Prevalence and Discordance of the "Startle Response" with True Discogenic Pain According to Spine Intervention Society Guidelines for Provocation Discography: A Cohort Study.

SUMMARY OF BACKGROUND DATA: The literature on cervical provocation discography (C-PD) is sparse. A "Startle Response" during C-PD is a known phenomenon that might be mistaken as an indicator of discogenic pain at the provoked disc level, but this has not been quantitatively described. OBJECTIVES: To determine the incidence of the Startle Response and its concordance/discordance with true-positive C-PD in patients referred for surgical planning or evaluation after ruling out other axial pain generators. METHODS: Retrospective cohort study of consecutive patients who received C-PD at an outpatient spine center. The primary outcome was the rate of discordance of the Startle Response with true-positive C-PD according to the operational criteria of the Spine Intervention Society (SIS) guidelines. RESULTS: One hundred five discs were provoked in 36 individuals (19 female, mean age [SD] = 45.7 [10.9] years). C-PD was performed at a median of three levels (range = 1-5) with C4/5 (N = 30), C5/6 (N = 30), and C6/7 (N = 31) the most commonly evaluated. Twenty-six of 36 patients reported responses consistent with true-positive C-PD. A Startle Response was observed in 14 patients (39%, 95% confidence interval [CI] = 23-57%), and 22 of 105 (21%, 95% CI = 14-30%) provoked discs. Of the 14 patients who exhibited a Startle Response, four had negative C-PD results (29%, 95% CI = 8-58%). As assessed per disc, C-PD results were positive in 12 of the 22 (55%, 95% CI = 32-76%) provoked discs that generated a Startle Response. CONCLUSIONS: The present data demonstrate high discordance, 45% (95% CI = 24-68%), between the Startle Response and true-positive C-PD. Clinicians should be aware of this phenomenon and take care to distinguish it from a true-positive response during C-PD, as defined by the SIS guidelines. Misinterpretation of the Startle Response as a positive C-PD result may lead to inappropriate future care decisions in a substantial proportion of patients.

Comparison of four different analgesic discogram protocols comparing the incidence of reported pain relief following local anesthetic injection into concordantly painful lumbar intervertebral discs.

OBJECTIVE: To compare the incidence of pain relief following injection of local anesthetic (LA) into lumbar discs that caused concordant pain during provocation testing. DESIGN: Prospective collected data review from two centers and compare with published results. OUTCOME MEASURES: We compared subjective reported pain relief following provocative testing using the following protocols at three separate facilities: 23 patients undergoing routine provocative discography using contrast alone (PD); 47 patients undergoing provocative discography performed using an equal combination of LA and contrast (CPD); 120 patients injected with LA following routine PD (ADPD); 33 patients undergoing stand-alone analgesic discography (SAAD); and 28 patients injected with LA through a catheter (FAD) placed during provocative discogaphy testing. RESULTS: Pressure-controlled PD showed a positive response rate of 34% per disc in patients with a clinical diagnosis of discogenic pain. None of the PD group without LA had pain relief and less than 10% of the CPD group reported pain relief. Forty percent of the SAAD group with positive pain reproduction reported ≥50% relief and 20% reporting ≥80% relief. Forty-six percent of the ADPD group reported ≥50% relief and 30% reporting ≥80% relief. The FAD group had a greater 80% patients reporting ≥50% pain relief although fewer 26% reporting more convincing ≥80% relief. CONCLUSIONS: If the criterion standard to confirm painful annular tears is concordant pain provocation and 80% or greater pain relief following LA injected into lumbar discs, the SAAD, ADPD, and FAD protocols show statistically similar 20% to 30% prevelance.

Lumbar diskogenic pain, provocation diskography, and imaging correlates.

Diskogenic pain refers to pain mediated by the intrinsic innervation of the intervertebral disk. It is experienced as pain centered at the symptomatic spine segment (axial pain) without radicular features or radiculopathy. There is no pathoanatomic gold standard; histologic examination cannot identify a painful disk. The current reference standard for diskogenic pain is provocation diskography. This article reviews diskogenic pain, the history of provocation diskography, and its current use in the diagnosis of lumbar diskogenic pain. The extensive literature describing imaging features which may predict a positive diskogram, and allow non-invasive diagnosis of diskogenic pain, is examined.

