Can Neurophysiology Help in the Early Detection of Alzheimer’s Risk?

Neurophysiological profile across different stages of the disease. From Maestú et al. 2021 https://www.sciencedirect.com/science/article/pii/S1568163721001197

With the pharmaceutical industry increasingly focused on preventive treatments for Alzheimer’s disease (AD), the ability to identify individuals at risk before symptoms appear has never been more important. What if a non-invasive EEG recording could detect early brain changes—serving as a simple yet powerful screening tool for clinical trials or even routine care?

From Protein Accumulation to Brain Waves: A Translational Perspective

While much of Alzheimer’s research has centered around the accumulation of amyloid-beta (Aβ) and tau proteins, our understanding of how these molecular changes translate into cognitive decline remains incomplete. However, new research is connecting the dots between cellular pathology, network dysfunction, and clinical symptoms—with neurophysiology playing a central role in this emerging picture.

A groundbreaking study by Gallego-Rudolf et al. (2024) provides strong evidence that EEG can capture early brain oscillatory changes linked to AD pathology:

• In asymptomatic individuals, early Aβ deposition is associated with a speeding up of brain activity:

  • ⬆️ Alpha-band activity

  • ⬇️ Delta-band activity

• When tau pathology appears alongside Aβ, this pattern reverses, reflecting a slowing of oscillatory activity:

  • ⬇️ Alpha-band

  • ⬆️ Delta-band

    
    

These findings highlight that changes in neural rhythms could serve as biomarkers of different disease stages—offering a window into the brain's evolving dysfunction long before memory loss becomes evident.

Evolution of pathological changes across the AD continuum. From Gallego-Rudolf et al. (2024) https://www.nature.com/articles/s41593-024-01763-8

The Deeper Cause: Excitation/Inhibition (E/I) Imbalance

What underlies these shifts in oscillatory activity?

According to an influential review by Maestú et al. (2021), the key may lie in a disruption of the brain’s excitation/inhibition (E/I) balance—a delicate mechanism that regulates how neurons communicate. The authors argue that E/I imbalance is a central neurophysiological consequence of AD pathology, acting as:

• ✅ The endpoint of cellular damage (e.g., synaptic loss, Aβ toxicity)

• ✅ The starting point for large-scale network disruptions and cognitive symptoms

  
  

This imbalance can result in neuronal hyperexcitability or hypersynchronization, both of which are detectable via EEG. In fact, the early "speeding up" of brain activity observed by Gallego-Rudolf et al. may reflect hyperactive circuits, while later "slowing" may indicate network breakdown and inhibition loss—two sides of the same neurophysiological coin.

From Theory to Practice: How EEG Can Help Today

At Starlab, we are committed to transforming these scientific insights into practical clinical tools. Our EEG Clinical Reporting Service extracts reliable, interpretable biomarkers from EEG data to:

• 🧠 Detect early neurophysiological changes in asymptomatic individuals

• 🧪 Improve participant selection in Alzheimer’s clinical trials

• 🧍‍♀️ Support clinical decision-making and risk stratification

  
  

By capturing signs of E/I imbalance and oscillatory alterations at the macro level, EEG provides a non-invasive bridge between molecular pathology and cognitive outcomes—exactly the kind of translational insight needed to make precision medicine a reality in AD. See our previous posts on our collaboration with ACE Alzheimer Center:

The Auditory Oddball Paradigm and Its Insights into Cognitive Decline

https://www.starlab.es/post/the-auditory-oddball-paradigm-and-its-insights-into-cognitive-decline

Unveiling the Brain's Response to Sound with the ASSR Task

https://www.starlab.es/post/unveiling-the-brain-s-response-to-sound-with-the-assr-task

Resting-State EEG: A Key to Understanding Brain Health

https://www.starlab.es/post/resting-state-eeg-a-key-to-understanding-brain-health

👉 Ready to explore EEG for early detection or trial optimization?

📩 Contact us at info@starlab.es to learn how we can support your work with tailored neurophysiological insights.