Stroke: Pathology and medical management

Question 1

Stroke

Answer 1

 Sudden loss of neurological function caused
by an interruption of blood flow to the brain
 Due to clot (ischemic stroke)
 Due to rupture of blood vessel (hemorrhagic
stroke)
 Neurological disturbance lasts > 24 hours
 Symptoms resolve within 24 hours =TIA
 Transient ischemic attack, “mini stroke”

Question 2

Prevalence of Stroke

Answer 2

 2.7% men, 2.5% women≥18 yrs have history of stroke

Question 3

Incidence of stroke

Answer 3

 ~795,000 each year
 610,000 first attacks
 185,000 recurrent attacks
 Someone in the US has a stroke every 40 sec

Question 4

Mortality of Stroke

Answer 4

Someone dies of stroke every 3‐4 mins
 1/17 deaths inUS (2005)
 53% deaths out of hospital
 3rd leading cause of death

Question 5

Types of Stroke

Answer 5

1. ) Ischemic stroke (infarct)
   - 87% all strokes
   - Blockage in blood vessel
2. ) Hemorrhagic stroke
   • Intracerebral hemorrhage (10%)
   • Subarachnoid hemorrhage (3%)

Question 6

Ischemic Stroke

Answer 6

Most common type (87% all strokes)
 Blood clot blocks blood flow
 Prolonged ischemia produces infarction
 Atherosclerosis common cause of clots
 “Thrombotic stroke”
Embolus can also cause occlusion in brain
 “Embolic stroke”
 Abrupt onset
 AF (cardioembolic stroke)
 ~20% ischemic strokes are cardioembolic
 Typically have worse prognosis; greater disability

Question 7

Etiology of Ischemic Stroke

Answer 7

Atherothromboemolism (50%)
Small vessel disease (25%)
Cardiac embolism (20%)
Rare causes (5%)

Question 8

General Risk Factors for Ischemic Stroke

Answer 8

Hypertension
 BP<120/80 have half lifetime risk of stroke of
people with HT
 Heart disease, especiallyAF
 AF increases risk ~5‐fold
 % of strokes attributable to AF increases with age
 Diabetes
 65% die from heart disease or stroke

Question 9

Modifiable Risk Factors of Ischemic Stroke

Answer 9

Hypertension
 Heart disease
 Diabetes
 Smoking
 Obesity
 High cholesterol

Question 10

Un-treatable Risk Factors of Ischemic Stroke

Answer 10

 Age
 Sex
 Race
 Prior stroke
 Family history

Question 11

Ischemic Penumbra

Answer 11

• Rapid intervention is
critical
• Ischemic core – cell
death, infarction
• Ischemic penumbra
Restoring blood flow to the
ischemic penumbra can
minimize neurological deficit

Question 12

Infarct Medical Management

Answer 12

 t‐PA
 Tissue plasminogen activator
 Thrombolytic agent breaks up clot
 3‐hour window
 “Time is brain”
 NIH Stroke Scale (NIHSS)
 Quantifies severity
▪ 0‐7mild
▪ 8‐16 moderate
▪ >16severe
 Nature of deficits
 Medical team, acute
 Used in decision making

Question 13

Early warning Signs of Stroke

Answer 13

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

Question 14

Hemorrhagic Transformation

Answer 14

A possible complication of thrombolytic
therapy with t‐PA
 Can occur naturally in the evolution of
cerebral infarction
 Most common after embolic stroke

Question 15

Cerebral Edema

Answer 15

 Begins within minutes of infarction
 Can increase intracranial pressure (ICP)
 Signs of increased ICP:
  consciousness; coma
  HR
 Irregular respirations
 Unreacting pupils
 Vomiting
 Major problem with large infarcts
 Frequent cause of death in acute stroke

Question 16

Hemorrhagic Stroke

Answer 16

 < 20% all strokes
 Abnormal bleeding in the brain
 Caused by head injury or burst aneurysm
 Intracerebral hemorrhage (ICH)
 Bleeding into brain tissue
 Subarachnoid hemorrhage (SAH)
 Blood vessel rupture on brain surface, bleeds into
subarachnoid space
Loss of blood supply affects brain cell
function
 Accumulated blood puts pressure on brain
tissue
 Increased pressure on brain can cause death
 Higher mortality rate than ischemic stroke
 e.g. 38%vs.8‐12%
 Despite greater mortality, recovery among
survivors is often better
 Recovery pattern: slow for first 6 weeks, then
improve rapidly
 Rehab!

Question 17

Etiology of Hemorrhagic Stroke

Answer 17

Intracerebral hemorrhage (ICH)
 High blood pressure
 Aneurysm
 Illicit drugs (e.g. cocaine)
Subarachnoid hemorrhage (SAH)
 Head injuries** (SAH due to head injury is not considered a stroke)
 Spontaneous SAH usually due to burst
aneurysm
 Rupture of arteriovenous malformation

Question 18

Symptoms of ICH

Answer 18

 Sudden rise in ICP (both ICH and SAH)
 Begins abruptly
 Severe headache
 Signs of brain dysfunction
 Confusion, trouble speaking
 Impaired / loss of vision
 Large pupils
 Nausea, vomiting, seizures, loss of
consciousness

Question 19

Symptoms of SAH

Answer 19

Sudden rise in ICP
 “Thunderclap headache”
 Facial / eye pain, double vision, loss of peripheral
vision
 Loss of consciousness
 Sleepy and confused, unresponsive, difficult to
arouse
 May feel restless
 Stiff neck, headaches, vomiting, dizziness, low
back pain
 Fever common first 5‐10 days

Question 20

Complications of SAH

Answer 20

Hydrocephalus
 Vasospasm
 A second rupture

Question 21

Hemorrhage Medical Management

Answer 21

 CT or MRI ± spinal tap
 Very high ICPs are often fatal if prolonged
 Anticoagulants, thrombolytics, and
antiplatelet drugs are NOT given
 Treatments to promote clotting
 e.g. in people taking anticoagulants

Question 22

Cerebral Stroke Syndromes

Answer 22

 Ischemic stroke
 Predict pattern of deficits when blood vessels
become blocked
 Left and right hemisphere differences
 Clinically identifiable subtypes:
 Oxfordshire Community Stroke Project
Classification
 Cerebral artery syndromes

Question 23

Left Cerebral Hemisphere

Answer 23

 Dominant hemisphere
 Speech and language
 Aphasia
 Slow and cautious
 Memory

Question 24

Right Cerebral Hemisphere

Answer 24

Non‐dominant
 Spatial and perceptual
 Unilateral neglect
 Impulsive, poor
judgment
 Short term memory

Question 25

OXFORDSHIRE COMMUNITY

STROKE PROJECT CLASSIFICATION

Answer 25

Total Anterior Circulation
Infarction (TACI)
 Partial Anterior Circulation
Infarction (PACI)
 Posterior Circulation
Infarction (PoCI)
 Lacunar Infarction (LaCI)

Question 26

CEREBRALARTERY STROKE

SYNDROME

Answer 26

Internal Carotid Artery
syndrome
 Anterior Cerebral Artery
syndrome
 Middle Cerebral Artery
syndrome
 Posterior Cerebral Artery
syndrome
 Lacunar syndromes