Current understanding of the mixed pain concept: a brief narrative review

Abstract

Despite having been referenced in the literature for over a decade, the term "mixed pain" has never been formally defined. The strict binary classification of pain as being either purely neuropathic or nociceptive once left a good proportion of patients unclassified; even the recent adoption of "nociplastic pain" in the IASP Terminology leaves out patients who present clinically with a substantial overlap of nociceptive and neuropathic symptoms. For these patients, the term "mixed pain" is increasingly recognized and accepted by clinicians. Thus, an independent group of international multidisciplinary clinicians convened a series of informal discussions to consolidate knowledge and articulate all that is known (or, more accurately, thought to be known) and all that is not known about mixed pain. To inform the group's discussions, a Medline search for the Medical Subject Heading "mixed pain" was performed via PubMed. The search strategy encompassed clinical trial articles and reviews from January 1990 to the present. Clinically relevant articles were selected and reviewed. This paper summarizes the group's consensus on several key aspects of the mixed pain concept, to serve as a foundation for future attempts at generating a mechanistic and/or clinical definition of mixed pain. A definition would have important implications for the development of recommendations or guidelines for diagnosis and treatment of mixed pain.

Effect of toe exercises and toe-grip strength on the treatment of primary metatarsalgia

“…The cause of pain in metatarsalgia is unclear, but it is presumed that the acute phase involves nociceptive pain. The improvement in pain was worse in chronic cases, suggesting that mixed pain, involving nociceptive, nociplastic, and neuropathic pain, is involved in chronic disease [19]. For patients with hallux valgus, waiting for elective surgery has been associated with less improvement in physical function outcomes following surgery [20], which supports our ndings.…”

Therapeutic Approaches for Peripheral and Central Neuropathic Pain

“…The characteristics of NP are clearly distinct from those of nociceptive pain, which together represent the two fundamental groups of pain conditions. However, according to a new mixed pain concept, an additional group of pain disorders is proposed, which is referred to as “nociplastic pain” [3]. Chronic NP includes peripheral and central NP conditions [4].…”

Pharmaceutical and Botanical Management of Pain Associated with Psychopathology: A Narrative Review

“…Recently, an international multidisciplinary research group proposed to the scientific community a fifth definition of pain called mixed pain, which is produced by a complex overlap of the different types of pain known (nociceptive, neuropathic, and nociplastic) in any combination, acting simultaneously and/or concurrently to cause pain in the same area of the body, either acutely or chronic [13]. This difficulty of evaluating pain makes possible to resort to instruments that, with the minimum effort of the patient, are easily understandable, reliable, and valid.…”