Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain

Background: Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain. Methods: The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year. Results: Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P,0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, P,0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P,0.001). Conclusion: Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse. Copyright

Predictive value of MRI in decision making for disc surgery for sciatica: Clinical article

Object. In a randomized controlled trial comparing surgery and prolonged conservative treatment for sciatica of 6-12 weeks' duration, more than one-third of patients assigned to conservative treatment underwent surgery. The objective of the present study was to evaluate whether MRI at baseline could have predicted this delayed surgery. Methods. Independently evaluated qualitative and quantitative MRI findings were compared between those patients who did and those who did not undergo surgery during follow-up in the conservative care group. In addition, area under the receiver operating characteristic (ROC) curve analysis was used to assess how well MRI parameters discriminated between those who did and those who did not undergo delayed surgery (0.5-0.7 poor discrimination, ≥ 0.7 acceptable discrimination). Results. Of 142 patients assigned to receive prolonged conservative care, 55 patients (39%) received delayed surgery. Of the 55 surgically treated patients, 71% had definite nerve root compression at baseline compared with 72% of conservatively treated patients (p = 0.76). Large disc herniations (size > 50% of spinal canal) were nearly equally distributed between those who did and those who did not undergo surgery (25% vs 21%, p = 0.65). The size of the dural sac was smaller in the patients who underwent surgery (101.2 vs 122.9 mm2, p = 0.01). However, the size of the dural sac discriminated poorly between those who did and those who did not undergo delayed surgery (area under ROC curve, 0.62). Conclusions. In patients who suffered from sciatica of 6-12 weeks' duration, MRI at baseline did not distinguish between patients who did and those who did not undergo delayed surgery. Clinical trial registration no.: ISRCTN26872154 (http://www.controlled-trials.com/ISRCTN/)

Influence of low back pain and prognostic value of MRI in sciatica patients in relation to back pain.

BACKGROUND: Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica patients with and without disabling back pain. METHODS: The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year. RESULTS: Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P<0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio [OR] 0.32, 95% Confidence Interval 0.18-0.56, P<0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P<0.001). CONCLUSION: Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse

Magnetic Resonance Imaging in Follow-up Assessment of Sciatica

<p>BACKGROUND</p><p>Magnetic resonance imaging (MRI) is frequently performed during follow-up in patients with known lumbar-disk herniation and persistent symptoms of sciatica. The association between findings on MRI and clinical outcome is controversial.</p><p>METHODS</p><p>We studied 283 patients in a randomized trial comparing surgery and prolonged conservative care for sciatica and lumbar-disk herniation. Patients underwent MRI at baseline and after 1 year. We used a 4-point scale to assess disk herniation on MRI, ranging from 1 for "definitely present" to 4 for "definitely absent." A favorable clinical outcome was defined as complete or nearly complete disappearance of symptoms at 1 year. We compared proportions of patients with a favorable outcome among those with a definite absence of disk herniation and those with a definite, probable, or possible presence of disk herniation at 1 year. The area under the receiver-operating-characteristic (ROC) curve was used to assess the prognostic accuracy of the 4-point scores regarding a favorable or unfavorable outcome, with 1 indicating perfect discriminatory value and 0.5 or less indicating no discriminatory value.</p><p>RESULTS</p><p>At 1 year, 84% of the patients reported having a favorable outcome. Disk herniation was visible in 35% with a favorable outcome and in 33% with an unfavorable outcome (P = 0.70). A favorable outcome was reported in 85% of patients with disk herniation and 83% without disk herniation (P = 0.70). MRI assessment of disk herniation did not distinguish between patients with a favorable outcome and those with an unfavorable outcome (area under ROC curve, 0.48).</p><p>CONCLUSIONS</p><p>MRI performed at 1-year follow-up in patients who had been treated for sciatica and lumbar-disk herniation did not distinguish between those with a favorable outcome and those with an unfavorable outcome. (Funded by the Netherlands Organization for Health Research and Development and the Hoelen Foundation; Controlled Clinical Trials number, ISRCTN26872154.)</p>

Magnetic Resonance Imaging Interpretation in Patients with Sciatica Who Are Potential Candidates for Lumbar Disc Surgery

