Abstract
This preliminary investigation aimed to assess beta (β) oscillation, a marker of the brain GABAergic signaling, as a potential objective pain marker, hence contributing at the same time to the mechanistic approach of pain management. This case–control observational study measured β electroencephalographic (EEG) oscillation in 12 right-handed adult male with chronic neuropathic pain and 10 matched controls (∼55 years). Participants were submitted to clinical evaluation (pain visual analog scale, Hospital Anxiety, and Depression scale) and a 24-min high-density EEG recording (BIOSEMI). Data were analyzed using the EEGlab toolbox (MATLAB), SPSS, and R. The global power spectrum computed within the low (Lβ, 13–20 Hz) and the high (Hβ, 20–30 Hz) β frequency sub-bands was significantly lower in patients than in controls, and accordingly, Lβ was negatively correlated to the pain visual analog scale (R = −0.931, p = 0.007), whereas Hβ correlation was at the edge of significance (R = −0.805; p = 0.053). Patients’ anxiety was correlated to pain intensity (R = 0.755; p = 0.003). Normalization of the low and high β global power spectrum (GPS) to the GPS of the full frequency range, while confirming the significant Lβ power decrease in chronic neuropathic pain patients, vanished the significance of the Hβ decrease, as well as the correlation between Lβ power and pain intensity. Our results suggest that the GABAergic Lβ EEG oscillation is affected by chronic neuropathic pain. Confirming the Lβ GPS decrease and the correlation with pain intensity in larger studies would open new opportunities for the clinical application of gamma-aminobutyric acid-modifying therapies.
Highlights
Pain is a major public health challenge, and a large number of available analgesic drugs do not prevent from high treatment failure rate (Mantha et al, 1993)
Only 12 patients and 10 controls were retained for the final analysis [mean age 54.4 (8.0) and 56.3 (15.6) years, respectively], as four patients had a Douleur Neuropathique 4 questions” (DN4) score
The present pilot study aimed at studying the β EEG oscillatory activity as a GABAergic marker indexing chronic pain, having in mind the need for a better and more objective evaluation and mechanistic classification of pain to improve analgesic treatment efficiency
Summary
Pain is a major public health challenge, and a large number of available analgesic drugs do not prevent from high treatment failure rate (Mantha et al, 1993). Pain can be evaluated by means of several clinical tools, among which the Visual Analog Scale (VAS), the Numerical Rating Scale (Haefeli and Elfering, 2006; Hawker et al, 2011), and the Brief Pain Inventory (BPI), the latter taking into account the complexity and the impact of pain on multiple domains of life, such as sleep and mood (Cleeland and Ryan, 1994; Tan et al, 2004; Shi et al, 2017) These scales are all based on the patient’s subjective pain perception, which is influenced by many factors, such as the cognitive state, mood, etc. The need for a complementary evaluation, based on more objective criteria, e.g., biomarkers related to physiological pain mechanisms, that could contribute to characterize further and hopefully better manage pain (Archibald et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
