Exam 1: Alterations of Neurologic Function

Question 1

Cerebrovascular Accident

Answer 1

impairment of one or more vessels in the cerebral circulation -> interrupts blood supply -> ischemia of brain tissue

Question 2

CVA is caused by

Answer 2

thrombosis
embolus
stenosis
hemorrhage

Question 3

CVA: Risk Factors

Answer 3

Age (mostly > 65 yrs; 28% occur in < 65 yrs)
Atherosclerotic risk factors
Associated with HTN & diabetes (↑ in stroke incidence)
Smoking (50% ↑)
Atrial fibrillation: 6-fold risk for stroke
Use of medications such as sympathomimetics and oral contraceptives

Question 4

Acute Manifestations of CVA

Answer 4

• focal neurologic changes
• may rapidly change
• depends greatly on area of brain damage

Question 5

Chronic Manifestations of CVA

Answer 5

Paralysis
Ptosis
Homonymous hemianopsia (visual field loss)
Aphasia (impairment of language ability)
Loss of bowel and bladder control
Emotional instability

Question 6

CVA: Pathophysiology

Answer 6

Involves occlusion of a cerebral vessel → ischemia of brain tissue supplied by that vessel

If obstruction not removed → tissue infarcts and dies → permanent neurological deficit or death

Question 7

Severity of CVA is dependent on

Answer 7

location and extent of obstruction
degree of collateral circulation
promptness of diagnosis and treatment

Question 8

Types of Stroke

Answer 8

1. Thrombotic Stroke (Cerebral Thromboses)
2. Embolic Stroke
3. Hemorrhagic Stroke
4. Lacunar Stroke

Question 9

Thrombotic Stroke develops most often from

Answer 9

Atherosclerosis with thrombus formation

Inflammatory disease processes damage arterial walls (arteritis)

Question 10

Conditions causing inadequate cerebral perfusion include

Answer 10

dehydration
hypotension
prolonged vasoconstriction from malignant hypertension

Question 11

Transient ischemic attacks precedes in about 80% of cases:

Answer 11

• temporary decrease blood flow; all neurologic deficits clear w/in 24 hours
• changes in vision, speech, motor function, dizziness or LOC

Question 12

Embolic Stroke

Answer 12

involves fragments that break from a thrombus formed outside the brain or in the heart, aorta or common carotid

Question 13

Embolic Stroke: Risk Factors

Answer 13

Myocardial infarction
Atrial fibrillation
Valvular disease
Endocarditis
Hypercoagulability
Air or fat emboli

Question 14

Hemorrhagic Stroke (intracranial hemorrhage)

Answer 14

Accounts for 10% of all strokes and is most catastrophic type.
Onset is sudden.
Acute hypertension is a risk factor.

Question 15

Hemorrhagic Stroke: Common Causes

Answer 15

HTN
Ruptured aneurysms or vascular malformation
Bleeding into a tumor
Hemorrhage associated with bleeding disorders
Anticoagulation
Head trauma
Illicit drug use

Question 16

What is the most important preventative measure of hemorrhagic stroke?

Answer 16

BP control

Question 17

Lacunar Stroke

Answer 17

• occurs where small perforating arterioles branch off large cerebral vessels in the basal ganglia, internal capsule and brainstem
• small arterioles exposed to constant high pressure flow of large arteries -> thickened, thrombosed, eventual obstructed small arterioles.
• motor and sensory deficits

Question 18

Lacunar strokes account for what percent of all CVAs

Answer 18

20%

Question 19

Lacunar Strokes are associated with

Answer 19

smoking
HTN
diabetes

Question 20

Complications of CVA

Answer 20

Coma or death
Permanent neurological deficits (paralysis, impaired intellectual capability, speech defects, loss of short-term memory, impaired judgment)

Question 21

Treatment of Strokes are directed at

Answer 21

prevention of ischemic injury

control of cerebral edema and increased ICP

Question 22

What is the goal for treatment of the acute phase of a stroke?

