Stroke: An Introduction

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StrokeAn Introduction

• Maarten Lansberg, MD, PhD
• Neil Schwartz, MD, PhD
• Stanford Stroke Center

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Outline

• Background
• Stroke Diagnosis
• Stroke Treatment
• Stroke Prevention

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What is a Stroke? (Brain Attack)

• Disruption of blood flow to part of the brain
  caused by
• Occlusion of a blood vessel (ischemic stroke)
• OR
• Rupture of a blood vessel (hemorrhagic stroke)

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Types of Stroke
Mohr JP, Caplan LR, Melski JW, et al. Neurology
197828754-62
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Anatomy
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MR Angiogram
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What happens with cutoff of blood supply?

• Oxygen deprivation to nerve cells in the affected
  area of the brain --gt
• Nerve cells injured and die --gt
• The part of the body controlled by those nerve
  cells cannot function.

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What Causes Ischemic Stroke?
Thrombotic
Embolic
Thrombus
Embolus
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Ischemic Stroke
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What happens with rupture of a blood vessel?

• Oxygen deprivation to nerve cells in the affected
  area of the brain and local destruction of nerve
  cells--gt
• Nerve cells injured and die --gt
• The part of the body controlled by those nerve
  cells cannot function.

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Intracerebral Hemorrhage
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Head CT Ischemic or Hemorrhagic Stroke?
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Head CT Ischemic or Hemorrhagic Stroke?
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Stroke Impact

• 750,000 strokes per year
• Third leading cause of death
• (1st heart disease, 2nd all cancers)
• Over 160,000 deaths per year
• Over 4 million stroke survivors
• 1. Williams GR, Jiang JG, Matchar DB, et al.
  Stroke 1999 302523-28.
• 2. Hoyert DL, Kochanek KD, Murphy SL. National
  Vital Statistics Report 1999 4719.

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Stroke Impact (2)

• Leading cause of adult disability
• Of those who survive, 90 have deficit
• Half of all patients hospitalized for acute
  neurological disease.
• Stroke costs the U.S. 30 to 40 billion per year.

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The Stroke Belt
Perry HM, Roccella EJ. Hypertension
199861206-15.
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2. Stroke Diagnosis
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Symptoms of Stroke

• Sudden numbness or weakness of face, arm or leg,
  especially on one side of the body
• Sudden confusion, trouble speaking or
  understanding
• Sudden trouble seeing from one or both eyes
• Sudden unsteadiness, dizziness, loss of balance
  or coordination
• Sudden severe headache with no known cause

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Other Stroke Symptoms

• Also common following stroke
• Depression
• Other emotional problems
• Memory problems

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Common Stroke Patterns

• Left (Dominant) Hemisphere
• Aphasia
• Right hemiparesis
• Right hemisensory loss
• Right visual field defect
• Left gaze preference
• Dysarthria
• Difficulty reading, writing, or calculating

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Common Stroke Patterns (2)

• Right (Nondominant) Hemisphere
• Left hemiparesis
• Left hemisensory loss
• Left neglect
• Left visual field defect
• Right gaze preference
• Dysarthria

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Common Stroke Patterns (3)

• Brainstem/Cerebellum/Posterior Circulation
• Motor or sensory loss in all 4 limbs
• Crossed signs (face vs. body)
• Limb or gait ataxia
• Dysarthria
• Dysconjugate gaze
• Nystagmus
• Amnesia
• Cortical blindness

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Common Stroke Patterns (4)

• Small Vessel (Lacunar) Strokes (Subcortical or
  Brain Stem)
• Pure Motor
• Weakness of face, arm, leg
• Pure Sensory
• Decreased sensation of face, arm, leg

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Differential Diagnosis

• Stroke (ischemic hemorrhagic)
• Intracranial mass
• Tumor
• Subdural hematoma
• Seizure with persistent neurological signs
• Migraine with persistent neurological signs
• Metabolic
• Hyper/Hypoglycemia
• Infectious
• Meningitis / Encephalitis / Cerebral abscess
• Systemic

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3. Stroke Treatment
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Time is Brain
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EMS/ED evaluation of acute stroke

• Assure adequate airway
• Monitor vital signs
• Conduct general assessment
• Evidence of trauma to head or neck
• Cardiovascular abnormalities

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EMS/ED evaluation of acute stroke (cont.)

