Stroke Looking Out, While We Are Looking In

The Initial Management of Ischemic StrokeJeremy Blanchard, MD, FCCP

Kadlec Medical Associates

Intensivist Program, Medical Director

Objectives

Introduction: the importance of stroke Clinical presentation: recognition and the pre-

hospital care Triaging stroke Etiology of stroke Treatment options Summary

Importance of Stroke: Epidemiology

It is estimated 700,000 people in the U.S. have a stroke each year. 200,000 of these are reoccurring strokes This does not account for TIA’s (transient ischemic

attacks). Stroke is the 3rd leading cause of death in the

U.S. and the leading cause of adult disability.

Sacco, et al. Guidelines for Prevention of Stroke in Patients with Ischemic Stroke or Transient Ischemic Attack: a Statement for Healthcare Professionals from the American Heart Association/American Stroke Association Council on Stroke. Circ 2006; 113:e409-449.

Importance of Stroke: Projected Costs of Stroke

The total cost of stroke from 2005-2050 in 2005 dollars is projected to be over $2.2 trillion.

Brown, et al. Projected Costs of Ischemic Stroke in the United States. Neurology 2006; 67:1390-1395.

Importance of Stroke: Definitions The definitions differentiating stroke and TIA

are of less importance because the they are representative of different degrees of disability of the same disease process and require the same interventions for prevention of a second episode. If the neurological deficit lasts less than 24 hours

then the episode is defined as a TIA, if greater then 24 hours then it is defined as a stroke.


Importance of Stroke: Definitions Importance of definitions:

It allows the inclusion of a homogenous population in a clinical research trial. Essential for validity of results

Thus, these definitions effect the care we provide. New definition of TIA: “a brief episode of

neurological dysfunction caused by a focal disturbance of brain or retinal ischemia, with clinical symptoms typically lasting less than 1 hour, and without evidence of infarction.

•Albers, et al. Transient Ischemic Attack: Proposal for a New Definition. NEJM 2002; 284:2901-2906.•Sacco, et al. Guidelines for Prevention of Stroke in Patients with Ischemic Stroke or Transient Ischemic Attack: a Statement for Healthcare Professionals from the American Heart Association/American Stroke Association Council on Stroke. Circ 2006; 113:e409-449.

Clinical Presentation: Diseases Predisposing to Stroke

Hypertension (HTN) It is estimated 50 million Americans have HTN. 30-40% stroke risk reduction with blood pressure

(BP) lowering. Systolic BP reductions have been associated with:

Weight loss Consumption of a diet rich in fruits, vegetables, and low

fat dairy products Regular aerobic physical activity Limited alcohol consumption



Diabetes Mellitus Present in 15-33% of patients presenting with stroke.

Lipids Unlike heart disease the clinical research done in

stroke has shown only a weak association between forms of hyperlipidemia and stroke occurrence.

AHA recommends treatment with lipid lowering drugs as standard care, especially in patients with CHD or symptomatic atherosclerotic disease with a comorbid stroke.



Cigarette Smoking There is strong and convincing evidence that

cigarette smoking is a major independent risk factor for stroke.

This risk is present in all ages, sexes, and among different racial/ethnic groups.

Randomized, controlled trials are not available because of ethical issues.

The risk of stroke decreases with cessation of smoking and is gone in five years.



Alcohol Consumption Controversial

Evidence exists that chronic, heavy drinking is associated with all types of stroke.

No more than 2 drinks per day for men and 1 drink per day for nonpregnent women may be associated with a reduced risk of stroke.


Clinical Presentation: Identifying the Patient with Stroke

Cincinnati Pre-hospital Stroke Scale (CPSS) Tests 3 physical findings:

1. Facial droop (have patient smile or try to show teeth)a. Sometimes comparing to a picture (drivers license can

be helpful)

2. Arm weakness (synonymous with pronator drift, have the patient close their eyes and hold out both arms)

3. Abnormal speech (have patient say, “you can’t teach an old dog new tricks”)

One finding on the CPSS indicates 72% probability of stroke, three abnormal findings increase probability to 85%.

American Heart Association. Advanced Cardiovascular Life Support: Professional Provider Manual . Copy right 2005.

Clinical Presentation: Identifying the Patient with Stroke

Los Angeles Pre-hospital Stroke Screen (LAPSS) Six criteria: age > 45 yrs., Lack of a history of

seizures, duration of symptoms < 24 hours, patient not normally wheel chair/bed bound, blood glucose between 60-400, obvious asymmetry (unilateral) in smile/grimace, grip or arm strength (pronator drift).

If all six are answered yes there is a 97% chance of stroke.


