New evaluation method using preoperative magnetic resonance imaging for cervical spondylotic myelopathy

Decoding unusual MR findings: Spinal cord edema in atypical cervical spondylotic myelopathy-A case report and literature review

We report a case of a young man with a slow progression of cervical spondylotic myelopathy (CSM). Cervical magnetic resonance imaging (MRI) revealed a mild cervical discbulging at C5-C6 and an area of atypically enlarged intramedullary high signal intensity extending from C4-C7 (T2-weighted) with contrast enhancement at C5-C6 (T1-weighted). Neurological and radiological diagnoses tend to favor demyelinating diseases, which interfere with the diagnosis of CSM. Patients were followed up and examined by MRI at 3 months, 1 year, and 2 years after surgery. The patient's symptoms improved immediately postoperatively. The functional result according to the modified Japanese Orthopedic Association (JOA) score improved from 10 to 13 within 3 months. He continued to improve neurologically over the first postoperative year. Two years postoperatively, a T2-weighted MRI showed that the edema signal had disappeared completely, and a fat-saturated T2-weighted MRI showed only slight abnormal signal. The numbness and weakness of the extremities had improved, and his JOA score was 16. Spinal cord edema is occasionally seen with CSM. In the case presented, the contrast enhancement was localized at the site of the greatest narrowing of the spinal canal and compression of the spinal cord. This coincidence was the best indicator of a mechanical cause of the spinal cord changes. This feature should increase physician's confidence in distinguishing CSM from intramedullary tumors and myelitis. Surgical decompression may be beneficial in improving neurologic outcomes.

Usefulness of K-line in predicting prognosis of laminoplasty for cervical spondylotic myelopathy

BACKGROUND

K-line is widely recognized as a useful index for evaluating cervical alignment and the size of the cervical ossification at the posterior longitudinal ligament (OPLL). The purpose of this study was to investigate whether the K-line could be a useful clinical tool for predicting the prognosis of laminoplasty (LP) for cervical spondylotic myelopathy (CSM).

METHODS

Adult CSM patients scheduled for cervical LP were recruited for this study. C2-7 angle, local kyphosis angle, and K-line was evaluated by T2-weighted sagittal magnetic resonance imaging (MRI). Clinical findings were evaluated by the JOA score and the recovery rate. Clinical and radiological findings were evaluated preoperation and final follow-up. Patients were grouped into K-line ( +) and K-line (-). Patients with Kline (-) were further divided into two sub-groups: disc type (anterior cord compression due to disc protrusion with kyphosis) and osseous type (due to osseous structure such as osteophyte).

RESULTS

Sixty-eight patients were included in the analysis. The recovery rate of K-line (-) group (n = 11,19.4%) was significantly worse than that of K-line ( +) group (n = 57, 50.6%, p<0.05). Among 11 K-line (-) patients, 7 were disc type and 4 were osseous type. Over the period of follow-up, the disc type K-line (-) patients changed to K-line ( +) and showed significantly better recovery rate (27.6%) compared to the osseous type K-line (-) group (5.0%, p < 0.05).

CONCLUSION

The present of this study indicate that K-line may have a predictive value for clinical outcome in patients undergoing LP for CSM. K-line (-) of osseous type was worse than k-line (-) of disc type.

Do quantitative magnetic resonance imaging parameters correlate with the clinical presentation and functional outcomes after surgery in cervical spondylotic myelopathy? A prospective multicenter study

STUDY DESIGN

A prospective multicenter cohort study.

OBJECTIVE

To establish the relationship between preoperative quantitative magnetic resonance imaging (MRI) parameters and clinical presentation and postoperative outcomes in patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Correlation of magnetic resonance imaging with clinical presentation and outcomes in cervical spondylotic myelopathy is poorly understood.

METHODS

A total of 134 magnetic resonance imaging scans were reviewed from 12 sites across North America. The transverse area (TA) of the spinal cord at the site of maximal compression was computed, and spinal cord signal intensity (SI) changes on T1-/T2-weighted imaging (WI) were evaluated. Detailed clinical assessments--neurological signs, symptoms, Nurick grade, modified Japanese Orthopaedic Association, segmental-tract score, and long-tract score of modified Japanese Orthopaedic Association, 30-m walk test, Short-Form 36 questionnaire, and neck disability index were performed at admission, 6 months, and 12 months postoperatively.

