Assessing central nervous system contributions to accelerate musculoskeletal pain diagnosis and treatment (CNS-MSK Pain)

BACKGROUND: Chronic pain continues for more than 12 weeks despite treatment.

Chronic pain is the main symptom of muscle and joint problems, but is rarely adequately explained by damage to the muscle and joints.

Activity in central nervous system (CNS; nerves, spinal cord, and brain) pathways governs our ability to describe pain intensity and our emotional response to pain.

Musculoskeletal conditions (e.g., inflammatory arthritis, osteoarthritis, low back pain, fibromyalgia) share altered CNS activity, acknowledged by recent classifications of ‘primary’ and ‘nociplastic’ pain.

Clinically useful tools to diagnose and measure activity and reveal abnormalities in these CNS pathways are needed to improve clinical decisions and accelerate new treatment development. Laboratory pain sensitivity testing and brain imaging confirm the often predominant CNS contribution to pain. These assessments are less acceptable or unfeasible for clinical practice.

Simpler clinical pain sensitivity assessments are being developed.

Our simple Central Aspects of Pain (CAP) questionnaire evaluates CNS pain processing, and detects some people with pain sensitivity with knee, rheumatoid arthritis or low back pain.

Combining the CAP questionnaire and bedside pain sensitivity assessment, two different dimensions, should be better than either approach alone.

PURPOSE: To optimise the diagnosis and measurement of CNS as the predominant contributor to chronic musculoskeletal pain by using the CAP questionnaire and simple bedside pain sensitivity assessment to ensure timely, effective diagnosis and treatment. OBJECTIVES: 1.

Assess the ease, ability and performance of the combined CAP questionnaire and simple pain sensitivity assessment to identify CNS as the predominant contributor to chronic pain across musculoskeletal conditions. 2.

Use the CAP questionnaire alone or with substitute measures of activity in CNS pathways, demographic, and clinical variables to indicate pain levels at six and twelve weeks. 3.

Understand the relationship of CAP and simple pain sensitivity assessment with laboratory pain sensitivity assessments as a tool to inform the current CNS activity contributing to pain. 4.

Evaluate associations between the CAP questionnaire and simple pain sensitivity assessments with patient-centred outcomes.

EXPERIMENTAL PLAN: 250 individuals who have experienced musculoskeletal pain (equal numbers for osteoarthritis, fibromyalgia, inflammatory arthritis, low back pain) for more than three months will be recruited from existing research cohorts, primary or secondary care.

At study inclusion, participants will complete CAP, pain and other patient-centred outcome questionnaires and undergo laboratory and simplified pain sensitivity assessments.

Characteristics associated with abnormal activity in the CNS will be measured using questionnaires and clinical assessments (sleep disturbance, brain functioning, and neuropathy). Questionnaires at 6 and 12 weeks after inclusion will evaluate changes over time.

RELEVANCE TO POTENTIAL PATIENT BENEFIT: Understanding what we are treating and how well it responds to treatment is crucial for effective, timely, targeted treatment.

This project will result in a clinical tool (questionnaire and simple sensitivity assessment) to identify CNS as the predominant contributor to pain and capture changes as pain and disease progression.

To enable proactive screening, early detection, classification of CNS as the predominant contributor to pain and identify potential treatment targets to improve clinical outcomes important to people with musculoskeletal pain.