Classification of low back-related leg pain—A proposed patho-mechanism-based approach

Cancer Pain: A Critical Review of Mechanism-based Classification and Physical Therapy Management in Palliative Care

Mechanism-based classification and physical therapy management of pain is essential to effectively manage painful symptoms in patients attending palliative care. The objective of this review is to provide a detailed review of mechanism-based classification and physical therapy management of patients with cancer pain. Cancer pain can be classified based upon pain symptoms, pain mechanisms and pain syndromes. Classification based upon mechanisms not only addresses the underlying pathophysiology but also provides us with an understanding behind patient's symptoms and treatment responses. Existing evidence suggests that the five mechanisms – central sensitization, peripheral sensitization, sympathetically maintained pain, nociceptive and cognitive-affective – operate in patients with cancer pain. Summary of studies showing evidence for physical therapy treatment methods for cancer pain follows with suggested therapeutic implications. Effective palliative physical therapy care using a mechanism-based classification model should be tailored to suit each patient's findings, using a biopsychosocial model of pain.

Combination therapy with transdermal buprenorphine and pregabalin for chronic low back pain

SUMMARY 

AIM

The aim of this study was to evaluate the efficacy and safety of combined transdermal buprenorphine and pregabalin in chronic low back pain.

PATIENTS & METHODS

A total of 45 patients with chronic low back pain were recruited into the study. For an initial 3-week period, all patients received transdermal buprenorphine 35 µg/h. After 3 weeks of only transdermal buprenorphine 35 µg/h, patients were randomized (single-blind) to receive transdermal buprenorphine 35 µg/h plus pregabalin 300 mg/day (group A) or transdermal buprenorphine 35 µg/h plus placebo (group B), and were observed for a further 3-week period. Efficacy parameters were weekly mean Visual Analog Scale (VAS) scores, the Pain Rating Index (PRI) of the Short-Form McGill Pain Questionnaire (SF-MPQ), the Present Pain Index (PPI) of the SF-MPQ and sleep interference. We also evaluated the use of rescue medication (paracetamol [acetaminophen]) and the presence of adverse events.

RESULTS

A total of 44 patients were evaluated for efficacy and safety parameters. Pain relief, as assessed by VAS, PPI and PRI, improved significantly (p < 0.05) in all patients after the first week of treatment with only transdermal buprenorphine. Following randomization, only patients in group A showed further reductions in the mean VAS, PPI and PRI scores. Moreover, patients in group A had a lower consumption of rescue medication than those in group B. There was a low incidence of mild adverse events in both group A and group B, with no serious adverse events in either group.

CONCLUSION

Pregabalin 300 mg/day as an add-on to transdermal buprenorphine 35 µg/h led to significant pain reduction and a significant reduction of interference with sleep quality in patients with chronic low back pain.

The role of classification of chronic low back pain

STUDY DESIGN

Systematic review.

OBJECTIVE

To describe the various ways chronic low back pain (CLBP) is classified, to determine if the classification systems are reliable and to assess whether classification-specific interventions have been shown to be effective in treating CLBP.

SUMMARY OF BACKGROUND DATA

A classification system by which individual patients with CLBP could be identified and directed to an effective treatment protocol would be beneficial. Those systems that direct treatment have the greatest potential influence on patient outcomes.

METHODS

A systematic search was conducted in MEDLINE and the Cochrane Collaboration Library for English language literature published through January 2011. We included articles that specifically described a clinical classification system for CLBP, reported on the reliability of a classification system, or evaluated the effectiveness of classification-specific interventions.

RESULTS

A total of 60 articles were initially reviewed. We identified 28 classification systems that met inclusion criteria: 16 diagnostic systems, 7 prognostic systems, and 5 treatment-based systems. In addition, we found 10 randomized controlled trials of CLBP treatment from which we compared inclusion and exclusion criteria. Treatment-based systems were all directed at nonoperative management. Four of the 5 treatment-based systems underwent reliability testing and were found to have interobserver agreement of 70% to 100%. Reliability increased with training and familiarity with a given classification. As the number of subgroups within a classification increased, interobserver agreement decreased. Function and pain were similar between patients treated with the McKenzie classification system and those treated with dynamic strengthening training after 8 months of follow-up in one randomized controlled trial. One prospective cohort study reported better pain and function using the Canadian Back Institute Classification system than with standard rehabilitation. An analysis of the admission criteria to recent randomized studies with either nonoperative care or another surgical intervention provided a methodology for refining criteria to be met by patients considering surgery.

