Relationship between depressive symptoms and acute low back pain at first medical consultation, three and six weeks of primary care

Background: Aim of the study was to test lagged reciprocal effects of depressive symptoms and acute low back pain (LBP) across the first weeks of primary care. Methods: In a prospective inception cohort study, 221 primary care patients with acute or subacute LBP were assessed at the time of initial consultation and then followed up at three and six weeks. Key measures were depressive symptoms (modified Zung Self-Rating Depression Scale) and LBP (sensory pain, present pain index and visual analogue scale of the Short-Form McGill Pain Questionnaire). Results: When only cross-lagged effects of six weeks were tested, a reciprocal positive relationship between LBP and depressive symptoms was shown in a cross-lagged structural equation model (β = .15 and .17, p < .01). When lagged reciprocal paths at three- and six-week follow-up were tested, depressive symptoms at the time of consultation predicted higher LBP severity after three weeks (β = .23, p < .01). LBP after three weeks had in turn a positive cross-lagged effect on depression after six weeks (β = .27, p < .001). Conclusions: Reciprocal effects of depressive symptoms and LBP seem to depend on time under medical treatment. Health practitioners should screen for and treat depressive symptoms at the first consultation to improve the LBP treatment.

What is the best time point to identify patients at risk of developing persistent low back pain?

BACKGROUND Early identification of patients at risk of developing persistent low back pain (LBP) is crucial. OBJECTIVE Aim of this study was to identify in patients with a new episode of LBP the time point at which those at risk of developing persistent LBP can be best identified.METHODS: Prospective cohort study of 315 patients presenting to a health practitioner with a first episode of acute LBP. Primary outcome measure was functional limitation. Patients were assessed at baseline, three, six, twelve weeks and six months looking at factors of maladaptive cognition as potential predictors. Multivariate logistic regression analysis was performed for all time points. RESULTS The best time point to predict the development of persistent LBP at six months was the twelve-week follow-up (sensitivity 78%; overall predictive value 90%). Cognitions assessed at first visit to a health practitioner were not predictive. CONCLUSIONS Maladaptive cognitions at twelve weeks appear to be suitable predictors for a transition from acute to persistent LBP. Already three weeks after patients present to a health practitioner with acute LBP cognitions might influence the development of persistent LBP. Therefore, cognitive-behavioral interventions should be considered as early adjuvant LBP treatment in patients at risk of developing persistent LBP.

Reliability of Quantitative Sensory Tests in a Low Back Pain Population.

BACKGROUND AND OBJECTIVES Reliability is an essential condition for using quantitative sensory tests (QSTs) in research and clinical practice, but information on reliability in patients with chronic pain is sparse. The aim of this study was to evaluate the reliability of different QST in patients with chronic low back pain. METHODS Eighty-nine patients with chronic low back pain participated in 2 identical experimental sessions, separated by at least 7 days. The following parameters were recorded: pressure pain detection and tolerance thresholds at the toe, electrical pain thresholds to single and repeated stimulation, heat pain detection and tolerance thresholds at the arm and leg, cold pain detection threshold at the arm and leg, and conditioned pain modulation using the cold pressor test.Reliability was analyzed using the coefficient of variation, the coefficient of repeatability, and the intraclass correlation coefficient. It was judged as acceptable or not based primarily on the analysis of the coefficient of repeatability. RESULTS The reliability of most tests was acceptable. Exceptions were cold pain detection thresholds at the leg and arm. CONCLUSIONS Most QST measurements have acceptable reliability in patients with chronic low back pain.

Linking altered central pain processing and genetic polymorphism to drug efficacy in chronic low back pain.

