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 Atherosclerotic vascular disease 20% Hypotension Artery-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

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 Evaluation History  Past history TIA/Stroke  Time of onset  Activity at onset  Temporal progression  Accompanying signs  Risk factors for vascular disease  Non atherosclerotic conditions

Clinical Evaluation Physical 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  EKG  Glucose/Electrolytes  BUN/Cr  CBC/platelet count  PT/INR  PTT  LFT  Toxicology  Blood Alcohol  Pregnancy test  O2 saturation/ABG  CXR  LP  EEG

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-PA  Endovascular procedures  Secondary stroke preventions

NINDS trial - Effect of IV t-PA at 0-3 Hours OutcomeLikelihood with PlaceboLikelihood 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) Mortality21%17% (Not significant)

IV t-PA at >3 hours  t-PA given 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, Print.  "Anatomy of Brain - Netter Medical Images." Anatomy of Brain - Netter Medical Images. Web. 26 Jan  "Acute Management - Stroke." Web. 26 Jan  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, Print.