Exploring the associations of cortical connectivity-modulation with clinical and psychological measures in acute low back pain.

BACKGROUND: Low back pain (LBP) represents a significant global health burden. Transitioning from the traditional "self-limiting" perspective, emerging evidence suggests that neural plasticity and central maladaptation in the acute phase are pivotal in the progression to chronicity. OBJECTIVES: This study investigated whole-brain functional connectivity and sensorimotor processing during acute LBP. METHODS: Thirteen participants with acute LBP (<4 weeks duration) underwent clinical, psychometric, and functional magnetic resonance imaging (fMRI) assessments. Brain activity and connectivity were mapped during lumbar mechanosensory stimulation, with a focused analysis on sensorimotor, salience, cerebellar, and limbic networks. RESULTS: Pain intensity demonstrated a negative correlation with posterior supramarginal-precuneus connectivity and a positive correlation with cerebellar activity. Fear-avoidance behavior was positively associated with connectivity across a cerebellar-limbic axis (cerebellum, brainstem, and hippocampus). Furthermore, mechanical pain summation (wind-up ratio) and movement control impairments were significantly linked to connectivity shifts within the salience and sensorimotor-lateral networks. CONCLUSION: These findings demonstrate that acute LBP is characterized by immediate widespread neuronal reorganization. The modulation of these networks by pain intensity and motor dysfunction suggests an early interplay between sensory, motor, and affective processing. Identifying these neural signatures provides a mechanistic framework for targeted biopsychosocial interventions designed to intercept the transition from acute pain to chronic disability.