Neuropathic pain in soft tissue complaints

The Effect of Neuropathic Pain Symptoms on Remission in Patients with Early Rheumatoid Arthritis

BACKGROUND

The presence of neuropatic pain (NeP) is common in subjects with established Rheumatoid Arthritis (RA), and it can influence the disease remission. These aspects have not been investigated in patients with Early Rheumatoid Arthritis (ERA).

OBJECTIVE

To investigate the effect of NeP on the achievement of remission in patients with ERA.

METHOD

The study involved consecutive ERA patients with moderate or high disease activity. The painDETECT Questionnaire (PDQ), the 36-item Short Form Health Survey (SF-36), and the Euro- QoL-5 Dimensions (EQ-5D) were administered to all the patients, and their co-morbidity data were used to calculate their modified Rheumatic Disease Comorbidity Index (mRDCI). After six months' follow-up, the presence or otherwise of NeP in each individual patient was calculated, and whether or not the Boolean remission criteria were satisfied.

RESULTS

The study was completed by 115 patients (76% females) whose PDQ scores indicated that 13% had probable NeP. At the end of the follow-up period, 25 patients (21.7%) met the Boolean remission criteria. Logistic regression analysis showed that baseline PDQ scores (p=0.0023) and the mRDCI (p=0.0054) were the strongest predictors of not being in Boolean remission. Only one of the 15 patients with concomitant NeP achieved Boolean remission.

CONCLUSION

The presence of NeP may affect the achievement of remission in ERA patients. The PDQ can be a useful tool to measure central pain sensitisation in such patients.

Amitriptyline for musculoskeletal complaints: a systematic review

BACKGROUND

The role of amitriptyline in musculoskeletal pain is not as clearly defined as in classical neuropathic pain conditions.

OBJECTIVE

To assess the efficacy and effectiveness of amitriptyline in the treatment of pain in musculoskeletal complaints.

METHODS

An extensive search (including Medline, Embase and Web of Science) was made up to April 2016 for randomised controlled trials on amitriptyline in musculoskeletal complaints compared to placebo, usual care, or other analgesic use. Included studies were assessed for risk of bias. Outcomes of interest were pain reduction and function improvement.

RESULTS

Of the 2066 articles identified, seven were finally included. These studies were performed in patients with low back pain (4), rheumatoid arthritis (2), and patients with arm pain from repetitive use (1). No meta-analysis was performed due to clinical heterogeneity of the studies. Two studies with low risk of bias found positive results. One study found that 50 mg/day of amitriptyline [Visual Analogue Scale (VAS) -3.9 points] resulted in a significantly greater reduction in pain than treatment with pregabalin 600 mg/day (VAS -2.9 points) and improved function (improvement on the Oswestry Disability Index >20%: 65% versus 49.5%). Amitriptyline improved function in arm pain compared to placebo (Upper Extremity Function Scale: -3.9 versus 0.8). A similar amount of side-effects occurred in the amitriptyline and the comparison groups.

CONCLUSION

Few studies have evaluated the use of amitriptyline in musculoskeletal complaints. Although amitriptyline may be effective in musculoskeletal complaints, more studies are required to establish for whom amitriptyline works better than other analgesics.

Neuropathic-like pain features and cross-sectional associations in rheumatoid arthritis

INTRODUCTION

Increasing evidence indicates that features suggestive of neuropathic pain may also be present in patients with common rheumatic conditions. The objective of this study was to examine neuropathic-like pain symptoms and associated factors in patients with rheumatoid arthritis.

METHODS

We used the painDETECT screening tool to identify possible or likely neuropathic pain in 159 outpatients with rheumatoid arthritis. Patients additionally completed other self-reported measures, while clinical measures were assessed to calculate the 28-joint Disease Activity Score. Univariate analyses and multivariable logistic regression were used to identify factors associated with neuropathic pain features.

RESULTS

According to the painDETECT, 27 patients (17.0 %) were classified as having likely neuropathic pain and 34 patients (21.4 %) as having possible neuropathic pain. Besides reporting more severe pain, patients with likely or possible neuropathic pain were more likely to meet the diagnostic criteria for fibromyalgia, to use analgesics, and to have more tender joints and a worse physical and mental health status as measured by the 36-item Short-Form health survey. In multivariable analysis, physical (P < 0.001) and mental health status (P = 0.006) remained significantly associated with neuropathic pain features, even after controlling for pain severity.

CONCLUSIONS

These findings suggest that a sizeable proportion of patients with relatively well-controlled rheumatoid arthritis report symptoms suggestive of neuropathic pain. Neuropathic-like pain symptoms are independently associated with worse self-reported physical and mental health.