Study suggests brainwave link between disparate disorders

May 24, 2018 by Stephen Fontenot, University of Texas at Dallas
This summary figure shows the spatial distribution of theta-beta and theta-gamma cross-frequency coupling as they relate to different syndromes. Credit: University of Texas at Dallas

A brainwave abnormality could be a common link between Parkinson's disease, neuropathic pain, tinnitus and depression—a link that authors of a new study suggest could lead to treatment for all four conditions.

Dr. Sven Vanneste, an associate professor in the School of Behavioral and Brain Sciences at The University of Texas at Dallas, is one of three authors of a paper in the journal Nature Communications regarding thalamocortical dysrhythmia (TCD), a theory that ties a disruption of brainwave activity to the symptoms of a wide range of neurological disorders.

Vanneste and his colleagues—Dr. Jae-Jin Song of South Korea's Seoul National University and Dr. Dirk De Ridder of New Zealand's University of Otago—analyzed electroencephalograph (EEG) and functional brain mapping data from more than 500 people to create what Vanneste believes is the largest experimental evaluation of TCD, which was first proposed in a paper published in 1996.

"We fed all the data into the computer model, which picked up the brain signals that TCD says would predict if someone has a particular disorder," Vanneste said. "Not only did the program provide the results TCD predicted, we also added a spatial feature to it. Depending on the disease, different areas of the brain become involved."

Brainwaves are the rapid-fire rhythmic fluctuations of electric voltage between parts of the brain. The defining characteristics of TCD begin with a drop in brainwave frequency—from alpha waves to theta waves when the subject is at rest—in the thalamus, one of two regions of the brain that relays sensory impulses to the cerebral cortex, which then processes those impulses as touch, pain or temperature.

A key property of alpha waves is to induce thalamic lateral inhibition, which means that specific neurons can quiet the activity of adjacent neurons. Slower theta waves lack this muting effect, leaving neighboring cells able to be more active. This activity level creates the characteristic abnormal rhythm of TCD.

"Because you have less input, the area surrounding these neurons becomes a halo of gamma hyperactivity that projects to the cortex, which is what we pick up in the brain mapping," Vanneste said.

While the signature alpha reduction to theta is present in each disorder examined in the study—Parkinson's, pain, tinnitus and depression—the location of the anomaly indicates which disorder is occurring.

"If it's in the auditory cortex, it's going to be tinnitus; if it's in the somatosensory cortex, it will be pain," Vanneste explained. "If it's in the motor cortex, it could be Parkinson's; if it's in deeper layers, it could be depression. In each case, the data show the exact same wavelength variation—that's what these pathologies have in common. You always see the same pattern."

EEG data from 541 subjects was used. About half were healthy control subjects, while the remainder were patients with tinnitus, chronic pain, Parkinson's disease or major depression. The scale and diversity of this study's data set are what set it apart from prior research efforts.

"Over the past 20 years, there have been pain researchers observing a pattern for pain, or tinnitus researchers doing the same for tinnitus," Vanneste said. "But no one combined the different disorders to say, 'What's the difference between these diseases in terms of brainwaves, and what do they have in common?' The strength of our paper is that we have a large enough data sample to show that TCD could be an explanation for several neurological diseases."

With these results in hand, the next step could be a treatment study based on vagus nerve stimulation—a therapy being pioneered by Vanneste and his colleagues at the Texas Biomedical Device Center at UT Dallas. A different follow-up study will examine a new range of psychiatric diseases to see if they could also be tied to TCD.

For now, Vanneste is glad to see this decades-old idea coming into focus.

"More and more people agree that something like thalamocortical dysrhythmia exists," he said. "From here, we hope to stimulate specific areas involved in these diseases at alpha frequencies to normalize the brainwaves again. We have a rationale that we believe will make this type of therapy work."

Explore further: Trial results positive for tinnitus sufferers

More information: Sven Vanneste et al. Thalamocortical dysrhythmia detected by machine learning, Nature Communications (2018). DOI: 10.1038/s41467-018-02820-0

Related Stories

Trial results positive for tinnitus sufferers

November 21, 2013
UT Dallas researchers have demonstrated that treating tinnitus, or ringing in the ears, using vagus nerve stimulation-tone therapy is safe and brought significant improvement to some of the participants in a small clinical ...

Study finds the frequency of alpha brain waves could be used to assess a person's predisposition to pain

March 28, 2018
The frequency of alpha brain waves can be used as a measure of an individual's vulnerability to developing and experiencing pain, researchers at the University of Birmingham in the UK and University of Maryland in the US ...

Personalizing therapeutic brain stimulation

May 21, 2018
A study of epilepsy patients with implanted electrodes provides an unprecedented view of the changes in brain activity created by electrical stimulation. These findings, published in JNeurosci, have the potential to improve ...

In search of tinnitus, that phantom ringing in the ears

April 23, 2015
About one in five people experience tinnitus, the perception of a sound—often described as ringing—that isn't really there. Now, researchers reporting in the Cell Press journal Current Biology on April 23 have taken advantage ...

Neurofeedback shows promise in treating tinnitus

November 27, 2017
Researchers using functional MRI (fMRI) have found that neurofeedback training has the potential to reduce the severity of tinnitus or even eliminate it, according to a study presented today at the annual meeting of the Radiological ...

Mindfulness—a new treatment for tinnitus

January 3, 2018
A randomized controlled trial published in the current issue of Psychotherapy and Psychosomatics discloses the effectiveness of mindfulness-based cognitive therapy as a treatment for chronic tinnitus. Tinnitus is experienced ...

Recommended for you

Classifying brain microglia: Which are good and which are bad?

December 6, 2018
Microglia are known to be important to brain function. The immune cells have been found to protect the brain from injury and infection and are critical during brain development, helping circuits wire properly. They also seem ...

Friend or foe? Brain area that controls social memory also triggers aggression

December 5, 2018
Columbia scientists have identified a brain region that helps tell an animal when to attack an intruder and when to accept it into its home. This brain area, called CA2, is part of the hippocampus, a larger brain structure ...

How the brain hears and fears

December 5, 2018
How is it that a sound can send a chill down your spine? By observing individual brain cells of mice, scientists at Cold Spring Harbor Laboratory (CSHL) are understanding how a sound can incite fear.

Adding new channels to the brain remote control

December 5, 2018
By enabling super-fast remote control of specific cells, light-activated proteins allow researchers to study the function of individual neurons within a large network—even an entire brain. Now one of the pioneers of 'optogenetics' ...

Microbial-based treatment reverses autism spectrum social deficits in mouse models

December 4, 2018
An unconventional approach has successfully reversed deficits in social behaviors associated with autism spectrum disorders (ASD) in genetic, environmental and idiopathic mouse models of the condition. Researchers at Baylor ...

'Error neurons' play role in how brain processes mistakes

December 4, 2018
New research from Cedars-Sinai has identified neurons that play a role in how people recognize errors they make, a discovery that may have implications for the treatment of conditions including obsessive-compulsive disorder ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.