Cognitive Problems in Parkinson's Disease
Date: March 2017
Author: Beth A. Vernaleo, PhD
Blog Editors: Michael S. Okun, MD, and Stella M. Papa, MD
In 2013, the Parkinson’s Disease Foundation (PDF) launched the Community Choice Research Award (CCRA), designed to advance research in areas that were identified as unmet needs within the PD community. People with Parkinson’s (PWP) and care partners (CP) were asked “what areas of research do you think scientists should be focusing on in order to make an impact in the PD community?” In 2015, over 300 people from eight countries responded with ideas.
One unmet need identified by many PWP and CP was addressing cognitive problems in PD and how to maintain cognitive function for as long as possible. As a result, the PDF organized a multidisciplinary working group of experts in several fields (Movement Disorders, Cognitive Neurology, Psychology, Social Work, Nutrition, Nursing, Physical Therapy, and Aging) as well as members of the PD community to address this need, with a focus on non-pharmacological interventions. We asked Beth Vernaleo PhD, Associate Director of Research Programs for the PDF, to summarize the recommendations emerging from the meeting.
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Beth Vernaleo, PhD: One outcome of the meeting held in June 2016 was a set of recommendations, for people with Parkinson’s and care partners, for what they can do at each stage of their PD to maintain cognitive health. These recommendations were based on the evidence presented at the meeting regarding effectiveness of various non-pharmacological interventions such as exercise, cognitive training, and nutrition.
Recommendations for early to mid-stage PD:
1. Exercise according to American Heart Association guidelines
2. Stay active socially; join a support group
3. Engage in cognitive training exercises
4. Learn coping strategies such as with an occupational therapist
5. Nutrition can affect cognition; try a Mediterranean diet
6. Take your time when doing tasks and do not multitask
7. Communicate with family and friends if you are struggling
Recommendations for advanced PD:
Keep following the above recommendations, PLUS:
1. Develop a highly structured daily routine that you follow
2. Consider the use of medication for cognitive impairment
3. Have an advanced directive in place (living will, treatments)
4. For care partners-- take care of your own health as well
5. For care partners-- seek out support such as counseling
A second, equally important outcome of the meeting was a set of recommendations for what healthcare professionals should be discussing with their PD patients. These recommendations were based not only on evidence presented at the meeting, but also feedback from the PD community representatives who attended the meeting.
Recommendations for healthcare professionals:
1. Provide information at diagnosis regarding cognitive aspects of PD
2. Follow-up with an appointment or discussion a few weeks later to answer questions regarding PD
3. Be honest with regard to what changes in cognition can be expected
4. Refer to a neuropsychologist for baseline cognitive testing
5. Have cognition assessed regularly
6. Refer to occupational therapy, physical therapy, speech language therapy, social work, and nutrition
7. Evaluate patients for depression and anxiety as they can affect cognition
8. Broach the subject of advance planning with patients and caregivers
Though some of these recommendations may seem like common sense, much of the feedback we received from the PD community pointed to a lack of information conveyed to them regarding cognitive changes when first being diagnosed.
Daniel Weintraub, MD: It is not surprising that the PDF found that many people with PD and care partners identified addressing cognitive problems in PD and how to maintain cognitive function for as long as possible as key unmet treatment needs. Since our pharmacologic treatments for significant cognitive impairment in PD are few and limited in effect, non-pharmacological approaches are key to preserving, and perhaps improving, cognitive abilities in PD patients. The most well-studied interventions are aerobic exercise and cognitive training, both of which are safe, simple, and even enjoyable. Social activities may also improve cognitive functioning. Specific diets, such as the Mediterranean diet, may potentially have long-term cognitive benefits. So staying active and healthy are common sense recommendations, but it is important to note that the scientific evidence supporting these recommendations, particularly for specific benefits in PD, is quite limited.
