Brain Connectomic Mechanisms of Spinal Manipulative Therapy on LDH Analgesia Based on Multimodal MRI

Overview

Low back and leg pain caused by lumbar disc herniation (LDH) is common. Lever positioning manipulation (LPM) is a spinal manual therapy used to relieve this pain, but how it affects the brain is unclear. This study will compare active LPM with a sham procedure and use multimodal magnetic resonance imaging (MRI) to investigate changes in brain networks associated with pain relief. A total of 84 adults with LDH will be randomly assigned in a 1:1 ratio to active LPM or sham LPM, with three sessions per week for 12 weeks. An additional 42 age- and sex-matched healthy adults will undergo baseline assessments without treatment. Participants with LDH will be assessed before treatment, immediately after the first session, at week 6, and at week 12. Outcomes include pain intensity, lumbar function, disability, adverse events, and MRI measures of functional and structural brain connectivity. The study aims to identify brain connectomic mechanisms associated with LPM-induced analgesia.

This is a single-center, prospective, randomized, participant- and outcome-assessor-masked, sham-controlled study with a matched healthy control cohort. Eighty-four participants with lumbar disc herniation will be randomly allocated 1:1 to active lever positioning manipulation or sham lever positioning manipulation using a computer-generated block randomization sequence prepared by an independent statistician. Allocation will be concealed in sequentially numbered, opaque, sealed envelopes. Forty-two age- and sex-matched healthy controls will complete baseline clinical and MRI assessments only. Active and sham treatments will be delivered three times weekly for 12 weeks, with approximately 20 minutes per session. The sham procedure will reproduce the treatment setting, participant position, preparatory procedures, and practitioner contact but will omit the rapid lever-pulling maneuver. Analgesics, neurotrophic drugs, sedatives, spinal manipulation, acupuncture, traction, and other therapies that could affect pain or MRI outcomes will be prohibited during the treatment period. Participants with LDH will be assessed at baseline before randomization, immediately after the first treatment session, at week 6, and at week 12. The primary outcome is change in pain intensity measured by the Visual Analog Scale from baseline to week 12. Secondary clinical outcomes include lumbar function measured by the Japanese Orthopaedic Association score and disability measured by the Oswestry Disability Index. Multimodal MRI will be used to evaluate longitudinal changes in functional network topology, white-matter structural connectivity, and structure-function coupling. Exploratory analyses will examine gray-matter covariance and associations between clinical improvement and imaging changes. Safety will be assessed through adverse-event monitoring and vital-sign checks at each treatment session.