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Neuropathology > Clinical Stroke > Flashcards

Flashcards in Clinical Stroke Deck (43):
1

What is a stroke

Clinical def

A sudden focal neurological deficit due to an interruption of the blood supply to the brain

2

What is a stroke

Ischemic or hemorrhagic

Ischemic: obstruction of a feeding blood vessel or a significant reduction in blood flow


Hemorrhagic: rupture of a blood vessel into or around the brain

3

Stroke

mechanisms

• Artery to artery embolism – Atherosclerotic damage to an artery (aorta, carotids, intracranial vessels) that produces local thrombosis and distal embolization of the clot
• Small artery thrombosis –Atherosclerosis, lipohyalinosis, vasculitis
• Cardiac embolism –Intracardiac thrombus with distal clot embolization
• Hypotension / hypovolemia / hypoxemia - Generalized brain ischemia; usually occur in combination

4

TIA prognosis

• 1 in 15 individuals over age 65 with TIA history
• Average duration at ED visit: 3 hr. 27 min.
• Alternative dx to TIA likely in 5.6% (syncope, vestibulopathy, anxiety, migraine, seizure, meds)
• 5% have stroke within 2 days; 10.5% stroke within 90 days
• 14% hospitalized

5

ABCD2 score

What does it do?

A simple score (ABCD2) to identify individuals at high early risk of stroke after transient ischemic attack

6

ABCD2

How is it calculated

 A (Age); 1 point for age >60 years,
 B (Blood pressure > 140/90 mmHg); 1 point for hypertension at the acute evaluation,
 C (Clinical features); 2 points for unilateral weakness, 1 for speech disturbance without weakness, and
 D (symptom Duration); 1 point for 10–59 minutes, 2 points for >60 minutes.
 D (Diabetes); 1 point

Total scores ranged from 0 (lowest risk) to 7 (highest risk). An ABCD2 score of 4 or greater can justify 24-48 hour admission in the USA solely on the basis of a greater opportunity to administer thrombolysis early if a subsequent stroke occurs

7

Stroke

Signs/sx

• Sudden onset (usually maximum within 10 seconds)
• Weakness of one side of the body / face
• Numbness / tingling of one side of the body or face
• Incoordination / clumsiness of one side of the body, falling to one side, spinning sensation
• Sudden change in speech or language
• Loss of vision, especially in one eye on or one side
• Double vision
• Acute confusion
• Sudden, severe headache

8

Stroke

Focused history

What should you ask about

Risk factors

High blood pressure (hypertension)
"High sugar" (diabetes)
Heart disease, heart attacks, irregular heart beats
High cholesterol
Smoking, alcohol use, illegal drugs
No regular physical exercise
Family history of stroke
Previous stroke
Sickle-cell disease

9

Stroke

Focused history

What should you ask about

Focal sx

Numbness, tingling, weakness, clumsiness, heaviness of one side of the body
Change or loss of language (understanding, comprehension, reading, writing)
Change or loss of steady walking, imbalance, falling
Headache (location, type, severity, duration)
Change or loss of vision (one eye? Both eyes?)

10

Stroke

Physical examination

general

ABCS
Vitals
Cardiac Auscultation
Presence of bruits

11

Stroke

Physical examination

Focused neurological examination



Level of consciousness (alert, lethargic / drowsy, stupor, coma)
Language (comprehension, fluency, repetition, naming, reading, writing)
Visual fields and eye movements (other CN)
Strength (face, arms, legs, drift) and reflexes
Coordination (gait, finger to nose, heel to shin)
Sensation (pinprick, temperature, joint position sense / vibration)

12

Stroke

Initial testing

Labs: CBC, chemistry, PT / INR / PTT, troponins, SaO2, type and screen

EKG

CT head without contrast
– IMPORTANT: Remember that we can’t tell the difference between ischemic and hemorrhagic stroke based on clinical features alone

13

Acute stroke management

• Evaluation and stabilization of patient – Vitals, cardiovascular, neurological assessment, O2 NC, HLIV x2
• Diagnostic work-up begun – Labs, brain imaging (CT, MRI)
• Consider “clot-buster”: t-PA therapy (call Stroke Team)

14

Acute stroke management

Other therapies

– Antiplatelet agent
– Manage / prevent stroke complications (seizures, pneumonia, aspiration, DVT)

