stroke.pdf

Management and Prevention

of

Ischemic Stroke

Kittawit Rungjang

• Ischemic stroke is defined as an infarction of

central nervous system tissue.

• Approximately 80 percent of strokes.

Stroke.2009;40:2276-2293; originally published online May 7, 2009 UpToDate 19.1

Etiology

• Atherothrombosis

• Embolism

• Low flow

• Other etiologies

Evaluation and Diagnosis

History

single most important piece of historical

information is the time of symptom onset

The time of onset is defined as when the

patient was last awake and symptom free or known to be “normal”

Stroke. 2007;38:1655-1711; originally published online April 12, 2007


History

signs and symptoms on initial presentation can

give an indication as to which vascular territory is affected


Vascular territory



Physical Examination

HEENT: signs of trauma or seizure activity

CVS: JVP, bruits, pulse all extremities

,valvular conditions, irregular rhythm

skin and extremities: jaundice, purpura, petechia


Stroke Mimics

Conversion disorder

Hypertensive encephalopathy

Hypoglycemia

Complicated migraine

Seizures



Neurological Examination and Stroke Scale Scores

degree of neurological deficit

facilitate communication between healthcare

identify the possible location of vessel

occlusion

provide early prognosis

Identify patient eligibility for various

interventions

complications Stroke. 2007;38:1655-1711; originally published online April 12, 2007

National Institutes of Health Stroke Scale


NIHSS-T

J Med Assoc Thai 2010;Establishment of the Thai version of National Institute of Health Stroke Scale (NIHSS) and a Validation Study

National Institutes of Health Stroke Scale

The level of stroke severity as measured by the NIH stroke scale scoring system:

0= no stroke

1-4= minor stroke

5-15= moderate stroke

15-20= moderate/severe stroke

21-42= severe stroke

*scores greater than 4 points to be treated with tPA


Diagnostic Tests


Non contrast brain CT or brain MRI

Blood glucose

Serum electrolytes/renal function tests

ECG

Complete blood count, including platelet count*

Prothrombin time/international normalized ratio

(INR)*

Activated partial thromboplastin time*

Oxygen saturation


Brain and Vascular Imaging

Both CT and MRI are options for imaging the brain

CT is relatively insensitive in detecting acute and small cortical or subcortical infarctions, especially in the posterior fossa

Limitations of MRI include cost, limited availability,

and patient contraindications such as claustrophobia, cardiac pacemakers, or metal implants

door-to-interpretation time of 45 minutes

(candidates for rtPA)


Non–Contrast-Enhanced CT Scan


Management

Admission

Approximately 25% of patients may have

neurological worsening during the first 24 to 48 hours

after stroke. It is difficult to predict which patients

will deteriorate


Admission

goals of treatment after admission

1. observe for changes in the patient’s condition that might prompt initiation of medical or surgical interventions

2. provide observation and treatment to reduce of bleeding complications after the use of rtPA

3. facilitate medical or surgical measures aimed at improving outcome after stroke

4. begin measures to prevent acute complications

5. plan for long-term therapies to prevent recurrent stroke

6. start efforts to restore neurological function through rehabilitation and good supportive care


Nutrition and Hydration

Some patients cannot receive food or fluids

because of impairments in swallowing or mental status

An assessment of the ability to swallow is important

before the patient is allowed to eat or drink

A water swallow test performed at the bedside is a

useful screening tool


Activity

Most patients are first treated with bed rest,

but mobilization usually begins as soon as the patient’s

condition is considered stable


EKG

Electrocardiography is routinely performed. To detect

paroxysmal atrial fibrillation, ambulatory monitoring

is useful.

