Table II.
Clinical Characteristics of Nociceptive, Neuropathic, and Nociplastic Post-Amputation Pain
| Nociceptive Post-Amputation Pain | Neuropathic Post-Amputation Pain | Nociplastic Pain in Amputees | |
|---|---|---|---|
| Etiology | Actual or potential tissue damage, referred pain from mechanical structures | Severing of nerve, neuroplastic changes in the peripheral and central nervous systems | Altered nociception despite no evidence of actual or threatened tissue damage, or evidence for a lesion affecting the somatosensory system. Trauma is a common antecedent to CRPS type I, uncommon for other types of nociplastic pain. |
| Frequency | Most common cause of residual limb pain | Most common cause of phantom limb pain | Infrequent stand-alone cause of post-amputation pain, though altered pain processing may accompany nociceptive and neuropathic postamputation pain |
| Descriptors | Throbbing, aching, pressure-like | Lancinating, shooting, electrical-like | Highly variable |
| Accompanying Sensory Changes | Infrequent, outside of a nerve or nerve root distribution | Phantom sensations very common | Common, but often outside the distribution of nerve or tissue injury |
| Hypersensitivity | Uncommon except for hypersensitivity in the immediate area after trauma or amputation, often elicited by palpation of pain generator | Allodynia and hyperalgesia may be present in residual limb | Hallmark of the condition |
| Location | Proximal radiation frequent | Distal radiation common, telescoping often observed | Diffuse, outside the distribution of an injured nerve(s) or amputated body part |
| Time course | Acute postsurgical pain decreases over several weeks. Pain from other sources stabilizes or slightly diminishes over time, though referred pain from degenerative diseases may persist or worsen | Often experienced within 1 week of amputation, prevalence peaks within 2 years and remains stable or declines in intensity | Pain post-injury disproportionate to inciting event. Delays in diagnosis common. |
| Paroxysms | Exacerbations less common and often associated with specific activities (putting on prostheses, ambulation) | Exacerbations common and unpredictable | May be superimposed on low-grade continuous pain |
| Autonomic signs | Uncommon | Can occur in 1/3 to 1/2 of patients | Frequent in CRPS type I and other types of nociplastic pain |
| Associated symptoms | Psychiatric co-morbidities common | Psychiatric co-morbidities common | High co-prevalence rate of other nociplastic pain conditions. Cognitive deficits, psychiatric co-morbidities, fatigue, poor sleep and sensitivity to light and other stimuli common |