Stroke
Stroke
Stroke
Stroke refers to focal neurological symptoms from a lack of cerebral perfusion (adequate blood flow). Stroke produces permanent brain injury but through brain adaptation, individuals can recover to varying degrees.
A transient ischemic attack (TIA) is a transient phenomena that gets better on its own within 24 hours, without an MRI finding of stroke. Historically TIAs were treated less aggressively but now we lump them together in how we handle their diagnostic work-up and management, so the distinction is functionally unimportant.
Ischemic vs Hemorrhagic Strokes
An ischemic stroke (~85%) is a non-bleeding stroke and a hemorrhagic stroke (~15%) is a bleeding stroke (a "brain bleed").
Embolic vs Thrombotic Infarcts
There are two key types of stroke:
Embolic, which is when a clot travels from the body and becomes lodged in the brain.
Thrombotic, which is when a clot forms within the brain vessel, itself.
Ischemic Stroke Classifications
Review this whiteboard tutorial to learn about Stroke Classifications
Stroke Patterns
There are many patterns of stroke, based on the vessel that is occluded.
Review this lecture primer to learn about various Stroke Syndromes
Here are some helpful localizing materials:
The Circle of Willis
Cerebral Angiography
Use this directory of Stroke Syndromes to review key patterns of stroke.
Stroke Therapies
Emergency stroke therapies are the things we do to reverse the stroke. We have at our disposal IV thrombolytics (currently, tPA and TNK), which are "clot busting drugs" and endovascular therapies (thrombectomy, mechanical clot removal).
To learn about these management capabilities review this lecture primer on Stroke Management.
Initially, there were an extensive number of absolute contraindications to thrombolytics. Over time, we've backed off on these precautions, which means there is a ton of contradicting information in the literature about absolute vs relative contraindications.
See the following calculator regarding contraindications to tpa in ischemic stroke..
Routine Work-Up
A routine diagnostic work-up generally includes a variety of imaging and laboratory tests.
To learn about these tests and preventative treatments, review this lecture primer on Stroke Risk Factors.