Source: Chen JJ, Nelson MV, Swope
DM. Parkinson’s Disease. In: DiPiro JT, Talbert RL, Yee
GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy:
A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=7986138.
Accessed June 9, 2012.
- Paralysis agitans
- Shaking palsy
- Progressive, chronic disorder of central nervous system
(CNS) characterized by impaired muscular coordination and tremor.
- Unknown; likely result of interactions between aging,
genetic constitution, and environmental factors.
- Loss of neurons and presence of Lewy bodies in substantia
nigra pars compacta.
- Degree of nigrostriatal dopamine loss correlates directly
with severity of motor symptoms.
- Reduced activation of dopamine-1 and dopamine-2 receptors
results in greater inhibition of thalamus.
- Loss of presynaptic nigrostriatal dopamine neurons inhibits
thalamic activity and reduces activation of motor cortex.
- Affects up to 1 million individuals in United States.
- Annual incidence ranges from 10 to 120 per 100,000 persons
depending on age.
- Affects 1% of people older than age 65 and 2.5% of
those older than age 80.
- Usual age at diagnosis is 55–65 years.
- Male-to-female ratio is 2:1.
- Increasing age
- Male sex
- Heredity (close relative with disease)
- Toxin exposure (e.g., herbicides, pesticides)
- General features
- Resting tremor
- Muscular rigidity
- Bradykinesia (usually asymmetric)
- Postural instability in advanced disease
- Motor symptoms
- Decreased manual dexterity
- Difficulty arising from seated position
- Diminished arm swing during ambulation
- Festinating gait
- Flexed posture
- “Freezing” at initiation of movement
- Autonomic and sensory symptoms
- Bladder and
anal sphincter disturbances
- Olfactory disturbance
- Orthostatic blood pressure changes
- Paroxysmal vascular flushing
- Sexual dysfunction
- Mental status changes
- Sleep disorders
Means of Confirmation
- At least two of the following clinical findings:
- Limb muscle rigidity
- Resting tremor (at 3–6 Hz and abolished by movement)
- Obtain medication history to exclude drug-induced parkinsonism,
- Phenothiazine antiemetics
- None available to diagnose Parkinson’s disease.
- Neuroimaging may be useful for excluding other diagnoses.
- Essential tremor
- Corticobasal ganglionic degeneration
- Multiple system atrophy
- Progressive supranuclear palsy
- Creutzfeldt-Jakob disease
- Minimize symptoms, disability, and side effects.
- Maintain quality of life.
- Ensure appropriate exercise and proper nutrition.
- Educate patients and caregivers about disease, treatments,
- Figure 1: Algorithm for management of early and late disease.
- Monoamine oxidase-B (MAO-B) inhibitor (e.g., rasagiline) as
monotherapy typically first treatment.
- Either rasagiline or dopamine agonist can be used first in
physiologically young patients.
- Levodopa (e.g., carbidopa/levodopa) is preferred
initial therapy for patients older, cognitively impaired, or who
have moderately severe functional impairment.
- Consider adding catechol-O-methyltransferase
(COMT) inhibitor to extend levodopa duration of activity when motor
fluctuations develop. Alternatively, consider adding MAO-B inhibitor
or dopamine agonist.
- Amantadine may be added to manage levodopa-induced peak-dose