ataxia

Sensory loss

What things mimic a stroke? (5)

Conversion disorder

Hypertensive encephalopathy

Hypoglycemia

Complicated migraine

Seizures

What is a TIA?

Transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction

How do TIAs and migraines differ?

TIAs

-Sudden, maximal onset

-Last 10-60 minutes

-Usually have vascular risk factors

Migraine

-Marching progression

-Usually numbness/dizziness

-Aura, nausea, mental dulling

What are the ABCDD features predictive of 7 day risk of stroke in patients with TIA?

Age

->59 years old = 1 point

BP

-Systolic >140 and/or diastolic >89 = 1 point

Clinical features

-Unilateral weakness = 2 points

-Speech disturbance without weakness = 1 point

-Other symptoms = 0 points

Duration (in minutes)

->59 minutes = 2 points

-10-59 minutes = 1 point

-<10 minutes = 0 points

Diabetes = 1 point

How does the scoring of ABCDD predict stroke risk after a TIA?

<5 = <1% risk

5 = 12% risk

>6 = 31% risk

What are the types of strokes?

Ischemic

-Thrombotic

-Embolic

Hemorrhagic

-Intracerebral

-Subarachnoid

How does the flow for stroke work up look?

Is it potentially a stroke?

If yes - CT head

-Hemorrhagic or non hemorrhagic?

If non hemorrhagic appearance - presumed ischemic stroke

What is the ischemic penumbra?

Perimeter around the core ischemic area

Area can progress to infarction

What does stroke treatment aim to recover?

Area of ischemic penumbra

What is used for acute treatment of a stroke?

IV thrombolytics

-tPA (alteplase)

-TNK-tPA/TNK (tenecteplase)

Mechanical thrombectomy

What are the inclusion criteria for IV thrombolytics? (5)

Clinical diagnosis of ischemic stroke causing measurable deficit

Symptom onset <4.5 hours

BP <185/110

>18 years old

Informed consent

-If no proxy or unable, implied consent

What is the goal time for administration of IV thrombolytics?

Administer within 60 minutes of ED admission

What are the absolute exclusion criteria for IV thrombolytics? (7)

Outside administration window

CT evidence of blood

BP >185/110 refractory to treatment

Concern for subarachnoid hemorrhage even with negative imaging

Platelets <100,000

LMWH treatment dose in last 24 hours

Anticoagulants - factor Xa, GbIIb/IIIa inhibitors

What should be done for a patient still symptomatic after IV thombolytics?

CT angiography or MR angiography (MRA) of brain to find clot

What is a mechanical thrombectomy? What timeframe can it be done?

Extraction of clot from large vessels

Can be done up to 24 hours after start of symptoms at a specialty center with advanced imaging

What are the types of ischemic strokes?

Lacunar

Hemispheric

Large artery stroke

How are ischemic strokes classified?

Lacunar

-Smaller vessel stroke

Hemispheric

-Involves whole hemisphere

Large artery stroke

-Anterior/middle/posterior cerebral arteries - MCA most common

-Vertebrobasilar artery

What areas and functions are supplied by the MCA?

MCA

-Temporal - receptive speech

-Portion of frontal - motor+sensory of face, arm, and expressive speech

-Parietal - neglect

What areas and functions are supplied by the ACA?

ACA

-Portion of frontal - motor+ sensory of legs

What areas and functions are supplied by the PCA?

PCA

-Occipital cortex

-Parietal - sensory

What area is supplied by the vertebrobasilar artery? What does a blockage of this artery cause?

Brainstem

- hemiparesis, bilateral weakness, hemisensory loss, bilateral sensory, CN deficits

How do plaque and embolism differ in clot formation?

Plaque - clot forms at site of blockage

Embolism - clot travels to site of blockage

What is the pathophysiology mechanism of large artery stroke?

Thrombotic

-Blood clot forms in blood vessel in brain

Embolic

-Blood clots forms in heart or major blood vessels dislodges and lodge in blood vessels of brain

Cryptogenic

-Mechanism for the stroke is unknown

What is the pathophysiology mechanism of cardioembolism ischemic stroke?

Embolic

-Blood clots forms in heart or major blood vessels dislodges and lodge in blood vessels of brain

What is the pathophysiology mechanism of lacunar stroke? How does it present?

Very small blood vessel of the brain progressively narrows until completely occluded

Pure motor deficit or ataxia hemiparesis

What is done for secondary ischemic stroke prevention? (4)

Control modifiable risks

Blood vessel imging

Antiplatelets of anykind

CHASVASC2 score for anticoagulants

What are the modifiable risks of a stroke? (10)

Hypertension

Hyperlipidemia

Diabetes

Smoking

Sleep apnea

Coronary artery disease

History of TIA

A fib

Carotid stenosis

Obesity

How is hypertension managed with a stroke?

Initially after a stroke hypertension is permissible for 24-48 hours unless

->220/120

-End organ failure

-Active ischemic coronary disease

-Aortic dissection

-Preeclampsia

After 48 hours - oral antihypertensives

What is blood vessel imaging looking for? (4)

Intracranial atherosclerosis

Carotid atherosclerosis

Dissection

TTE if suspected cardioemboic source

What is done for subacute/chronic management post stroke?

Management of risk factors

Rehab with speech, PT, OT, and rehab physician

How does a hemorrhagic stroke present?

Same as ischemic stroke - based on location

Symptoms can rapidly change

What is the most common cause of a hemorrhagic stroke?

Hypertension

What additional things can cause a hemorrhagic stroke? (4)

Transition of ischemic to hemorrhagic stroke

Aneurysm rupture

Cerebral amyloid angiopathy

Subarachnoid hemorrhage - berry aneurysm rupture

What is the treatment for hemorrhagic stroke?

Acute

-Reverse INR

-Clotting factor replacement

how should hemorrhagic strokes be evaulated?

Is it in the brain (intraparenchymal) or around the brain subarachnoid)

Was it secondary hemorrhage to ischemic stroke, hypertension, or vascular malformation

What imagining is used for acute diagnostic evaluation of a stroke? What are the advantages/disadvantages of each

Noncontrast head CT

-Quick

-May miss acute ischemia

-Better for blood/mass effect

Rapid MRI

Better for

-Localization

-Size

-Etiology

-Both ischemia and hemorrhage