The IASP classification of chronic pain for ICD-11: chronic secondary visceral pain.

Chronic visceral pain is a frequent and disabling condition. Despite high prevalence and impact, chronic visceral pain is not represented in ICD-10 in a systematic manner. Chronic secondary visceral pain is chronic pain secondary to an underlying condition originating from internal organs of the head or neck region or of the thoracic, abdominal, or pelvic regions. It can be caused by persistent inflammation, by vascular mechanisms or by mechanical factors. The pain intensity is not necessarily fully correlated with the disease process, and the chronic visceral pain may persist beyond successful treatment of the underlying cause. This article describes how a new classification of chronic secondary visceral pain is intended to facilitate the diagnostic process and to enable the collection of accurate epidemiological data. Furthermore, it is hoped that the new classification will improve the tailoring of patient-centered pain treatment of chronic secondary visceral pain and stimulate research. Chronic secondary visceral pain should be distinguished from chronic primary visceral pain states that are considered diseases in their own right.

Visceral pain as a triggering factor for fibromyalgia symptoms in comorbid patients.

Fibromyalgia syndrome (FMS) is a central sensitization syndrome; however, peripheral pain sources potentially exacerbate its symptoms of chronic diffuse musculoskeletal pain and hyperalgesia. This prospective study evaluated visceral pain as a possible triggering factor for FMS pain and hyperalgesia in comorbid patients. Women with (1) FMS + irritable bowel syndrome (IBS); (2) FMS + primary dysmenorrhea (Dys); (3) FMS + Dys secondary to endometriosis (Endo); (4) FMS + colon diverticulosis (Div) were compared with FMS-only women, for fibromyalgia pain (number and intensity of episodes and analgesic consumption) over comparable periods and for somatic hyperalgesia (electrical and pressure pain thresholds) in painful (tender points) and control areas (trapezius, deltoid, quadriceps muscles, and overlying subcutis and skin). In comorbid subgroups, FMS symptoms were also reassessed after treatment of the visceral condition or no treatment. All comorbid groups vs FMS-only had significantly higher FMS pain (number/intensity of episodes and analgesic consumption) and hyperalgesia in deep somatic tissues (subcutis and muscle) at all sites (0.05 < P < 0.0001). Visceral pain (number of IBS days, painful menstrual cycles, and abdominal pain episodes from diverticulitis) correlated directly with all parameters of FMS pain and inversely with muscle pain thresholds at all sites (0.03 < P < 0.0001). Fibromyalgia syndrome pain and hyperalgesia in all tissues and all sites significantly decreased in patients after visceral comorbidity treatment (dietary for 6 months [IBS], hormonal for 6 months [dysmenorrhea], laser [endometriosis], and surgery [diverticulosis]) (0.05 < P < 0.0001) vs no change in untreated patients. Visceral pain enhances FMS symptoms, probably augmenting the level of central sensitization typical of the syndrome. Systematic assessment and treatment of visceral pain comorbidities should be a part of FMS management strategy.

Neuromodulation of pelvic visceral pain: review of the literature and case series of potential novel targets for treatment.

Chronic pelvic pain (CPP) is complex and often resistant to treatment. While the exact pathophysiology is unknown, the pain states resultant from conditions such as interstitial cystitis and the like yield patients with a presentation that bears a striking similarity to neuropathic syndromes that are known to respond to neuromodulation. While there has been past success using the sacral region as a target for spinal cord stimulation (SCS) to treat these patients, there remains to be a consensus on the optimal location for lead placement. In this article, the authors discuss the potential etiology of CPP, examine the current literature on lead placement for SCS as a method of treatment, as well as present several cases where novel lead placement was successfully employed.