<p>Background: Magnetic Resonance Imaging (MRI) is considered the mainstay imaging investigation in patients suspected of lumbar disc herniations. Both imaging and clinical findings determine the final decision of surgery. The objective of this study was to assess MRI observer variation in patients with sciatica who are potential candidates for lumbar disc surgery.</p><p>Methods: Patients for this study were potential candidates (n = 395) for lumbar disc surgery who underwent MRI to assess eligibility for a randomized trial. Two neuroradiologists and one neurosurgeon independently evaluated all MRIs. A four point scale was used for both probability of disc herniation and root compression, ranging from definitely present to definitely absent. Multiple characteristics of the degenerated disc herniation were scored. For inter-agreement analysis absolute agreements and kappa coefficients were used. Kappa coefficients were categorized as poor (</p><p>Results: Excellent agreement was found on the affected disc level (kappa range 0.81-0.86) and the nerve root that most likely caused the sciatic symptoms (kappa range 0.86-0.89). Interobserver agreement was moderate to substantial for the probability of disc herniation (kappa range 0.57-0.77) and the probability of nerve root compression (kappa range 0.42-0.69). Absolute pairwise agreement among the readers ranged from 90-94% regarding the question whether the probability of disc herniation on MRI was above or below 50%. Generally, moderate agreement was observed regarding the characteristics of the symptomatic disc level and of the herniated disc.</p><p>Conclusion: The observer variation of MRI interpretation in potential candidates for lumbar disc surgery is satisfactory regarding characteristics most important in decision for surgery. However, there is considerable variation between observers in specific characteristics of the symptomatic disc level and herniated disc.</p>

Clinical outcome measures at one year according to subgroups at baseline.

<p>Subgroups defined by the presence of disabling back pain and the presence of a disc herniation or nerve root compression on MRI at baseline. Values are n (%) or means ± SD. N = 379.</p>∫<p>Perceived recovery was defined as complete or nearly complete disappearance of symptoms according to the Likert-7 point scale.</p>‡<p>The Roland Disability Questionnaire for Sciatica is a disease-specific disability scale that measures the functional status of patients with pain in the leg or back. Scores range from 0 to 23, with higher scores indicating worse functional status.</p>¶<p>The intensity of pain is indicated on a horizontal 100 mm visual analogue scale (VAS) with 0 representing no pain and 100 the worst pain ever experienced.</p

Comparison of the characteristics of the herniated disc on MRI between sciatica patients with and without disabling back pain at baseline.

<p>N = 330. Values are n (%).</p>¶<p>Vertebral Endplate Signal Changes were defined according to criteria of Modic. Type 1 lesions: hypointense in T1-weighted sequences and hyperintense in T2-weighted sequences. Type 2 lesions: increased signal on T1 weighted sequences and isointense or slightly hyperintense signal on T2 weighted sequences. Type 3 lesions: hypointense both in T1- and T2-weighted sequences.</p

Repeated measurement analysis curve of Mean Scores for back pain on the Visual-Analogue Scale.

<p>Sciatica patients with both disabling back pain and nerve root compression on MRI were compared with patients with disabling back pain but who did not depict nerve root compression on MRI at baseline. The vertical bars represent 95% confidence intervals.</p

Baseline characteristics stratified by presence of disabling back pain.

<p>Values are n (%) or means ± SD.</p>||<p>Body-mass index (BMI) is the weight in kilograms divided by the square of the height in meters.</p>¶<p>The Roland disability questionnaire for sciatica is a disease-specific disability scale that measures functional status in patients with pain in the leg or back. Scores range from 0 to 23, with higher scores indicating worse functional status.</p>‡<p>The intensity of pain was indicated on a horizontal 100 mm visual analogue scale, with 0 representing no pain and 100 the worst pain ever experienced.</p>∫<p>Perceived recovery was defined as complete or nearly complete disappearance of symptoms according to the Likert-7 point scale.</p

Interobserver agreement regarding characteristics of the impaired disc level.

<p>The number between brackets on the first row is the number of patients of which the observers suggested the same disc level as the symptomatic disc level. A en B represent the two neuroradiologists, while C represents the neurosurgeon.</p>‡<p>Categories were: bulging disc versus disc herniation.</p>∫<p>Categories were: yes versus no.</p>∥<p>Categories were: 1) Hypointensity 2) Normal 3) Hyperintensity.</p>∥<p>Categories were: 1) No vertebral endplate signal changes (VESC) 2) VESC type I 3) VESC type II.</p><p>4) VESC type III 5) Mixed VESC type I/II 6) Mixed VESC type II/III.</p>Ψ<p>Categories were: 1) Yes, completely disappeared 2) Yes, partly disappeared 3) No disappearance.</p>§<p>Categories were: 1) Sub-articular zone 2) Foraminal zone 3) Extra-foraminal zone.</p><p>^|--Categories were: 1) Normal 2) Thickened 3) Narrowed.</p>*<p>Prevalence of findings too low (<10% of the reports) to calculate kappa values.</p>**<p>Prevalence of spinal canal stenosis too low (<10% of the reports) to calculate kappa values.</p>***<p>Prevalence of thickened nerve roots too low (<10% of the reports) to calculate kappa values.</p