February 2010
Stacy MA, Murck H, Kroenke
K
Background: The duration
of clinical control of motor symptoms of Parkinson disease (PD) treated
with levodopa/carbidopa preparations eventually starts to shorten, a
phenomenon known as end-of-dose “wearing off.” The involvement of core
nonmotor symptoms of “wearing off” (depressed mood, pain/aching,
anxiety, and cloudy/slowed thinking) is not well understood.
Methods: A
post hoc analysis from a study to validate the self-rated 9-item,
Wearing-Off Questionnaire (WOQ-9), which was designed to identify motor
and nonmotor symptoms of “wearing off” in PD patients, was performed to
compare the frequency and sensitivity of motor and nonmotor symptoms of
“wearing off” from dopaminergic therapy.
Results: Analysis
of responses to the WOQ-9 from 216 PD patients found that individual
nonmotor symptoms were reported by 25% to 50% and motor symptoms by 55%
to 80% of patients. Individual nonmotor symptoms improved following the
next dose of dopaminergic therapy in 43% to 53% of the patients who
presented with such symptoms, whereas motor symptoms improved in 48% to
66% of the cases, suggesting both types of symptoms respond to
dopaminergic therapies.
Conclusion: Nonmotor
symptoms of PD appear sensitive to dopaminergic treatment. These
symptoms resemble those seen with depressive, anxiety, and somatoform
disorders suggesting potential shared mechanisms as well as possible
treatment implications.