RESULTS

The total number of neurological signs in a patient correlated with TA (P = 0.01) and SI changes on T1-/T2WI (P = 0.05). Pre- and postoperative Nurick grade (P = 0.03, P = 0.02), modified Japanese Orthopaedic Association score (P = 0.005, P = 0.001), segmental-tract score (P = 0.05, P = 0.006), and long-tract score (P = 0.006, P = 0.002), 30-m walk test (P = 0.002, P = 0.01) correlated with TA. There was no significant difference in pre- and postoperative clinical scores in patients with/without SI changes. Patients with severe cord compression showed SI changes on T1-/T2WI more frequently (r =-0.27, r =-0.38). Pyramidal signs--plantar response, Hoffmann reflex and hyper-reflexia correlated with TA (P = 0.003, P = 0.0004, P = 0.024, respectively) and SI changes on T1/T2WI (P = 0.02).

CONCLUSION

TA closely mirrors the clinical presentation of cervical spondylotic myelopathy and may be used in predicting surgical outcomes. Pyramidal signs correlated with TA and/or SI changes on T1-/T2WI. The total number of neurological signs in a patient correlated with TA. There was no significant relationship between TA, age and duration of symptoms.

LEVEL OF EVIDENCE

3.

Overactive bladder in cervical spondylotic myelopathy

BACKGROUND

Overactive bladder (OAB) is a new disease concept defined by the International Continence Society in 2002. There have been no reports of OAB among patients with cervical spondylotic myelopathy assessed on the basis of symptom questionnaires.

METHODS

One-hundred-and-six patients diagnosed with cervical spondylotic myelopathy and treated by use of laminoplasty were examined. The patients were classified into two groups, those identified as having OAB (OAB group) and those identified as not having OAB (non-OAB group), by use of the Overactive Bladder Symptom Score collected before and 1 year after surgery. The clinical results for the two groups were assessed. OAB symptom prevalence and post-operative symptom improvement were investigated 1 year postoperatively.

RESULTS

Of the 106 patients, 50 were identified as having OAB (symptom prevalence 47.2%). Of these 50 patients, symptom improvement was observed for only 14 (28%) 1 year after surgery. For both groups good improvement on the basis of the Japanese Orthopedic Association score was observed 1 year postoperatively, but there were no significant differences between them.

CONCLUSIONS

Post-operative improvement of OAB symptoms in cervical spondylotic myelopathy patients was low, which indicated that OAB was most frequently attributable to non-neurogenic and idiopathic, but not neurogenic, causes. It is considered necessary to tell patients with cervical spondylotic myelopathy that the possibility of post-operative OAB symptom improvement is not high when the explanation for informed consent is given before the operation.

Outcomes of surgical intervention for cervical spondylotic myelopathy accompanying local kyphosis (comparison between laminoplasty alone and posterior reconstruction surgery using the screw-rod system)

PURPOSE

The surgical strategy for cervical spondylotic myelopathy (CSM) accompanying local kyphosis is controversial. The purpose of the present study was to compare and evaluate the outcomes of two types of surgery for CSM accompanying local kyphosis: (1) laminoplasty alone (LP) and (2) posterior reconstruction surgery (PR) in which we corrected the local kyphosis using a pedicle screw or lateral mass screw.

METHODS

Sixty patients who presented with local kyphosis exceeding 5° were enrolled. LP and PR were each performed on a group of 30 of these patients; 30 CSM patients without local kyphosis, who had undergone LP, were used as controls. The follow-up period was 2 years or longer. Preoperative local kyphosis angles in LP and PR were 8.3° ± 4.4° and 8.8° ± 5.7°, respectively. Preoperative C2-7 angles in LP, PR and controls were -1.7° ± 9.6°, -0.4° ± 7.2° and -12.0° ± 5.6°, respectively. The recovery rate of the JOA score, local kyphosis angle and C2-7 angle at post-op and follow-up were compared between the groups.

RESULTS

The recovery rate of the JOA score in the LP group (32.6 %) was significantly worse than that in the PR group (44.5 %) and that of controls (53.8 %). Local kyphosis angles in the PR and LP groups at follow-up were 4.0° ± 8.6° and 8.0° ± 6.0°, respectively. However, although the C2-7 angle at follow-up was improved to -11.1° ± 12.7° in PR, and maintained at -11.6° ± 6.2° in controls, it deteriorated to 0.5° ± 12.7° in LP.

