Objective: To identify the prevalence of Parkinson disease mild cognitive impairment (PD-MCI) in a group of persons with young onset Parkinson disease (YOPD) consecutively referred for neuropsychological evaluation to a tertiary care center. The study also sought to explore the cognitive domains most impacted by PD-MCI in YOPD.

Background: It has been consistently shown that age is a major risk for dementia in PD and that dementia occurs much more frequently in PD than YOPD. It seems to be often assumed that cognition is thus intact in YOPD and virtually no attention has been paid to potential cognitive issues in YOPD. Importantly, PD-MCI has been estimated to occur at time of diagnosis in about 20-35% of PD, but it is unknown whether MCI occurs in YOPD and, if so, which cognitive domains are impacted.

Method: 89 consecutively referred persons with YOPD underwent neuropsychological evaluation using at least two tests per each of 5 cognitive domains: attention, executive function, language, visuospatial function, and memory. Diagnosis of PD-MCI was established using the MDS Level II criteria and using a test score cutoff of 1.5 SD below the normative mean (age and/or education corrected). Analyses were undertaken using chi-square, t-tests and analysis of covariance.

Results: 40 of 89 (44.9%) of YOPD had PD-MCI but none had dementia. Groups with and without PD-MCI were of similar age, gender, and disease duration. The most frequent impairments occurred on tests of memory (48.7% had at least 2 scores below cutoff) and executive function (15.4% had had at least 2 scores below cutoff). By contrast, attention, language, and visuoperceptual task performance rarely revealed impairments via 2 scores or tests (0-5%).

Conclusion: PD-MCI occurs more frequently than expected in YOPD although rates might be lower in community samples. This finding of common PD-MCI in YOPD is of clinical significance, because cognitive compromise has the potential to detrimentally impact quality of life given that persons with YOPD are often still working and caring for younger family members. Impact of PD-MCI on quality of life will be explored in a future study.

« Back to 2019 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/mild-cognitive-impairment-in-young-onset-parkinson-disease/