Somatosensory changes in the referred pain area in patients with cholecystolithiasis

Gastrointestinal pain

Gastrointestinal (GI) pain - a form of visceral pain - is common in some disorders, such as irritable bowel syndrome, Crohn's disease and pancreatitis. However, identifying the cause of GI pain frequently represents a diagnostic challenge as the clinical presentation is often blurred by concomitant autonomic and somatic symptoms. In addition, GI pain can be nociceptive, neuropathic and associated with cancer, but in many cases multiple aetiologies coexist in an individual patient. Mechanisms of GI pain are complex and include both peripheral and central sensitization and the involvement of the autonomic nervous system, which has a role in generating the symptoms that frequently accompany pain. Treatment of GI pain depends on the precise type of pain and the primary disorder in the patient but can include, for example, pharmacological therapy, cognitive behavioural therapies, invasive surgical procedures, endoscopic procedures and lifestyle alterations. Owing to the major differences between organ involvement, disease mechanisms and individual factors, treatment always needs to be personalized and some data suggest that phenotyping and subsequent individual management of GI pain might be options in the future.

Differential Diagnosis in a Patient Presenting With Both Systemic and Neuromusculoskeletal Pathology: Resident's Case Problem

Study Design Resident's case problem. Background Patients presenting with multiple symptomatic areas pose a diagnostic challenge for the physical therapist. Though musculoskeletal and nonmusculoskeletal symptoms typically present separately, they can occur simultaneously and mimic each other. Consequently, the ability to differentiate between musculoskeletal and nonmusculoskeletal symptoms is an important skill for physical therapists. The purpose of this resident's case problem was to describe the clinical-reasoning process leading to medical and physical therapy management of a patient presenting with upper and lower back pain, bilateral radiating arm and leg pain, and abdominal pain. Diagnosis The patient was a 30-year-old woman referred to physical therapy for upper and lower back pain. A detailed history and thorough examination revealed that the patient had signs and symptoms consistent with a possible abdominal aortic aneurysm. She was referred for medical management and was diagnosed with symptomatic cholelithiasis. She subsequently had a cholecystectomy, which ultimately resolved her abdominal pain and reduced her pain in other areas significantly. Although many of her symptoms resolved postoperatively, her pain in other areas remained and was potentially musculoskeletal in origin. Following re-evaluation and 3 physical therapy treatments over a 2-month period, she was relatively symptom free at discharge and had achieved all functional rehabilitation goals. Discussion This resident's case problem provides an opportunity to discuss the differential diagnosis, clinical reasoning, and outcome of a patient who presented with both systemic and neuromusculoskeletal pathology. Level of Evidence Differential diagnosis, level 5. J Orthop Sports Phys Ther 2018;48(6):496-503. Epub 6 Feb 2018. doi:10.2519/jospt.2018.7652.

Post-cholecystectomy syndrome: A new look at an old problem

Background

Despite being the most commonly performed operations, sometimes cholecystectomy fails to relieve symptoms; this is now a well-recognised clinical entity termed 'post-cholecystectomy syndrome' (PCS). Very few studies from India deal with PCS, and the present study was carried out to find the incidence and risk factors for PCS in patients undergoing elective laparoscopic cholecystectomy (LC).

Materials and Methods

The records of 207 patients undergoing elective LC were prospectively maintained for 6 months after surgery. Persistence or appearance of new symptoms after surgery was documented and investigated only when they persisted beyond 30 days of surgery.

Results

There were 185 (89.4%) female patients and 22 (10.6%) male patients with a mean age of 44.4 years (age range: 12-79 years). Conversion to open cholecystectomy was done in 18 patients (8.69%), mainly due to adhesions and unclear anatomy. The incidence of symptoms was found to be 13% at 6 months follow-up, showing a reducing trend from 58% in the 1^st week after LC; the most common symptom in symptomatic patients was dyspepsia (55.56%). On investigation, a cause for symptoms could be detected in only 0.97%.

Conclusion

Symptoms are common after LC, but they settle over time. Very few patients have a detectable cause for symptoms after LC, and it is difficult to predict which patients will become symptomatic after LC; in the present series, previous attacks of cholecystitis and presence of co-morbid conditions were the only consistent risk factors for symptoms after LC.

