Cerebrovascular Disorders PDF

Jason Ryan, MD, MPH  Ischemic (80%) Insufficient blood flow Thrombosis, embolism, hypoperfusion Symptom onset over hours Hemorrhagic (20%) Brain bleeding Sudden onset Best first test: Non-contrast CT of head Main Cerebral Arteries: MCA, ACA, PCA MCA: Upper limb, face...

Jason Ryan, MD, MPH  Ischemic (80%) Insufficient blood flow Thrombosis, embolism, hypoperfusion Symptom onset over hours Hemorrhagic (20%) Brain bleeding Sudden onset Best first test: Non-contrast CT of head Main Cerebral Arteries: MCA, ACA, PCA MCA: Upper limb, face ACA: Lower limb PCA: Vision Image courtesy of Wikipiedia and OpenStax College  Caudate Putamen Globus Pallidus Internal Capsule Thalamus  A 75-year-old man presents with recent onset loss of movement of his right arm. The right side of his face also droops and there is drooling from the corner of his mouth on the right side. He has difficulty speaking.  Most common site of stroke Contralateral motor/sensory sx Arm>leg, face Spastic (UMN) paralysis If left sided Aphasia Speech center is left sided most patients If right (nondominant) side Hemineglect Facial Motor Nucleus Pons  Upper face: Dual UMN supply; right & left Lower face: Single UMN supply Contralateral Motor Cortex Fibers run in corticobulbar tract MCA stroke damage  UMN damage Upper face intact (dual supply) Lower face affected Image courtesy of Wikipiedia and Lucien Monfils  A 75-year-old man presents with acute loss of ability to move his right hip and leg. On exam, he has decreased sensation to pinprick and vibration of his right leg.  Left ACA stroke Leg>Arm Second most common stroke site Medial cortex (midline portion) Leg-foot area (motor and sensory)  An 80-year-old man presents with acute visual loss. He reports difficulty seeing objects on his right side. His wife said he also reports seeing people who are not in the room. On exam, there are no motor or sensory deficits. Visual fields are shown below (black = no vision).  Posterior portion of brain Visual cortex Visual hallucinations Visual agnosia (seeing things but can’t recognize) Contralateral hemianopia with macular sparing  Left PCA Stroke Left Optic Tract Lesion Right visual loss L Eye R Eye Right PCA Stroke Right Optic Tract Lesion Left visual loss Left Right Posterior Posterior Lobe Lobe  Macula: central, high-resolution vision (reading) Dual blood supply: MCA and PCA PCA strokes often spare the macula  PCA  lateral thalamus Contralateral sensory loss: face, arms, legs Proprioception deficit: loss of balance, falls No motor defects Chronic pain contralateral side Thalamus  Loss of CNS blood flow Loss of consciousness