A correlation of cervical magnetic resonance imaging and discography/computed tomographic discograms

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.

Systematic review of the incidence of discitis after cervical discography

BACKGROUND CONTEXT

Cervical discography is not uniformly used in part because of the fear of discitis. Studies report widely varying rates of this life-threatening infection.

PURPOSE

The aim of this study was to estimate the incidence of discitis after cervical discography, delineate the consequences of discitis, and identify factors that may influence this complication.

STUDY DESIGN

Meta-analysis.

METHODS

Studies pertaining to cervical discography were identified by a literature review and bibliographic search. These were screened for inclusion into the meta-analysis by two reviewers. Data were collected on a wide range of clinical and demographic variables including age, gender, morbidities, number of patients, number of discograms, use of prophylactic antibiotics, type of surgical prep, number of needles used, and the number of patients and discs infected. Primary data were used to calculate the incidence of discitis per patient and per disc.

RESULTS

Fourteen studies were included in the analysis. Both procedural details and demographic information on patients were missing from eight studies. The mean age of patients ranged from 41 to 47 years, and gender distribution varied greatly. Antibiotics use was reported in three studies. Cervical discography was complicated by postprocedural discitis in 22 of 14,133 disc injections (0.15%) and 21 of 4,804 patients (0.44%). Only one patient suffered from an infection at more than one spinal level.

CONCLUSIONS

The rate of discitis after cervical discography is relatively low. This can perhaps be further decreased by the use of prophylactic intradiscal antibiotics. Should the ability of cervical discography to improve surgical outcomes be proven, the fear of discitis should not preclude performance of disc provocation.

Cervical intradiscal radiofrequency lesioning: a feasiblity study

OBJECTIVE

The objective of this benchtop study was to establish if single site, long duration intradiscal radiofrequency (RF) at two different positions could generate adequate heating throughout the intervertebral disc to potentially ablate intradiscal nociceptors.

DESIGN

The disarticulated cervical spines from four fresh frozen cadavers were studied. Temperature recording was completed from two different positions of the RF needle. The needle was either placed in the middle of the disc in four discs, or it was inserted in the posterior quarter of the disc, in eight discs. Thermocouple measurements were made every 2 minutes from three positions: middle of the disc, posterolateral aspect of the disc, and in the anterior third of the disc.

SETTING

Fluoroscopy suite.

MATERIALS

Disarticulated cervical spine specimens.

INTERVENTIONS

Intradiscal RF lesioning in the middle and posterior portion of the cervical disc at 85 degrees C for 10 minutes.

OUTCOME MEASURES

Local temperature within the disc.

RESULTS

Lesioning in either the middle or posterior portion of the disc failed to provide sufficient temperature increases throughout the cervical disc to achieve adequate denervation.

CONCLUSIONS

As in the lumbar spine, intradiscal cervical RF provides too focal a thermal profile to effectively denervate the disc even in an ex vivo experiment. Thus, single site, long duration cervical intradiscal RF lesioning in vivo cannot be recommended.

SURGERY FOR NECK PAIN

AXIAL NECK PAIN is a common finding that typically represents a spectrum of clinical Arlington Orthopedic Associates, disorders affecting the cervical spine. Controversy exists concerning the ultimate treatment of the patient who presents with cervical spondylosis and primarily axial neck pain without radicular symptoms or myelopathy and who has failed to respond to extensive nonoperative treatment methods. Cervical discography has been used to assist in determining the specific level or levels causing the neck pain and, potentially, which levels to fuse; however, controversy regarding the specificity of cervical discograms has also been debated in the literature. Los Angeles, California We recommend exhausting all conservative means of treatment of axial neck pain. Surgery is offered only after conservative treatment fails and appropriate psychological testing is performed, as well as diagnostic imaging and discography that confirm a specific level or levels as the pain source. Cervical fusion may demonstrate good results in appropriately chosen patients with cervical spondylosis and axial neck pain.

Percutaneous discography: comparison of low-dose CT, fluoroscopy and MRI in the diagnosis of lumbar disc disruption

AIM

To compare the diagnostic accuracy of low-dose computed tomography (CT), magnetic resonance imaging (MRI) and fluoroscopy in percutaneous discography in patients scheduled for lumbar spondylodesis.

MATERIAL AND METHODS

Within a prospective pilot study, 18 disc segments of 11 patients with radicular or pseudoradicular pain prior to anteroposterior spondylodesis were evaluated. After injection of a mixture of non-ionic iodine-containing contrast agent and gadolinium-based contrast medium into the disc spaces, all patients underwent conventional fluoroscopy, as well as low-dose CT and MRI. The occurrence of memory pain during contrast injection was recorded. CT, MRI and fluoroscopic images were analyzed independently by two readers blinded to the clinical findings.

