Diagnostic blocks for chronic pain

2010 ◽  
Vol 1 (4) ◽  
pp. 186-192 ◽  
Author(s):  
Michele Curatolo ◽  
Nikolai Bogduk

AbstractMany conditions associated with chronic pain have no detectable morphological correlate. Consequently, the source of pain cannot be established by clinical examination or medical imaging. However, for some such conditions, the source of pain can be established using diagnostic blocks. The aim of this paper is to review the available evidence concerning the validity and utility of diagnostic blocks, and to identify areas where research is needed.Diagnostic blocks for cervical and lumbar zygapophysial joint pain have been extensively studied. Single blocks are associated with about 30% false-positive responses. Patients can report relief of pain for reasons other than the effect of a local anaesthetic injected during a diagnostic block, e.g. as the result of placebo effect. Therefore, in order to be valid, diagnostic blocks must be controlled in each patient. Many practitioners find limitations in the clinical applicability of placebo-controlled blocks. Comparative blocks (comparison lidocaine-bupivacaine for each block within each patient) have been investigated as alternatives to placebo-controlled blocks. A positive response requires short-lasting relief when lidocaine is used, and long-lasting relief when bupivacaine is used. The validity of comparative blocks is high when the disease under investigation is common. This is the case for zygapophysial joint pain after whiplash injury. However, the validity of comparative blocks strongly decreases with decreasing prevalence of the condition. This is the case for lumbar zygapophysial joint pain in young subjects: in these patients, the expected false-positive rate with comparative blocks is unacceptably high. Diagnostic blocks for cervical and lumbar zygapophysial joint have therapeutic utility. When positive, radiofrequency denervation is expected to produce substantial pain relief in 60-80% of patients.For all other types of blocks, very little research has been conducted. The few studies that have been published did not use controlled blocks. This may have produced a high rate of false-positive responses. Some data on spinal nerve root blocks suggest that these procedures may be valid for the diagnosis of radicular pain and are perhaps predictive for the success of surgery. The validity of diagnostic sympathetic blocks and their prognostic value in relation to outcomes of sympathectomy are unclear. There is lack of data on the validity of diagnostic intra-articular blocks. Discogenic pain is typically diagnosed by provocative discography, but this procedure remains controversial. Intradiscal and sinuvertebral nerve blocks with local anaesthetics are possible alternatives to provocation discography. At present, the sparse data available on these procedures do not allow an estimation of their validity.In conclusion, nerve blocks have an important potential role in the management of chronic pain. These procedures are not suitable to identify the pathology that is the cause of the pain (e.g. inflammatory, neuropathic, etc.). However, they can reveal the anatomical source of pain, thereby allowing the development of targeted treatments. Unfortunately, there is currently very little research on the validity and prognostic value of blocks. The potential usefulness of this practice remains therefore largely unexplored.

2018 ◽  
Vol 29 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Kazuyoshi Kobayashi ◽  
Kei Ando ◽  
Ryuichi Shinjo ◽  
Kenyu Ito ◽  
Mikito Tsushima ◽  
...  

OBJECTIVEMonitoring of brain evoked muscle-action potentials (Br[E]-MsEPs) is a sensitive method that provides accurate periodic assessment of neurological status. However, occasionally this method gives a relatively high rate of false-positives, and thus hinders surgery. The alarm point is often defined based on a particular decrease in amplitude of a Br(E)-MsEP waveform, but waveform latency has not been widely examined. The purpose of this study was to evaluate onset latency in Br(E)-MsEP monitoring in spinal surgery and to examine the efficacy of an alarm point using a combination of amplitude and latency.METHODSA single-center, retrospective study was performed in 83 patients who underwent spine surgery using intraoperative Br(E)-MsEP monitoring. A total of 1726 muscles in extremities were chosen for monitoring, and acceptable baseline Br(E)-MsEP responses were obtained from 1640 (95%). Onset latency was defined as the period from stimulation until the waveform was detected. Relationships of postoperative motor deficit with onset latency alone and in combination with a decrease in amplitude of ≥ 70% from baseline were examined.RESULTSNine of the 83 patients had postoperative motor deficits. The delay of onset latency compared to the control waveform differed significantly between patients with and without these deficits (1.09% ± 0.06% vs 1.31% ± 0.14%, p < 0.01). In ROC analysis, an intraoperative 15% delay in latency from baseline had a sensitivity of 78% and a specificity of 96% for prediction of postoperative motor deficit. In further ROC analysis, a combination of a decrease in amplitude of ≥ 70% and delay of onset latency of ≥ 10% from baseline had sensitivity of 100%, specificity of 93%, a false positive rate of 7%, a false negative rate of 0%, a positive predictive value of 64%, and a negative predictive value of 100% for this prediction.CONCLUSIONSIn spinal cord monitoring with intraoperative Br(E)-MsEP, an alarm point using a decrease in amplitude of ≥ 70% and delay in onset latency of ≥ 10% from baseline has high specificity that reduces false positive results.


