Chapter 65 Management of Patients w/ Oncologic or Degenerative Neurologic Disorders

Question 1

Parkinson’s Disease

Answer 1

Slow, progressive neurologic movement disorder associated with decreased levels of dopamine

Clinical symptoms do not appear until 60% of the pigmented neurons are lost and the striatal dopamine level is decreased by 80%

Question 2

Pathophysiology of Parkinson’s Disease

Answer 2

1) Destruction of dopaminergic neuronal cells in the substantia nigra in basal ganglia

2) Depletion of dopamine stores

3) Degeneration of the dopaminergic nigrostriatal pathway

4) Imbalance of excitatory (acetylcholine) & inhibiting (dopamine) neurotransmitters in the corpus striatum

5) Impairment of extrapyramidal tracts controlling complex body movements

6) Results in tremors, rigidity, bradykinesia, & postural changes

Question 3

Clinical Manifestations of Parkinson’s Disease

Answer 3

CARDINAL SIGNS & SYMPTOMS
- Tremor
- Rigidity
- Bradykinesia/akinesia
- Postural instability

Autonomic:
- Sweating
- Drooling
- Flushing
- Orthostatic hypotension
- Gastric and urinary retention

Dysphagia

Psychiatric changes: depression, anxiety, dementia, delirium, hallucinations

Hypokinesia (abnormally diminished movement), shuffle and decreased arm swing, micrographia, dysphonia (voice impairment or altered voice production)

Question 4

Bradykinesia

Answer 4

Abnormally slow voluntary movements & speech

Question 5

Akinesia

Answer 5

Loss of voluntary movement control

Question 6

Hypokinesia

Answer 6

Abnormally diminished motor activity

Question 7

Dysphonia

Answer 7

Voice impairment/ altered voice production

Question 8

Micrographia

Answer 8

Small, cramped handwriting

Question 9

Complications Associated w/ Parkinson’s Disease

Answer 9

Risk for respiratory and urinary tract infections, skin breakdown, and injury from falls

Adverse effects of medications – dyskinesia (impaired ability to execute voluntary movements) and orthostatic hypotension

Question 10

What makes it difficult for patients w/ Parkinson’s disease to receive an early diagnosis?

Answer 10

Patients rarely are able to pinpoint when the symptoms started

Usually family members will notice a change:
- Stooped posture
- Stiff arm,
- A slight limp, tremor, or slow, small handwriting

Question 11

How is a Parkinson’s disease diagnosis confirmed?

Answer 11

Confirmed w/ a positive response to levodopa trial

Question 12

Diagnostic Findings Associated w/ Parkinson’s Disease

Answer 12

PET and single-photon emission CT scanning

Careful evaluation of medical history

Assessment of presenting symptoms (presence of 2 or more cardinal manifestations)

Neurologic examination

Response to pharmacologic management (positive response to levodopa trial)

Question 13

Goal of Parkinson’s Disease Management

Answer 13

Treatment directed toward controlling symptoms and maintaining functional independence

Question 14

Pharmacological Treatment of Parkinson’s Disease

Answer 14

Levodopa: Most effective agent & mainstay of treatment
- Converted to dopamine in the basal ganglia-> produce symptom relief

Carbidopa: Often added to levodopa to avoid metabolism before it can reach the brain

Question 15

During which time period are the therapeutic effects of levodopa & carbidopa more pronounced?

Answer 15

Within the 1st year or 2 of treatment

Question 16

Special Considerations of Levodopa & Carbidopa

Answer 16

Benefits begin to wane & adverse effects become more severe over time

W/in 5-10 years most patients develop a response to the medication characterized w/ these manifestations:
- Dyskinesia
- Facial grimacing
- Rhythmic jerking movements of the hands
- Head bobbing
- Chewing & smacking movements
- Involuntary movements of the trunk & extremities

Patients may experience an on-off syndrome
- “Off”: Sudden periods of near immobility
- “On”: Sudden return of effectiveness of me

Changing drug dosing regimen or med can help minimize on-off syndrome

Question 17

Other Adverse Effects of Levodopa

Answer 17

Delaying Levodopa use can help minimize long-term adverse effects

N/V

Appetite loss

Decreased BP

Dystonia

Dyskinesia

Confusion

Question 18

Dystonia

Answer 18

Involuntary muscle contractions that cause repetitive or twisting movements

Question 19

Anticholinergic Agents Used in Parkinson’s Disease Treatment

Answer 19

Trihexyphenidyl hydrochloride
- Therapeutic Use: Controls tremor in patients w/ early onset
- Common side effects:
-> Blurred vision
-> Flushing
-> Rash
-> Constipation
-> Urinary retention
-> Acute confusional states

Benztropine Mesylate
- Therapeutic Use: Counteract the action of acetylcholine
- Common side effects: Contraindicated in patients w/ narrow-angle glaucoma

Question 20

Antiviral Agent Used in Treatment of Parkinson’s Disease

Answer 20

Amantadine Hydrochloride

Indications:
- Reduce rigidity
- Tremor
- Bradykinesia
- Postural changes in early Parkinson’s Disease (PD)

Common Side Effects:
- Psychiatric Disturbances: Mood changes, confusion, depression, hallucinations
- Lower extremity edema
- Nausea
- Epigastric distress
- Urinary retention
- Headache
- Visual impairment

Question 21

Dopamine Agonists Used in Treatment of Parkinson’s Disease

Answer 21

Bromocriptine Mesylate Pergolide

Indications: Early PD as well as secondary drug therapy after carbidopa or levodopa loses effectiveness

Common Side Effects:
- N/V
- Diarrhea
- Lightheadedness
- Hypotension
- Impotence
- Psychiatric effects

Question 22

Nonergot Derivatives Used in Treatment of Parkinson’s Disease (PD)

Answer 22

Ropinorole Hydrochloride Pramipexole: Early stages of PD

Common Side Effects: May cause drowsiness or dizziness

Question 23

Monoamine-Oxidase Inhibitors Used in Treatment of Parkinson’s Disease (PD)

Answer 23

Selegiline Rasagiline: Inhibits dopamine breakdown

Common Side Effects:
- Agitation
- Dizziness
- Nausea
- Headache
- Rhinitis
- Back pain
- Stomatitis
- Orthostatic hypotension
- Insomnia