Brain activity alterations following lumbar discectomy in people with chronic low back pain

Chronic low back pain (CLBP) remains a major clinical and socioeconomic challenge, particularly among individuals who continue to experience pain following lumbar discectomy. Despite advances in imaging and treatment, the neural mechanisms underlying persistent postoperative pain are not fully understood.

To evaluate cortical brain activity using quantitative electroencephalography (QEEG) in individuals with a history of L5/S1 discectomy and CLBP, compared with healthy controls.

In this cross-sectional study forty participants (20 with post-discectomy (PD) low back pain and 20 healthy controls) underwent EEG recordings under three conditions: eyes open, eyes closed, and visual stimulation with pain-related lumbar spine images. EEG data were analyzed using standardized low-resolution electromagnetic tomography (sLORETA) to assess relative power and current source density (CSD) across eight frequency bands. Group differences were evaluated using mixed repeated-measures ANOVA. Pain intensity and psychosocial factors were assessed using the Visual Analog Scale (VAS) and the Pain Catastrophizing), fear avoidance, Kinesiophobia and quality of life questionnaires.

Significant group differences in cortical activity were observed across conditions. During pain-related visual stimulation, the post-discectomy group demonstrated reduced delta power and elevated theta and alpha power. Source localization indicated altered CSD in multiple cortical regions, including areas involved in processing of pain-related visual stimuli. Psychosocial factors and VAS scores were significantly higher in the patient group, suggesting that cognitive-emotional factors may be associated with the experience of persistent postoperative pain.

QEEG showed distinct cortical activity patterns in individuals with CLBP after discectomy, especially during pain-related visual stimulation. These findings may reflect alterations in cortical processing associated with persistent postoperative pain and suggest that QEEG may provide useful insights into the neurophysiological changes associated with chronic pain.