N Engl J Med 366;20 nejm.org may 17, 2012

General Supportive Care

Ventilatory Support:monitored with pulse

oximetry with a target oxygen saturation level ≥ 92%

Temperature: ≤38o

Cardiac Monitoring: cardiac monitoring for at least

the first 24 hours

Hyperglycemia: desired level of blood glucose

has been in the range of 80 to 140 mg/dL



Arterial Hypertension

<185/110 :if eligible for rtPA

<180/105 :24 hours after rtPA

<220/120 :if NOT eligible for rtPA



Patient is eligible for treatment with intravenous

rtPA

Labetalol 10 to 20 mg IV over 1 to 2 minutes, may

repeat x1

Nicardipine infusion, 5 mg/h, titrate up by 2.5 mg/h at

5- to 15-minute, maximum dose 15 mg/h; when

desired blood pressure attained, reduce to 3 mg/h

If blood pressure does not decline and remains > 185/110 mm Hg, do not administer rtPA


General Supportive Care Blood pressure during and after treatment with rtPA

or other

Labetalol 10 mg IV over 1 to 2 minutes, may repeat

every 10 to 20 minutes, maximum dose of 300 mg

Nicardipine infusion, 5 mg/h, titrate up to desired

effect by increasing 2.5 mg/h every 5 minutes to

maximum of 15 mg/h

goal would be to lower blood pressure by ~15% during the first

24 hours after onset of stroke


Intravenous Thrombolysis

Recombinant Tissue Plasminogen Activator

Intravenous rtPA (0.9 mg/kg, maximum dose 90 mg) is

recommended for selected patients who may be treated

within 4.5 hours of onset of ischemic stroke

should be aware of the potential side effect of angioedema that

may cause partial airway obstruction



AHA/ASA Stroke 2007; 38:1655.

N Engl J Med 2008; 359:1317. AHA/ASA Stroke 2009 May 28

Inclusion criteria

Clinical diagnosis of ischemic stroke causing measurable

neurologic deficit with the onset of symptoms <4.5 hours

before beginning treatment; if the exact time of stroke onset is

not known, it is defined as the last time the patient was known to be normal




Exclusion criteria

Historical

Stroke or head trauma in the previous 3 months

Any history of intracranial hemorrhage

Major surgery in the previous 14 days

Gastrointestinal or urinary tract bleeding in the previous 21 days

Myocardial infarction in the previous 3 months

Arterial puncture at a noncompressible site in the previous 7 days

For treatment from 3 to 4.5 hours,

additional relative exclusions (where the risk/benefit ratio is less clear) are age >80 years and/or a combination of both previous stroke and diabetes mellitus




Exclusion criteria

Clinical

Spontaneously clearing stroke symptoms

Seizure at the onset of stroke is an exclusion if the residual impairments are

due to postictal phenomenon

Symptoms of stroke suggestive of subarachnoid hemorrhage

Persistent blood pressure elevation (systolic ≥185 mmHg, diastolic ≥110

mmHg)

Active bleeding or acute trauma (fracture) on examination


additional relative exclusions (where the risk/benefit ratio is less clear) is an NIH Stroke Scale score of >25




Exclusion criteria

Laboratory

Platelets <100,000/mm3**

Serum glucose <50 mg/dL (<2.8 mmol/L)

International normalized ratio (INR) >1.7 if on oral

anticoagulant**

Elevated partial thromboplastin time (aPTT) if on heparin**


additional relative exclusions (where the risk/benefit ratio is less clear) is oral anticoagulant use regardless of INR




Exclusion criteria

Head CT scan

Evidence of hemorrhage

Evidence of a multilobar infarction with hypodensity involving

>33 percent of the cerebral hemisphere

Intra-Arterial Thrombolysis

Recombinant prourokinase

is an option for treatment of selected patients who have major

stroke of < 6 hours’ duration due to occlusions of the MCA and

who are not otherwise candidates for intravenous rtPA


Antiplatelet Agents

The oral administration of aspirin (initial dose is 325

mg) within 24 to 48 hours after stroke onset is recom-

mended for treatment of most patients

The administration of clopidogrel alone or in

combination with aspirin is not recommended for the

treatment of acute ischemic stroke


Anticoagulants

early administration of either heparin or a LMW

heparin/danaparoid is associated with an increased

risk of bleeding complications


Volume Expansion

Hemodilution with or without venesection and

volume expansion is not recommended for treatment

of patients with acute ischemic stroke

The only possible exception for the use of

hemodilution is in stroke patients with severe

polycythemia


Neuroprotective Agents

At present, no intervention with putative neuroprotec-

tive actions has been established as effective in improv-

ing outcomes after stroke


Surgical Interventions Carotid Endarterectomy: Data on the safety and

effectiveness of carotid endarterecto-my and other operations for

treatment of patients with acute ischemic stroke are not sufficient

to permit a recommendation

Stenting and Clot Extraction: MERCI device is a

reasonable intervention for extraction of intra-arterial thrombi in

carefully

selected patients, the panel also recognizes that the

utility of the device in improving outcomes after stroke

is unclear


MERCI device


Conclusion of Mx Admission (Class I, Level of Evidence A)

water swallow test performed at the bedside (Class

I, Level of Evidence B)

mobilization begins as soon as the patient’s

is considered stable (Class I, Level of Evidence C)

rtPA (Class I, Level of Evidence A) or Recombinant

prourokinase (Class I, Level of Evidence B)

