Contralateral Sensory and Pain Perception Changes in Patients With Unilateral Neuropathy.

OBJECTIVE: To test whether contralateral sensory abnormalities in the clinically unaffected area of patients with unilateral neuropathic pain are due to the neuropathy or pain mechanisms. METHODS: We analyzed the contralateral clinically unaffected side of patients with unilateral painful or painless neuropathy (peripheral nerve injury [PNI], postherpetic neuropathy [PHN], radiculopathy) by standardized quantitative sensory testing following a validated protocol. Primary outcome was the independent contribution of the following variables on the contralateral sensory function using generalized linear regression models: pain intensity, disease duration, etiology, body area, and sensory patterns in the most painful area. RESULTS: Among 424 patients (PNI n = 256, PHN n = 78, radiculopathy n = 90), contralateral sensory abnormalities were frequent in both painful (n = 383) and painless (n = 41) unilateral neuropathy, demonstrating sensory loss for thermal and mechanical nonpainful stimuli and both sensory loss and gain for painful test stimuli. Analysis by etiology revealed contralateral pinprick hyperalgesia in PHN and PNI. Analysis by ipsilateral sensory phenotype demonstrated mirror-image pinprick hyperalgesia in both mechanical and thermal hyperalgesia phenotypes. Pain intensity, etiology, and affected body region predicted changes in only single contralateral somatosensory parameters. Disease duration had no impact on the contralateral sensory function. CONCLUSION: Mechanisms of sensory loss seem to spread to the contralateral side in both painful and painless neuropathies. Contralateral spread of pinprick hyperalgesia was restricted to the 2 ipsilateral phenotypes that suggest sensitization; this suggest a contribution of descending net facilitation from supraspinal areas, which was reported in rodent models of neuropathic pain but not yet in human patients.

One stop multidisciplinary pain clinic for survivors of torture.

Bianca Kuehler and Susan Childs speak to Jade Parker, Commissioning Editor: Dr Bianca Kuehler initially qualified in Germany as an anesthetist in 1993 and is on the specialist register in the UK. After moving to the UK she obtained a Diploma in Occupational Health to supplement the understanding and implication of chronic pain on the work environment. She is very interested in multidisciplinary approaches in treatment of chronic and acute pain patients and, therefore, working closely with Dr Childs opened a plethora of opportunities to develop new services including a fibromyalgia clinic and a specialist clinic for patients who are survivors of torture. Dr Susan Childs is an experienced clinical psychologist who has worked within health psychology and mental health since 1997. Her particular area of expertise is chronic pain. Alongside this, she has developed expertise in the assessment and treatment of a wide range of psychological issues. She has more recently focused upon co-developing services alongside her medical lead and co-facilitator, Dr Bianca Kuehler, for patients who are survivors of torture. Susan leads therapy services at a major London National Health Service trust in a Consultant capacity and supports a team of physicians, surgeons, pain specialist physicians, physiotherapists and clinical specialist nurses.

Symptom profiles in the painDETECT Questionnaire in patients with peripheral neuropathic pain stratified according to sensory loss in quantitative sensory testing.

The painDETECT Questionnaire (PDQ) is commonly used as a screening tool to discriminate between neuropathic pain (NP) and nociceptive pain, based on the self-report of symptoms, including pain qualities, numbness, and pain to touch, cold, or heat. However, there are minimal data about whether the PDQ is differentially sensitive to different sensory phenotypes in NP. The aim of the study was to analyze whether the overall PDQ score or its items reflect phenotypes of sensory loss in NP as determined by quantitative sensory testing. An exploratory analysis in the Innovative Medicines Initiative Europain and Neuropain database was performed. Data records of 336 patients identified with NP were grouped into sensory profiles characterized by (1) no loss of sensation, (2) loss of thermal sensation, (3) loss of mechanical sensation, and (4) loss of thermal and mechanical sensation. painDETECT Questionnaire profiles were analyzed in a 2-factor analysis of variance. Patients with loss of thermal sensation (2 and 4) significantly more often reported pain evoked by light touch, and patients with loss of mechanical sensation (3 and 4) significantly more often reported numbness and significantly less often burning sensations and pain evoked by light touch. Although the PDQ was not designed to assess sensory loss, single items reflect thermal and/or mechanical sensory loss at group level, but because of substantial variability, the PDQ does not allow for individual allocation of patients into sensory profiles. It will be useful to develop screening tools according to the current definition of NP.

