Week 5: Alterations in Cerebral Function Flashcards
Agnosia
can’t recognize familiar objects
Agnosognosia
fail to recognize themself. May not recognize half the body, or that they’ve even had a stroke.
Aphasia
inability to understand and speak
apraxia
the inability to move purposefully
ataxia
impaired gait
dysphagia
impaired swallowing
hemianopsia
ex: right sided stroke, can’t see on left vision field
hemiplegia
half of body has paralysis or weakness
pneumbra
around where the ischemia is. It’s the area we hope we can salvage
subluxation
partial dislocation of the shoulder on the opposite side of the stroke
non-modifiable risk factors of stroke
- AGE: 55 and older – incidence doubles every decade
- GENDER: Men
- RACE: African Americans 2X more likely than Caucasians
modifiable cva risk factors
- Hypertension – major risk factor
- A-Fib
- Hyperlipidemia
- Diabetes
- Smoking
- Carotid Stenosis, valvular heart disease
- Obesity
- ETOH – excessive consumption
- Periodontal Disease
- Sudden loss of function resulting from disruption of the blood supply to the brain
- Accounts for 80% of Brain Attacks
- Needs to be treated early to have fewer stroke symptoms, less loss of function, less permanent loss, etc.
- Causes – 1. atherosclerotic plaques in the large blood vessels of the brain result in thrombus formation and occlusion at site, and result in ischemia and infarction
Type of CVA?
ischemic brain attack
ISCHEMIC BRAIN ATTACK – CAUSES
- several small vessels affected, but they are ones that penetrate deeper into the brain (small penetrating artery thrombotic attack)
- heart can throw clots (a-fib, etc.)
- other causes: some are just unknown, illicit drug use, coagulopathies, spontaneous dissection of the carotid artery
- Disruption of cerebral blood flow because of an obstruction of a blood vessel
- This starts a series of events known as the Ischemic Cascade
Type of cerebral attack?
Thrombus related cerebral attack
THE ISCHEMIC CASCADE, describe?
- Blood flow decreases to a point where neurons are no longer able to maintain aerobic respiration
- So the mitochondria in the cells switch to anaerobic respirations (less efficient)
- Anaerobic respirations causes a large amount of lactic acid to be produced
- The large amount of lactic acid causes a change in the pH level (acidosis)
- Anaerobic respirations cause less ATP to be produced (because it is less efficient system), and depolarization of the cells is inhibited
- Ultimately the process leads to cellular death
Penumbra
- an area of low cerebral blood flow around the site of the infarction
- It is an area of ischemic brain tissue that can be saved with timely intervention
If ischemic cascade continues?
- it threatens the area of the penumbra also, causing cell death in that area and enlarging the infarction
- If this happens , it is called “extending the stroke”
Clinical manifestations of stroke
- Symptoms depend upon the location and size of the affected area
- Numbness or weakness of face, arm, or leg, especially on one side - Hemiplegia, Hemiparesis
- Aphagia, Drooping of 1 side of mouth
- Confusion or change in mental status
- Trouble speaking or understanding speech – Dysarthria, Aphasia (expressive vs. receptive)
- Difficulty in walking, dizziness, or loss of balance or coordination, Apraxia
- Sudden, severe headache (more hemmorrhagic)
- Perceptual disturbances – Hemianopsia, Agnosia
Spot a stroke saying?
FAST
- facial drooping
- arm weakness
- speech difficulty
- time to call 911
- Temporary neurological deficit resulting from a temporary impairment of blood flow
- “Warning of an impending stroke”
- Diagnostic work-up is required to treat and prevent irreversible deficit
Type of stroke?
TIA: transient ischemic attack
Medical managment of stroke
- ABC’s, stabilizing the pt., and preventing complications
- Mainly focusing on preventing extending the attack, and secondary prevention
- t-PA Tx
- Carotid Stents
- Carotid Endarterectomy
- Medications
- Innovations in Treatment: Clot removal catheter, Laser Treatments to the prenumbra
TPA what it does, time frame, contraindications
- Dissolves the clot - Works by binding fibrin, and converts plasminogen to plasmin, which stimulates fibrinolysis of the clot
- Must be given within 3 hrs of the onset of the attack
- Revascularization of necrotic tissue (>3 hrs) increases the risk for cerebral edema and hemorrhage
- Leads to a decrease in the size of the attack and an overall improvement in outcome