Beyond that, minimizing adverse effects of commonly used medications and co-occurring medical conditions is important. For medications, those with anticholinergic properties, both prescribed for PD and for other medical conditions, should be used sparingly in PD patients. In addition, certain anti-anxiety medications (benzodiazepines) and pain medications (opioids) can impair cognitive abilities, especially when used chronically. In terms of co-morbid medical conditions, it is important to closely monitor and manage any chronic vascular diseases (e.g., hypertension, hypercholesterolemia and diabetes) that can damage brain blood vessels and lead to cognitive impairment. Regarding PD treatments, there is no evidence that initial choice of PD medication has an impact on long-term cognitive status, but deep brain stimulation (DBS) surgery can lead to mild worsening in specific cognitive domains in a subset of patients. It is also known that certain common psychiatric (e.g. depression and psychosis) and other non-motor symptoms (e.g., insomnia, excessive daytime sleepiness and orthostatic hypotension) in PD can adversely affect cognitive performance, so routinely screening for and managing key non-motor symptoms is important.
Jennifer G. Goldman, MD, MS: There is great interest in studying non-pharmacological interventions to treat cognitive impairment or prevent cognitive decline, but little evidence-based medicine or data at present. The reasons for this may be many. For example, studies of non-pharmacological interventions differ from our “gold standard” pharmacological studies of double-blind, placebo-controlled, randomized trials as there is not always a clear way to have a “placebo” group for these interventions. For this reason, some study designs have opted to include groups participating in other activities of daily living, different lifestyle behaviors, different types of exercise, or “usual” behavior. To date, many studies lack comparator groups and thus, would be considered the equivalent of “open label” pharmacological studies, with the associated caveat of potential bias. Sample sizes in physical and cognitive exercise studies in PD have typically been on the smaller side. Although some clinical trials of physical and cognitive exercise interventions reveal positive benefit on performance on cognitive tests, other studies demonstrate minimal to no effect. Understanding why there are conflicting results among studies is an important aspect that may influence and improve future study designs.
At present, there is much to learn about the different types of physical and cognitive exercise interventions, dose and duration, and maintenance of the intervention should it be effective. More information is needed to understand the molecular, cellular, and biological effects of these interventions on brain, mind, and body. In addition, regarding study design, there are many choices for the selection of outcome measures, different cognitive domains, and neuropsychological tests and this represents an area of active study. It may be important to also understand not only effects of interventions on cognitive performance, but also how these translate into everyday function. Whether the effects of non-pharmacological interventions are generalizable and durable also remain to be seen. For example, training on exercises for a certain cognitive domain (e.g., memory or executive function) may improve that particular area, but may not generalize to other cognitive functions. We do not yet know how long the effects of the intervention may last, whether effects last once the exercise training is complete, or whether it can be regained once stopped. Motivation for participating in exercise programs and maintaining activity is another factor to consider. Changing behaviors and sticking to new routines are hard work!
While further research is needed, there are great opportunities ahead in PD research to investigate effects of non-pharmacological interventions, such as physical and cognitive exercise among others, on improving brain health and brain adaptations as well as treating cognitive symptoms and preserving cognitive function.
Michael S. Okun, Medical Director, Parkinson’s Foundation: We receive hundreds of patient and caregiver calls and dozens of questions about cognition and Parkinson’s disease on our website. In addition to stressing the unmet needs and the areas of focus suggested by the PDF, we also emphasize to each person with PD the importance of employing an interdisciplinary approach to cognition and to be cautious about multi-tasking. Trying to do too many things at once can stress cognitive reserve. There are numerous interventions that may have merit for cognition, and we emphasize to families to think beyond the medications.
Connie Marras, MD, PhD: It is clear that maintaining cognitive abilities is a high priority for people with PD and their caregivers, and that there is insufficient evidence to provide well-supported recommendations on how to do this. While in the interim we must rely largely on our common sense, it is imperative to fill the gaps in knowledge that currently exist.