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Analysis Details the Heavy Burden of Neuropsychiatric Symptoms in Parkinson’s Disease

NICE, France—Parkinson's patients face a heavy burden of neuropsychiatric symptoms that only grow over time, according to a presentation here at the International Congress of Parkinson's Disease and Movement Disorders.

The analysis was based on data collected prospectively from a study of markers of Parkinson's disease (PD) progression.

About 78 percent of patients had at least one neuropsychiatric symptom at the first yearly visit in the Parkinson's Progression Markers Initiative, and 29 percent had three or more, said Daniel Weintraub, MD, professor of psychiatry at the University of Pennsylvania. By the fifth year, that burden had mushroomed to 88 percent with at least one symptom and 56 percent with three or more.

Researchers evaluated the prevalence and treatment of 10 symptoms, as well as correlates with those symptoms: depression, anxiety, REM sleep behavior disorder (RBD), impulse control disorders (ICDs) and related behaviors, psychosis, apathy, insomnia, excessive daytime sleepiness, fatigue and cognitive impairment. There were 423 PD participants and 196 healthy controls enrolled at the start of the study; 315 of the PD participants remained in the study at the fifth year.

When prevalence was defined as meeting a threshold using an instrument, such as the General Depression Scale, the most common symptoms at baseline were RBD at 26 percent, anxiety at 25 percent, and insomnia at 24 percent.

In this analysis, researchers took an unusual step and factored in treatment for a disorder in a separate prevalence calculation, so that treatment counted as having the symptom. In some cases this made for just a small difference, but in the case of depression, prevalence jumped from 14 percent at baseline to 27 percent.

"You also have to consider the people who are starting treatment of these disorders," Dr. Weintraub said. "If they're treated, that means the symptom may no longer be present or the clinician, even if it didn't cross the threshold of the instrument, felt they had the symptom and wanted to treat."

Researchers found that at some point over the five years, 70 percent of patients either had instrument-measured insomnia or had been treated for it. That was true for 51 percent of patients in the case of depression, for 54 percent for anxiety, 52 percent for excessive sleepiness, 61 percent for RBD, 52 percent for impulse control disorders (which did not take into account treatment), and 57 percent for cognition.

"By year five, it's just really high for a lot of these [patients]," Dr. Weintraub said.

By year five, seven of the 10 disorders had either been present in a patient or treated for at some point over the course of the study in at least half of the patients.

Use of antidepressants and anti-anxiety medications was common at baseline—18 percent and 13 percent of patients were already on these medications at year one—and their use increased over time, to 27 percent for antidepressants and 24 percent for anti-anxiety drugs. Use of anti-psychotic and cognitive-enhancing drugs was uncommon throughout the study.

Commenting on the study, Suketu Khandhar, MD, medical director of the Kaiser Permanente Northern California Movement Disorders Program, said it's important to understand that baseline is not a pure baseline, and that the early prevalence of these non-motor symptoms underscores this.

"Baseline implies that you have no disease at a certain time—the reality is that the vast majority of Parkinson's patients are diagnosed well into the pathology of this disease," said Dr. Khandhar, who was not involved with the study. "There's a prodrome to this condition that we are not capturing, and that prodrome is all these non-motor neurologic symptoms like REM sleep behavior disorder, constipation, anxiety, and depression."

"There are studies that show that, if you were to see an individual who had an understanding that these prodromal symptoms actually have an increased likelihood of developing Parkinson's, we could capture the disease early, capture a better baseline, and better understand the trajectory of this condition. So I think this [study] is really unfortunately falsely representing what's truly happening."

Drs. Weintraub and Khandar had no disclosures.

Link Up for Related Information:

International Congress Abstract 1644: Weintraub D, Caspell-Garcia C, Cho H, et al. Cognitive and psychiatric course in the initial lustrum of Parkinson disease: The glass is half full.