2007 ◽  
Vol 20 (7) ◽  
pp. 539-545 ◽  
Author(s):  
Rajeev Manchukonda ◽  
Kavita N. Manchikanti ◽  
Kimberly A. Cash ◽  
Vidyasagar Pampati ◽  
Laxmaiah Manchikanti

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 212 ◽  
Author(s):  
Jonathan Benzaquen ◽  
Jacques Boutros ◽  
Charles Marquette ◽  
Hervé Delingette ◽  
Paul Hofman

Early-stage treatment improves prognosis of lung cancer and two large randomized controlled trials have shown that early detection with low-dose computed tomography (LDCT) reduces mortality. Despite this, lung cancer screening (LCS) remains challenging. In the context of a global shortage of radiologists, the high rate of false-positive LDCT results in overloading of existing lung cancer clinics and multidisciplinary teams. Thus, to provide patients with earlier access to life-saving surgical interventions, there is an urgent need to improve LDCT-based LCS and especially to reduce the false-positive rate that plagues the current detection technology. In this context, LCS can be improved in three ways: (1) by refining selection criteria (risk factor assessment), (2) by using Computer Aided Diagnosis (CAD) to make it easier to interpret chest CTs, and (3) by using biological blood signatures for early cancer detection, to both spot the optimal target population and help classify lung nodules. These three main ways of improving LCS are discussed in this review.


2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 416-416 ◽  
Author(s):  
Andrew Mount ◽  
Stephen Bentley Williams ◽  
Colin P. N. Dinney ◽  
H. Barton Grossman ◽  
Curtis Alvin Pettaway ◽  
...  

416 Background: One of the criticisms of blue-light cystoscopy (BL) is the relatively high rate of false positive biopsies when used in the real world setting. There is no consensus on which patient factors, if any, might be contributing to this high false positive rate. The purpose of this study is to determine whether having a cystoscopy, TURBT or BCG treatment recently resulted in higher rates of false positive blue-light (BL) biopsies. Methods: We performed an IRB-approved retrospective study looking at a total of 116 consecutive patients who underwent simultaneous BL and WL between January 2013 to December 2014. Pathology and operative reports were reviewed to determine the grade and stage of the tumors. Clinical notes were utilized to determine how recently they had a cystoscopy, TURBT, and BCG treatment. The false positive rates of both BL and WL were calculated, and Fisher’s exact test was utilized to determine if the time from the patients’ most recent bladder manipulation or BCG treatment had a significant effect on the false positive BL rate. Results: Of the 46 (28.6%) BL positive biopsies, 29 (63.0%) were false positives. When stratified by potential causes of false positive for BL we found the following: one (3.4%) had bladder manipulation within 14 days, 8 (27.6%) within 30 days, 19 (65.5%) within 60 days, and 10 (34.5%) had bladder manipulation beyond 60 days prior to the biopsy. When looking at intravesical BCG as a cause for false positive, we found prior BCG use in 18 (62%) patients of those with false positive BL compared to 12 (70.6%) patients of those with true positive BL biopsies (p = 1.0). Of the 18 patients with false positive BL biopsies who had BCG previously: 1 (5.6%) had BCG within 6 weeks, 5 (27.8%) had BCG within 12 weeks, and 13 (72.2%) had BCG greater than 12 weeks prior to biopsy. None of these associations were found to be statistically significant. Despite the high percentage of false positive lesions, it is important to note that in patients who had tumors visualized only with BL, 11 (26.8%) were high-grade, including one patient with T1 tumor and 8 with CIS. Conclusions: There was no relationship between recent bladder manipulation or BCG treatment and false positive BL biopsies.


2007 ◽  
Vol 106 (3) ◽  
pp. 591-614 ◽  
Author(s):  
Steven P. Cohen ◽  
Srinivasa N. Raja

Lumbar zygapophysial joint arthropathy is a challenging condition affecting up to 15% of patients with chronic low back pain. The onset of lumbar facet joint pain is usually insidious, with predisposing factors including spondylolisthesis, degenerative disc pathology, and old age. Despite previous reports of a "facet syndrome," the existing literature does not support the use of historic or physical examination findings to diagnose lumbar zygapophysial joint pain. The most accepted method for diagnosing pain arising from the lumbar facet joints is with low-volume intraarticular or medial branch blocks, both of which are associated with high false-positive rates. Standard treatment modalities for lumbar zygapophysial joint pain include intraarticular steroid injections and radiofrequency denervation of the medial branches innervating the joints, but the evidence supporting both of these is conflicting. In this article, the authors provide a comprehensive review of the anatomy, biomechanics, and function of the lumbar zygapophysial joints, along with a systematic analysis of the diagnosis and treatment of facet joint pain.


