Chronic low back pain as a multisystemic phenotype: an exploratory analysis of neurosensory and psychovisceral associations

Background: Chronic low back pain (CLBP) is a major global cause of disability. In some patients, persistent pain may coexist with sensory, neurological, visceral, autonomic, and other extra-musculoskeletal symptoms. These manifestations have been discussed in the literature in relation to central sensitization and altered sensory processing, although such mechanisms require specific psychophysical or neurophysiological assessment. Aim: To identify clinical symptom profiles in CLBP across sensory, neurological, gastrointestinal, urinary, autonomic, and related domains and to examine their association with pain intensity. Methods: A cross-sectional observational study was conducted at XXXX. Adults with non-specific CLBP ≥ 12 weeks were included. Patients were classified into three mutually exclusive clinical profiles according to the distribution of symptoms across predefined domains: isolated, psychovisceral, and neurosensory. Pain intensity was assessed using the Visual Analog Scale (VAS). Analyses included the Shapiro-Wilk test, Kruskal-Wallis test with Bonferroni-adjusted Mann-Whitney U tests, and chi-square test. Results: A total of 208 patients were included (n = 64 isolated, n = 27 psychovisceral, and n = 117 neurosensory). Age and gender did not differ significantly across groups. VAS scores differed significantly among the three profiles (Kruskal-Wallis p = 0.001), with higher pain intensity in both the psychovisceral and neurosensory groups compared with the isolated CLBP group (Bonferroni-adjusted p = 0.0134 and p = 0.0024, respectively). No significant difference was observed between the psychovisceral and neurosensory groups. Conclusions: Distinct multisystemic clinical symptom profiles were observed in patients with CLBP and were associated with differences in pain intensity. These findings support further investigation of multisystemic symptom patterns in CLBP but do not establish central sensitization or altered sensory processing as underlying mechanisms.