Departments: Your Questions Answered
Q My husband has trouble smelling odors. Should he be tested or treated for Parkinson's disease?
Dr. KAPIL SETHI RESPONDS:
A Since no therapy exists that protects against the onset of Parkinson's disease (PD), there is no advantage to being tested when only non-motor symptoms are present. PD is diagnosed by the presence of motor symptoms, including slowness of movement, resting tremor, rigidity, and impaired posture and balance. In some cases, a special imaging technology called a DaTscan, which can determine how much dopamine is available in a person's brain, may be helpful in confirming the diagnosis.
Often, people with PD do experience non-motor symptoms, such as reduced ability to detect and differentiate odors, constipation, excessive daytime sleepiness, and rapid eye movement (REM) sleep behavior disorder. During REM sleep, the body is usually still except for eye movement; in REM sleep behavior disorder, the individual may talk and kick during REM sleep. Many patients and caregivers recall the presence of these non-motor symptoms before the motor problems of PD begin—sometimes years before.
However, these non-motor problems are common in the general population as well. Also, the period of time between the onset of non-motor symptoms and the development of motor symptoms is not known.
Ongoing research, such as the Parkinson Associated Risk Study (PARS) study, is working to identify the frequency and risk factors for the development of PD in individuals with non-motor problems (see www.parsinfosource.com). Overall, it seems that the risk of someone with only the non-motor problems developing PD is rather low.