RESULTS

There was 100% agreement between CT and MRI discography in the detection, localization and grading of degenerative changes. In contrast, conventional fluoroscopy identified only 9 of the 12 abnormal segments. Memory pain following puncture was identified in 3 of the 12 affected segments.

SUMMARY

Low-dose CT and MRI discography have a similar accuracy in the assessment of disc disruption and they are superior to fluoroscopic discography.

Sonographic characterization of the lumbar intervertebral disk with anatomic correlation and histopathologic findings

OBJECTIVE

The purpose of this study was to describe the normal anatomy and abnormalities of the lumbar intervertebral disk with sonography in cadaveric specimens and to correlate the sonographic findings with pathologic findings.

METHODS

Sonographic imaging with both 4.5- and 10-MHz linear array transducers was performed on 35 lumbar intervertebral disks in 13 human cadaveric spines. The cadaveric specimens were sectioned for anatomic and histopathologic evaluation. Findings on anatomic sections were correlated with the findings on corresponding sonographic images with respect to the sonographic appearance of disk components in 30 intervertebral disks.

RESULTS

High-resolution sonography with a 10-MHz frequency transducer enabled distinction of the nucleus pulposus from the annulus fibrosus and assessment of the echogenic characteristics of these structures. Sonography showed numerous fine linear echoes in the outer portion of the intervertebral disk in 26 (87%) of 30 specimens, which corresponded to the normal concentric arrangement of the fibers in the periphery of the annulus fibrosus. Amorphous areas of low echogenicity in the inner portion of the annulus fibrosus (n = 14, 47%) correlated with degenerative changes of the disk on corresponding microscopic sections. The nucleus pulposus appeared relatively isoechoic (n = 5, 17%) or hyperechoic (n = 4, 13%) to the annulus fibrosus. In degenerative disks (n = 21, 70%), the nucleus pulposus showed decreased echogenicity, and differentiation between the nucleus pulposus and annulus fibrosus was difficult.

CONCLUSIONS

High-resolution sonography is a simple imaging method that can show the normal lumbar intervertebral disk and degenerative changes in appropriate subjects. High-resolution sonography proves superior to conventional sonography for evaluation of the lumbar intervertebral disk.

Value of magnetic resonance imaging and discography in determining the level of cervical discectomy and fusion

STUDY DESIGN

The correlation between magnetic resonance imaging and discography of the cervical spine in degenerative disc disease was studied. In addition, the results of cervical discectomy and fusion were evaluated.

OBJECTIVES

To compare the value of cervical magnetic resonance imaging versus discography in selecting the level for discectomy and fusion and to evaluate the surgical outcome.

SUMMARY OF BACKGROUND DATA

The value of magnetic resonance imaging and discography in patients with cervical discogenic pain is less clear. Also, the status of a hypointense signal (dark) cervical disc and/or a small herniated disc on magnetic resonance imaging has not been determined.

METHODS

The magnetic resonance imaging studies and discography followed by computed tomography in 55 patients with cervical discogenic pain were evaluated. Surgical planning was based on the complete information of clinical symptoms, magnetic resonance imaging, and discography as well as computed tomography discography. Anterior cervical discectomy and keystone fusion was performed. Postoperative pain relief was assessed by the patients, and the follow-up radiographs were viewed by an independent reviewer. The overall surgical outcome was evaluated using Odom's criteria.

RESULTS

There were 161 disc levels that successfully underwent cervical discography with 79 positive levels. A positive discography result was found in 63% of dark (hypointense signal) discs and 45% of speckled discs. Fifty-nine percent of small herniated discs and 59% of torn discs had a positive discography, respectively. There were 100 abnormal cervical discs on magnetic resonance imaging. Magnetic resonance imaging had a false-positive rate of 51% and a false-negative rate of 27%. Successful cervical fusion was achieved in 95% of patients, and the overall satisfactory result was 76%.

CONCLUSIONS

Magnetic resonance imaging can identify most of the painful discs but still has relatively high false-negative and false-positive rates. There is a high chance that hypointense signal and small herniated discs are the pain generators, but they are not always symptomatic. Discography can save the levels from being unnecessarily fused. The combination of clinical symptoms, magnetic resonance imaging, and discography provides the most information for decision making and can improve the management of cervical discogenic pain.

