2-Minute Neuroscience: Stroke Video Lecture | A-Z Guide to Neuroscience - Personal Learning

Welcome to 2 minute neuroscience, where I
explain neuroscience topics in 2 minutes or
less.
In this installment I will discuss stroke.
Stroke occurs when blood flow to part of the
brain is suddenly disrupted.
It is the second leading cause of death in
the world.
There are two major categories of stroke:
ischemic and hemorrhagic.
Ischemia is a term that refers to a reduction
in blood supply to a bodily tissue, and ischemic
strokes occur when blood flow to a part of
the brain is blocked or restricted.
This is most commonly due to a blood clot
blocking a blood vessel.
When a blood clot forms in same area where
the blockage occurs, it is known as a thrombus.
When a blood clot forms at a distant site
and then travels to another part of the body
or the brain to block a blood vessel, it is
known as an embolus.
Hemorrhagic stroke occurs when a vessel begins
to bleed into the brain.
This might happen, for example, if an aneurysm
bursts or if a small artery ruptures in someone
with chronic hypertension.
Hemorrhagic stroke can lead to ischemia when
blood supply to an area of the brain is disrupted,
but it can also result in tissue damage due
to blood collecting outside of blood vessels.
In either case, when neurons are deprived
of the oxygen and glucose found in blood,
mechanisms that are dependent upon energy
begin to fail.
This can result in a series of biochemical
reactions that cause the death of neurons
and an area of dead tissue called an infarct,
a term that refers to tissue that has died
due to a loss of blood supply.
The symptoms of a stroke vary depending on
the artery affected and the area of the brain
it supplies.
Some common symptoms include weakness and
loss of sensation on the side of the body
opposite where the stroke is occurring---especially
in the face and arm, visual impairment, speech
difficulties, confusion, loss of balance or
coordination, and severe headache.