Answer 22

stabilization of respiratory and cardiovascular function

Question 23

Ischemic Stroke Treatment

Answer 23

Thrombolytic (fibrinolytic) drugs: tissue plasminogen activator (TPA)

- Reestablishes blood flow to the brain by dissolving clots.    - Should be given w/in 3 hours to be effective.

Question 24

Hemorrhagic Stroke Treatment

Answer 24

Focuses on stopping or reducing the bleed.

Neurosurgical consult.

Question 25

Secondary Prevention: What medications could you use to prevent another stroke?

Answer 25

Statins (greatly reduces risk of stroke with prior TIA) Antihypertensives Antiplatelets (keeps platelets from sticking together) Anticoagulants (prevents clots from forming and keep existing clots from getting bigger)

Question 26

Circle of Willis

Answer 26

provides an alternative route for blood flow when one of the communicating arteries is obstructed.

Question 27

Intracranial aneurysm may result from

Answer 27

``` arteriosclerosis congenital abnormality trauma inflammation cocaine ```

Question 28

Intracranial Aneurysm

Answer 28

most occur in or near the circle of willis | 20-25% of cases.... more than one

Question 29

Intracranial Aneurysm: Pathophysiology

Answer 29

no pathologic mechanism exists

Question 30

Intracranial Aneurysms can be classified on shape and form:

Answer 30

1. saccular aneurysms | 2. fusiform aneurysms

Question 31

Saccular aneurysms

Answer 31

result from congenital abnormalities | highest incidence of rupturing or bleeding 20-50 y.o.

Question 32

Fusiform aneurysms

Answer 32

giant aneurysms | result of diffuses arteriosclerotic changes.. mostly found terminal portion of internal carotid arteries

Question 33

Clinical Manifestations of Intracranial Aneurysms

Answer 33

- often asymptomatic - first indication is an acute subarachnoid hemorrhage, intracerebral hemorrhage or both. - CN III, IV, V, and VI are most often affected

Question 34

Treatment of intracranial aneurysm

Answer 34

surgical management

Question 35

Subarachnoid Hemorrhage

Answer 35

blood escapes from defect or injured vessel into the subarachnoid space

Question 36

Risk for Subarachnoid Hemorrhages include:

Answer 36

Existing intracranial aneurysm Existing intracranial arteriovenous malformation Prior head injury HTN

Question 37

Pathophysiology of Subarachnoid Hemorrhages

Answer 37

- Vessel leaks...blood enters subarachnoid space - Vessel tears..blood under pressure pumped into subarachnoid space - Blood increases intracranial volume.. produces inflammatory reaction. - Cerebral blood flow and perfusion decrease. - Autoregulation of blood flow impaired -> leads to increased systolic blood pressure.

Question 38

Clinical Manifestations of Subarachnoid Hemorrhages: Leaking Vessel

Answer 38

Headache Changes in mental status or LOC N/V Focal neurologic effects

Question 39

Clinical Manifestations of Subarachnoid Hemorrhages: Ruptured Vessel

Answer 39

``` Sudden, throbbing “explosive” headache N/V Visual disturbances Motor deficits LOC due to increased ICP Meningeal irritation/inflammation occurs (neck stiffness “nuchal rigidity”, photophobia, blurred vision, irritability, restlessness, low-grade fever) ```

Question 40

Treatment of Subarachnoid Hemorrhages are directed at

Answer 40

Controlling ICP Preventing ischemia and hypoxia of neural tissues Preventing rebleeding episodes

Question 41

Subarachnoid Hemorrhages Treatment

Answer 41

Address patient’s airway, breathing, and circulatory status (ABCs). Avoid excessive sedation. May encounter osmotic agents (Mannitol), loop diuretics (Furosemide) to reduce ICP; IV steroid therapy to control brain edema.