A pilot randomized clinical trial on the relative effect of instrumental (MFMA) versus manual (HVLA) manipulation in the treatment of cervical spine dysfunction

OBJECTIVE

To determine the relative effect of instrument-delivered thrust cervical manipulations in comparison with traditional manual-delivered thrust cervical manipulations in the treatment of cervical spine dysfunction.

DESIGN

Prospective, randomized, comparative clinical trial.

SETTING

Outpatient chiropractic clinic, Technikon Natal, South Africa.

PATIENTS

Thirty patients diagnosed with neck pain and restricted cervical spine range of motion without complicating pathosis for at least 1 month were included in the study.

INTERVENTIONS

The patients were randomized into 2 groups. Those in one group received mechanical force, manually assisted (MFMA) manipulation to the cervical spine, delivered by means of a hand-held instrument (Activator II Adjusting Instrument). Those in the other group received specific contact high-velocity, low-amplitude (HVLA) manipulation consisting of standard Diversified rotary/lateral break techniques to the cervical spine. Each group received only the specific therapeutic intervention, no other treatment modalities or interventions (including medication) being used, until asymptomatic status was achieved or a maximum of 8 treatments had been received.

MAIN OUTCOME MEASURES

Both treatment groups were assessed through use of subjective (Numerical Pain Rating Scale 101, McGill Short-Form Pain Questionnaire, and Neck Disability Index) and objective (goniometer cervical range of motion) measurement parameters at specific intervals during the treatment period and at 1-month follow-up. The data were assessed through use of 2-tailed nonparametric paired and unpaired analysis, descriptive statistics, and power analysis of the data.

RESULTS

The results indicate that both treatment methods had a positive effect on the subjective and objective clinical outcome measures, no significant difference being observed between the 2 groups (P < .025). The subjective data from all 3 questionnaires showed statistically significant changes from initial to final consultations as well as from initial consultation to 1-month follow-up (P < .025). The objective range of motion measures showed statistically significant changes in the MFMA group for left and right rotation and left and right lateral flexion from initial consultation to final consultations and for right rotation and right lateral flexion from initial consultation to 1-month follow-up. The HVLA group showed only the change in left rotation from initial to final consultations and from initial consultation to 1-month follow-up to be statistically significant.

CONCLUSIONS

The results of this clinical trial indicate that both instrumental (MFMA) manipulation and manual (HVLA) manipulation have beneficial effects associated with reducing pain and disability and improving cervical range of motion in this patient population. A randomized, controlled clinical trial in a similar patient base with a larger sample size is necessary to verify the clinical relevance of these findings.

Cervical discography: clinical implications from 12 years of experience

STUDY DESIGN

Positive pain responses provoked in an inclusive series of cervical discograms performed over a 12-year period were categorized by level and reviewed.

OBJECTIVES

To report the prevalence of cervical pathology over an entire series of patients, to determine whether a reproducible pattern of concordant pain could be associated with each symptomatic level identified, and to calculate the rate of complications.

SUMMARY OF BACKGROUND DATA

Cloward wrote the first articles explaining the technique of cervical discography and reported on the pain responses induced. Currently, the technique is viewed as an invaluable diagnostic tool, but it also is criticized for failing to contribute unique information beyond that available from imaging studies despite the inherent risks.

METHODS

A series of 173 cervical discograms performed over 12 years was examined. Pain responses provoked and recorded during discography were grouped by disc level and examined for recurring patterns. The prevalence of disc pathology was calculated.

RESULTS

In all, 807 discs were injected, and 404 concordant pain responses (50%) were elicited. Three or more abnormal disc levels were identified in more than half of the patients. Complications developed in four patients (2.3%). No further complications were reported. Surgical treatment was indicated as viable in only 35 studies.

CONCLUSIONS

Discography is a safe and valuable diagnostic procedure showing characteristic pain patterns that may have clinical significance. In more than half of the studies, three or more levels were identified as pain generators, suggesting that treatment decisions based on information from fewer discs injected during discography may be tenuous.

The relation between cervical discographic pain responses and radiographic images

OBJECTIVE

The purpose of this study was to investigate the relation between cervical discographic pain responses and radiographic images.

DESIGN

Records were reviewed for a series of patients who had undergone cervical discography.

SETTING

All patients were being treated at a spine specialty clinic.

PATIENTS

A total of 269 discs were studied in 161 discographic procedures in patients with neck, shoulder, or arm pain. All patients underwent other diagnostic procedures before discography, including magnetic resonance imaging, computed tomography (CT), and CT/myelography.

