Background & Aims
Neuropathic eye pain arises from damage or disease affecting sensory corneal nerves, causing abnormal sensations. Additionally, systemic conditions impacting the somatosensory pathway can contribute to development of this type of pain. Neuropathic eye pain is minimally responsive to available medications and other treatments. Current evidence shows the potential for electroencephalography (EEG) neurofeedback to reduce neuropathic pain. The objective of this trial was to evaluate the efficacy and usability of a home-based self-directed EEG neurofeedback intervention for people with neuropathic eye pain in a single-case experimental design (SCED) with four participants.
Methods
The EEG neurofeedback system used in this study was an in-house-developed headset with gamified software. Games were designed to reinforce sensorimotor rhythms and suppress high-beta and theta bands. Four individuals with neuropathic eye pain underwent the intervention in a SCED trial with random baseline phase durations (7, 10, 14, or 17 days), followed by a 20-day intervention (5×2.5-minute games daily). Pain severity was assessed daily throughout baseline and intervention phases, by averaging the BPI-Pain Severity questions. In visual analyses, we tested the stability of the baseline phase and calculated the Percentage Exceeding the Median (PEM) effect size for each participant. For statistical analysis, Tau-U effect size was computed to determine the overall intervention effect size across all participants, accounting for any baseline trend. Further, the System Usability Scale (SUS) and a Zoom interview post-intervention were used to assess the system’s usability and acceptability.
Results
Visual analyses indicated stable pain severity assessment during the baseline phase for all participants. Notably, participant (P) 1 and P4 had high percentages (60% and 95%) of intervention datapoints exceeding the baseline median, reflecting substantial pain reduction between the baseline and intervention phases based on the PEM effect size. Additionally, statistical analysis revealed a moderate Tau-U effect size (-0.33, 95%CI: [-0.54, -0.10], p<.001) in pain severity between the baseline and intervention phases across all participants, accounting for the baseline trend in P4. In essence, this suggests a moderate yet significant improvement in pain severity between baseline and intervention phases across all participants. Further, both quantitative (SUS scores) and qualitative (Zoom interview) assessments revealed that the participants with neuropathic eye pain found the intervention easy to use and acceptable.
Conclusions
This trial provides preliminary evidence for the possible efficacy and user experience of a home-based self-directed EEG neurofeedback intervention in reducing neuropathic eye pain. While the visual analyses support the efficacy in pain severity for two participants, the statistical analysis indicates an overall moderate effect size across all four. In addition, quantitative and qualitative assessments confirmed the intervention’s perceived ease-of-use and acceptability. Although a SCED is a valuable approach to evaluate technological health interventions with small sample sizes and a focus on individual-level effects, further investigations through group-based designs are necessary for drawing more definitive conclusions about the efficacy of this approach.
References
Moshirfar M, Benstead EE, Sorrentino PM, et al. Ocular Neuropathic Pain. [Updated 2023 Aug 25]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542282/
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Presenting Author
Negin Hesam-Shariati
Poster Authors
Negin Hesam-Shariati
PhD
NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, Australia
Lead Author
Lara Alexander
NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, Australia
Lead Author
Fiona Stapleton
School of Optometry and Visual Science, University of New South Wales, Sydney, Australia
Lead Author
Toby Newton-John
Graduate School of Health, University of Technology Sydney, Sydney, Australia
Lead Author
Chin-Teng Lin
CIBCI Lab, Australian AI Institute, FEIT, University of Technology Sydney, Sydney, Australia
Lead Author
Pauline Zahara
NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, Australia
Lead Author
Kevin Chen
NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, Australia
Lead Author
Ian W. Skinner
Graduate School of Health, University of Technology Sydney, Sydney, Australia
Lead Author
Paul A. Glare
Faculty of Medicine and Health, University of Sydney, Sydney, Australia
Lead Author
James McAuley
Centre for Pain IMPACT, Neuroscience Research Australia, Sydney, Australia
Lead Author
G. Lorimer Moseley
IIMPACT in Health, University of South Australia, Adelaide, Australia
Lead Author
Mark P. Jensen
Department of Rehabilitation Medicine, University of Washington, Seattle, USA
Lead Author
Sylvia M. Gustin
NeuroRecovery Research Hub, School of Psychology, University of New South Wales, Sydney, Australia
Lead Author
Topics
- Specific Pain Conditions/Pain in Specific Populations: Neuropathic Pain - Peripheral