Stroke 101 – Overview of Anatomy and Pathology
Robin Raju, DO
Medical Director
St. Luke’s Acute Rehabilitation Center
Objectives
Basic classification of stroke events Common types of ischemic stroke Ischemic stroke mechanisms Locate the damage from a stroke based on
the patient’s presentation
Differential diagnosis
Acute interventions
Cerebrovascular Accident
Sudden or rapid onset of focal neurological deficit or symptoms
TIA not only on the basis of duration but also on the absence of acute infarct on brain imaging
Types of Stroke
Stroke
Atheroscleroticvascular
disease 20%
HypotensionArtery-artery
emboli
Penetrating artery disease(lacunes) 25%
Cardiogenic embolism 20%
Cryptogenic stroke 30%
Unusual causes 5%
Primary Hemorrhage
15%
Ischemic Stroke 85%
Thrombotic vs Embolic
Anatomy
Basal Ganglia
Caudate nucleus
Internal capsule
Putamen
Globus Pallidus
Amygdaloid complex
Corpus Callosum
Circulation
Right Hemisphere Stroke
Both cortical and subcortical strokes: Lt hemiparesis
Lt sensory loss
Cortical strokes also include: Lt spatial neglect
Lt homonymous hemianopsia
Impaired Lt conjugate gaze
Left Hemisphere Stroke
Both cortical and subcortical strokes: Rt hemiparesis
Rt sensory loss
Cortical strokes also include: Aphasia
Rt spatial neglect
Rt homonymous hemianopsia
Impaired Rt conjugate gaze
Deep Subcortical Strokes
Hemiparesis (pure motor) or sensory loss (pure sensory)
Dysarthria and clumsy-hand with dysarthria
Ataxic hemiparesis
No cognitive, visual or language abnormalities
Brain Stem - The “D’s”
Motor or sensory loss in 4 limbs Crossed signs (same side of face and opposite on
body) Dysconjugate gaze Dizziness/Disequilibrium
Nystagmus Ataxia
Dysarthria Dysphagia Deafness (Change in hearing)
Differential Diagnosis
Unrecognized seizures
Confused states, psychiatric disorders
Syncope
Toxic/metabolic derangements
Tumors, abscess and subdural hematoma
Migraine
Meningitis, encephalitis
Clinical EvaluationHistory
Past history TIA/Stroke
Time of onset
Activity at onset
Temporal progression
Accompanying signs
Risk factors for vascular disease
Non atherosclerotic conditions
Clinical EvaluationPhysical exam
ABC’s
Signs of trauma
Neck stiffness and bruits
Cardiac auscultation
Abdomen - aneurysm, bruits
Peripheral vascular exam
Clinical Evaluation-Initial studies
CT acutely/MRI in selected Pts
EKGGlucose/ElectrolytesBUN/CrCBC/platelet countPT/INRPTTLFT
ToxicologyBlood AlcoholPregnancy testO2 saturation/ABGCXRLPEEG
Clinical Evaluation-Later studies
MRI contrast, MRA/CTA
Carotid duplex ultrasound
Angiography
Echocardiogram (TTE/TEE)
EEG
Cardiac monitoring
Labs: lipid panel, RPR, ESR/C-reactive protein, ANA, anticardiolipin antibodies, homocysteine, fibrinogen
Interventions
Ischemic core - irreversibly damaged brain tissue
Ischemic penumbra – an area of under perfused but still viable tissue
Interventions
IV administered rt-PA – 3 hour window
IA administered rt-PAEndovascular procedures Secondary stroke preventions
NINDS trial - Effect of IV t-PA at 0-3 Hours
Outcome Likelihood with Placebo Likelihood with t-PA
Good functional outcome (mRS score 0-1) at 3 months
26.5% 42.5% (NNT 7)
Symptomatic intracranial hemorrhage (NINDS definition) at 36 hours
0.6% 6.4% (NNH 17)
Mortality 21% 17% (Not significant)
IV t-PA at >3 hours
t-PA given 3-4.5 hours after stroke onset
Increases risk of symptomatic intracranial hemorrhage and risk of fatal intracranial hemorrhage within 7 days (level 1 evidence)
Might increase 90-day mortality (level 2 evidence) while effect on improving functional outcomes is uncertain and inconsistent across trials
Intra-arterial t-PA
Considered beneficial for selected patients with major ischemic stroke < 6 hours old due to proximal cerebral artery occlusion and not eligible for IV t-PA (level 2 evidence)
May reduce disability but increase risk of intracranial hemorrhage (level 2 evidence)
References:
Ropper, Allan H., Martin A. Samuels, Raymond D. Adams, and Maurice Victor. Adams and Victor's Principles of Neurology. New York: McGraw-Hill Medical, 2005. Print.
"Anatomy of Brain - Netter Medical Images." Anatomy of Brain - Netter Medical Images. Web. 26 Jan. 2015.
"Acute Management - Stroke." www.dynamed.com. Web. 26 Jan. 2015.
Dachs, Robert J., John H. Burton, and Jeremy Joslin. "A User's Guide to the NINDS Rt-PA Stroke Trial Database." PLoS Medicine 5.5 (2008): E113. Web.
Bhidayasiri, Roongroj, Michael F. Waters, and Christopher C. Giza. Neurological Differential Diagnosis: A Prioritized Approach. Malden, MA: Blackwell, 2005. Print.