CONCLUSIONS

The present study is the first to compare the outcomes between LP alone and PR for CSM accompanying local kyphosis. It revealed that PR resulted in a better clinical outcome than did LP alone. This result may be due to reduction of local kyphosis, stabilization of the unstable segment, and/or the maintenance of C2-7 angle until follow-up in the PR group.

Assessment of spinal cord compression by magnetic resonance imaging--can it predict surgical outcomes in degenerative compressive myelopathy? A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

We sought to conduct a systematic review to examine the role of magnetic resonance imaging in predicting outcomes after surgery and to evaluate the evidence currently available critically.

SUMMARY OF BACKGROUND DATA

Degenerative compressive myelopathy is a common clinical problem associated with adverse health outcomes. Although a number of studies have investigated the association between preoperative magnetic resonance imaging characteristics and outcomes after surgery for degenerative compressive myelopathy, the conclusions of these studies have often yielded differing results.

METHODS

Articles examining the predictive value of magnetic resonance imaging were obtained from MEDLINE, EMBASE, and PubMed databases (1980-2011). Thirty publications that met the inclusion criteria were reviewed. Two reviewers independently assessed each study regarding the level of evidence (using the criteria proposed by Sackett) and methodological quality based on revised Cochrane quality assessment checklist.

RESULTS

Three excellent, 1 good, and 10 poor quality studies assessed cord compression--transverse area (4), compression ratio (5), and anteroposterior diameter (1). Relationship between signal intensity (SI) changes and surgical outcomes were reviewed by 28 studies--8 excellent, 9 good, and 13 poor quality studies. SI changes within the spinal cord included the presence of SI on T2-weighted image (WI) (17), area of SI on T2WI (8), degree of SI on T2WI (5), presence of SI on both T1-/T2WI (2), SI ratio on T2WI (2), and the position of SI on T2WI (1).

CONCLUSION

Based on a combination of excellent and good quality studies, transverse area correlates with recovery ratio but not with postoperative functional score assessed by Japanese Orthopaedic Association/modified Japanese Orthopaedic Association scores. SI changes defined by (1) its presence on T2WI, (2) its extent (focal or multisegmental), (3) its brightness, and (4) its presence on both T1-/T2WI can predict surgical outcomes in degenerative compressive myelopathy.

Preoperative magnetic resonance imaging is associated with baseline neurological status and can predict postoperative recovery in patients with cervical spondylotic myelopathy

STUDY DESIGN

A blinded observational study of consecutive patients, prospectively enrolled and followed up to 1 year postoperatively.

OBJECTIVE

To assess whether quantitative assessment of preoperative magnetic resonance imaging (MRI) predicts baseline patient status and postoperative neurological recovery.

SUMMARY OF BACKGROUND DATA

Factors that can predict neurological recovery in patients with cervical spondylotic myelopathy (CSM) postoperatively are of great interest. Currently, the literature regarding the significance of MRI signal changes in relation to prognosis is inconsistent and conflicting.

METHODS

A total of 57 consecutive patients with CSM were studied preoperatively and 1 year postoperatively. Modified Japanese Orthopaedic Association (mJOA), Nurick Grade, SF-36, neck disability index, 30-meter walk cadence (Wc) and time (Wt), grip strength, and Berg Balance Scale were administered at baseline and 1 year after surgery. Preoperative status and postoperative recovery were assessed in relation to quantitative MRI measurements pre- and postoperatively using univariate and multivariate analysis.

RESULTS

Low T1 signal change preoperatively was associated with a lower mJOA (P = 0.0030), higher Nurick Grade (P = 0.0298), decreased grip (P = 0.0152), impaired Wt, Wc (P≤ 0.0001) and poor Berg Balance Scale (P = 0.0005) at baseline. Focal high T2 signal was associated with lower mJOA scores and higher Nurick Grade compared with diffuse T2 (P = 0.0035 P = 0.0079) or no T2 signal (P = 0.0680 P = 0.0122). Preoperative segmentation of T2 signal, showed a significant increase in Wt, Wc, and Berg Balance Scale (P = 0.0266; P = 0.0167; P = 0.0042). Preoperative T1 signal was associated with lower postoperative grip (P = 0.0260), greater Wt, Wc (P = 0.0360, P = 0.0090). Preoperative focal T2 signal had a significant association with poorer postoperative Wt, Wc (P = 0.0220) and Nurick Grade (P = 0.0230). Preoperative maximal cord compromise was negatively correlated with postoperative SF-36 mental score (P = 0.0130).