Scratching the surface: the processing of pain from deep tissues

Although most pain research focuses on skin, muscles, joints and viscerae are major sources of pain. We discuss the mechanisms of deep pains arising from somatic and visceral structures and how this can lead to widespread manifestations and chronification. We include how both altered peripheral and central sensory neurotransmission lead to deep pain states and comment on key areas such as top-down modulation where little is known. It is vital that the clinical characterization of deep pain in patients is improved to allow for back translation to preclinical models so that the missing links can be ascertained. The contribution of deeper somatic and visceral tissues to various chronic pain syndromes is common but there is much we need to know.

Central sensitization in humans: assessment and pharmacology

It is evident that chronic pain can modify the excitability of central nervous system which imposes a specific challenge for the management and for the development of new analgesics. The central manifestations can be difficult to quantify using standard clinical examination procedures, but quantitative sensory testing (QST) may help to quantify the degree and extend of the central reorganization and effect of pharmacological interventions. Furthermore, QST may help in optimizing the development programs for new drugs.Specific translational mechanistic QST tools have been developed to quantify different aspects of central sensitization in pain patients such as threshold ratios, provoked hyperalgesia/allodynia, temporal summation (wind-up like pain), after sensation, spatial summation, reflex receptive fields, descending pain modulation, offset analgesia, and referred pain areas. As most of the drug development programs in the area of pain management have not been very successful, the pharmaceutical industry has started to utilize the complementary knowledge obtained from QST profiling. Linking patients QST profile with drug efficacy profile may provide the fundamentals for developing individualized, targeted pain management programs in the future. Linking QST-assessed pain mechanisms with treatment outcome provides new valuable information in drug development and for optimizing the management regimes for chronic pain.

Changes in responses of neurons in spinal and medullary subnucleus reticularis dorsalis to acupoint stimulation in rats with visceral hyperalgesia

The purpose of this study was to explore the mechanism of acupoints sensitization phenomenon at the spinal and medulla levels. Experiments were performed on adult male Sprague-Dawley rats and visceral noxious stimuli was generated by colorectal distension (CRD). The activities of wide dynamic range (WDR) and subnucleus reticularis dorsalis (SRD) neurons were recorded. The changes of the reactions of WDR and SRD neurons to electroacupuncture (EA) on acupoints of “Zusanli-Shangjuxu” before and after CRD stimulation were observed. The results showed that visceral nociception could facilitate the response of neurons to acupoints stimulation. In spinal dorsal horn, EA-induced activation of WDR neurons further increased to 106.84 ± 17.33% (1.5 mA) (P < 0.001) and 42.27 ± 13.10% (6 mA) (P < 0.01) compared to the neuronal responses before CRD. In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P < 0.001) and 25.02 ± 7.47% (6 mA) (P < 0.01) compared to that before CRD. Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization. But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

Chronic pain in children after cardiac surgery via sternotomy

INTRODUCTION

Chronic pain is common after sternotomy in adults with reported prevalence rates of 20-50%. So far, no studies have examined whether children develop chronic pain after sternotomy.

MATERIAL AND METHODS

Postal questionnaires were sent to 171 children 10-60 months after undergoing cardiac surgery via sternotomy at the age of 0-12 years. The children were asked to recall the intensity and duration of their post-operative pain, if necessary with the help from their parents, and to describe the intensity and character of any present pain. Another group of 13 children underwent quantitative sensory testing of the scar area 3 months after sternotomy.

RESULTS

A total of 121 children, median (range) age 7.7 (4.2-16.9) years, answered the questionnaire. Their age at the time of surgery was median (range) 3.8 (0-12.9) years, and the follow-up period was median (range) 4 (0.8-5.1) years. In all, 26 children (21%) reported present pain and/or pain within the last week located in the scar area; in 12 (46%) out of the 26 children, the intensity was ≥4 on a numeric rating scale (0-10). Quantitative sensory testing of the scar area revealed sensory abnormalities--pinprick hyperalgesia and brush and cold allodynia--in 10 out of 13 children.

CONCLUSION

Chronic pain after cardiac surgery via sternotomy in children is a problem that should not be neglected. The pain is likely to have a neuropathic component as suggested by the sensory abnormalities demonstrated by quantitative sensory testing.

