Can MEG Help Detect Early Signs of Neurodegenerative Disease?

We’re continuing our Magnetoencephalography (MEG) focus with a look at its role in the early detection of neurodegenerative diseases, including Alzheimer’s Disease (AD) and Parkinson's (PD).

Sep 23, 2024

In case you haven’t read the first two parts of this series, you can check them out here:

MEG: The gold standard for measuring brain function (link)
Comparing MEG to MRI, fMRI, EEG and other brain scanning modalities (link)

Curious about your brain function? Book your non-invasive MYndspan analysis or join the waitlist for our future locations today.

There is extensive literature that speaks to both MEG’s effectiveness and potential as a more broadly applicable preventative brain health analysis tool:

MEG provides insights into targetable pathophysiological effects of neurodegeneration and markers for treatment studies. It is sensitive to disease and individual differences in pathophysiology, reliable, safe, well-tolerated and sufficiently scalable for early phase trials. MEG evidence of selective neuronal dysfunction and network reorganization can couple with microcircuit models for synaptic assays, or be used directly as a readout for interventional studies

Translation: MEG identifies brain changes associated with neurodegeneration, as well as the changes in brain activity during, or due to, treatment. Read more.

Since AD and PD are diagnosed only once neuronal death and the first symptoms have appeared, the early detection of these diseases is currently impossible.

The role(s) that MEG can play:

1) Early detection

MEG can identify early functional changes in brain activity that occur before structural changes become apparent on other imaging modalities, providing potential biomarkers for early diagnosis.

This is especially important because with up to 40% of dementias being preventable (according to the World Health Organization and other studies), early detection allows for lifestyle interventions that can be more effective than any drug prescribed later. This reduces the reliance on medication and improves long-term outcomes.

MEG can also help to differentiate between various types of neurodegenerative diseases, such as distinguishing Alzheimer's disease (AD) from other forms of dementia based on distinct patterns of brain activity. Symptom overlap can make disease identification challenging, but recognizing the subtle differences in brain function is crucial for ensuring accurate diagnosis and optimizing treatments.

MEG is already being used to identify early changes in brain activity associated with AD. Studies have shown that MEG can detect alterations in brain rhythms and connectivity patterns that precede the onset of clinical symptoms. For example, MEG can identify decreased complexity and increased regularity in brain activity, which are indicative of neuronal dysfunction in AD patients.

2) Monitoring disease progression

By performing repeated MEG scans, clinicians can monitor changes in brain activity over time, offering insights into disease progression. MEG provides quantitative metrics that can be used to track the severity and progression of neurodegenerative diseases, aiding in the assessment of the effectiveness of treatments.

3) Understanding pathophysiology

Pathophysiology is the change in the body’s function caused by an abnormal state like a disease, disorder or injury. MEG allows researchers to study the functional connectivity between different brain regions, enhancing the understanding of how neurodegenerative diseases affect brain networks.

It provides data on neural oscillations (brain waves) which are often disrupted in neurodegenerative diseases, offering clues about the underlying pathophysiology, i.e. what’s happening and why.

4) Guiding treatment

Insights from MEG can guide the development of personalized therapeutic and rehabilitation strategies based on the specific patterns of brain dysfunction observed in individual patients. MEG can be used to monitor the brain’s response to treatments, allowing for adjustments to therapeutic strategies based on real-time feedback.

5) Looking at the whole picture

It’s easy to see the role that MEG can play in early detection of neurodegenerative disease. Its non-invasive nature, combined with its high temporal and spatial resolution, enable earlier identification of disease biomarkers, enable better tracking of disease progression, and can potentially lead to earlier and more effective interventions.

Let’s take a closer look at MEG with a few diseases of focus.

Alzheimer’s Disease:

Alzheimer’s Disease (AD) is one of the common neurodegenerative diseases, affecting over 60 percent of the nearly 50 million people with dementia across the world. The onset of AD typically happens several years before clinical diagnosis, and it is characterized by three stages.

The first stage is a pre-clinical phase, which lasts for over a decade. Towards the end of the first stage, neurodegeneration or injury is found. The second phase exhibits Mild Cognitive Impairment (MCI) and the third state is AD.

MEG can detect abnormal brain activity patterns and connectivity issues before significant cognitive decline occurs. With AD, MEG has been used to identify and differentiate control subjects, those with MCI, and AD patients by analyzing the neuronal dysfunction with MEG at each of the 3 stages of disease.

While there is currently no definitive way to prevent AD, research suggests that certain lifestyle changes (exercise, healthy diet, mental and social engagement, reducing stress and avoiding alcohol and tobacco) may reduce the risk or delay the onset of the disease.

Parkinson’s Disease:

Parkinson’s Disease (PD) is the second most common neurodegenerative disease after Alzheimer’s. As the disease progresses, it spreads from the brainstem to other cortical regions in the brain. PD is a whole brain disease, causing functional disturbances both in cortical and subcortical brain regions. Clinically, PD is characterized by its motor and non-motor symptoms.

MEG can assess abnormalities in motor control and sensorimotor integration, which are hallmark features of PD. It can also be helpful in studying the impact of dopaminergic treatments on brain activity, providing insights into therapeutic efficacy.

Other Neurodegenerative Diseases:

Additionally, MEG's ability to assess functional connectivity and network disruptions in the brain has been applied to frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS).

MEG in the future

It is clear from presymptomatic studies across a range of neurodegenerative disorders that the earliest events occur many years, possibly decades, before the onset of symptoms. Primary prevention of neurodegeneration will require sensitivity to very subtle changes in brain activity that seem likely to operate at the network level.

MEG's non-invasive nature and its ability to provide detailed insights into cortical neural excitability, synchronization, and connectivity make it a promising tool for early detection and monitoring of neurodegenerative diseases at scale.