Chapter 65 Management of Patients w/ Oncologic or Degenerative Neurologic Disorders Flashcards
Parkinson’s Disease
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%
Pathophysiology of Parkinson’s Disease
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
Clinical Manifestations of Parkinson’s Disease
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)
Bradykinesia
Abnormally slow voluntary movements & speech
Akinesia
Loss of voluntary movement control
Hypokinesia
Abnormally diminished motor activity
Dysphonia
Voice impairment/ altered voice production
Micrographia
Small, cramped handwriting
Complications Associated w/ Parkinson’s Disease
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
What makes it difficult for patients w/ Parkinson’s disease to receive an early diagnosis?
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
How is a Parkinson’s disease diagnosis confirmed?
Confirmed w/ a positive response to levodopa trial
Diagnostic Findings Associated w/ Parkinson’s Disease
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)
Goal of Parkinson’s Disease Management
Treatment directed toward controlling symptoms and maintaining functional independence
Pharmacological Treatment of Parkinson’s Disease
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
During which time period are the therapeutic effects of levodopa & carbidopa more pronounced?
Within the 1st year or 2 of treatment
Special Considerations of Levodopa & Carbidopa
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
Other Adverse Effects of Levodopa
Delaying Levodopa use can help minimize long-term adverse effects
N/V
Appetite loss
Decreased BP
Dystonia
Dyskinesia
Confusion
Dystonia
Involuntary muscle contractions that cause repetitive or twisting movements
Anticholinergic Agents Used in Parkinson’s Disease Treatment
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
Antiviral Agent Used in Treatment of Parkinson’s Disease
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
Dopamine Agonists Used in Treatment of Parkinson’s Disease
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
Nonergot Derivatives Used in Treatment of Parkinson’s Disease (PD)
Ropinorole Hydrochloride Pramipexole: Early stages of PD
Common Side Effects: May cause drowsiness or dizziness
Monoamine-Oxidase Inhibitors Used in Treatment of Parkinson’s Disease (PD)
Selegiline Rasagiline: Inhibits dopamine breakdown
Common Side Effects:
- Agitation
- Dizziness
- Nausea
- Headache
- Rhinitis
- Back pain
- Stomatitis
- Orthostatic hypotension
- Insomnia