BACKGROUND Inability to predict the therapeutic effect of a drug in individual pain patients prolongs the process of drug and dose finding until satisfactory pharmacotherapy can be achieved. Many chronic pain conditions are associated with hypersensitivity of the nervous system or impaired endogenous pain modulation. Pharmacotherapy often aims at influencing these disturbed nociceptive processes. Its effect might therefore depend on the extent to which they are altered. Quantitative sensory testing (QST) can evaluate various aspects of pain processing and might therefore be able to predict the analgesic efficacy of a given drug. In the present study three drugs commonly used in the pharmacological management of chronic low back pain are investigated. The primary objective is to examine the ability of QST to predict pain reduction. As a secondary objective, the analgesic effects of these drugs and their effect on QST are evaluated. METHODS/DESIGN In this randomized, double blinded, placebo controlled cross-over study, patients with chronic low back pain are randomly assigned to imipramine, oxycodone or clobazam versus active placebo. QST is assessed at baseline, 1 and 2 h after drug administration. Pain intensity, side effects and patients' global impression of change are assessed in intervals of 30 min up to two hours after drug intake. Baseline QST is used as explanatory variable to predict drug effect. The change in QST over time is analyzed to describe the pharmacodynamic effects of each drug on experimental pain modalities. Genetic polymorphisms are analyzed as co-variables. DISCUSSION Pharmacotherapy is a mainstay in chronic pain treatment. Antidepressants, anticonvulsants and opioids are frequently prescribed in a "trial and error" fashion, without knowledge however, which drug suits best which patient. The present study addresses the important need to translate recent advances in pain research to clinical practice. Assessing the predictive value of central hypersensitivity and endogenous pain modulation could allow for the implementation of a mechanism-based treatment strategy in individual patients. TRIAL REGISTRATION Clinicaltrials.gov, NCT01179828.

Superior outcomes of decompression with an interlaminar dynamic device versus decompression alone in patients with lumbar spinal stenosis and back pain: a cross registry study.

INTRODUCTION Surgical decompression for lumbar spinal stenosis (LSS) has been associated with poorer outcomes in patients with pronounced low back pain (LBP) as compared to patients with predominant leg pain. This cross registry study assessed potential benefits of the interlaminar coflex® device as an add-on to bony decompression alone. METHODS Patients with lumbar decompression plus coflex® (SWISSspine registry) were compared with decompressed controls (Spine Tango registry). Inclusion criteria were LSS and a preoperative back pain level of ≥5 points. 1:1 propensity score-based matching was performed. Outcome measures were back and leg pain relief, COMI score improvement, patient satisfaction, complication, and revision rates. RESULTS 50 matched pairs without residual significant differences but age were created. At the 7-9 months follow-up interval the coflex® group had higher back (p=0.014) and leg pain relief (p<0.001) and COMI score improvement (p=0.029) than the decompression group. Patient satisfaction was 90% in both groups. No revision was documented in the coflex® and one in the decompression group (2.0%). DISCUSSION In the short-term, lumbar decompression with coflex® compared with decompression alone in patients with LSS and pronounced LBP at baseline is a safe and effective treatment option that appears beneficial regarding clinical and functional outcomes. However, residual confounding of non-measured covariables may have partially influenced our findings. Also, despite careful inclusion and exclusion of cases the cross registry approach introduces a potential for selection bias that we could not totally control for and that makes additional studies necessary.

Spine radiography in the evaluation of back and neck pain in an orthopaedic emergency clinic

BACKGROUND AND OBJECTIVES Despite the recommendations of national and international societies for the treatment of patients with acute neck and back pain, still too many radiologic examinations were performed. The purpose of this study was to analyze and optimize diagnostics and treatment of patients with acute back pain. METHODS The medical records of 484 patients presented to the emergency clinic with acute neck or back pain were analyzed for clinical history, physical examination, radiographic findings and therapy. RESULTS Radiographs of the lumbar, cervical, or thoracic spine were performed in 338 cases (70%). Radiographs were normal in 142 patients (42%) and degenerative changes were identified in 123 patients (36%). Only 2 patients (0.4%) had radiographic findings that had direct therapeutic relevance: 1 patient with metastatic disease and 1 patient with posttraumatic C1-C2 instability. For most patients without sensorimotor deficits and absent specific indications for radiography (“red flags”), therapy was not affected by the results of radiography. CONCLUSIONS Plain radiography of the spine was unnecessary in most patients initially evaluated with non-specific acute back pain and does not improve the clinical outcome. The implementation of national and international guidelines is a slow process, but helps to reduce costs and to protect patients from unnecessary ionizing radiation exposure.