Background & Aims

The use of EEG has been suggested as a useful biomarker of brain function in chronic pain. However, there are few reports using EEG to identify specific changes in brain activity associated with chronic low back pain. The purpose of this study was to examine the correlation between current source density distribution in resting EEG and symptoms in patients with chronic low back pain using open EEG data.

Methods

EEGs of 34 patients with chronic low back pain (18 women, mean age: 56.56 ± 12.74 years) and 34 healthy subjects (20 women, mean age: 58.53 ± 13.32 years) in an open data set obtained at the Technical University of Munich were analyzed [1].The 5-minute resting closed-eye EEG was performed using the international 10-20 system, based on 19 channels (reference electrode: FCz); a 1-50 Hz bandpass filter was set to remove AC noise, and independent component analysis was performed to remove artifactual components. The current source density distribution was then analyzed using exact low-resolution electromagnetic tomography analysis (eLORETA), and the results were compared between chronic low back pain patients and healthy subjects using the statistical nonparametric mapping method (SnPM) [2]. We also analyzed the correlation between pain symptoms and current source density distribution in patients with chronic low back pain.

Results

Current source density distribution was not significantly different between the two groups; in the theta (6.5-8 Hz) frequency band, there was a positive correlation between pain symptom values from the McGill total score and current source density distribution in the left prefrontal cortex. In the delta (1.5-6.0 Hz) frequency band, there was a positive correlation between pain symptom values measured by Current Pain and current source density distribution in the left prefrontal cortex.

Conclusions

In patients with chronic low back pain, subjective pain symptoms correlated with slow wave activity in the left prefrontal cortex. These results are consistent with previous findings [3] and suggest that increased ?- and ?-frequency activity in the left prefrontal cortex may be involved in the pathophysiology of chronic low back pain and may be a promising biomarker for noninvasive brain stimulation and neurofeedback.

References

1. May ES, Ávila CG, Dinh ST et al. Dynamics of brain function in patients with chronic pain assessed by microstate analysis of resting-state electroencephalography. Pain. 2021;162(12):2894-2908. doi: 10.1097/j.pain.0000000000002281.
2. Pascual-Marqui RD, Lehmann D, Koukkou M et al. Assessing interactions in the brain with exact low-resolution electromagnetic tomography. Philos Trans A Math Phys Eng Sci. 2011;369(1952):3768-84. doi: 10.1098/rsta.2011.0081.

Presenting Author

Keiko Yamada

Poster Authors

Keiko Yamada

MD

Juntendo University

Lead Author

E-mail

Keita Ueno

Graduate School of Rehabilitation Science, Osaka Metropolitan University

Lead Author

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Masaya Ueda

Graduate School of Rehabilitation Science, Osaka Metropolitan University

Lead Author

E-mail

Yasuo Naito

Graduate School of Rehabilitation Science, Osaka Metropolitan University

Lead Author

E-mail

Ryouhei Ishii

Graduate School of Rehabilitation Science, Osaka Metropolitan University

Lead Author

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Topics

  • Pain Imaging

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