Somatosensory and trophic findings in the referred pain area in patients with kidney stone disease

Background and purpose

Visceral and somatic afferents activate the same neuronal structures in the central nervous system. Assessing somatosensory function and trophic changes in the referred pain area may therefore indirectly increase information on mechanisms involved in painful visceral diseases. The aim of this study was to evaluate the sensory and trophic changes in the flank corresponding to the referred pain area in patients with kidney stone disease.

Methods

A total of 24 patients with unilateral pain-causing kidney stone disease were studied before and after endoscopic percutaneous kidney stone surgery. Trophic changes and sensitivity on the affected and on the contra-lateral side in the pain free period were investigated. For this purpose we used standardized experimental sensory testing including pressure stimulation and electrical (single and repeated) skin stimulation. Five repeated stimuli were used to investigate temporal summation (increased responses to repeated stimuli). To investigate trophic changes ultrasound as well as CT-scan was used, since the latter is considered more precise for exact tissue layer measurements.

Results

The pain tolerance thresholds to pressure and pain thresholds to electrical stimulation were not significantly different on the two sides (all P>0.1). After surgery no significant alterations in sensitivity were detected, but there was a tendency to higher pain thresholds to electrical stimuli on the affected side (single stimuli P=0.06; repeated stimuli P=0.09). No trophic changes were observed (all P>0.3), and there were no relations between the pain thresholds or trophic findings and the number of colics (all P >0.08).

Conclusion

In patients with unilateral pain-causing kidney stone disease the pain to experimental pressure and electrical stimuli were comparable on the affected and contra-lateral side. For the first time a CT-scan was used to evaluate tissue thickness in the referred pain area. No trophic changes were seen in the muscle or subcutaneous tissue at the affected side, and there were no correlations between the pain thresholds or trophic findings and the patients history of number of colics. After the operation no significant alterations in sensitivity were detected.

Implications

This study could not confirm previous studies showing referred hyperalgesia in the skin and trophic changes in the referred pain area to painful visceral disease. Differences in the pain intensity/duration between different diseases and hence the corresponding central neuronal changes may explain the negative findings in the present study.

Somatosensory hypersensitivity in the referred pain area in patients with chronic biliary pain and a sphincter of Oddi dysfunction: new aspects of an almost forgotten pathogenetic mechanism

BACKGROUND AND AIMS

Somatosensory hyperalgesia in the referred pain area (RPA) in patients with acute or chronic abdominal pain syndromes may result from the convergence of nerve fibers from visceral and somatic tissues at the spinal and supraspinal levels. Chronic biliary pain in patients with the postcholecystectomy syndrome (i.e., biliary hypersensitivity) may be explained by persistent hyperexcitability of neurons in the central nervous system (CNS). The aim of this study was to evaluate the cutaneous neural sensory perception in the RPA in patients with chronic postcholecystectomy biliary pain and a sphincter of Oddi (SO) dysfunction (SOD).

METHODS

Forty-two patients with persistent biliary pain and suspected SOD, 27 age-matched healthy volunteers, and 18 age-matched asymptomatic cholecystectomized controls were prospectively investigated by quantitative sensory testing (Neurometer CPT). The biliary symptoms and the severity of pain were classified on a visual analog pain severity scale system via a previously validated and standardized questionnaire. The patients helped the doctors locate the RPA in the right upper quadrant. The sensory detection threshold was determined noninvasively (Neurometer CPT) with transcutaneous electrical stimulation at 5, 250, and 2,000 Hz, and different current intensities (range from 0.01 to 9.99 mA) applied in a single (patient) blinded method. These three frequencies selectively excite small unmyelinated (C fibers), small myelinated (A-delta), and large myelinated (A-beta) fibers, which transmit dull pain, sharp pain, and touch, respectively. The contralateral region of the abdomen left upper quadrant served as the control area. The sensory current perception threshold ratio (SCPTR) of the data measured in the contralateral area and the RPA was calculated.

