EEG brain patterns and functions in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome

Updated: Oct 26

Living with CFS/ME can be difficult. Extreme tiredness and other physical symptoms can make it hard to carry out everyday activities. People suffering from it may have to make some major lifestyle changes. CFS/ME can also affect mental and emotional health and have a negative effect on self-esteem.

Mainstream treatments that are offered for ME/CFS include medicine to control pain, nausea and sleeping problems, emotional/mental support (such as CBT), while structured exercise programmes, such as graded exercise therapy (GET) are no longer recommended to treat CFS/ME.

When mapping brain activity (EEG) in ME patients, studies have found specific patterns to be present.



Before we list those, it is important to remember:

• Not all patterns show in all ME brains.

• The approach to understanding the brain activity is to relate to the brain as a whole system, with activity assessed for cognitive functions, emotional processing and filtering, language and sensory processing and sleep patterns as examples.

• As ME/CFS does not tend to have one trigger, and its onset can happen following physiological as well as emotional/trauma events, it is important to understand your specific case and client before correlating it with their EEG patterns.

• Many of the patterns found in ME/CFS can show in other conditions as well.

• Different EEG methods/sites measures were used by the different studies mentioned in this article. Some findings mentioned here were found using other brain imaging techniques such as SPECT.



EEG brain patterns and functions in ME/CFS brains


1. Imbalanced functioning of the Anterior Insula

The anterior insular cortex (AIC) mediates interoceptive attention which refers to attention towards physiological signals arising from the body. Part of it’s role is to screen and differentiate between relevant and non-relevant information at any given time.


If the anterior insula is unable to filter out irrelevant from non-irrelevant stimuli, the brain’s ability to focus on a single stimulus will be impaired. Or if the anterior insula focuses too much attention on less relevant issues or stimuli problems with anxiety or pain can result.


Getting easily upset or anxious over small things that failed to bother one before and/or problems with pain sensitivity (e.g. too much attention being focused on internal stimuli), could derive from problems with the anterior insula telling a person to focus on irrelevant stimuli.


2. Very fast phase shifts and locks

There is a chain of little brain events that need to happen when we are trying to focus on a task or something new. The reticular formation will wake up the cortex, who will then decide (by different networks) which information to focus one. (Again, which is the relevant for me to with attentive to, and which information is “background noise”). The cortex will then put the energy facilities towards processing of the chosen piece of information/stimuli.


If the filtering of this “information choice” is not efficiently, it is hard to focus and can create a state of anxiety in some people.


One process that gets the cortex to shift into a state of attention and focus is called PHASE LOCKING, which occurs when millions of neurons become synchronized on the order of milliseconds in order to assess a new event. During phase shifts the neurons become unsynchronized so that a new set of neurons can become recruited to assess the next event.

In ME brains, the phase locking is very fast. Phase shifts need to last long enough for the brain to recruit enough neurons to assess new event but that didn’t appear to be happening in the ME/CFS patient. Plus, the phase lock process was being broken so quickly that the few neurons that were engaged didn’t have the time needed to analyse the event.


3. Alpha Rhythms Down

Study by Zinn et.al. found reduced alpha across the entire occipital lobe and extending into portions of the parietal, temporal and limbic lobes.

The reduced alpha wave activity found across a large part of the brain can help explain why it’s so difficult sometimes for people with ME/CFS to get into action, and why they have both sensory and movement problems.

Another study by Katherine M. Billiot (1997) found low alpha peak at Cz in ME/CFS brains.


4. Excess of slow frequencies, Theta and Delta Rhythms Increased

In contrast to the decreased alpha rhythms, the Zinn’s found increased delta rhythms across another large swath of the brain (frontal-limbic regions in the superior frontal gyrus, the entire cingulate gyrus, medial frontal gyrus, orbito-frontal cortex, middle frontal gyrus, insula, superior temporal gyrus and in the rectal gyrus.

Katherine M. Billiot (1997) found that CFS subjects displayed greater impairment than non-patient comparison subjects in that they generated higher activity in the lower frequencies (5-7 Hz Theta) under both conditions.