• Conduct neurological examination
• Level of consciousness (Glasgow Coma Scale)
• Presence of seizure activity
• NIH Stroke Scale

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ED evaluation of acute stroke diagnostic tests

• Non-contrast Head CT
• EKG
• Blood Glucose
• CBC, platelets, PTT, PT/INR
• Serum electrolytes

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t-PA therapy
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tPA therapy for acute stroke

• Candidate for IV tPA?
• Stroke onset lt 3 hours (When was the patient last
  seen at baseline ?)

• Benefit 12 increased chance of good recovery
• Risk bleeding (up to 6)

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tPA exclusion criteria

• Symptoms mild or rapidly resolving
• SBP gt 180 or DBP gt 110
• Blood on head CT
• History of ICH
• CNS tumor or vascular malformation
• Bacterial endocarditis
• Known bleeding disorder
• PTT gt 40 PT gt 15 (INR gt 1.7)
• Stroke within 3 months
• Significant trauma in last 3 months
• GI/GU/Resp hemorrhage within 21 days
• Major surgery within 14 days / minor surgery
  within 10 days
• Peritoneal dialysis or hemodialysis
• Seizure at onset of stroke
• Glucose lt50 or gt400
• Pregnant

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Other therapies for acute stroke

• IV t-Pa outside the three hour window

• IA t-PA
• IA mechanical thrombolysis/thrombectomy
• Neuroprotective agents

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Stroke Management

• If not a candidate for acute intervention, then
  focus on
• Prevention of recurrent stroke
• Diagnostic evaluation for stroke etiology
• Risk factor assessment
• Rehabilitation (PT/OT/SLP)
• Prevention of Complications
• DVT, aspiration PNA, decubitus ulcers, falls

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Diagnostic stroke evaluation

• Purpose Identify location, size, and cause of
  stroke
• Tests may include
• Follow-up head CT
• Brain MRI/MRA
• Carotid ultrasound
• Cardiac echo (transthoracic or transesophageal)
• Cerebral angiogram or CT angiogram
• Lipid panel
• Hemoglobin A1c
• Hypercoagulable tests antiphospholipid
  antibodies, Protein C S, Antithrombin III,
  Factor V Leiden mutation, Prothrombin 20210A
  mutation

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4. Stroke Prevention
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Stroke survivors greatest risk is another
stroke
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Stroke
Heart Attack
14
14
13
13
12
10
10
Percent of patients with events
8
7
6
4
3
3
2
2
CATS
TASS
CAPRIE
ESPS 2
Stroke patient subgroup only (n 6,431)
Albers, G.W. Neurology. 20001454(5)1022-8.
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Transient Ischemic Attack (TIA)

• Stroke symptoms resolve in less than 24 hours
  (most resolve in lt 1 hour)
• Warning sign for stroke and heart attack
• One third go on to have a stroke within 5 years
• Stroke risk can be reduced
• Opportunity to prevent full stroke

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Stroke risk factors
Non - Modifiable

• Age
• Gender (men)
• Heredity family history of stroke,
  hypercoagulable states
• Race/ethnicity (e.g. African Americans)
• Sacco RL, Benjamin EJ, Broderick JP, et al.
  Stroke 1997281507-17.

