Changes on brief cognitive instruments over time in Parkinson's disease.

Area of Science:

• Neurology
• Neuropsychology
• Gerontology

Background:

• Parkinson's disease (PD) is a neurodegenerative disorder affecting motor function and often associated with cognitive impairment.
• Accurate assessment of cognitive changes is crucial for managing PD progression and patient care.
• Existing cognitive screening tools may have varying sensitivities in detecting early or longitudinal cognitive deficits in PD.

Purpose of the Study:

• To compare the sensitivity of the Montreal Cognitive Assessment (MoCA) and the Mini-Mental Status Examination (MMSE) in identifying cognitive deficits in individuals with Parkinson's disease.
• To evaluate the longitudinal performance of MoCA and MMSE in tracking cognitive changes over time in a PD cohort.

Main Methods:

• A cohort of 221 subjects with Parkinson's disease (PD) underwent cognitive assessment using both MoCA and MMSE.
• A subset of 98 participants were re-evaluated up to 3 years later to assess longitudinal changes.
• Statistical analyses were performed to compare the tools' sensitivity and track changes across different patient strata.

Main Results:

• The MoCA demonstrated higher sensitivity than the MMSE in detecting cognitive deficits, particularly in visuospatial, language, and memory domains.
• The MMSE showed significant changes over time, especially in patients with PD duration exceeding 10 years.
• The MoCA did not exhibit significant changes over the study period, irrespective of age, MMSE score, or disease duration.

Conclusions:

• The MoCA appears more effective for identifying early-stage cognitive impairment in Parkinson's disease.
• The MMSE may be a more suitable tool for monitoring the progression of cognitive decline over extended periods in PD patients.
• These findings suggest a complementary role for MoCA and MMSE in the comprehensive neuropsychological evaluation of Parkinson's disease.