The pyrite standard: the Midas touch in the diagnosis of axial pain syndromes

The Spine Journal (Impact Factor: 2.8). 01/2007; 7(1):27-31. DOI: 10.1016/j.spinee.2006.07.010
Source: PubMed
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    ABSTRACT: Background In the absence of a suitable reference standard, diagnostic local anesthetic blocks cannot be validated in the manner conventionally used for diagnostic tests. Consequently, diagnostic blocks are vulnerable to criticism for lacking validity, or being “not proven.”Study DesignPhilosophical essay.Methods Inspired by the “viewpoints” proposed by Bradford Hill for testing cause and effect in epidemiology, a set of axiomatic criteria was developed with which the validity of diagnostic blocks could be assessed.ResultsEight criteria were established: plausibility, experiment, target-specificity, effect, duration, consistency, control, and replication. Applying weighted scores to these criteria produces a metric by which the validity of a particular diagnostic block can be quantified.Conclusion The eight criteria provide an axiomatic, philosophical basis for diagnostic blocks in general, and serve to show what empirical evidence needs to be gathered in order to validate a particular block. The associated metric allows the scientific evidence for different blocks to be quantified and compared.
    Pain Medicine 04/2014; DOI:10.1111/pme.12436 · 2.24 Impact Factor
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    ABSTRACT: Study Design. A systematic review and meta-analysis of randomized controlled trials.Objective. To assess treatment effects (benefits and harms) of radiofrenquency denervation for patients with facet joint related chronic low back pain.Summary of Background Data. There is no consensus regarding the treatment efficacy of facet joint radiofrequency denervation (FJRD) and how it compares to nerve blockades and joint infiltration with anesthetics and/or corticosteroids.Methods. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and LILACS for randomized controlled trials (RCTs) that compared FJRD with blockades, infiltrations, or placebo. Primary outcomes were pain, functional status, and quality of life. Secondary outcomes were cost-effectiveness and complications.Results. Fifteen studies were selected and nine were eligible. Overall quality of evidence was rated low to moderate. The evidence favored FJRD regarding pain control. There was no sufficient evidence for cost-effectiveness and complications.Conclusion. The available evidence reviewed in this study should be interpreted with caution. The data indicates that FJDR is more effective than placebo in pain control and functional improvement, and is also possibly more effective than steroid injections in pain control. Complications and adverse effects were not sufficiently reported to allow comparisons, and there was no evidence for cost-effectiveness. High-quality RCTs addressing pain, function, quality of life, complications, and cost-effectiveness are urgently needed.
    Spine 04/2014; 39(14). DOI:10.1097/BRS.0000000000000337 · 2.45 Impact Factor
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    ABSTRACT: Cervical facet block (FB) procedures are often used as a diagnostic precursor to radiofrequency neurotomies (RFN) in the management of chronic whiplash associated disorders (WAD). Some individuals will respond to the FB procedures and others will not respond. Such responders and non-responders provided a sample of convenience to question whether there were differences in their physical and psychological features. This information may inform future predictive studies and ultimately the clinical selection of patients for FB procedures. This cross-sectional study involved 58 individuals with chronic WAD who responded to cervical FB procedures (WAD_R); 32 who did not respond (WAD_NR) and 30 Healthy Controls (HC)s. Measures included: quantitative sensory tests (pressure; thermal pain thresholds; brachial plexus provocation test); nociceptive flexion reflex (NFR); motor function (cervical range of movement (ROM); activity of the superficial neck flexors during the cranio-cervical flexion test (CCFT). Self-reported measures were gained from the following questionnaires: neuropathic pain (s-LANSS); psychological distress (General Health Questionnaire-28), post-traumatic stress (PDS) and pain catastrophization (PCS). Individuals with chronic whiplash attended the laboratory once the effects of the blocks had abated and symptoms had returned. Following FB procedures, both WAD groups demonstrated generalized hypersensitivity to all sensory tests, decreased neck ROM and increased superficial muscle activity with the CCFT compared to controls (p < 0.05). There were no significant differences between WAD groups (all p > 0.05). Both WAD groups demonstrated psychological distress (GHQ-28; p < 0.05), moderate post-traumatic stress symptoms and pain catastrophization. The WAD_NR group also demonstrated increased medication intake and elevated PCS scores compared to the WAD_R group (p < 0.05). Chronic WAD responders and non-responders to FB procedures demonstrate a similar presentation of sensory disturbance, motor dysfunction and psychological distress. Higher levels of pain catastrophization and greater medication intake were the only factors found to differentiate these groups.
    BMC Musculoskeletal Disorders 11/2013; 14(1):313. DOI:10.1186/1471-2474-14-313 · 1.90 Impact Factor