Paraplegia following image-guided transforaminal lumbar spine epidural steroid injection: two case reports.

OBJECTIVE: To present two case reports of a rare but devastating injury after image-guided, lumbar transforaminal injection of steroids, and to explore features in common with previously reported cases. BACKGROUND: Image (fluoroscopic and computed tomography [CT])-guided, lumbar transforaminal injections of corticosteroids have been adopted as a treatment for radicular pain. Complications associated with these procedures are rare, but can be severe. CASE REPORTS: An 83-year-old woman underwent a fluoroscopically guided, left L3-L4, transforaminal injection of betamethasone (Celestone Soluspan). A 79-year-old man underwent a CT-guided, right L3-L4, transforaminal injection of methylprednisolone (DepoMedrol). Both patients developed bilateral lower extremity paralysis, with neurogenic bowel and bladder, immediately after the procedures. Magnetic resonance imaging scans were consistent with spinal cord infarction. There was no evidence of intraspinal mass or hematoma. CONCLUSION: These cases consolidate a pattern emerging in the literature. Distal cord and conus injury can occur following transforaminal injections at lumbar levels, whether injection is on the left or right. This conforms with the probability of radicular-medullary arteries forming an arteria radicularis magna at lumbar levels. All cases used particulate corticosteroids, which promotes embolization in a radicular artery as the likely mechanism of injury. The risk of this complication can be reduced, and potentially eliminated, by the utilization of particulate free steroids, testing for intra-arterial injection with digital subtraction angiography, and a preliminary injection of local anesthetic.

Clinical predictors of screening lumbar zygapophyseal joint blocks: development of clinical prediction rules.

BACKGROUND: Only controlled intra-articular zygapophyseal joint (ZJ) injections or medial branch blocks can diagnose ZJ-mediated low back pain. The low prevalence of ZJ pain implies that identification of clinical predictors of a positive response to a screening block is needed. PURPOSE: To estimate the predictive power of clinical findings in relation to pain reduction after screening ZJ blocks. STUDY DESIGN: As part of a wider prospective blinded study investigating diagnostic accuracy of clinical variables, a secondary analysis was carried out to seek evidence of variables potentially valuable as predictors of screening ZJ block outcomes. PATIENT SAMPLE: Chronic low back pain patients received screening ZJ blocks (n=151) with 120 patients included in the analysis after exclusions. OUTCOME MEASURES: Pain intensity was measured using a 100-mm visual analog scale, and responses were categorized according to 75% through 95% or more pain reduction in 5% increments. METHODS: Patients completed pain drawings, questionnaires, and a clinical examination before screening lumbar ZJ blocks. History, demographic and clinical variables were evaluated in cross tabulation and regression analyses with diagnostic accuracy values calculated for variables and variable clusters in relation to different pain reduction standards. RESULTS: At the 75% pain reduction standard, 24.5% responded to screening ZJ blocks and 10.8% responded at the 95% standard. The centralization phenomenon is not associated with pain reduction using any standard. No variables were useful predictors of post-ZJ block pain reduction of less than 90%. Seven clinical findings were associated with 95% pain reduction after blocks. Five useful clinical prediction rules (CPRs) were found for ruling out a 95% pain reduction (100% sensitivity), and one CPR had a likelihood ratio of 9.7, producing a fivefold improvement in posttest probability. CONCLUSIONS: A negative extension rotation test, the centralization phenomenon, and four CPRs effectively rule out pain ablation after screening ZJ block. One CPR generates a fivefold improvement in posttest probability of a negative or positive response to ZJ block.

Clinical predictors of lumbar provocation discography: a study of clinical predictors of lumbar provocation discography.

