This pilot randomized controlled trial (RCT) aims to investigate the feasibility and efficiency of delivering different rTMS protocols in individuals with CLBP and insomnia. Participants will be randomly assigned to either the primary motor cortex (M1) rTMS, the dorsolateral prefrontal cortex (DLPFC) rTMS, or sham stimulation.

Sleep disturbance exacerbates pain perception, disability, and poor prognosis in individuals with chronic low back pain (CLBP). A recent systematic review demonstrated that improvements in sleep disturbance were associated with corresponding improvements in pain intensity, recovery, and disability in individuals with CLBP. These findings indicate that achieving restorative sleep is likely to mitigate chronic pain symptoms. The application of rTMS at a specific frequency over a focal brain area has been proposed as a promising treatment for chronic pain and insomnia independently. To date, no studies have compared the effectiveness of different rTMS protocols in treating comorbid CLBP and insomnia. Given the above, the current study aims to investigate the feasibility and acceptability of delivering different rTMS protocols in individuals with CLBP and insomnia and explore the relative therapeutic efficacy of these protocols on pain and sleep parameters at immediate post-treatment and one-month follow-up.

Inclusion Criteria:

1. participants aged between18 and 65 years;
2. willing to participate in the study and randomization;
3. having stable pharmacological or nonpharmacological treatments for pain or sleep at least one month prior to study participation;
4. having CLBP (defined as pain between 12 ribs and gluteal crease with or without leg pain that has persisted for at least three months)
5. diagnosing insomnia using the Brief Insomnia Questionnaire (BIQ) based on the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5)

Exclusion Criteria

1. specific causes of CLBP (e.g., spondylosis, spondyloarthropathy, or vertebral fracture);
2. pregnancy or nursing;
3. previous spinal surgery;
4. inflammatory or autoimmune diseases;
5. other sleep disorders (e.g., sleep apnea or restless leg);
6. presence of severe psychopathologies, neurological, or physical disease directly related to the onset of insomnia (e.g., depression, substance abuse, or alcohol abuse);
7. severe dependence on hypnotic drugs;
8. concurrent receipt of new treatments outside the scope of the study;
9. contraindications to use rTMS (e.g., severe head trauma, intracranial hypertension, implanted ferromagnetic devices, history of epilepsy).

Group assignment will be concealed through opaque and sealed envelopes, which will be administered by a research assistant who is not involved in the study. The envelopes will be opened after the participant consented to participate in the trial. Assessors, participants, and therapists will be blind to the allocation of rTMS.