Pain Phenotypes

Nociceptive pain

pain arising from the activation of nociceptors in non-neural tissue in response to an actual or threatened noxious mechanical, thermal, or chemical stimulus, with no lesion or disease of the somatosensory nervous system

Examples of causes of nociceptive pain

Cuts, scrapes, bruises, sprains

Clinical indicators of nociceptive pain

Localized to area of injury or dysfunction

Proportional to identifiable mechanical or anatomical aggravating or easing factors

Clear, consistent, and reproducible relationship between pain and mechanical provocation or relief

Sharp pain with movement/loading or dull ache/throb at rest

Peripheral Neuropathic pain

pain caused by lesion or disease of the somatosensory nervous system with the symptoms following a neuroanatomic distribution (dermatome or peripheral nerve)

Clinical indicators of peripheral neuropathic pain

Burning, shooting, or electric-shock-like pain, often with dysesthesia (numbness, tingling, pins-and-needles)

Follow a dermatomal or peripheral nerve distribution

Positive neurodynamic tests

Associated with greater self-reported disability and psychological distress than nociceptive pain

Assessment tools for peripheral neuropathic pain

painDETECT and DN4 questionnaires can help identify neuropathic component

Nociplastic Pain (Central sensitization)

pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing activation of peripheral nociceptors

What is there a lack of with nociplastic pain?

Evidence of disease or lesion of the somatosensory system causing the pain

Clinical indicators for nociplastic pain

Widespread pain that does not follow a specific anatomical or dermatomal pattern

Pain disproportionate to nature or extent of any identifiable injury or pathology

Diffuse, unpredictable pattern of aggravating and easing factors

Accompanied by poor sleep, fatigue, and cognitive or emotional disturbance

Generalized hypersensitivity to light touch, pressure, or movement

Hyperalgesia

overreaction to pain, perceiving painful stimulus as more painful than is

Allodynia

perceiving non-painful stimulus as painful

Assessment tools for nociplastic pain

Symptom-clustering model

Central Sensitization Inventory (CSI)

Quantitative Sensory testing (QST)

Nociceptive pain treatment implications

Manual therapy, exercise, postural/mechanical correction

Peripheral neuropathic pain treatment implications

Neurodynamic techniques and/or pharmacologic treatment targeting nerve sensitization

Nociplastic pain treatment implications

Pain neuroscience education, graded exposure, cognitive behavioral strategies

What are key exam findings for nociplastic pain?

Diffuse hyperalgesia/allodynia not explained by local pathology

Inconsistent mechanical findings