RESULTS

The SCPTRs in the definite SOD patients with biliary pain, healthy volunteers, the asymptomatic cholecystectomized controls, and the symptomatic cholecystectomized patients but without SOD were 2.32 +/- 1.4 versus 1.06 +/- 0.24 versus 0.97 +/- 0.16 versus 0.83 +/- 0.35 at 2,000 Hz; 2.19 +/- 1.0 versus 1.01 +/- 0.26 versus 1.02 +/- 0.25 versus 0.88 +/- 0.35 at 250 Hz; and 2.19 +/- 1.1 versus 1.12 +/- 0.26 versus 0.99 +/- 0.37 versus 0.84 +/- 0.32 at 5 Hz, respectively. Significant hypersensitivity was detected in the RPA at different stimulation frequencies in the SOD patients with biliary pain versus the cholecystectomized controls: at 5 Hz: P = 0.00001; at 250 Hz: P = 0.00001; and at 2,000 Hz: P = 0.0001, respectively.

CONCLUSION

Continuous visceral pain (biliary pain) caused by local inflammatory/sensitizing processes or a CNS malfunction could lead to significant hypersensitivity of the peripheral nociceptive nerve fibers in SOD patients. Postcholecystectomy pain may be explained by persistent hyperexcitability of the nociceptive neurons in the CNS with or without objective motility disorders of the SO.

Only half of the chronic pain after thoracic surgery shows a neuropathic component

Chronic pain is a common complication after thoracic surgery. The cause of chronic post-thoracotomy pain is often suggested to be intercostal nerve damage. Thus chronic pain after thoracic surgery should have an important neuropathic component. The present study investigated the prevalence of the neuropathic component in chronic pain after thoracic surgery. Furthermore, we looked for predictive factors for prevalence and intensity of chronic pain. We contacted 243 patients who underwent a video-assisted thoracoscopy (VATS) or thoracotomy in the period between January 2004 and September 2006 by mail. Patients retrospectively received a questionnaire with the Dutch version of the PainDETECT Questionnaire, a validated screening tool for neuropathic pain. Results were analyzed from 204 patients (144 thoracotomies, 60 VATS). The prevalence of chronic pain was 40% after thoracotomy and 47% after VATS. Definite chronic neuropathic pain was present in 23% of the patients with chronic pain, with an additional 30% having probable neuropathic pain. Greater probability of neuropathic pain (ie, a higher total score of the PainDETECT) correlated with more intense chronic pain. Predictive factors for chronic pain were younger age (P = .01), radiotherapy (P = .043), pleurectomy (P = .04) and more extensive surgery (P < .001).

PERSPECTIVE

Up to half the chronic pain after thoracic surgery is not associated with a neuropathic component, which has not been reported to date. More extensive surgery and pleurectomy are predictive factors for chronic pain after thoracic surgery, suggesting a visceral component apart from nerve injury.

Hind paw incision in the rat produces long-lasting colon hypersensitivity

Visceral injury has been shown to alter somatic sensitivity, but little is known about the effect of somatic insult on the viscera. In the present study, we examined (1) the effect of colon inflammation on somatic sensitivity and (2) the affect of hind paw incision on colon sensitivity. After intracolonic administration of trinitrobenzene sulfonic acid (TNBS) or zymosan, visceromotor responses to colorectal distension were increased to post-treatment day 8. Mechanical withdrawal thresholds in the hind paw were decreased in TNBS- and in zymosan-treated rats until post-intracolonic treatment day 2. There was no change in hind paw heat withdrawal latency in either group. Plantar incision of the hind paw resulted in a decrease in both hind paw mechanical withdrawal threshold and heat withdrawal latency and significantly increased the visceromotor response to colorectal distension from postincision days 1 to 8. The colon hypersensitivity was of longer duration than hyperalgesia at the site of hind paw incision. These results support the hypothesis that somatic injury and visceral inflammation can alter central processing of visceral and somatic inputs, respectively.

PERSPECTIVE

Surgical procedures are common and typically associated with hyperalgesia at and around the site of incision. This report establishes in a model of postsurgical pain and hyperalgesia that a long-lasting visceral hypersensitivity may also accompany postsurgical hyperalgesia.

