Change in cognitive function in idiopathic Parkinson disease

Area of Science:

• Neurology
• Cognitive Neuroscience

Background:

• Parkinson disease (PD) is a neurodegenerative disorder affecting motor function.
• Cognitive impairment is a common non-motor symptom in PD, impacting daily life.
• Longitudinal studies are crucial to understand the progression of cognitive changes in PD.

Purpose of the Study:

• To assess the frequency and magnitude of cognitive function changes in idiopathic Parkinson disease (PD).
• To determine changes in Mini-Mental State Examination (MMSE) performance over a two-year period in PD patients.
• To compare cognitive changes in PD patients with those in a healthy elderly control group.

Main Methods:

• A longitudinal study involving 77 patients with idiopathic PD and 43 normal elders.
• Neuropsychological testing, including the MMSE, was administered twice, two years apart.
• A 4-point MMSE score difference was defined as statistically significant (p < 0.05).

Main Results:

• Over two years, 17% (22%) of PD patients showed a significant decline (≥4 points) in MMSE scores, while 2 individuals improved.
• No significant changes in MMSE scores were observed in the normal elderly control group.
• PD patients taking dopamine agonists at the second test time showed a higher frequency of cognitive change.

Conclusions:

• A significant decline in cognitive function, as measured by a 4-point MMSE change, occurred in 22% of PD patients over two years.
• Cognitive changes in PD patients were not associated with education, disease duration, age, or baseline cognitive status.
• Dopamine agonist use may be associated with cognitive changes in Parkinson disease patients.