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New Penn Medicine studies have shown that neuropsychiatric symptoms such as depression, anxiety and fatigue are more common in newly diagnosed Parkinson’s disease (PD) patients compared to the general population. The study also discovered that initiation of dopamine replacement therapy, the most common treatment for PD, was related to increasing frequency of impulse control disorders and excessive daytime sleepiness. The brand new findings, the very first longitudinal study to come out of the Parkinson’s Progression Markers Initiative (PPMI), were published within the August 15, 2014, issue of Neurology, the medical journal from the American Academy of Neurology.
The PPMI, a landmark, multicenter observational clinical study sponsored through the Michael J. Fox Foundation for Parkinson’s Research, utilizes a mixture of advanced imaging, biologics sampling and behavioral assessments to identify biomarkers of Parkinson’s disease progression. The Penn study, addressing neuropsychiatric and cognitive data from baseline with the first Two years of follow up, was conducted in collaboration with the Philadelphia VA Medical Center and the University Hospital Donostia vacation.
The study examined 423 newly diagnosed, untreated Parkinson’s patients and 196 healthy controls at baseline and 281 individuals with PD at 6 months. Of those, 261 PD patients and 145 healthy controls were evaluated at Twelve months, and 96 PD patients and 83 healthy controls evaluated at 24 months.
PD patients were able to begin dopamine therapy at any time after their baseline evaluation.
“We hypothesized that neuropsychiatric symptoms could be common and stable in severity right after diagnosis and that the initiation of dopamine replacement therapy would modify their natural progression in some way,” says senior author, Daniel Weintraub, MD, associate professor of Psychiatry and Neurology in the Perelman Med school at the University of Pennsylvania along with a fellow in Penn’s Institute on Aging.
The Penn team demonstrated that while there wasn’t any significant difference between PD patients and healthy controls in the frequency of impulse control disorders, a neuropsychiatric symptom that can lead to compulsive gambling, sexual behavior, eating or spending, 21 percent of newly diagnosed PD patients screened positive for such symptoms at baseline. That percentage didn’t increase significantly over the 24-month period.
However, six patients who was simply on dopamine therapy for more than a year in the 24-month evaluation showed impulse control disorders or related behavior symptoms while no impulse control incident symptoms were reported in PD patients who hadn’t commenced dopamine therapy. Dopamine therapy did assist with fatigue, with 33 percent of patients improving their fatigue test score over Two years in contrast to only 11 percent of patients not on dopamine therapy.
The investigators also found evidence that depression may be undertreated in early PD patients: Two-thirds of patients who screened positive for depression at any time point weren’t taking an antidepressant.
PPMI follows volunteers for 5 years, so investigators plan to expand upon these results, which Weintraub still considers preliminary. “We will more closely look at cognitive changes over time,” he says. “Two years isn’t a sufficient period of follow-up to really take a look at meaningful cognitive decline.”
The perspective of time is the reason why the PPMI this kind of important initiative, Weintraub highlights, since many patients using the disease live for 10 to 20 years following their diagnosis. “It’s a real opportunity to assess the frequency and characteristics of psychiatric and cognitive symptoms in PD, compare it with healthy controls, after which also take a look at its evolution with time,” he states. “The hope is that we will be able to continue this work so that we are able to obtain long-term follow up data on these patients,” says Weintraub.