ASA within 24-48 hrs. (Class I, Level of Evidence A)

Incorporating rehabilitation (Class I, Level of Evidence A)


Prevention

Aggressive risk-factor management

10 risk factors

1. hypertension

2. current smoking,

3. a high waist-to-hip ratio

4. a high dietary risk score

5. lack of regular physical activity

6. diabetes mellitus

7. excess alcohol consumption

8. psychosocial stress or depression

9. cardiac causes

10. high ratio of apolipoprotein B to apolipoprotein A1


Secondary prevention 1. blood-pressure lowering

2. cholesterol lowering with Statins

3. antiplatelet therapy


Blood-Pressure Lowering The PROGRESS trial showed a greater reduction

in the risk of stroke and other vascular outcomes among

patients treated with a combination of an ACE inhibitor

and a diuretic than among those treated with an ACE

inhibitor alone


Cholesterol Lowering Statin therapy with intensive lipid-lowering effects is

recommended to reduce risk of stroke and cardiovascular events

among patients with ischemic strokeor TIA who have evidence of

atherosclerosis, an LDL-C level >100 mg/dL, and who are

without known CHD

For patients with atherosclerotic ischemic stroke or

TIA and without known CHD, it is reasonable to target

a reduction of at least 50% in LDL-C or a target LDL-C

level of <70 mg/dL

Stroke; published online Oct 21, 2010

Cholesterol Lowering Cholesterol lowering with statin drugs, which is

effective in primary stroke prevention, has also

proved effective in secondary prevention after

stroke or TIA

simvastatin (at a dose of 40 mg per day)

atorvastatin (at a dose of 80 mg per day)

Despite the overall benefit, statins have been associated with a slightly

increased risk of intracerebral hemorrhage, and their use may be

contraindicated in patients with the disorder


Antiplatelet Therapy Low doses of aspirin (ranging from 75 to 325 mg

per day) appear to be as effective as higher doses in

reducing the risk of stroke, with a lower risk of

gastrointestinal toxic effects

Current guide-lines indicate that

Aspirin alone (50 mg/d to 325 mg/d) or

Clopidogrel (75 mg/day)

combination of aspirin 25 mg and extended-release

dipyridamole 200 mg twice daily


Antiplatelet Therapy The addition of aspirin to clopidogrel increases

the risk of hemorrhage and is not recommended for

routine secondary prevention after ischemic stroke

For patients who have an ischemic stroke while

taking aspirin, there is no evidence that increasing the

dose of aspirin provides additional benefit


Carotid Endarterectomy and Carotid-Artery Stenting

Carotid endarterectomy is indicated for the

treatment of patients with a history of TIA or

nondisabling ischemic stroke who have

high-grade (70 to 99%) carotid stenosis or

selected cases,moderate (50 to 69%) stenosis


Atrial Fibrillation and Anticoagulation

Dose-adjusted warfarin has been the mainstay of

therapy

For patients with ischemic stroke or TIA with

paroxysmal (intermittent) or permanent AF, antico-

agulation with a vitamin K antagonist (target INR 2.5;

range, 2.0 to 3.0) is recommended


Atrial Fibrillation and Anticoagulation

Newer oral anticoagulant strategies, which do

not require monitoring, are now available and are

likely to replace warfarin in many cases


Take home messages Always R/O Stroke Mimics

Last seen normal, NOT first seen abnormal!

oral administration of aspirin (initial dose is 325

mg) within 24 to 48 hours after stroke onset

combination antiplatelet therapy was

recently terminated

secondary prevention: BP lowering,cholesterol lowering, and antiplatelet therapy


Thank you

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