2015 ◽  
Vol 18;4 (4;18) ◽  
pp. E497-E533 ◽  
Author(s):  
Mark Boswell

Background: Spinal zygapophysial, or facet, joints are a source of axial spinal pain and referred pain in the extremities. Conventional clinical features and other noninvasive diagnostic modalities are unreliable in diagnosing zygapophysial joint pain. Study Design: A systematic review of the diagnostic accuracy of spinal facet joint nerve blocks. Objective: To determine the diagnostic accuracy of spinal facet joint nerve blocks in chronic spinal pain. Methods: A methodological quality assessment of included studies was performed using Quality Appraisal of Reliability Studies (QAREL). Only diagnostic accuracy studies meeting at least 50% of the designated inclusion criteria were utilized for analysis. The level of evidence was classified as Level I to V based on the grading of evidence utilizing best evidence synthesis. Data sources included relevant literature identified through searches of PubMed and other electronic searches published from 1966 through March 2015, Cochrane reviews, and manual searches of the bibliographies of known primary and review articles. Outcome Measures: Studies must have been performed utilizing controlled local anesthetic blocks. The criterion standard must have been at least 50% pain relief from baseline scores and the ability to perform previously painful movements. Results: The available evidence is Level I for lumbar facet joint nerve blocks with the inclusion of a total of 17 studies with dual diagnostic blocks, with at least 75% pain relief with an average prevalence of 16% to 41% and false-positive rates of 25% to 44%. The evidence for diagnosis of cervical facet joint pain with cervical facet joint nerve blocks is Level II based on a total of 11 controlled diagnostic accuracy studies, with significant variability among the prevalence in a heterogenous population with internal inconsistency. The prevalence rates ranged from 36% to 67% with at least 80% pain relief as the criterion standard and a false-positive rate of 27% to 63%. The level of evidence for the diagnostic accuracy of thoracic facet joint nerve blocks is Level II with 80% or higher pain relief as the criterion standard with a prevalence ranging from 34% to 48% and false-positive rates ranging from 42% to 48%. Limitations: The shortcomings of this systematic review include a paucity of literature related to the thoracic spine, continued debate on an appropriate gold standard, appropriateness of diagnostic blocks, and utility. Conclusion: The evidence is Level I for the diagnostic accuracy of lumbar facet joint nerve blocks, Level II for cervical facet joint nerve blocks, and Level II for thoracic facet joint nerve blocks in assessment of chronic spinal pain. Key words: Chronic spinal pain, lumbar facet or zygapophysial joint pain, cervical facet or zygapophysial joint pain, thoracic facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks


2020 ◽  
Vol 5;23 (9;5) ◽  
pp. 519-529
Author(s):  
Laxmaiah Manchikanti

Background: Lumbar facet joints are a clinically important source of chronic low back pain. There have been extensive diagnostic accuracy studies, along with studies of influence on the diagnostic process, but most of them have utilized the acute pain model. One group of investigators have emphasized the importance of the chronic pain model and longer lasting relief with diagnostic blocks. Objective: To assess the diagnostic accuracy of lumbar facet joint nerve blocks with controlled comparative local anesthetic blocks and concordant pain relief with an updated assessment of the prevalence, false-positive rates, and a description of a philosophical paradigm shift from an acute to a chronic pain model. Study Design: Retrospective study to determine diagnostic accuracy, prevalence and falsepositive rates. Setting: A multidisciplinary, non-university based interventional pain management practice in the United States. Methods: Controlled comparative local anesthetic blocks were performed initially with 1% lidocaine, followed by 0.25% bupivacaine if appropriate response was obtained, in an operating room under fluoroscopic guidance utilizing 0.5 mL of lidocaine or bupivacaine at L3, L4 medial branches and L5 dorsal ramus. All patients non-responsive to lidocaine blocks were considered to be negative for facet joint pain. All patients were assessed after the diagnostic blocks were performed with ≥ 80% pain relief for their ability to perform previously painful movements. Results: The prevalence of lumbar facet joint pain in chronic low back pain was 34.1% (95% CI, 28.8%, 39.8%), with a false-positive rate of 49.8% (95% CI, 42.7%, 56.8%). This study also showed a single block prevalence rate of 67.9% (95% CI, 62.9%, 73.2%). Average duration of pain relief ≥ 80% was 6 days with lidocaine block and total relief of ≥ 50% of 32 days. With bupivacaine, the average duration of pain relief ≥ 80% was 13 days with total relief of ≥ 50% lasting for 55 days. Conclusion: This study demonstrated that the chronic pain model is more accurate and reliable with concordant pain relief. This updated assessment also showed prevalence and false-positive rates of 34.1% and 49.8%. Key words: Chronic spinal pain, lumbar facet or zygapophysial joint pain, facet joint nerve blocks, medial branch blocks, controlled comparative local anesthetic blocks, diagnostic accuracy, prevalence, false-positive rate


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