Causes of Brain Dysfunction Flashcards
Cause of brain dysfunction
- Stroke
- Tumours, infections, toxins
- Traumatic brain injury and concussion
The brain is highly vulnerable to disturbances in blood supply - what can happen after seconds?
Blood vessels of the brain
neurological symptoms
The brain is highly vulnerable to disturbances in blood supply - what can happen after minutes?
irreversible damage
Cerebral arteries supply specific territories (3)
- Anterior cerebral artery: supplies to the front of the cortex (anterior side)
- Middle cerebral artery: supplying between anterior and posterior
- Posterior cerebral artery: supplying blood to posterior region
Stroke
neurological symptoms or signs resulting from diseases involving blood vessels
What happens to the actual brain tissue following a stroke?
- Infarct = dead or dying tissue (not getting any meaningful blood supply)
- Penumbra = dysfunctional area surrounding the infarct; this tissue may either recover or die
- Increase in infarct can show progressive “dying” of brain tissue
Strokes are the _ leading cause of death in Canada
3rd
_ of people 65+ in Canada have had a stroke
10%
Signs of stroke: F.A.S.T.
- Face
- Arms
- Speech
- Time (to call 911)
Consequences of strokes are varied but include (4)
- memory (amnesia),
- language (aphasia),
- motor function (paralysis),
- consciousness
Stroke risk factors
- High blood pressure
- High cholesterol
- Diabetes
- Smoking
- Cardiovascular conditions
- Psychosocial stress (what happens to you in your life)
What can count as psychosocial stress?
Lack of access to quality food, inadequate public health education, and experiences of discrimination all increase risk and worsen outcomes
Strokes are either
- Ischemic = blockage of a blood vessel
- Hemorrhagic = bleeding from a vessel
Types of ischemic stroke
Ischemic stroke
- Thrombosis
- Embolism
- Arteriosclerosis
Thrombosis
Types of ischemic stroke
Ischemic stroke
Thrombosis: occlusion due to blood clot or other substance
Embolism
Types of ischemic stroke
Ischemic stroke
results from a moving Thrombus; formed from somewhere else (EX: remaining matter - fat, oil, air bubble - from a surgery)
Where can either (thrombosis or embolism) form?
Ischemic stroke
arterial or venous
Arteriosclerosis
Types of ischemic stroke
Ischemic stroke
thickening, hardening, and narrowing of arteries due to fatty plaque build up (associated with high cholesterol) (“artery” + “hardening”)
Damage due to ischemic stroke (3)
Ischemic stroke
- Takes a while to develop (hours to days)
- Some brain areas are more vulnerable (e.g., hippocampus)
- Multiple mechanisms of damage
Multiple mechanisms of damage
Ischemic stroke
- Excitotoxicity
- Cell death signaling
- Neuroinflammation
- Oxidative stress
Excitotoxicity
Multiple mechanisms of damage
excessive glutamate release, which is hard on the cells (binding to NMDA receptors)
Cell death signaling
Multiple mechanisms of damage
triggering a pathway of cell death
Neuroinflammation
Multiple mechanisms of damage
triggers microglia to clean up dead neurons
Oxidative stress
Multiple mechanisms of damage
As cells break apart, they start releasing reactive oxygen species that can damage other cells