The Role of Angina Pectoris in Chronic Pain After Coronary Artery Bypass Graft Surgery

Visceral nociception readily sensitizes the central nervous system, causing referred somatic pain and hyperalgesia via somato-visceral convergence. Hyperalgesia in the perioperative period may increase vulnerability to subsequent development of chronic pain. The study aim is to investigate the role of angina pectoris, an ischemic visceral pain, in long-term pain after coronary artery bypass surgery (CABG). We sent questionnaires to 369 patients who underwent CABG surgery in 2003. Questions were asked about angina pectoris and other pain in the period before surgery, the first week postoperatively (= acute pain), and the period after 3 months after surgery (= chronic pain). We obtained results from 256 patients (response rate = 69%). The point prevalence of chronic pain after CABG was 27% after a mean follow-up of 16 months (SD +/- 3 months). Patients with chronic pain after CABG had more angina pectoris than those without chronic pain: Before surgery (P = .07), early on postoperatively (P = .004), and more than 3 months after surgery (P = .000004). We found cumulative prevalences of chronic pain after CABG at 3 months of 39%, and of 32% after 6 months. Other predictive factors for chronic pain after CABG were acute postoperative pain (P = .00002) and younger age (P = .002). Angina pectoris is associated with chronic pain after CABG surgery. Other predictive factors include acute postoperative pain and younger age.

PERSPECTIVE

The influence of postoperative angina pectoris for chronic pain after CABG surgery has not been described in the literature to date. Visceral nociception may play an important role in the development of chronic pain after surgery and should be taken into account in future studies.

Reversibility of central neuronal changes in patients recovering from gallbladder stones or acute cholecystitis

AIM: To investigate the referred pain area in patients 2-7 years after cholecystectomy in order to test the hypothesis that neuroplastic changes could give rise to post cholecystectomy pain.

METHODS: Forty patients were tested. Twenty five were cholecystectomized due to uncomplicated gallbladder stones and 15 because of acute cholecystitis. Sensitivity to pinprick, heat, cold, pressure and single and repeated electrical stimulation was studied both in the referred pain area and in the control area on the contra lateral side of the abdomen.

RESULTS: Five patients still intermittently suffered from pain. But in the objective test of the 40 patients, no statistical significant difference was found between the referred pain area and the control area.

CONCLUSION: This study does not support the hypothesis that de novo neuroplastic changes could develop several years after cholecys-tectomy.

Somatosensory changes in the referred pain area before and after cholecystectomy in patients with uncomplicated gallstone disease

OBJECTIVE

It is estimated that 25-40% of patients have continuing symptoms after cholecystectomy and that 5-10% have pain. The pain may be related to central neuroplastic changes of sensory pathways induced by the gallstone disease. Such neuronal hyperexcitability can be reflected in the somatic referred pain area sharing central pathways with the gallbladder. The aim of this study was to examine somatosensory changes in the referred pain area evoked by painful gallstone attacks before and after cholecystectomy in patients with uncomplicated gallstone disease.

MATERIAL AND METHODS

Thirty-seven patients with uncomplicated gallstone disease were included in the study. The sensations and pain thresholds to pinprick, pinching, pressure, thermal and electrical stimulation were studied before and 4-12 weeks after surgery in the area where the pain was referred to during the previous gallstone attacks. An area on the contralateral side of the abdomen served as the control.

RESULTS

Somatosensory hyperalgesia in the referred pain area was observed in 84% of the patients before surgery. After elective cholecystectomy, none of the patients had pain complaints, and the sensibility in the referred area was normalized.

CONCLUSIONS

Uncomplicated gallstone disease leads to significant hyperalgesia in the somatic referred pain area. At the time of the postoperative investigation none of the patients suffered from pain, which was reflected in the normal sensory findings in the previous referred pain area.

Evaluation of the biliary tract in patients with functional biliary symptoms

The aim of this paper was to describe functional biliary syndromes and methods for evaluation of the biliary tract in these patients. Functional biliary symptoms can be defined as biliary symptoms without demonstrable organic substrate. Two main syndromes exist: Gallbladder dysfunction and sphincter of Oddi dysfunction. The most important investigative tools are cholescintigraphy and endoscopic sphincter of Oddi manometry. In gallbladder dysfunction a scintigraphic gallbladder ejection fraction below 35% can select patients who will benefit from cholecystectomy. Endoscopic sphincter of Oddi manometry is considered the gold standard in sphincter of Oddi dysfunction but recent development in scintigraphic methods is about to change this. Thus, calculation of hilum-to-duodenum transit time and duodenal appearance time on cholescintigraphy have proven useful in these patients. In conclusion, ambient methods can diagnose functional biliary syndromes. However, there are still a number of issues where further knowledge is needed. Probably the next step forward will be in the area of sensory testing and impedance planimetric methods.