Pre-Hospital Treatment

Identify Signs and Symptoms-CPSS, LAPSS Support ABCs-Oxygen if needed Establish time of stroke if possible-essential for

future treatment options The last time the patient was known to be normal or

at neurological baseline. Alert hospital Assess neurological status-initial and monitor

during transport. Check glucose


Triaging Ischemic Stroke Patients from the Emergency Department

Exam is consistent with stroke , CT of

Head, no evidence of hemorrhage

Supportive care

Greater than

3 Hrs.Less than 3 hours

Therapy Options:•Intravenous thrombolytics•Intra-arterial thrombolysis•Mechanical clot disruption

Etiology of Stroke

Extracranial carotid disease For patients with recent TIA or stroke within the last 6

months and ipsilateral severe (70-99%) stenosis, a carotid endarterectomy by a surgeon with a < 6% perioperative morbidity and mortality is recommended.

Extracranial vertebrobasilar disease Endovascular treatment with stents, angioplasty or

coiling may be considered for repeating symptoms despite medical therapy.


Etiology of Stroke

Cardiogenic embolism Responsible for approximately 20% of ischemic

strokes. Nonvalvular atrial fibrillation in ½ of the cases. Valvular heart disease ¼ of the cases. Left ventricular mural thrombus 1/3 of patients

Arterial Dissection 50% of patients with dissections of the carotid or

vertebral arteries have no clear history of antecedent neck trauma. Recurrent stroke rate is low in this etiology of

stroke.Sacco, et al. Guidelines for Prevention of Stroke in Patients with Ischemic Stroke or Transient Ischemic Attack: a Statement for Healthcare Professionals from the American Heart Association/American Stroke Association Council on Stroke. Circ 2006; 113:e409-449.

Etiology of Stroke

Patent foramen ovale Present in 27% of the general population

Hyperhomocysteinemia Hypercoagulable states Sickle cell disease


Therapy Options: Intravenous Thrombolysis

Recombinant tissue plasminogen activator (rtPA) Intravenous rtPA 0.9 mg/kg maximum dose of 90 mg

for selected patients who may be treated within 3 hours of ischemic stroke onset.

Major side effects include bleeding and angioedema If the patient is hypertensive (SBP >185, DBP >110)

the patient may be eligible is blood pressure is able to be safely lowered with antihypertensive and stays stable.


Characteristics of Patients with Ischemic Stroke Who Could Be Treated with rtPA

Diagnosis of ischemic stroke causing a neurological deficit.

Neurological signs should not be clearing spontaneously. Neurological signs should not be minor or isolated. The symptoms of the stroke should not be suggestive of

a SAH Onset < 3 hours No head trauma, prior stroke, nor MI in the last 3 months No GI or urinary hemorrhage in the last 21 days No major surgery in last 14 days No arterial puncture at a noncompressible site in the

previous 7 days No history of previous intracranial hemorrhage SBP < 185 Hg and DBP < 110 No evidence of active bleeding or acute trauma INR < 1.7, aPTT in normal range Platelet count > 100,000 Blood glucose > 50 mg/dl No seizure with postictal residual neurological

impairment CT does not show > 1/3 of cerebral hemisphere

involvement The patient and family members understand the

potential risks and benefits from treatment


Intra-arterial Thrombolytics

Recombinant prourokinase appears to be of some benefit in treatment of carefully selected patients with acute ischemic stroke secondary to occlusion of the middle cerebral artery (MCA). Not FDA approved and not clinically available

rtPA is used instead of prourokinase It is selected for patients presenting < 6 hours with

MCA occlusion who are not otherwise candidates for intravenous thrombolysis (is a consideration in patients with recent major surgery). Sacco, et al. Guidelines for Prevention of Stroke in Patients with Ischemic Stroke

or Transient Ischemic Attack: a Statement for Healthcare Professionals from the American Heart Association/American Stroke Association Council on Stroke. Circ 2006; 113:e409-449.

Clot Extraction

Mechanical Embolus Removal in Cerebral Embolism (MERCI procedure) FDA approved Clinical utility in improving outcomes of stroke is not

as of yet established. Similar results in one study to the prourokinase

treatment study.

MERCI Retriever Devise

Summary

Stroke is the 3rd leading cause of death in the U.S. and the leading cause of adult disability.

Time is brain. Establishing the suspicion of the diagnosis

allows the receiving institution to prepare for a stroke team activation.

Therapies are being developed to allow alternatives to patients who don’t qualify for thrombolytics.

References

1. Sacco, et al. Guidelines for Prevention of Stroke in Patients with Ischemic Stroke or Transient Ischemic Attack: a Statement for Healthcare Professionals from the American Heart Association/American Stroke Association Council on Stroke. Circ 2006; 113:e409-449.

2. Albers, et al. Transient Ischemic Attack: Proposal for a New Definition. NEJM 2002; 284:2901-2906.

3. Brown, et al. Projected Costs of Ischemic Stroke in the United States. Neurology 2006; 67:1390-1395.

4. American Heart Association. Advanced Cardiovascular Life Support: Professional Provider Manual . Copy right 2005.

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Stroke Looking Out, While We Are Looking In