Biomarkers.

Area of Science:

• Neuroscience
• Cognitive Neurology
• Biomarker Discovery

Background:

• The cerebellum's role in cognition is increasingly recognized, yet overlooked in Alzheimer's disease (AD) research.
• Cerebellar involvement in memory, learning, and executive functions is mediated via cerebro-cerebellar circuits.
• Current AD diagnostics primarily focus on the cerebrum, neglecting the cerebellum's potential contribution to early detection.

Purpose of the Study:

• To investigate electrocerebellogram (ECeG) characteristics in Alzheimer's disease (AD) patients across different disease stages.
• To identify sensitive ECeG biomarkers for the early detection of mild cognitive impairment (MCI) and AD.
• To explore alterations in cerebellar electrical activity and cerebro-cerebellar functional connectivity.

Main Methods:

• Recruited 31 healthy controls (HC), 40 mild cognitive impairment (MCI) patients, and 16 Alzheimer's disease (AD) patients.
• Utilized 71-channel electroencephalography (EEG) and electrocerebellogram (ECeG) for continuous resting-state recordings.
• Analyzed spectral changes in ECeG and functional connectivity between the cerebellum and cerebrum across groups.

Main Results:

• Reduced delta (δ) band power in the cerebellum was observed in the MCI group compared to HC and AD groups.
• Increased theta (θ) band power was found in both MCI and AD groups relative to HC.
• Enhanced functional connectivity between the cerebellum and frontal/parieto-occipital lobes was noted in the MCI group.

Conclusions:

• Alterations in ECeG delta and theta frequency bands show potential as sensitive biomarkers for MCI detection.
• Changes in cerebro-cerebellar functional connectivity may also aid in identifying early-stage cognitive impairment.
• ECeG analysis offers a promising avenue for early diagnosis and understanding of Alzheimer's disease progression.