Discography is the only available method of directly challenging the discs for pain sensitivity. However, it is invasive, expensive and there is a debate about its clinical value. There is a need to identify clinical signs that may indicate the need for a discography examination. Pain centralization (retreat of referred pain to towards the spinal midline) has been associated with positive discography and possesses specificity between 80 and 100% depending on levels of disablement and psychosocial distress. Less than half of positive discography patients reports centralization and there is a need to identify other potentially valuable predictors. This study estimated the diagnostic accuracy of clinical variables in relation to provocation discography. In a blinded, prospective reference standard design in a private interventional radiology clinic, chronic low back patients received a detailed clinical examination followed by discography. Patients were typically disabled with high levels of psychosocial distress. Logistic regression modelling identified potentially useful clinical variables, and sensitivity, specificity and likelihood ratios were calculated for promising specific variables and combinations of variables. Of 118 consecutive discography cases, 107 had unconfounded data on discography results. History of persistent pain between acute episodes, a significant loss of extension and a subjective report of 'vulnerability' in what is termed as the 'neutral zone' had specificities of 83-92% and likelihood ratios between 2.0 and 4.1. Two combinations of variables were highly specific to positive discography, but no suitable screening test useful for ruling out positive discography was established. Three clinical variables have modest predictive power in relation to lumbar discography results and two combinations of variables were highly specific to positive discography.

Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of tests.

Previous research indicates that physical examination cannot diagnose sacroiliac joint (SIJ) pathology. Earlier studies have not reported sensitivities and specificities of composites of provocation tests known to have acceptable inter-examiner reliability. This study examined the diagnostic power of pain provocation SIJ tests singly and in various combinations, in relation to an accepted criterion standard. In a blinded criterion-related validity design, 48 patients were examined by physiotherapists using pain provocation SIJ tests and received an injection of local anaesthetic into the SIJ. The tests were evaluated singly and in various combinations (composites) for diagnostic power. All patients with a positive response to diagnostic injection reported pain with at least one SIJ test. Sensitivity and specificity for three or more of six positive SIJ tests were 94% and 78%, respectively. Receiver operator characteristic curves and areas under the curve were constructed for various composites. The greatest area under the curve for any two of the best four tests was 0.842. In conclusion, composites of provocation SIJ tests are of value in clinical diagnosis of symptomatic SIJ. Three or more out of six tests or any two of four selected tests have the best predictive power in relation to results of intra-articular anaesthetic block injections. When all six provocation tests do not provoke familiar pain, the SIJ can be ruled out as a source of current LBP.

Centralization as a predictor of provocation discography results in chronic low back pain, and the influence of disability and distress on diagnostic power.

BACKGROUND CONTEXT: The "centralization phenomenon" (CP) is the progressive retreat of referred pain towards the spinal midline in response to repeated movement testing (a McKenzie evaluation). A previous study suggested that it may have utility in the clinical diagnosis of discogenic pain and may assist patient selection for discography and specific treatments for disc pain. PURPOSE: Estimation of the diagnostic predictive power of centralization and the influence of disability and patient distress on diagnostic performance, using provocation discography as a criterion standard for diagnosis, in chronic low back pain patients. STUDY DESIGN/SETTING: This study was a prospective, blinded, concurrent, reference standard-related validity design carried out in a private radiology clinic specializing in diagnosis of chronic spinal pain. PATIENT SAMPLE: Consecutive patients with persistent low back pain were referred to the study clinic by orthopedists and other medical specialists for interventional radiological diagnostic procedures. Patients were typically disabled and displayed high levels of psychosocial distress. The sample included patients with previous lumbar surgery, and most had unsuccessful conservative therapies previously. DIAGNOSIS: results of provocation discography. INDEX TEST: The CP. Psychometric evaluation: Roland-Morris, Zung, Modified Somatic Perception questionnaires, Distress Risk Assessment Method, and 100-mm visual analog scales for pain intensity. METHODS: Patients received a single physical therapy examination, followed by lumbar provocation discography. Sensitivity, specificity, and likelihood ratios of the CP were estimated in the group as a whole and in subgroups defined by psychometric measures. RESULTS: A total of 107 patients received the clinical examination and discography at two or more levels and post-discography computed tomography. Thirty-eight could not tolerate a full physical examination and were excluded from the main analysis. Disability and pain intensity ratings were high, and distress was common. Sensitivity, specificity, and positive likelihood ratios for centralization observed during repeated movement testing for pain distribution and intensity changes were 40%, 94%, and 6.9 respectively. In the presence of severe disability, sensitivity, specificity, and positive likelihood ratios were 46%, 80%, 3.2 and for distress, 45%, 89%, 4.1. In the subgroups with moderate, minimal, or no disability, sensitivity and specificity were 37%, 100% and for no or minimal distress 35%, 100%. CONCLUSIONS: Centralization is highly specific to positive discography but specificity is reduced in the presence of severe disability or psychosocial distress.

Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain.

BACKGROUND: The tissue origin of low back pain (LBP) or referred lower extremity symptoms (LES) may be identified in about 70% of cases using advanced imaging, discography and facet or sacroiliac joint blocks. These techniques are invasive and availability varies. A clinical examination is non-invasive and widely available but its validity is questioned. Diagnostic studies usually examine single tests in relation to single reference standards, yet in clinical practice, clinicians use multiple tests and select from a range of possible diagnoses. There is a need for studies that evaluate the diagnostic performance of clinical diagnoses against available reference standards. METHODS: We compared blinded clinical diagnoses with diagnoses based on available reference standards for known causes of LBP or LES such as discography, facet, sacroiliac or hip joint blocks, epidurals injections, advanced imaging studies or any combination of these tests. A prospective, blinded validity design was employed. Physiotherapists examined consecutive patients with chronic lumbopelvic pain and/or referred LES scheduled to receive the reference standard examinations. When diagnoses were in complete agreement regardless of complexity, "exact" agreement was recorded. When the clinical diagnosis was included within the reference standard diagnoses, "clinical agreement" was recorded. The proportional chance criterion (PCC) statistic was used to estimate agreement on multiple diagnostic possibilities because it accounts for the prevalence of individual categories in the sample. The kappa statistic was used to estimate agreement on six pathoanatomic diagnoses. RESULTS: In a sample of chronic LBP patients (n = 216) with high levels of disability and distress, 67% received a patho-anatomic diagnosis based on available reference standards, and 10% had more than one tissue origin of pain identified. For 27 diagnostic categories and combinations, chance clinical agreement (PCC) was estimated at 13%. "Exact" agreement between clinical and reference standard diagnoses was 32% and "clinical agreement" 51%. For six pathoanatomic categories (disc, facet joint, sacroiliac joint, hip joint, nerve root and spinal stenosis), PCC was 33% with actual agreement 56%. There was no overlap of 95% confidence intervals on any comparison. Diagnostic agreement on the six most common patho-anatomic categories produced a kappa of 0.31. CONCLUSION: Clinical diagnoses agree with reference standards diagnoses more often than chance. Using available reference standards, most patients can have a tissue source of pain identified.

Percutaneous puncture of zygapophysial joint synovial cyst with fluoroscopic guidance.

OBJECTIVE: To introduce a minimally invasive, percutaneous fluoroscopic technique for treating symptomatic zygapophysial joint (z-joint) synovial cysts. METHODS: Chart review to describe the clinical presentation, representative imaging, technical procedural details, and follow-up of a 72-year-old female with a symptomatic lumbar z-joint synovial cyst. RESULTS: Before the cyst puncture, the patient failed conservative care including transforaminal epidural and intra-articular z-joint injections. Immediately after the puncture, and at 4-month follow-up, the patient was free of left lower extremity radicular pain. Computed tomography at 4 months post puncture showed resolution of the cyst. There was no recurrence of left leg pain at 30-month follow-up. CONCLUSION: This technical case report illustrates that puncture of an intraspinal z-joint synovial cyst using an interlaminar approach with fluoroscopic guidance may be safely performed with effective relief of radicular symptoms.

A new classification system for degenerative disc disease of the lumbar spine based on magnetic resonance imaging, provocative discography, plain radiographs and anatomic considerations.