CONCLUSION

MRI signal changes are predictive of baseline neurological status and postoperative recovery. MRI indicators of poorer outcome include the presence of low T1 signal, focal increased T2 signal and segmentation of T2 signal changes.

LEVEL OF EVIDENCE

2.

Comparison between cranial thoracic intervertebral disc herniations in German Shepherd dogs and other large breed dogs

Cranial thoracic intervertebral disc herniations have been reported to be rare in dogs due to the presence of the intercapital ligament, however some studies have proposed they may not be uncommon in German Shepherd dogs. The purpose of this retrospective study was to compare cranial thoracic intervertebral disc herniations in German Shepherd dogs and other large breed dogs (control group). Medical records at the Ontario Veterinary College were searched for German Shepherd dogs and other large breed dogs that had magnetic resonance imaging studies including the T1-T9 region. For each dog and each disc space from T1-T9, three variables (compression, disc degeneration, and herniation) were recorded and graded based on review of sagittal T2-weighted images. Twenty-three German Shepherd dogs and 47 other large breed dogs met inclusion criteria. The German Shepherd dog group had higher scores than the control group for compression (P = 0.0099) and herniation (P < 0.001), but not disc degeneration (P = 0.97). In the German Shepherd dog group, intervertebral discs T2-T3 and T4-T5 had an increased risk for compression and T3-T4 had an increased risk for compression and herniation. Findings from this study indicated that German Shepherd dogs may be more likely than other large breed dogs to have spinal cord compression due to cranial thoracic disc herniations. Imaging of the cranial thoracic spine, including T2-T3, is recommended for German Shepherd dogs with T3-L3 neurological signs.

Preoperative patient selection with magnetic resonance imaging, computed tomography, and electroencephalography: does the test predict outcome after cervical surgery?

OBJECT

The objective of this systematic review was to use evidence-based medicine to assess whether preoperative imaging or electromyography (EMG) predicts surgical outcomes in patients undergoing cervical surgery.

METHODS

The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to the preoperative imaging and EMG. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I-III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

RESULTS

Preoperative MR imaging and CT myelography are successful in confirming clinical radiculopathy (Class II). Multilevel T2 hyperintensity, T1 focal hypointensity combined with T2 focal hyperintensity, and spinal cord atrophy each convey a poor prognosis (Class III). There is conflicting data concerning whether focal T2 hyperintensity or cervical stenosis are associated with a worse outcome. Electromyography has mixed utility in predicting outcome (Class III).

CONCLUSIONS

Magnetic resonance imaging or CT myelography are important for preoperative assessment. Magnetic resonance imaging may be helpful in assessing prognosis, whereas EMG has mixed utility in assessing outcome.

Atypical cervical spondylotic myelopathy mimicking intramedullary tumor

STUDY DESIGN

Case report and a review of the literature.

OBJECTIVE

We report the case of a young man with a short course of progressive cervical myelopathy (CM). Cervical magnetic resonance imaging (MRI) revealed a stenosis of the cervical spinal canal at C4-C6 and an atypically enlarged intramedullary high intensity extending from C1-T1 (T2-weighted) with contrast enhancement at C4-C5 (T1-weighted). Neurologic and radiologic diagnosis therefore favored a tumor of the spinal cord.

SUMMARY OF BACKGROUND DATA

CM is a clinical diagnosis of mostly degenerative origin in older patients that features circumscribed high-intensity signals near the point of compression in T2-weighted MRI. Contrast enhancement in those high-intense areas is rarely described in the literature, and the differentiation from neoplastic and infective lesions might be very difficult in these cases.

METHODS

Retrospective case study with follow-up examination and MRI-control 3 months after surgery.

RESULTS

The patient was decompressed and stabilized from dorsally, and a biopsy was taken. The exact diagnosis of a myelopathy and an exclusion of a neoplastic origin succeeded through histopathological examination. Three months after first surgery, the patient had improved significantly and underwent an additional anterior stabilization, while the MRI remained almost unchanged.

CONCLUSION

In case of a fast progressive CM with atypical radiographic appearance initial decompression with inspection of the spinal cord and a short-term clinical follow-up with an MRI control might be the procedure of choice, if a clear diagnosis for a causative treatment cannot be made. In still suspicious cases, a biopsy could be considered to exclude a neoplastic or inflammatory process.