Admit to Stroke Unit

15

NINDS targets for thrombolytics



Time target

Door to Doctor
10 minutes
Door to CT completion
25 minutes
Door to CT read
45 minutes
Door to tx
60 minutes
Access to neurological expertise
15 minutes
Access to neurosurgical expertise
2 hours
Admit to monitored food
3 hours

16

T-PA criteria







Inclusion criteria:
Age > 18
Ischemic stroke with measurable deficit
80 years of age
Taking oral anticoagulants (even if INR 25
Hx of diabetes and stroke

17

Inpatient evaluation and tx







If not tPA or other intervention: ASA 325mg (or other antiplatelet daily)
NPO if unable to swallow: feed w/in 72 hours, many need tube feeds
SQ heparin or compression device to prevent DVT
Control serum glucose
Echocardiogram
Cardiac telemetry
MRI brain (with DWI/ADC)
Carotid duplex ultrasound/MRA
Labs: RPR, fasting lipids
Begin rehabilitation

18

Acute stroke and BP management

Observation and frequent checks if BP 185/110

19

HTN

When to tx and how aggressively

• BP often elevated at onset, improves spontaneously over next week
• Small studies suggest poorer outcomes with BP lowering in acute stroke – 2-fold increase in dependency per 10% BP reduction
• Usually safe to slowly attempt JNC VII BP targets within 1-2 weeks following stroke
• Should not decrease BP unless MAP >130, and < 20% per day acutely

20

Stroke

complications

• Seizures
• Cardiovascular (MI, arrhythmia, sudden death)
• Respiratory (aspiration pneumonia, DVT / PE)
• Endocrine (hyperglycemia, hyponatremia)
• Urinary tract infection
• Decubitus ulcers
• Psychological / Psychiatric
– Depression (40%)
– Confusion / combativeness / hallucinations
Abulia (lack of motivation, inability to make decisions)

21

Acute ischemic stroke study

summary

• Prompt recognition, early assessment and evaluation are critical elements for intervention
• Thrombolytic therapy is our best option to improve function, MERCI retriever holds promise
• Antiplatelet agents should be used for those who are not rtPA candidates
• Goal of all monitoring and treatment is to improve outcomes and prevent complications

22

Options for stroke prevention

• Antiplatelet therapy
• Anticoagulation
• Risk factor modification
• Antihypertensive agents
• Statin therapy
• Carotid surgery or stenting

23

Risk factors Post CV event

1,252 MI or stroke patients f/u 8-10.6 yrs
• 53% hypertensives not controlled, 11% previously undiagnosed
• 46% patients with hypercholesterolemia not controlled, 13% previously undetected
• 49% diabetics poorly controlled
• 18% still smoking
• 43% overweight
• 33% physically inactive

24

HTN recommendations

• Patients with previous stroke / TIA should aim to gradually lower BP through lifestyle changes and drug therapy
• Secondary prevention
– Diuretics and ACE inhibitors are effective and complementary to other therapies
– NNT ~ 150 (NNT is number needed to treat to prevent one stroke/year)
• Primary prevention
– All major classes are effective
– NNT ~ 500

25

HMGcoA reductase inhibitors

benefits

Multiple studies demonstrated benefit of statins for stroke prevention with CHD (coronary heart disease)

26

Use of antiplatelet agents in CV disease

• Small vessel (lacunar) strokes
• Large-vessel (carotid) disease
• Cardioembolic – if not warfarin candidates
• Stroke of unknown etiology (20 - 30%)
• After CEA / stenting

27

CV disease

Tx options

Aspirin: Easy, safe, inexpensive; effective

Clopidogrel: Well tolerated, costly and equal in efficacy to aspirin used alone, combinations being studied in stroke

ASA/dipyridamole: Most effective; costly with bothersome side effects

28

Why not use agents in combination to prevent stroke
If one is good, wouldn’t 2 be better?