Different measures, different outcomes? Survey into the effectiveness of chronic pain clinics in a London tertiary referral center.

BACKGROUND: Chronic pain clinics aim to improve challenging conditions, and although numerous studies have evaluated specific aspects of therapies and outcomes in this context, data concerning service impact on outcome measures in a general pain population are sparse. In addition, current trends in commissioning increasingly warrant services to provide evidence for their effectiveness. While a plethora of outcome measures, such as pain-intensity or improvement scores, exist for this purpose, it remains surprisingly unclear which one to use. It also remains uncertain what variables predict treatment success. OBJECTIVES: This cross-sectional study was conducted to evaluate clinic performance employing different tools (pain scores, pain categories, responder analysis, subjective improvement, satisfaction), and to determine predictors of outcome measures. PATIENTS AND METHODS: Patients attending scheduled clinic follow-up appointments were approached. They were asked to complete the modified short-form Brief Pain Inventory (BPI-SF) that also included assessments for satisfaction and subjective improvement. Comparisons were made with BPI-SF responses that were completed by each patient on admission. Nonparametric tests were employed to evaluate service impact and to determine predictors for outcome. RESULTS: Data of 118 patients were analyzed. There was considerable variation in impact of pain clinics depending on the outcome measure employed. While median pain scores did not differ between admission and follow-up, scores improved individually in 30% of cases, such that more patients had mild pain on follow-up than on admission (relative risk 2.7). Furthermore, while only 41% reported at least moderate subjective improvement after admission to the service, the majority (83%) were satisfied with the service. Positive treatment responses were predicted by "number of painful regions" and "changes in mood", whereas subjective improvement was predicted by "helpfulness of treatments". CONCLUSION: Depending on the outcome measure employed, pain clinics showed varying degrees of impact on patients' pain experiences. This calls into question the current practice of using nonstandardized outcome reporting for evaluation of service performances.

The clinical psychologist and the management of inpatient pain: a small case series.

Recent research has confirmed that between 25% and 33% of all hospitalized patients experience unacceptable levels of pain. Studies further indicate that this reduces patient satisfaction levels, lengthens hospital stays, and increases cost. Hospitals are aiming to discharge patients earlier, and this can interfere with adequate pain management. Therefore, the pain service at Chelsea and Westminster Hospital has adapted to this changing model of care. An increasing body of evidence demonstrates that psychological factors are key components of patients' pain experiences in both acute and chronic pain. Therefore, it is reasonable to suggest a clinical psychologist should be involved in inpatient pain management. This small study discusses three cases that highlight how patient care could be improved by including a clinical psychologist as part of the inpatient pain team. Two cases particularly highlight the active role of the psychologist in the diagnosis and management of common conditions such as fear and anxiety, along with other psychiatric comorbidities. The management therefore employed an eclectic approach adapted from chronic pain and comprising of behavioral, cognitive behavioral, and dialectical behavioral therapeutic techniques blended with brief counseling. The third case exemplifies the importance of nurse-patient interactions and the quality of nurse-patient relationships on patient outcomes. Here, the psychologist helped to optimize communication and to resolve a difficult and potentially risk-laden situation. This small case series discusses the benefits derived from the involvement of a clinical psychologist in the management of inpatient pain, and therefore illustrates the need for novel initiatives for inpatient pain services. However, future research is warranted to validate this approach.