Central sensitization adversely affects quality of recovery following lumbar decompression surgery

Is chronic pain caused by central sensitization? A review and critical point of view

Chronic pain causes disability and loss of health worldwide. Yet, a mechanistic explanation for it is still missing. Frequently, neural phenomena, and among them, Central Sensitization (CS), is presented as causing chronic pain. This narrative review explores the evidence substantiating the relationship between CS and chronic pain: four expert researchers were divided in two independent teams that reviewed the available evidence. Three criteria were established for a study to demonstrate a causal relationship: (1) confirm presence of CS, (2) study chronic pain, and (3) test sufficiency or necessity of CS over chronic pain symptoms. No study met those criteria, failing to demonstrate that CS can cause chronic pain. Also, no evidence reporting the occurrence of CS in humans was found. Worryingly, pain assessments are often confounded with CS measures in the literature, omitting that the latter is a neurophysiological and not a perceptual phenomenon. Future research should avoid this misconception to directly interrogate what is the causal contribution of CS to chronic pain to better comprehend this problematic condition.

Does Central Sensitization Influence Outcomes of Lumbar Discectomy Surgery in Patients With Lumbar Disc Herniation? A Multicenter Prospective Study

STUDY DESIGN

Multicenter prospective study.

OBJECTIVE

Patients with central sensitization (CS) are reported to be at high risk of poor outcomes after spinal surgery. However, the influence of CS on surgical outcomes for lumbar disc herniation (LDH) remains unknown. This study aimed to examine the association between preoperative CS and surgical outcomes in LDH patients.

METHODS

A total of 100 consecutive patients with LDH (mean age 51.2) who underwent lumbar surgery were included in this study. The extent of CS was evaluated using the central sensitization inventory (CSI), a screening tool for CS-related symptoms. The patients completed the following CSI and clinical outcome assessments (COAs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for back pain, JOA back pain evaluation questionnaire (JOABPEQ), and Oswestry Disability Index (ODI). The association between preoperative CSI scores, and preoperative and postoperative COAs was analyzed, and the postoperative changes were statistically evaluated.

RESULTS

The preoperative CSI score significantly decreased 12 months postoperatively. Preoperative CSI scores showed a significant correlation with most COAs; however, a significant correlation was only identified in the social function and mental health domains of JOABPEC postoperatively. Higher preoperative CSI showed worse preoperative COAs; however, all COAs significantly improved regardless of CSI severity. There were no significant differences in any COAs among the CSI severity groups 12 months postoperatively.

CONCLUSIONS

The results of this study showed that lumbar surgeries significantly improved the COAs regardless of preoperative severity of CS in patients with LDH.