5. Slower brain speed and energy facilities

In order for the brain to work properly it should arouse itself, focus on a task and then carry it out. The Zinn’s found evidence of lags in all three phases. The brain took longer than normal to arouse itself, stumbled as it tried to focus on a task, and then stumbled again as it tried to carry it out.


6. Weakened connectivity within the Default Mode Network

While most research studies focus was put on which brain areas are becoming MORE active when we are performing a cognitive task or trying to focus, there are some areas that become LESS active during task, and it is not less important that they do! The brain needs to learn when to activate and deactivate the relevant areas so our cognitive processing will be the most efficient.


The Default Mode Network (DMN) is one of them. The DMN is very active when we are doing "nothing" or resting, and it DECREASE its activity when we are on a cognitive task such as visual search, spatial attention, language and the practice of language, memory and imagery tasks.


The weakened coupling found within the salience network in ME brains – which determines how much attention to pay to internal or external stimuli – could be producing the different hypersensitivities found in ME/CFS.

This could lead to problems with self-reflection and mental activity. The capacity for self-reflection – which requires being in a rested yet wakeful state – can diminished greatly after getting ME/CFS.



7. High Beta on the left hemisphere and arousal of the amygdala

One study demonstrated the appearance of a 33.87 Hz localization including the left temporal lobe, Brodmann area 38 which according to NRF is injured in ME/CFS patients (Hyde, 2017), (LaBar & Phelps, 1998).


8. Hypoperfusion found in SPECT imaging assessment of ME/CFS Broca’s and Wernicke’s areas (F7 and F8 by the EEG 10-20 system)

Those areas are known to hold the brains primary tonotopic map and are the primary site of language comprehension in most humans; disturbances in these regions are highly correlated with receptive aphasia where incoming information both spoken and written is no longer intelligible to variable degrees (Weiner & Levitt, 1989). These are common NRF findings in ME/CFS (Hyde, 2017).


9. Imbalanced activity in the left fusiform gyrus

Inferior view of the SLORETA map shows the left fusiform gyrus is also affected. Left hemispheric disturbances in this region are known to be essential for the visual aspects of reading fluency, i.e. transcribing abstract symbols into visual percepts and is included among the ME/CFS cognitive deficits (McCandliss et al, 2003, Hyde 2017).


The right fusiform gyrus, in contrast to its left hemispheric counterpart is highly correlated with prosopagnosia - the inability to recognize faces and represents a common NRF finding in ME/CFS (Barton et al, 2002, Hyde, 2017).


10. Imbalanced activity in the left hippocampus (Garouette 1987).

Lesions in this area have long been associated with the impairments of both immediate and delayed memory recall as exemplified in Alzheimer’s dementia (Kohler, et al, 1998). Specifically, the left hippocampus is associated with memory of spoken words termed verbal memory, and episodic memory i.e. recall of sequentially ordered events (Stepankova et al, 2004).


Moments of insight where new ideas burst forth into consciousness are known to be correlated with the right hippocampus representing a significant reduction in problem solving ability and creativity (Luo & Niki, 2003).


11. Low SMR at Cz

The study by Katherine M. Billiot (1997) found significantly lower SMR frequency range during performance of a cognitive task







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Materials in this article were extracted and organised from the following full articles:


• Full article by Zinn: https://www.sciforschenonline.org/journals/clinical-research/article-data/CLROA-2-110/CLROA-2-110.pdf

https://www.healthrising.org/blog/2016/07/25/chronic-fatigue-syndrome-brain-under-functioning/

• Duffy FH, McAnulty GB, McCreary MC, Cuchural GJ, Komaroff AL. EEG spectral coherence data distinguish chronic fatigue syndrome patients from healthy controls and depressed patients--a case control study. BMC Neurol. 2011 Jul 1;11:82. doi: 10.1186/1471-2377-11-82. PMID: 21722376; PMCID: PMC3146818.

• M.A, Katherine & Ph.D, Thomas & Andrasik, Frank. (1997). EEG Patterns and Chronic Fatigue Syndrome. Journal of Neurotherapy. 2. 20-30. 10.1300/J184v02n02_04.