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Stroke risk factors
Modifiable

• Medical Conditions
• Hypertension
• Heart disease
• Atrial fibrillation
• High Cholesterol
• Diabetes
• Carotid stenosis
• Prior stroke or TIA

• Behaviors
• Cigarette smoking
• Alcohol abuse
• Physical inactivity

Sacco RL. et al. Stroke. 1997281507-1517 Pancio
li AM et al. JAMA. 19982791288-1292
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How many strokes can be prevented?
Adapted from Gorelick PB. Arch Neurol
199552347-55
Based on an estimated 731,000 strokes annually
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HypertensionJNC VII Guidelines
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Lower blood pressure Lower Risk
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PROGRESS Trial
Blood pressure reduction following stroke
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28 relative risk reduction
14
15
Stroke Rate ()
10
10
Placebo
Active
5
0 1 2 3 4
Follow-up time (years)
Progress, Lancet. 20013581033-41
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Risk factor modificationsfor blood
lipidsNational Cholesterol Education Program
(NCEP) Guidelines

• Condition
• Hyperlipidemia or
• atherosclerotic disease
• (LDL gt100 mg/dL)

• Recommendation
• Diet decrease fat and cholesterol
• Exercise
• Add pharmacologic therapy statin agents

Expert Panel on Detection, Evaluation, and
Treatment of High Blood Cholesterol in Adults.
JAMA 19932693015-23.
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Risk factor modifications for DMADA
Recommendations to Reduce Microvascular
Complications

• Average pre-prandial glucose lt120 mg/dL
• Average bedtime glucose 100 to 140 mg/dL
• HbA1c lt7
• 1. Lukovitis TG, Mazzone T, Gorelick PB.
  Neuroepidemiology 1999181-14.
• 2. Diabetes Care 199821 (Suppl 1)1-200

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Lifestyle Risk Factor Modifications

• Lifestyle Factor
• Cigarette Smoking
• Alcohol use
• Physical activity
• Diet

• Recommendation
• Counseling
• Nicotine replacement therapy
• Bupropion
• Up to 2 drinks/day for men, 1 drink/day for
  women, or lighter individuals
• Brisk activity (30 to 60 min/day)
• 5 servings/day fruit and vegetables
• Limit saturated fat (lt30 total energy)

Gorelick PB, Sacco RL, Smith DB, eet al. JAMA
19992811112-1120.
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Prevention of Blood Clot Formation
Müller, 1997
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Medications that prevent strokeBlood thinners

• Anticoagulants
• Coumadin (warfarin)
• Exanta
• Heparins

• Antiplatelet Agents
• Aspirin
• Aspirin/extended release dipyridamole (Aggrenox)
• Clopidogril (Plavix)
• Ticlopidine (Ticlid)

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Aspirin for prevention of stroke

• Aspirin benefit independent of dose and gender

• FDA, AHA ACCP all recommend
• an aspirin dose between 50 and 325 mg/day

Albers GW at al Neurology 199953(suppl.
4)S25-S38 FDA. Federal Register.
19986356802. Albers GW, et al. Chest 2001, 119
300S-320S.
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Choice of medication for stroke prevention
What is the cause of the stroke?
Atherosclerosis
Unknown
Heart
Warfarin (Coumadin)
Antiplatelet therapy
Albers GW, et al. Chest 1998114683S-698S Barnett
HJ et al. N Engl J Med. 19983391415-1425
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Prevention of recurrent stroke Stroke caused by
atrial fibrillation
Relative Risk Reduction
80
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Benefit of aspirin
60
Benefit of warfarin
40
20
15
0
EAFT Study Group Lancet 1993, 342 1255-62
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How to prevent a stroke

• Control treatable risk factors
• Take an anti-platelet agent or an anti-coagulant
• Surgical therapy for carotid stenosis

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Changing the perception of stroke

• MYTH
• Stroke is unpreventable
• Cannot be treated
• Strikes only the elderly
• Recovery ends 6 months after a stroke

• REALITY
• Stroke is largely preventable
• Requires urgent treatment
• Can happen to anyone
• Stroke recovery can continue throughout life

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Stroke Websites

• American Stroke Association
• www.strokeassociation.org
• National Stroke Association
• www.stroke.org
• Stanford Stroke Center
• www.stanford.edu/group/neurology/stroke/