INTERVENTIONS

During the injection of contrast in each disc evaluated, the patient was asked if any pain was felt, and if so, was it similar or dissimilar to the pain typically experienced.

OUTCOME MEASURES

Results were determined by analyzing the pain responses during disc injection with respect to imaged pathology seen on the axial CT discographic image of the disc. Results were further analyzed based on patient age.

RESULTS

There was a significant relation between the radiographic image of the disc and the results of clinical pain provocation (p < 0.01; chi2). Among the 35 discs appearing as normal, clinical pain was provoked in only 14.3%. Among the 234 discs appearing as abnormal, clinical pain was provoked in 77.8%. The mean age of the patients with painless radiographically abnormal discs was significantly greater than that of the patients in the other subgroups of the study population.

CONCLUSIONS

There was good agreement between the radiographic appearance of the disc and the pain provocation results. Discs that were painless but disrupted were found among older patients. Among such patients, discography may be particularly helpful in differentiating clinically significant abnormalities from those associated with aging.

Thoracic discography in healthy individuals. A controlled prospective study of magnetic resonance imaging and discography in asymptomatic and symptomatic individuals

STUDY DESIGN

A prospective case-control investigation.

OBJECTIVES

To determine the responses to thoracic discography of asymptomatic individuals.

SUMMARY OF BACKGROUND DATA

Literature regarding lumbar and cervical discography reveals that even morphologically abnormal discs often are not painful, whereas painful discs typically exhibit anular or endplate disruption.

METHODS

Ten adult lifelong asymptomatic volunteers, ages 23 to 45 years, underwent magnetic resonance imaging of the thoracic spine, followed by four-level discography. Provocative responses were graded on a scale of 0 (no sensation) to 10 (extreme pain or pressure), and filmed discs were graded using a modified Dallas scheme. Concomitantly, 10 nonlitigious adults (6 men and 4 women, ages 31 to 55 years) experiencing chronic thoracic pain were similarly studied as a control group.

RESULTS

The mean pain response in the asymptomatic volunteers was 2.4/10. Three discs were intensely painful (scores of 7/10, 8/10, 10/10), with all three exhibiting prominent endplate irregularities and anular tears typical of thoracolumbar Scheuermann's disease. On discography, 27 of 40 discs were abnormal, with endplate irregularities, anular tears, and/or herniations. Ten discs read as normal on magnetic resonance imaging showed anular pathology on discography. In the group with chronic thoracic pain, the average pain response was 6.3/10 (P < 0.05). Of the 48 discs studied, 24 were concordantly painful, with a pain response of 8.5/10 (P < 0.05); 17 had nonconcordant pain/pressure, with an average pain of 4.8/10 (P < 0.05); and 5 had no response. On magnetic resonance imaging 21 of the 48 discs appeared normal. However, on discography, only 10 were judged as normal.

CONCLUSIONS

On discography, thoracic discs with prominent Schmorl's nodes may be intensely painful, even in lifelong asymptomatic individuals, but the pain is unfamiliar or nonconcordant. Thoracic discography may-demonstrate disc pathology not seen on magnetic resonance imaging.

Strain on intervertebral discs after anterior cervical decompression and fusion

STUDY DESIGN

An analysis of the change in strain distribution of intervertebral discs present after anterior cervical decompression and fusion by an original method. The analytical results were compared to occurrence of herniation of the intervertebral disc on magnetic resonance imaging.

OBJECTIVES

To elucidate the influence of anterior cervical decompression and fusion on the unfused segments of the spine.

SUMMARY OF BACKGROUND DATA

There is no consensus regarding the exact significance of the biomechanical change in the unfused segment present after surgery.

METHODS

Ninety-six patients subjected to anterior cervical decompression and fusion for herniation of intervertebral discs were examined. Shear strain and longitudinal strain of intervertebral discs were analyzed on pre- and postoperative lateral dynamic routine radiography of the cervical spine. Thirty of the 96 patients were examined by magnetic resonance imaging before and after surgery, and the relation between alteration in strains and postsurgical occurrence of disc herniation was examined.

RESULTS

In the cases of double- or triple-level fusion, shear strain of adjacent segments had increased 20% on average 1 year after surgery. Thirteen intervertebral discs that had an abnormally high degree of strain showed an increase in longitudinal strain after surgery. Eleven (85%) of the 13 discs that showed an abnormal increase in longitudinal strain had herniation in the same intervertebral discs with compression of the spinal cord during the follow-up period. Relief of symptoms was significantly poor in the patients with recent herniation.

