Stability of mild cognitive impairment in newly diagnosed Parkinson's disease
Rachael A Lawson1, Alison J Yarnall1, Gordon W Duncan1,2
1Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK.
Background:
Mild cognitive impairment (MCI) is common in early Parkinson's disease (PD). We evaluated the stability of PD-MCI over time to determine its clinical utility as a marker of disease.
Methods:
212 newly diagnosed participants with PD were recruited into a longitudinal study and reassessed after 18 and 36 months. Participants completed a range of clinical and neuropsychological assessments. PD-MCI was classified using Movement Disorders Society Task Force level I (Montreal Cognitive Assessment <26) and level II (using cut-offs of 1, 1.5 and 2SD) criteria.
Results:
After 36 months, 75% of participants returned; 8% of patients had developed a dementia all of which were previously PD-MCI. Applying level I criteria, 70% were cognitively stable, 19% cognitively declined and 11% improved over 36 months. Applying level II criteria (1, 1.5 and 2SD), 25% were cognitively stable, 41% cognitively declined, 15% improved and 19% fluctuated over 36 months. 18% of participants reverted to normal cognition from PD-MCI.
Discussion:
Cognitive impairment in PD is complex, with some individuals' function fluctuating over time and some reverting to normal cognition. PD-MCI level I criteria may have greater clinical convenience, but more comprehensive level II criteria with 2SD cut-offs may offer greater diagnostic certainty.
Insights
Parkinson's disease mild cognitive impairment (PD-MCI) can fluctuate, with some patients improving or declining over 36 months. Cognitive assessment in PD is complex and requires careful consideration of diagnostic criteria.
Area of Science:
- Neurology
- Neuroscience
- Cognitive Science
Background:
- Mild cognitive impairment (MCI) is a frequent comorbidity in early Parkinson's disease (PD).
- Understanding the stability of PD-MCI is crucial for its clinical utility as a disease marker.
Purpose of the Study:
- To evaluate the longitudinal stability of mild cognitive impairment in early Parkinson's disease.
- To assess the clinical utility of PD-MCI as a biomarker.
Main Methods:
- A cohort of 212 newly diagnosed Parkinson's disease patients was followed for 36 months.
- Cognitive status was assessed using Movement Disorders Society Task Force level I and level II criteria.
- Neuropsychological and clinical assessments were performed at baseline, 18, and 36 months.
Main Results:
- After 36 months, 8% of patients developed dementia, all from the PD-MCI group.
- Using Level I criteria, 70% of PD-MCI patients remained cognitively stable.
- Level II criteria revealed greater variability, with 41% declining and 19% fluctuating, while 18% reverted to normal cognition.
Conclusions:
- Cognitive impairment in Parkinson's disease is dynamic, exhibiting fluctuations and reversibility.
- Level II criteria, particularly with 2SD cut-offs, offer more diagnostic certainty for PD-MCI compared to Level I.
- The complexity of PD-MCI necessitates careful selection of assessment tools for accurate clinical management.
Related Concept Videos
01:24Parkinson's Disease: Treatment
Parkinson's Disease is primarily a result of the loss of dopaminergic neurons in the substantia nigra pars compacta. The cornerstone of...
01:15Parkinson's Disease: Overview
01:26Alzheimer's Disease: Overview
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ...
01:37Neural Regulation
01:22Alzheimer's Disease: Treatment