Contrast enhancement of the spinal cord in a patient with cervical spondylotic myelopathy

We wish to report a patient with cervical spondylotic myelopathy that demonstrated contranst enhancement on MRI which resolved following a decompressive procedure.

Morphologic and morphometric magnetic resonance imaging features of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy

OBJECTIVE

To compare morphologic and morphometric features of the cervical vertebral column and spinal cord of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome) detected via magnetic resonance imaging (MRI).

ANIMALS

16 clinically normal and 16 CSM-affected Doberman Pinschers.

PROCEDURES

For each dog, MRI of the cervical vertebral column (in neutral and traction positions) was performed. Morphologically, MRI abnormalities were classified according to a spinal cord compression scale. Foraminal stenosis and intervertebral disk degeneration and protrusion were also recorded. Morphometric measurements of the vertebral canal and spinal cord were obtained in sagittal and transverse MRI planes.

RESULTS

4 of 16 clinically normal and 15 of 16 CSM-affected dogs had spinal cord compression. Twelve clinically normal and all CSM-affected dogs had disk degeneration. Foraminal stenosis was detected in 11 clinically normal and 14 CSM-affected dogs. Vertebral canal and spinal cord areas were consistently smaller in CSM-affected dogs, compared with clinically normal dogs. In neutral and traction positions, the intervertebral disks of CSM-affected dogs were wider than those of clinically normal dogs but the amount of disk distraction was similar between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The incidence of intervertebral disk degeneration and foraminal stenosis in clinically normal Doberman Pinschers was high; cervical spinal cord compression may be present without concurrent clinical signs. A combination of static factors (ie, a relatively stenotic vertebral canal and wider intervertebral disks) distinguished CSM-affected dogs from clinically normal dogs and appears to be a key feature in the pathogenesis of CSM.

Relationship between Northwick Park neck pain questionnaire and cervical spine MR imaging findings

The study was aimed at determining the association between the self-report of pain and disability by means of Northwick neck pain questionnaire (NPQ) and cervical spine MR imaging findings. A random sample of 251 patients, 132 men and 119 women aged 43+/-13 years, submitted with neck pain were investigated. Patients with previous discitis, surgery, neoplasm or hospitalized for cervical spine trauma were excluded. All patients completed the NPQ and were studied with sagittal gradient-echo T1 and turbo spin-echo T2, axial gradient-echo T2* and heavily T2 weighted MR myelographic weighted images. MR images of the two most affected disc levels were read, offering an MR imaging score from 0 to 30. There was no statistically significant correlation between NPQ and MR imaging scores. From the NPQ items, only difficulty in sleeping and numbness were related to the MR imaging score. Disc extrusion was the only MR finding almost significantly associated with NPQ (P=0.054). Neck injury did not increase NPQ scores. In patients with neck pain, NPQ scores do not correlate with MR imaging findings. NPQ and cervical spine MR imaging show different facets of the multidimensional complex of neck pain.

Outcome of late surgical treatment in patients with incomplete paraplegia due to spinal degenerative diseases

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To assess the outcome of late surgical intervention in patients with incomplete paraplegia due to spinal degenerative diseases.

SETTING

Three men and four women with cervical or thoracic spinal degenerative diseases, who preoperatively were unable to walk for more than 6 months in Mie prefecture, Japan.

METHODS

Review of clinical records and questionnaire survey regarding the walking ability of patients 2 years after surgery.

RESULTS

All seven patients were unable to walk postoperatively.

CONCLUSION

A late surgical intervention may not lead to functional recovery in patients with spinal degenerative disease who were unable to walk for at least 6 months.

Surgical decompression for cervical spondylotic myelopathy: correlation between operative outcomes and MRI of the spinal cord

Forty-two patients who underwent decompressive surgery for cervical spondylotic myelopathy were studied. The pre- and postoperative magnetic resonance imaging (MRI) findings and the Japanese Orthopedic Association score were analyzed to evaluate whether the different appearances of intramedullary high-signal intensity on T2-weighted MRI are related to the surgical prognosis. Magnetic resonance imaging signal intensities were classified as type 0 if no intramedullary high-signal intensity on T2-weighted images was noted, type 1 if high-signal intensity involved only one segment, and type 2 if high-signal intensity extended over two segments. Statistical analyses of the recovery ratio showed that type 0 and type 1 intramedullary high-signal intensity indicates better prognosis than type 2.