CONCLUSION

There currently are many classification systems for CLBP; some that are descriptive, some prognostic, and some that attempt to direct treatment. We recommend that no one classification system be adopted for all purposes. We further recommend that future efforts in developing a classification system focus on one that helps to direct both surgical and nonsurgical treatments.

CLINICAL RECOMMENDATIONS

There currently are many classification systems for CLBP; some that are descriptive, some prognostic, and some that attempt to direct treatment. We recommend that no one classification system be adopted for all purposes. We further recommend that future efforts in developing a classification system focus on one that helps to direct both surgical and nonsurgical treatments.

Application of a classification system and description of a combined manual therapy intervention: a case with low back related leg pain

Low back pain and leg pain commonly occur together. Multiple factors can cause low back related leg pain; therefore, identification of the source of symptoms is required in order to develop an appropriate intervention program. The patient in this case presented with low back and leg pain. A patho-mechanism based classification is described in combination with the patient's subjective and objective examination findings to guide treatment. The patient's symptoms improved marginally with intervention addressing primarily the musculoskeletal impairments and with intervention addressing primarily the neurodynamic impairments. Full functional improvements were attained with a manual therapy intervention directed at both mechanisms simultaneously. The approach described in this case address a mixed pathology utilizing passive accessory and passive physiological lumbar mobilizations in combination with lower extremity neurodynamic mobilization. The patient reported complete resolution of symptoms after a total of seven visits over a period of 6 weeks. While specific guidelines do not yet exist for treatment based on the classification approach utilized, this case report provides an example of manual therapy to address low back related leg pain of mixed pathology.

Mechanism-based Classification of Pain for Physical Therapy Management in Palliative care: A Clinical Commentary

Pain relief is a major goal for palliative care in India so much that most palliative care interventions necessarily begin first with pain relief. Physical therapists play an important role in palliative care and they are regarded as highly proficient members of a multidisciplinary healthcare team towards management of chronic pain. Pain necessarily involves three different levels of classification–based upon pain symptoms, pain mechanisms and pain syndromes. Mechanism-based treatments are most likely to succeed compared to symptomatic treatments or diagnosis-based treatments. The objective of this clinical commentary is to update the physical therapists working in palliative care, on the mechanism-based classification of pain and its interpretation, with available therapeutic evidence for providing optimal patient care using physical therapy. The paper describes the evolution of mechanism-based classification of pain, the five mechanisms (central sensitization, peripheral neuropathic, nociceptive, sympathetically maintained pain and cognitive-affective) are explained with recent evidence for physical therapy treatments for each of the mechanisms.

Upper Limb Neurodynamic Test 1 and symptoms reproduction in carpal tunnel syndrome. A validity study

The aim of this study was to estimate the validity of the Upper Limb Neurodynamic Test 1 (ULNT1) for the diagnosis of Carpal Tunnel Syndrome (CTS) with blind comparison to a reference criterion of a compatible clinical presentation and abnormal nerve conduction. 47 subjects with suspected CTS were enrolled. All patients were tested with nerve conduction studies and ULNT1. Considering results as positive in the presence of reproduction of symptoms on affected upper limb, or side-to-side differences in elbow extension, or symptoms modified by lateral neck side-bending, we estimated sensitivity as 91.67%, specificity as 15%, positive likelihood ratio as 1.0784, negative likelihood ratio as 0.5556, and post-test probability for negative test as 40%. Using a new criterion, i.e. the reproduction of symptoms only in the first three digits of the affected hand, we estimated sensitivity as 54.17%, specificity as 70%, positive and negative likelihood ratios as 1.8056 and 0.6548, respectively, and post-test probability for positive test as 68%. Our investigation suggests that the reproduction of the typical current CTS symptoms in the affected hand during ULNT1 testing, improves estimation of the probability of the presence of this condition, even if this test alone cannot be used to diagnose CTS.

Outcomes differ between subgroups of patients with low back and leg pain following neural manual therapy: a prospective cohort study

The objective is to determine if pain and disability outcomes of patients treated with neural mobilisation differ for sub-classifications of low back and leg pain (LB&LP). Radiating leg pain is a poor prognostic factor for recovery in patients with LBP. To improve outcome, a new pathomechanism-based classification system was proposed: neuropathic sensitization (NS), denervation (D), peripheral nerve sensitization (PNS) and musculoskeletal (M). Seventy-seven patients with unilateral LB&LP were recruited. Following classification, all subjects were treated seven times with neural mobilisation techniques. A successful outcome was defined as achieving a minimal clinically important change in pain intensity (11-point numerical rating scale), physical function (Roland Morris disability questionnaire) and global perceived change (7-point Likert scale: from 1 = "completely recovered" to 7 = "worse than ever"). The proportion of responders was significantly greater in PNS (55.6%) than the other three groups (NS 10%; D 14.3% and M10%). After adjusting for baseline differences, mean magnitude of improvement of the outcome measures were significantly greater in PNS compared to the other groups. Patients classified as PNS have a more favourable prognosis following neural mobilisation compared to the other groups.

