Chronic Pain Syndromes Overview

Chronic Pain Syndromes: Overview

• Chronic pain is defined as pain lasting ≥ 3 months.

• Primary pain lacks an underlying condition, while secondary pain stems from a known condition.

• Chronic pain significantly reduces quality of life. NICE estimates 48% of the UK population experiences it.

Pain Categories

• Nociceptive pain arises from tissue injury (e.g., muscle, joint, bone).

• Neuropathic pain results from nerve damage (e.g., demyelination, laceration, crush injuries, viral infections).

• Nociplastic pain stems from a sensitized nervous system.

• Central sensitization involves the brainstem and spinal cord, leading to amplified pain signals.

• Peripheral sensitization affects nociceptors in the affected and surrounding areas, making them more responsive to stimuli.

Central Sensitization (CS)

• Brainstem releases inflammatory chemicals, increasing pain perception.

• Nociceptors fire with less stimulus.

• Nociceptors in adjacent areas become activated.

• Neural plasticity strengthens pain pathways.

• CS patients often perceive pain as more threatening, have lower pain tolerance, and employ maladaptive coping mechanisms.

Primary Pain Conditions

• Fibromyalgia, headache, complex regional pain syndrome (CRPS), non-specific lower back pain, sacroiliac joint (SIJ), lumbar, and neck/shoulder pain.

Secondary Pain Conditions

• Osteoarthritis, headache, temporomandibular joint (TMJ) disorders, diabetic neuropathy, endometriosis, rheumatoid arthritis (RA), and psoriatic arthritis.

Diagnosing Chronic Pain

• Establish an underlying condition first.

• Assess patient's symptoms comprehensively.

• Consider potential differentials and employ relevant tests to confirm or exclude a diagnosis.

• Consider the patient's perspective, fears, coping mechanisms, and impact on daily activities to identify potential CS involvement.

Treatment Approaches

• Explain the biomechanical cause of the problem and address patient concerns and fears.

• If there any concerns about an underlying condition, how the possibility is excluded?

• Explain the lack of correlation between pain and imaging findings.

• Educate patients about central and peripheral sensitization, emphasizing that pain isn't necessarily "made up" or "exaggerated".

• Treat the underlying musculoskeletal condition appropriately.

• Implement strategies to manage hypersensitivity, such as low force techniques and gradually increasing stimulation.

• Address maladaptive illness perceptions, and encourage movement and activity, starting at a low level and gradually increasing.

• Incorporate both pharmacological (e.g., pregabalin, gabapentin) and non-pharmacological approaches (pain gating techniques, mindfulness, cognitive behavioural therapy, rehabilitation).

Myofascial Pain

• Pain resulting from muscle or fascia inflammation/irritation.

• Characterized by trigger points (hypercontracted areas of muscle).

• Latent trigger points are tender only on compression, while active trigger points are spontaneously painful or triggered by movement.

• Trigger points can refer pain to other areas.

Discogenic Low Back Pain

• Chronic low back pain caused by disc damage and endplate changes.

• Disc degeneration is common with age, but not always indicative of pain.

• Inflammatory chemicals in the nucleus pulposus can lead to a cycle of inflammation, potentially with involvement of sinuvertebral nerves.

• Treatment may include corticosteroid injections, radiofrequency treatments or surgery.

Complex Regional Pain Syndrome (CRPS)

• Characterized by persistent noxious stimuli leading to amplified pain.

• CRPS Type 1 has no nerve injury evident, while CRPS Type 2 does.

• It typically manifests in a distal extremity and presents with burning, aching, throbbing, and tingling pain.

Fibromyalgia

• Characterized by widespread muscle pain, fatigue, concentration difficulties, and joint stiffness without deformity.

• Fibromyalgia is associated with central nervous system changes, sensitizing the nervous system to pain.

• Numerous factors, including genetics, past trauma, immune responses, and environmental factors, contribute to the development of fibromyalgia.

Hypermobility Hallmarks

• Widespread joint pain, typically worsening later in the day or after activity.

• Postural adaptations (e.g., leaning against walls, sitting in odd positions).

• Fidgeting/increased movement.

Benign Hypermobility Joint Syndrome (BHS)

• A connective tissue disorder, characterized by generalised laxity.

• Diagnosed through the Brighton criteria and the Beighton scale.

Ehlers-Danlos Syndrome (EDS)

• A heterogeneous group of genetic disorders affecting connective tissue.

• Characterized by joint hypermobility.

Marfan's Syndrome

• A connective tissue disorder with significant impacts on musculoskeletal, cardiac, and ocular systems.

Trigeminal Neuralgia

• Characterized by severe, episodic facial pain, affecting one or both branches of the trigeminal nerve.
• Two major classifications: idiopathic (possible ischemia to the nerve) and symptomatic (actual nerve damage).