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Infra-Low Frequency Neurofeedback for the Treatment of Post-Concussive Symptoms: Findings from a New Study

04. April 2025

Concussions, also known as mild traumatic brain injury (mTBI), are often considered a temporary injury. However, many victims, especially veterans, suffer from chronic headaches, sleep disorders and cognitive impairment for years after the original event. Despite existing therapeutic approaches, the treatment of these symptoms remains a challenge.

A recently published randomised controlled trial by Carlson et al. investigated the efficacy of Infra-Low Frequency Neurofeedback (ILF NFB) as a potential non-invasive treatment method. Veterans with long-lasting post-coma symptoms were treated with ILF NFB over several weeks. The results show significant improvements in several key areas.

What is Infra-Low Frequency Neurofeedback?
Neurofeedback is a form of biofeedback in which patients can improve their ability to self-regulate by visualising their brain activity in real time. Electrical signals from the brain are recorded via electrodes and played back in the form of sounds or visual elements. In this way, the activity of the brain and the symptoms of illnesses can be better regulated.
Infra-Low Frequency Neurofeedback (ILF NFB) focusses on extremely slow brain waves below 0.1 Hz.

The study: design and methodology
In order to investigate whether ILF NFB can actually help to alleviate post-commotion symptoms, researchers conducted a randomised controlled trial with 87 veterans suffering from persistent symptoms.

Participants and procedure
The participants in the study were randomly divided into two groups.
The intervention group received 20 sessions of ILF NFB, each lasting 30 minutes, over a period of 8 to 10 weeks.
The control group instead received eight short health talks covering general topics such as stress management and sleep hygiene.
During the study, all participants continued their regular medical treatments.

Measurement of symptoms
Various standardised test procedures were used to assess the effects of the treatment:

  • Headache: Headache Impact Test (HIT-6)
  • Sleep quality: Insomnia Severity Index (ISI)
  • Cognitive performance: attention tests (QIK test)
  • Mental stress: questionnaires on depression, PTSD and quality of life

Measurements were taken before treatment, after 4-6 weeks, after completion of therapy (after 8-10 weeks) and two months after the end of treatment.

Results: Clinically relevant improvements
At the end of the treatment, participants who received ILF NFB experienced significant improvements in several areas.

Headaches and pain perception
The ILF NFB group reported a noticeable reduction in headache intensity and frequency. The average score on the Headache Impact Test (HIT-6) decreased by 12.6 points, while the control group reported an improvement of only 1.9 points.

Sleep quality
Participants in the ILF NFB group fell asleep faster, had fewer waking phases at night and reported a higher quality of sleep.
The Insomnia Severity Index (ISI) improved by 11.7 points - a clear difference to the control group, which only showed an improvement of 1.4 points.

Cognitive performance
Participants in the ILF NFB group also performed significantly better than those in the control group in tests of attention and impulse control.

Mental stress and quality of life
The ILF NFB group recorded a noticeable improvement in depressive symptoms and post-traumatic stress disorder (PTSD).
The general quality of life increased significantly, which was reflected in better scores on the QOLIBRI test.

Conclusion
The results of the study suggest that ILF NFB may be a promising non-drug treatment option for post-coma symptoms. Of particular note are the improvements in headache, sleep quality and cognitive performance, which remained stable over the study period. The secondary results of the present study also indicate that ILF neurofeedback may be an effective treatment option for symptoms associated with depression and PTSD. In addition, it has a significant positive impact on the subjective quality of life of veterans with mTBI.

The detailed explanation, the implementation and the results of the study can be found here.