Lecture 16 - Acute Stroke Flashcards
What is a stroke/CVA
Interruption of cerebral blood flow resulting in cell death (infarction) and loss of brain function
What are 5 warning signs of a stroke
What causes strokes in young adults
What are the stroke outcomes
What is the recurrence of strokes
What are some modifiable and non-modifiable risk factors of stroke
Majority of individuals will have [blank] impairment following a stroke
Moderate-severe
Risk of stroke reoccurrence [blank] over time
Increases
Diet/Inactivity are examples of [blank] risk factors
Modifiable
Does the brain require higher or lower blood flow
Higher (50 cc/100 gm/min) and if blood flow decreases below 15 cc, neuron damage/death will occur
What are 3 types of strokes
- Ischemic (87%): artery within the brain is blocked usually do to atherosclerosis (plaque build up). It can be thrombotic (60%) or embolic (30%) and cause generalized hypoperfusion. Can be TIA’s and lacunar stroke also.
- Hemorrhagic (13%): Artery bursts within or just outside the brain leading to increased pressure causing a cascade of cell death and inflammation. Typically occurs in the basal ganglia, brain stem, cerebellum, or cortex and can be caused by hypertension.
- Other (Dissection): cervical extension and rotation = dissect an artery (vertebral) -> usually traumatic injury or accident
Severity and symptoms of strokes are related to (4)
Explain the ischemic core and penumbra
Red = core area where stroke occurs (ischemic core) = most tissue will die here
Ischemic Penumbra (other colors) = inflammatory cascade occurs because of stroke bringing additional fluid to the area causing compression of other areas of the brain impacting the brain function in this area. This tissue is salvable with intervention and time is crucial to catching a stroke to reduce amount of tissue affected by ischemic penumbra.
Compare thrombotic vs embolic strokes
Lacunar strokes
Small vessel thrombotic strokes that can be symptomatic or silent/asymptomatic in non-cortical areas of the brain (basal ganglia, subcortical white matter, pons) and is most commonly caused by hypertension and diabetes mellitus (other risk factors: smoking, LDL levels, PAD) and results in decreased cognition and post-stroke dementia
Transient Ischemic Attacks
Transient episode of neurological dysfunction due to focal ischemia without acute infarction or tissue injury that is less than 1 hour and is of sudden onset with similar stroke symptoms. It can be a warning sign for ischemic stroke with highest risk being within the first 4 hours. Treatment is focused on reducing risk of stroke.
What are 2 complications post-ischemic stroke and there signs and symptoms
Intracerebral hemorrhage
Rupture of small arteries within the brain increased intracranial pressure caused by hypertension, trauma, vascular malformations, amyloid angiopathy, and anticoagulated medications. Signs and symptoms (increase over time) are headache, nausea, vomiting, decreased level of consciousness, and papilledema.
NOTE:
Do not want to increase blood flow to the brain when it is already under a lot of pressure (increased ICP)
Subarachnoid Hemorrhage
Rupture in subarachnoid space that is caused by either traumatic or non traumatic injuries. Signs and symptoms include severe headache, nausea, vomiting, nuchal rigidity, photophobia, and possible cranial nerve impairment
What are 4 types of brain hemorrhages
Aneurysms
Artery dilations that occur in weak points in the brain circulation (85% in anterior circulation especially in circle of willis). Can be small, med, or large and most are saccular (berry), but can also be fusiform (circumferential) Not all will rupture and but an increased risk of rupturing could be due to increased hypertension, smoking, larger size of aneurysm, location, growth, family history or a previous rupture.
Locations for strokes (NEED TOO KNOW)
What happens if there is a stroke in the middle cerebral artery
-Contralateral face and UE motor impairment (possible sensory)
What happens if there is a stroke in the anterior cerebral artery
Contralateral LE motor and sensory impairment, executive function (planning, working memory), emotions, possible frontal lobe reflexes (eg. Glabellar, snouting)
What happens if there is a stroke in the posterior cerebral artery
Contralateral homonymous hemianopia, possible contralateral motor and sensory impairment
What happens if there is a stroke in the cerebellar artery
Ataxia, dizziness, tremors (test to use would be dysdiakonesia)
Spinal Strokes
Rare because there is a high degree of collateral circulation in the spine but can be due to arthrosclerosis in the aorta and a significant increased risk with thoracoabdominal aortic surgery. More common in the anterior spinal artery than posterior spinal artery
NOTE:
Anterior spinal artery: spinothalamic and corticospinal tracts
Posterior Spinal Arteries: supplies dorsalcolumn tracts
The most common type of stroke is
Ischemic
Ischemic strokes can undergo [blank] transformation
Hemorrhagic
Normal intracranial pressure is
> 10 mmHG -> high is 25 mmHg
What are 2 stroke prevention surgeries
Carotid Endarterectomy = CEA
Carotid Angioplasty and Stenting = CAS
What are strategies we use to determine the type of stroke