Quantitative EEG changes in Alzheimer patients during long-term donepezil therapy

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline.
• Acetylcholinesterase inhibitors (AChEIs) are a common treatment for mild-to-moderate AD.
• Quantitative EEG (qEEG) can detect electrophysiological changes associated with AD progression.

Purpose of the Study:

• To investigate the long-term effects of donepezil (Dz) on cognitive function and qEEG parameters in mild-to-moderate AD patients.
• To compare the progression of AD in patients treated with donepezil versus a historical control group.

Main Methods:

• A cohort of 20 probable mild-to-moderate AD patients receiving donepezil (Dz group) was compared to 11 AD patients from the pre-AChEI era (C group).
• Quantitative EEG (qEEG) was recorded at baseline (t(0)) and approximately 1 year later (t(1).
• Cognitive function was assessed using the Mini-Mental Status Examination (MMSE). A qEEG ratio (6.5-12 Hz / 2-6 Hz) was calculated for frontal and temporoparietal regions.

Main Results:

• The donepezil group showed significantly less decline in MMSE scores compared to the control group.
• qEEG ratio significantly decreased in the right frontal region of the control group but not significantly in the donepezil group.
• The change in qEEG ratio in frontal regions correlated with the change in MMSE scores.

Conclusions:

• Long-term donepezil treatment in mild-to-moderate AD patients is associated with slower neuropsychological decline.
• Donepezil treatment appears to mitigate the deterioration of qEEG patterns, particularly in frontal regions.
• These findings suggest a potential neuroprotective effect of donepezil, preserving brain electrophysiology alongside cognitive function.