Use these resources to provide understandable information about this study to patients, families, and health care providers:

The present randomized clinical trial (RCT), conducted at the IRCCS Carlo Besta Neurological Institute, aims to evaluate the effectiveness of Pain Reprocessing Therapy (PRT), a form of psychological support/psychotherapy based on cognitive-behavioral therapy, which has already proven effective in the treatment of other types of primary chronic pain.

Chronic Primary Orofacial Pain (CPOP) is a rare and complex form of chronic pain that predominantly affects adult women and occurs without evident lesions, yet has a significant emotional and functional impact. It was recently classified among chronic primary pain conditions in the ICD-11 and is considered a form of nociplastic pain, associated with alterations in brain connectivity. At present, pharmacological treatments have shown limited effectiveness.

This randomized clinical trial (RCT), conducted at the IRCCS Carlo Besta Neurological Institute, aims to evaluate the effectiveness of Pain Reprocessing Therapy (PRT), a form of psychological support/psychotherapy based on cognitive-behavioral therapy, which has already proven effective in the treatment of other types of primary chronic pain.

Sixty participants, all diagnosed with CPOP according to ICD-11 criteria, will be selected and randomly assigned to two groups: one will receive PRT, the other will receive treatment as usual (TAU).

The primary outcome of the study is the assessment of pain intensity reduction. Secondary outcomes include a broad range of psychosocial variables: improvement in quality of life, reduction of anxiety-depressive symptoms, catastrophizing, and other psychopathological traits. The effects of the therapy on brain connectivity will also be analyzed using fMRI, and on pain neurophysiology through the Conditioned Pain Modulation (CPM) paradigm. The protocol provides for the evaluation of therapy effectiveness at three follow-ups (3, 6, and 12 months) in order to measure the duration of effects.

Finally, through advanced statistical analysis tools and the support of artificial intelligence, the study also aims to identify specific clinical-neurofunctional profiles that may be useful for differential diagnosis and for tailoring therapeutic interventions.

Inclusion Criteria:

• Diagnosis of Chronic Primary Orofacial Pain (CPOP) according to ICD-11 criteria.
• Patient-reported pain rating of 4 or higher out of 10 on the Brief Pain Inventory (BPI) question assessing average pain over the past week, consistent with inclusion criteria from previous chronic pain studies.
• Written informed consent.
• Age 18 years or older.

Exclusion Criteria:

• Age over 70 years.
• Current use of immunosuppressive medications (e.g., steroids).
• History of cancer (breast, thyroid, prostate, blood cancers, etc.).
• History of stroke, neurosurgical interventions, or brain tumors.
• History of specific inflammatory diseases (lupus, scleroderma, rheumatoid arthritis, polymyalgia rheumatica).
• History of psychiatric disorders such as schizophrenia, personality disorders, dissociative identity disorder, or other severe psychoses.
• Unexpected or unintentional weight loss of 10 kg or more in the year prior to recruitment.
• Difficulty participating due to logistical problems.
• Contraindications to undergoing functional magnetic resonance imaging (fMRI).
• Psychotherapy treatment of any kind within 15 months prior to the assessment date.