2 RCTs comparing combinations of ASA and clopidogrel (Plavix) to either agent alone for secondary stroke prevention

Conclusion: No proven benefit of combination for stroke prevention, trends toward harm
Preventative agents of choice for CV disease

29

summary

• Aspirin is still the treatment of choice when compared with anticoagulation (except atrial fibrillation)
• The role of drug combinations is still being explored
• Clopidogrel-ASA combo: no proven benefit
• Patients are at high-risk of recurrence, regardless of the agent chosen
• Discussions of the ideal agent should be conducted in context of other strategies with proven benefit, cost

30

Sources of cardiogenic emboli

list

Afib 45%
Acute MI 15%
Ventricular aneurysm 10%
Rheumatic heart dz 10%
Prosthetic valves 10%
Other 10%

31

Afib and stroke

epidemiology

• AF is the most common arrhythmia, especially in patients >60 y/o
• Median age of AF population is 75 y/o
• AF carries 6-fold increase in stroke risk
• Annual risk of stroke is 5% (average)
• 15% of all ischemic stroke patients have AF
• Two thirds of ischemic strokes in patients with AF are from left atrial thrombi

32

Afib

Risk stratification

High risk

High Risk (≥8%/yr)

• Stroke/TIA (12%/yr)
• CHF/LV dysfunction
• Systolic HTN
• Age >75 y/o
• Diabetes
• Tx: OAC (=oral anti-coagulation)

33

Afib

Risk stratification

Medium risk

Medium Risk (3.5%/yr)


History of hypertension
Age 65-75 y/o
Tx: OAC or ASA

34

Afib

Risk stratification

Low risk

Low Risk (1%/yr)

• No high-risk factors
• No history of HTN
• <65y/o
• Tx: ASA

35

Afib and stroke

Gen chars

• A major treatable cause of stroke particularly in the elderly population
• Risk stratification is essential in selecting therapy
• Many patients with AF at increased risk for stroke are not treated with anticoagulation
• Proper management of anticoagulation can reduce stroke risk by over 65% and can minimize risk of major bleeding
• INR goal: 2.0 – 3.0

36

Carotid artery stenosis

incidence

• Accounts for 10 – 15% of ischemic strokes.
• One third of anterior circulation strokes and TIAs are associated with CAS.
• About 80,000 strokes and 45,000 TIAs / yr in USA are related to CAS.

37

Look at ipsilateral stroke at 2 years

Pg. 135
Do it

Look at ipsilateral stroke at 2 years

Pg. 135
Do it

38

Carotid endartectomy

Greatest benefit

• Symptomatic: NNT = 6
• Asymptomatic: NNT = 100
• 90% > 80% > 70% > 60% stenosis
• Benefit regardless of age, but older > younger
• Ulcerated plaque
• Hemispheric TIA / stroke (vs. retinal)
• Men > women
• Associated stroke risk factors
– Hypertension, diabetes, tobacco, lipids

39

Carotid angioplasty and stenting

chars

• The results of randomized trials have not shown consistent outcome differences between CAS and CEA
• CAS may be superior to CEA in certain patient groups
• When performed in conjunction with an embolic protection device (EPD), the risks of CAS may be lower than CEA in patients at elevated risk of surgical complications
• The in-hospital stroke rate for asymptomatic patients undergoing CAS is 2-fold higher than for CEA
• FDA approved only for high-risk patients
• With few exceptions, vertebrobasilar and intracranial stenting should be limited to RCTs- there is insufficient evidence from randomized trials to demonstrate that endovascular management is superior to best medical management.

40

Primary prevention

Asymptomatic carotid stenosis

Stenosis 80%/100% occlusions

Stenosis < 80%:
Aspirin 50-350 mg/d or Clopidogrel 75 mg/d or
ER-DP + Aspirin 25 mg bid
Risk factor (RF) management

Stenosis >80%:
Possible CEA / stent or RF management and antiplatelet therapy

100% occlusion
RF management, antiplatelet tx

41

Primary prevention

symptomatic carotid stenosis

Stenosis <50%/stenosis 50-69%/stenosis 70-99%/ 100% occlusion

Stenosis <50%:
Aspirin 50-350 mg/d or Clopidogrel 75 mg/d or
ER-DP + Aspirin 25 mg bid
Risk factor (RF) management

Stenosis 50-69%:
Possible CEA / stent or RF management and antiplatelet therapy

Stenosis 70-99%: CEA/stent, RF management, antiplatelet therapy

100% occlusion
RF management, antiplatelet tx

42

Lifestyle changes and stroke prevention

• Quit smoking
• Drink some, not too much
• Be physically active
• Eat fish and whole grains
• Cholesterol-lowering diet
• Avoid infections

43

Stroke prevention summary

• Manage hypertension, smoking, diabetes, alcohol, obesity, exercise, other risks
• Determine probable source of stroke: large artery atherosclerosis, atrial fibrillation, small artery disease
• Select therapy based on mechanism: CEA, warfarin for cardioembolic, ASA for most
• Educate patient about risks
• Monitor compliance and risk factor management