By Michelle Koidin Jaffee
Two new studies by University of Florida neuroscientists offer insights into differing types of cognitive symptoms that can develop in some people with Parkinson’s disease who do not have dementia.
Using clinical findings, neuropsychological assessments and neuroimaging, two separate teams of investigators led by Catherine C. Price, Ph.D., provided validation for three distinct cognitive types of Parkinson’s disease, showing that adults age 60 and older who have Parkinson’s disease but not dementia can have various cognitive symptoms.
“These two papers provide important clinical and neuroimaging validation for cognitive types of Parkinson’s disease,” said Price, associate professor of clinical and health psychology and anesthesiology and director of UF’s Perioperative Cognitive Anesthesia Network program for Alzheimer’s Disease and Related Dementias.
In one paper, published in the Journal of Parkinson’s Disease, the researchers reported that some non-dementia Parkinson’s patients experienced working memory and inhibitory difficulties (called “the executive group”) while others had learning and memory difficulties (called “the memory group”) while still others had minimal to no cognitive deficits. The study involved 116 people with non-dementia Parkinson’s and 62 non-Parkinson’s peers, followed over several years’ time. Of the participants with Parkinson’s, 25 were classified in the “executive” group, 35 in the “memory” group and 56 in the cognitively well group.
The research team, co-led by doctoral student Samuel J. Crowley, also found there were differences in gray and white brain matter associated with the three distinct kinds of Parkinson’s cognitive profiles when compared with peers without Parkinson’s disease.
Separately, a companion paper in the Journal of Parkinson’s Disease showed that people with the three distinct cognitive profiles of Parkinson’s performed differently on a digital cognitive screening test. In a study involving 115 people with Parkinson’s and 115 non-Parkinson’s participants, the team, co-led by doctoral student Catherine Dion, showed that people with Parkinson’s but not dementia who are experiencing subtle memory or executive problems exhibit different pen-to-paper drawing behaviors compared with their cognitively well peers without Parkinson’s disease.
Only the people in the “executive group” showed smaller drawing sizes and showed slower drawing patterns, while the people in the “memory group” and the cognitively well Parkinson’s group were similar to their non-Parkinson’s peers.
“Taken together, we hope these studies will advance our understanding of disease progression and possible avenues of intervention, depending on the type of cognitive profile,” Price said.