CONCLUSIONS

Close attention should be paid to long-term biomechanical changes in the unfused segment.

Imaging of the cervical spine

The emergence of multiplanar spiral computed tomography and high-resolution magnetic resonance imaging has resulted in the ability to see cervical spine anatomy and pathologic conditions in detail. Appropriately chosen and performed, these imaging studies can provide an anatomic basis for a clinical diagnosis and a therapeutic plan. In the evaluation of cervical spondylosis, magnetic resonance imaging is more commonly performed than computed tomography because of its superior depiction of soft tissue anatomy, including intervertebral discs and spinal cord disease. However, computed tomography still has a role, particularly in the assessment of osseous neural foraminal stenosis. In cervical spine trauma, routine radiography remains the procedure of choice. Computed tomography is performed in patients who have abnormal plain radiographs or in patients in whom there is a strong clinical suspicion of fracture with inconclusive radiographs. In the neurologically compromised patient, magnetic resonance imaging is useful in the diagnosis of cord and nerve root injury. Magnetic resonance imaging is the most sensitive and specific imaging study in the assessment of spinal infection, including osteomyelitis, discitis, and epidural abscess. Magnetic resonance imaging has also supplanted all other imaging methods in the evaluation of primary and secondary tumors of the spinal cord and spinal column. Despite the precise depiction of cervical spine anatomy provided by these imaging methods, the role of the clinician in determining the true cause of a patient's symptoms is in no way diminished. The presence of an imaging study abnormality does not automatically imply causality.

Disc degeneration and cervical instability. Correlation of magnetic resonance imaging with radiography

STUDY DESIGN

An imaging study was designed to evaluate disc degeneration and segmental instability in the cervical spine.

OBJECTIVES

To compare the magnetic resonance imaging assessment of disc degeneration with the conventional plain radiographic evaluation of cervical segmental instability.

SUMMARY OF BACKGROUND DATA

No studies have been conducted to investigate the association of disc degeneration with cervical instability.

METHODS

Two hundred sixty consecutive patients with suspected cervical spine disorders were analyzed for horizontal and angular displacements on lateral flexion and extension radiographs and disc degeneration on T2-weighted magnetic resonance images of the cervical vertebrae.

RESULTS

In all intervertebral levels, the grade of disc degeneration increased significantly (P < 0.01) with age. Cervical instability was identified in 151 segments (14.5%) and correlated with Grade 1 and Grade 2 degeneration in the intervertebral discs (P < 0.01).

CONCLUSIONS

Cervical segmental instability may indicate early degeneration of intervertebral disc in the cervical vertebrae.

Discography 2000

Discography is an invasive and controversial procedure that can be used as a complementary test to MR imaging or a CT myelogram prior to surgery. The examination may be performed in the prone or decubitus position. Pain provocation is the most important part of the examination. CT discography provides valuable information regarding pattern, number, extent, and degree of annular tears. Correlation of discography with cross-sectional imaging studies is reviewed and the surgical outcome is discussed.

Cervical discogenic pain. Prospective correlation of magnetic resonance imaging and discography in asymptomatic subjects and pain sufferers

STUDY DESIGN

Asymptomatic subjects and chronic head/neck pain sufferers were studied with high-field magnetic resonance imaging and cervical discography to compare and correlate both tests.

OBJECTIVES

To assess the accuracy of magnetic resonance imaging and discography in identifying the source(s) of cervical discogenic pain.

SUMMARY OF BACKGROUND DATA

Previous retrospective studies describe a generally poor correlation between magnetic resonance imaging and provocative discography in the cervical spine.

METHODS

Ten lifelong asymptomatic subjects and 10 nonlitigious chronic neck/head pain patients underwent discography at C3-C4 through C6-C7 after magnetic resonance imaging. Disc morphology and provoked responses were recorded at each level studied.

RESULTS

Of 20 normal discs by magnetic resonance from the asymptomatic volunteers, 17 proved to have painless anular tears discographically. The average response per disc (N = 40) for this group was 2.42, compared to 5.2 (N = 40) for the neck pain group. In the pain patients, 11 discs appeared normal at magnetic resonance imaging, whereas 10 of these proved to have anular tears discographically. Two of these 10 proved concordantly painful with intensity ratings of at least 7/10. Discographically normal discs (N = 8) were never painful (both groups), whereas intensely painful discs all exhibited tears of both the inner and outer aspects of the anulus.

CONCLUSIONS

Significant cervical disc anular tears often escape magnetic resonance imaging detection, and magnetic resonance imaging cannot reliably identify the source(s) of cervical discogenic pain.