What is a cerebral vascular accident?
Stroke:
Distrubance of blood supply
What are the two types of strokes?
- Bleed: leakage from blood vessels
*Most fatal - Block: blood can’t get through vessels (ischemia)
*Most common
What structures are vulnerable to a hemorrhagic stroke?
Stroke due to aruptured vessel because of:
- *Aneurysm:**
- Abnormal expansion weakens vessel
- Especially at bifurcations
- *Arteriovenous Malformation:**
- Abnormal connection between arteries and veins
What are the usual causes of Ischemic stroke?
- *Thrombosis:**
- Block from clot formed in vessel
- Develops slowly
- *Stenosis:**
- arteriosclerosis: gradual thickening of vessel walls
- *Embolism:**
- dislodged clot, air bubble, fat particle
- Develops rapidly
What CNS issues can result from cardiac arrest?
Cerebral vascular accident (stroke) due to cessation of blood flow to CNS
- lack of energy to maintain ion pumps in membranes
- Edema: swelling of cells in brain
What are transient ischemic attacks (TIA)?
Similar to stroke, but temporary
- Usually resolve within a day
- Clinical follow-up very important b/c it may be a warning of a larger stroke to come
What are symptoms of a TIA?
Symptoms vary with site of blood supply deficit:
- Motor or sensory symptoms
- visual
- memory (transient global amnesia due to ischemia in hippocampus)
What are medical concerns to consider after a TIA?
- subsequent stroke
Cause of TIA:
- Atherosclerosis
- Cardiovascular disease
What are the two main arterial sources of the brain?
- internal carotid artery
- Vertebral artery
What are the branches of the vertebral artery?
- Anterior spinal artery
- Bulbar artery
- Posterior Inferior Cerebellar Artery (PICA)
- Basilar Artery formed by two vertebral arteries
What areas are affected by an anterior inferior cerebellar artery cerebral vascular accident?
Caudal pontine tegmentum
and
Caudal cerebellum
What areas are affected by an labryrinthine cerebellar vascular accident?
Inner ear: deafness
and
Vertigo
What areas are affected by a paramedian arteries (those along the basilar artery)?
Medial pons
(CST, VI N., & Nuc.)
What is the “watershed area” of the cerebral artery supply to the cortex?
It’s a junctionl area between blood supplies
–> these areas of the brain could potentially get blood supply from either of the cerebral arteries bordering it
What artery should be considered if a patient presents with leg motor and sensory deficits?
Anterior cerebral artery
What artery should be considered if a patient presents with face and arm motor and sensory deficits?
Middle cerebral artery
What artery should be considered if a patient presents with leg, arm, and face motor and sensory deficits?
Consider a capsular cerebral vascular accident:
Lateral striats
Medial striats
or
Anterior Choroidal
