Understand the Basics of Central Sensitization

Understanding the experience of pain is important in the treatment of painful conditions.

Peripheral Sensitization

When a tissue in the body is damaged, peripheral sensitization of nociceptors occurs as a protective mechanism by the body in order to prevent further use of a damaged structures. This response is a considered a local phenomenon.

Central Sensitization

Central sensitization is a central nervous system phenomenon which encompasses altered sensory processing in the brain, malfunctioning of descending anti-nociceptive mechanisms, increased activity of pain facilitory pathways, temporal summation of second pain and long term potentiation of neuronal synapses. This process can enhance ones sensativity to different peripheral stimuli and can decrease ones tolerance to stimuli places on the senses and neuromusculoskeletal system.

Clinical Considerations of Central Sensitization

Central sensitization is present in many chronic musculoskeletal disorders such as chronic whiplash, low back pain, TMJ, fibromyalgia, etc.  Central sensitization is often challenging for us to treat because it limits our ability to predict pain (it lacks predictable mechanical provocating and easing factors). These patients are often questioned by healthcare practitioners because they're symptoms just don't seem to make sense.

A 2010 article in Manual Therapy examined how to recognize the process of central sensitization in patients with musculoskeletal pain and found:

• Chronic whiplash, fibromyalgia, chronic fatigue syndrome and irritible bowel syndrome all include central sensitization as a characteristic of each respected disorder (It is also present in subgroups of low back pain, TMJ, myofascial pain syndrome, OA, RA and chronic headaches).
• Symptoms related to the presence of central sensitization include hypersensativity to bright light, touch, noise, mechanical pressure, pesticides, medication and temperature (Considerations we must make when choosing interventions in its management)
• If present, central sensitization is suggestive of general load intolerance to physical and emotional stressors
• If present, there is usually a generalized rather than a localized decrease in the patients pain pressure threshold (for example, there may be increased sensitivity in the lower extremities in a patient with whiplash—two segmentally unrelated sites).
• Increased neural tension as facilitated by the brachial plexus test or ULTT is also generally present in patients with central sensitization

Nijs J, Houdenhove BV, Oostendorp RAB. Recognition of central sensitization in patients with musculoskeletal pain: Application of pain neurophysiology in manual therapy practice. Manual Therapy 2010: 15;135-41.