An investigation of somatosensory profiles in work related upper limb disorders: a case-control observational study protocol

Background

Work related upper limb disorders constitute 45% of all occupational diseases and are a significant public health problem. A subgroup, non specific arm pain (NSAP), remains elusive in terms of understanding its pathophysiological mechanisms with its diagnosis based on the absence of specific clinical findings. One commonly proposed theory is that a neural tissue disorder is the primary dysfunction in NSAP and findings from previous studies lend some support to this theory. However, it is not clear if changes identified are simply a consequence of ongoing pain rather than due to specific neural changes. The presence of neuropathic pain has been investigated in several other musculoskeletal conditions but currently, there is no specific diagnostic tool or gold standard which permits an unequivocal diagnosis of neuropathic pain. The purpose of this study is to further describe the somatosensory profiles in patients with NSAP and to compare these profiles to a group of patients with MRI confirmed cervical radiculopathy who have been previously classified as having neuropathic pain.

Methods/Design

Three groups of participants will be investigated: Groups 1 and 2 will be office workers with either NSAP or cervical radiculopathy and Group 3 will be a control group of non office workers without upper limb pain. Participants will undergo a clinical assessment, pain questionnaires (LANSS, Short Form McGill, DASH and TSK) and quantitative sensory testing comprising thermal detection and pain thresholds, vibration thresholds and pressure pain thresholds.

Discussion

The spectrum of clinically suspected neuropathic pain ranges from more obvious conditions such as trigeminal neuralgia to those with vague signs of nerve disorder such as NSAP. A thorough description of the somatosensory profiles of NSAP patients and a comparison with a more defined group of patients with evidence of neuropathic pain will help in the understanding of underlying neurophysiology in NSAP and may influence future classification and intervention studies relating to this condition.

Classification of low back-related leg pain: do subgroups differ in disability and psychosocial factors?

It has been proposed that patients with low back-related leg pain can be classified according to pain mechanisms into four distinct subgroups: Central Sensitization (CS), Denervation (D), Peripheral Nerve Sensitization (PNS), and Musculoskeletal (M). The purpose of this study was to determine whether there were any differences in terms of disability and psychosocial factors between these four subgroups. Forty-five subjects with low back-related leg pain completed the Oswestry Disability Index, the hospital Anxiety and Depression Scale, and the Fear Avoidance Beliefs Questionnaire. Subsequently, an examiner blinded to the questionnaire results classified the subjects into one of the four subgroups, according to the findings of the self-administered Leeds Assessment of Neuropathic Signs and Symptoms questionnaire and a physical examination. It was found that the PNS subgroup had significantly greater disability compared to all other subgroups and significantly greater fear avoidance beliefs about physical activity compared to the CS and D subgroups. This highlights the importance of sub-classification but also the need to take into account disability and psychosocial factors in the management of low back-related leg pain.

Interrater reliability of a new classification system for patients with neural low back-related leg pain

The aim of this study was to investigate the reliability of a new classification system for low back-related leg pain arising from neural tissue dysfunction. Leg pain is a frequent accompaniment to back pain and is an indicator of the severity and prognosis of the disorder. For optimal patient care, treatment should be directed according to the identified pathophysiological mechanisms. The authors have proposed a sub-classification of neural low back-related leg pain into four categories, each requiring a different management strategy: Central Sensitization (CS), comprising major features of sensitization of the somatosensory system; Denervation (D), arising from significant axonal compromise without evidence of major central nervous system changes; Peripheral Nerve Sensitization (PNS), arising from nerve trunk inflammation without clinical evidence of significant denervation; and Musculoskeletal pain (M), referred from non-neural structures such as the disc or facet joints. The purpose of this study was to investigate the interrater reliability of this classification system. Forty consecutive patients with unilateral low back-related leg pain were independently assessed by five pairs of examiners using a physical examination protocol, screening for central sensitization of the somatosensory system, neurological deficit, and nerve tissue mechano-sensitization. Subjects were classified as follows: CS 30%, D 27.5%, PNS 10%, and M 32.5%. Interrater reliability was good with 80% agreement and a k of 0.72 (95% Confidence Interval (CI) .57-.86). The findings of the study demonstrate that patients with low back-related leg pain can be reliably classified to one of the four proposed groups.