Prior attempts to classify degenerative disc disease (DDD) of the lumbar spine have been based on magnetic resonance imaging (MRI) signal intensity. Internal disruption of the disc is not reliably diagnosed by MRI alone. No attempt has been made to include provocative discography and plain radiographs. The intervertebral joint is a three-joint complex consisting not only of the end plate-disc-end plate joint of the anterior column, but also the two facet joints of the posterior column. To date, no classification system for lumbar DDD has taken into account the state of degeneration of the facet joints. In the past this may not have been important with regard to arthrodesis. But as early experience indicates, the degree of degeneration of the facet joints is paramount to the clinical success of an artificial disc replacement. As we transition from intervertebral joint fusion to intervertebral joint replacement, it is imperative that the state of degeneration of the three-joint complex be classified in such a way that all can evaluate lumbar DDD using the same terminology. A new classification system for lumbar DDD is presented. The intervertebral segment is graded in two parts: the anterior column and the posterior column, based on MRI, discography and plain radiographs. The system will be validated through a blinded study of 100 patients requiring stand-alone anterior lumbar interbody fusion or circumferential fusion. Although the debate over which discs are best treated surgically with indication for total disc replacement, or with indication for fusion will continue for some time, the basic understanding of intervertebral disc and posterior facet joint pathology, classified and validated in a simple forthright manner, is essential as we move forward with artificial disc technology.

Zygapophysial joint blocks in chronic low back pain: a test of Revel's model as a screening test.

BACKGROUND: Only controlled blocks are capable of confirming the zygapophysial joints (ZJ) as the pain generator in LBP patients. However, previous workers have found that a cluster of clinical signs ("Revel's criteria"), may be valuable in predicting the results of an initial screening ZJ block. It was suggested that these clinical findings are unsuitable for diagnosis, but may be of value in selecting patients for diagnostic blocks of the lumbar ZJ's. To constitute evidence in favour of a clinical management strategy, these results need confirmation. This study evaluates the utility of 'Revel's criteria' as a screening tool for selection of chronic low back pain patients for controlled ZJ diagnostic blocks. METHODS: This study utilized a prospective blinded concurrent reference standard related validity design. Consecutive chronic LBP patients completed pain drawings, psychosocial distress and disability questionnaires, received a clinical examination and lumbar zygapophysial blocks. Two reference standards were evaluated simultaneously: 1. 75% reduction of pain on a visual analogue scale (replication of previous work), and 2. abolition of the dominant or primary pain. Using "Revel's criteria" as predictors, logistic regression analyses were used to test the model. Estimates of sensitivity, specificity, predictive values and likelihood ratios for selected variables were calculated for the two proposed clinical strategies. RESULTS: Earlier results were not replicated. Sensitivity of "Revel's criteria" was low sensitivity (<17%), and specificity high (approximately 90%). Absence of pain with cough or sneeze just reached significance (p = 0.05) within one model. CONCLUSIONS: "Revel's criteria" are unsuitable as a clinical screening test to select chronic LBP patients for initial ZJ blocks. However, the criteria may have use in identifying a small subset (11%) of patients likely to respond to the initial block (specificity 93%).

Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac provocation tests.

Research suggests that clinical examination of the lumbar spine and pelvis is unable to predict the results of diagnostic injections used as reference standards. The purpose of this study was to assess the diagnostic accuracy of a clinical examination in identifying symptomatic and asymptomatic sacroiliac joints using double diagnostic injections as the reference standard. In a blinded concurrent criterion-related validity design study, 48 patients with chronic lumbopelvic pain referred for diagnostic spinal injection procedures were examined using a specific clinical examination and received diagnostic intraarticular sacroiliac joint injections. The centralisation and peripheralisation phenomena were used to identify possible discogenic pain and the results from provocation sacroiliac joint tests were used as part of the clinical reasoning process. Eleven patients had sacroiliac joint pain confirmed by double diagnostic injection. Ten of the 11 sacroiliac joint patients met clinical examination criteria for having sacroiliac joint pain. In the primary subset analysis of 34 patients, sensitivity, specificity and positive likelihood ratio (95% confidence intervals) of the clinical evaluation were 91% (62 to 98), 83% (68 to 96) and 6.97(2.70 to 20.27) respectively. The diagnostic accuracy of the clinical examination and clinical reasoning process was superior to the sacroiliac joint pain provocation tests alone. A specific clinical examination and reasoning process can differentiate between symptomatic and asymptomatic sacroiliac joints