Prevalence of Extreme Trait Sensory Profiles and Personality Types in Nonspecific Chronic Low Back Pain with Predominant Central Sensitization: Secondary Analysis of an International Observational Study

Abstract

Background: Individuals with nonspecific chronic low back pain (NSCLBP) and central sensitization (CS) exhibit sensory hypersensitivity that may be related to pre-existing trait characteristics. Sensory profiles and trait anxiety-related characteristics have sensory sensitivity in common with CS. Objectives: The objectives of this study were 1) to observe the prevalence of 4 personality types and extreme scores of 4 trait sensory profiles in people with NSCLBP and predominant CS; and 2) to compare these between 2 subgroups based on high and low self-reported CS symptoms. Study Design: An international cross-sectional observational study was undertaken. Setting: Adults (n = 165; mean age = 45 ± 12 standard deviation) were recruited from physiotherapy clinics across 3 countries and 2 continents. Methods: The inclusion criteria were: NSCLBP, aged 18-64 years, with clinically identified predominant CS pain, without specific pathology. The outcome measures were: Central Sensitization Inventory (CSI), Adolescent/Adult Sensory Profile, State/Trait Anxiety Inventory, and Marlowe Crowne Social Desirability Scale. Descriptive and comparative statistics were used. Results: CSI scores ranged from 19-79 (mean = 50). There was a high prevalence of extreme 1) trait sensory hyper- and, unexpectedly, hyposensitivity profile scores (P < 0.001) and Defensive High Anxious personality type (P < 0.01) in the high-CSI (CSI ≥ 40; 78%) subgroup, and 2) trait sensory hyposensitivity profile scores (P < 0.01) and Repressor personality type (P < 0.01) in the low-CSI subgroup (CSI < 40; 22%). Limitations: Self-report measures only were used; limited demographics. Conclusions: To our knowledge, these results are the first to demonstrate extreme trait sensory profiles and personality types in people with NSCLBP and predominant CS. A subgroup who reports low levels of CS symptoms may have a hyposensitive sensory profile and Repressor personality type. Further study is required to investigate the extent to which these trait characteristics may predict CS symptoms in people with NSCLBP. Key words: Central sensitization, nonspecific chronic low back pain, prevalence of extreme trait characteristics, sensory profiles, trait anxiety-related personality types