Here are detailed lecture notes on strokes and other brain lesions based on the new transcript:
Title: Strokes and Other Brain Lesions
I. Strokes
A. Types of Strokes
1. Ischemic Stroke (90% of cases)
- Lack of oxygen due to blocked blood vessel
2. Hemorrhagic Stroke
- Ruptured blood vessel, bleeding into brain tissue
B. Sudden Onset - Defining characteristic of strokes
C. Effects Depend on Location 1. Large vessel blockage → Massive effect on brain area it supplies 2. Small vessel blockage → Minor/No noticeable symptoms
D. Causes of Blocked Vessels 1. Atherosclerotic plaques 2. Arteriovenous malformations
E. Treatment Differences 1. Ischemic - Give blood thinners to restore flow 2. Hemorrhagic - Blood thinners contraindicated, will worsen bleeding
F. Need to Discriminate Stroke Type Without Imaging
G. Neurological Effects Based on Stroke Location - Aphasia, body paralysis, vision loss etc.
II. Tissue Damage Around Stroke A. Ischemia/Hemorrhage → Neuron death in core region B. Treatment targets “penumbra” - at-risk surrounding neurons
III. Other Brain Lesions
A. Tumors
- Can infiltrate brain, destroy neurons
- More gradual onset than stroke
B. Symptoms may appear suddenly after crossing threshold