Cervical neural foraminal canal stenosis: computerized tomographic myelography diagnosis

Morphometric analysis of cervical neuroforaminal dimensions from C2-T1 using computed tomography of 1,000 patients

BACKGROUND

Race and sex differences are not consistently reported in the literature. Fundamentally, anatomical differences of cervical neuroforaminal dimensions (CNFD) amongst these groups would be important to know.

PURPOSE

To establish normative radiographic morphometric measurements of CNFD and uncover the influence of patient sex, race, and ethnicity while also considering anthropometric characteristics.

STUDY DESIGN

Retrospective radiographic morphometric study.

PATIENT SAMPLE

A total of 1,000 patients between 18 and 35 years of age who were free of spinal pathology.

OUTCOME MEASURES

Foraminal height, axial width, and area of cervical neural foramen.

METHODS

Cervical CTs were reviewed to measure CNFD, defined as follows: foraminal height, axial width, and area. Statistical analyses were performed to assess associations between CNFD, and patient height, weight, sex, race, and ethnicity.

RESULTS

CNFD measurements followed a bimodal distribution pattern moving caudally from C2-T1. Irrespective of disc level, cervical CNFD were as follows: left and right widths of 6.6±1.5 and 6.6±1.5 mm, heights of 9.4±2.4 and 9.4±3.2 mm, and areas of 60.0±19.5 and 60.6±20.7 mm2. Left and right foraminal width were highest at C2-C3 and lowest at C3-C4. Left and right foraminal height were highest at C7-T1 and C6-C7, respectively and lowest at C3-C4. Left and right foraminal areas were highest at C2-C3 and lowest at C3-C4. Significant differences were observed for all CNFD measurements across disc levels. CNFD did not vary based on laterality. Significant CNFD differences were observed with respect to patient sex, race, and ethnicity. Male height and area were larger compared to females. In contrast, female foraminal width was larger compared to males. The Asian cohort demonstrated the largest foraminal widths. White and Hispanic patients demonstrated the largest foraminal heights and areas. Black patients demonstrated the smallest foraminal widths, heights, and areas. Patient height and weight were only weakly correlated with CNFD measurements across all levels from C2-T1.

CONCLUSIONS

This study describes 36,000 normative measurements of 12,000 foramina from C2-T1. CNFD measurements vary based on disc level, but not laterality. Contrasting left- versus right-sided neuroforamina of the same level may aid in determining the presence of unilateral stenosis. Patient sex, race, and ethnicity are associated with CNFD, while patient anthropometric factors are weakly correlated with CNFD.

Utility of Oblique Sagittal Reformatted and Three-dimensional Surface Reconstruction Computed Tomography in Foraminal Stenosis Decompression

Determining the responsible level of cervical radiculopathy can be difficult. Because asymptomatic findings are common in cervical radiculopathy, diagnoses based on imaging studies can be inaccurate. Therefore, we investigated whether the application of oblique sagittal reformatted computed tomography (oblique sagittal CT) and three-dimensional surface reconstruction CT (3DCT) affects surgical plans for patients with cervical foraminal stenosis and whether it assists diagnosis of foraminal stenosis. Accordingly, four reviewers, with office notes, observed the CT and magnetic resonance imaging (MRI) images of 18 patients undergoing surgical treatment for cervical radiculopathy. After reviewing the MRI and sagittal, coronal, and axial CT images, the reviewers recorded the operation to be performed; they examined oblique sagittal CT and 3DCT images of the same patients and noted any differences from their surgical plans. Consequently, we analyzed these changes in the decompressed foramina in the surgical plan; mean percent change in the plan was 18.1%. Inter-rater reliability improved from κ - 0.194 to κ - 0.240. Therefore, the addition of oblique and 3DCT images improves inter-rater reliability owing to changes in a part of decompressed foramina. The addition of oblique sagittal CT and 3DCT is helpful in evaluating the foramen and planning surgical treatment of cervical radiculopathy.

Clinical correlation of a new and practical magnetic resonance grading system for cervical foraminal stenosis assessment

BACKGROUND

No systematic and quantitative system for evaluation of cervical neural foraminal stenosis (CNFS) has been reported.

PURPOSE

To evaluate whether the new magnetic resonance (MR) grading system for CNFS correlates with clinical manifestations and to propose a modified grading system more useful for clinical practice.

MATERIAL AND METHODS

We examined 356 patients who underwent MR imaging (MRI) of the cervical spine. The presence and grade of cervical foraminal stenosis at the maximal narrowing point were assessed using the new grading system suggested by Kim et al. (Kim system) and a modification of this grading system (modified Kim system) based on T2 axial images. Grade 0: narrowest neural foramen > extraforaminal root; Grade 1: ≤ extraforaminal root; Grade 2: <50% of extraforaminal root. Modified Kim system: Grade 0: >80%, Grade 1: <80% but >50%, Grade 2 as for the Kim system. Results were correlated with clinical manifestations and neurologic physical examination findings (positive neurologic manifestation [PNM]).

RESULTS

Analysis of correlation coefficients (Rs) showed moderate correlation between grades and clinical manifestations using the Kim system (0.484-0.562) and moderate to high correlation between grades and PNMs using the modified Kim system (0.517-0.782).

CONCLUSION

The Kim system showed moderate correlation clinical findings, while the modified Kim system still showed moderate but slightly stronger correlation. In both systems, grade 0 could denote negative neurologic manifestations. Although a considerable number of grade 1 and 2 cases in both systems had PNM, fulfilling the criteria for grades 1 and 2 CNFS, it does not perfectly predict PNM.

Virtual pathology of cervical radiculopathy based on 3D MR/CT fusion images: impingement, flattening or twisted condition of the compressed nerve root in three cases

Background

There have been several imaging studies of cervical radiculopathy, but no three-dimensional (3D) images have shown the path, position, and pathological changes of the cervical nerve roots and spinal root ganglion relative to the cervical bony structure. The objective of this study was to introduce a technique that enables the virtual pathology of the nerve root to be assessed using 3D magnetic resonance (MR)/computed tomography (CT) fusion images that show the compression of the proximal portion of the cervical nerve root by both the herniated disc and the preforaminal or foraminal bony spur in patients with cervical radiculopathy.

Findings

MR and CT images were obtained from three patients with cervical radiculopathy. 3D MR images were placed onto 3D CT images using a computer workstation.

The entire nerve root could be visualized in 3D with or without the vertebrae. The most important characteristic evident on the images was flattening of the nerve root by a bony spur. The affected root was constricted at a pre-ganglion site. In cases of severe deformity, the flattened portion of the root seemed to change the angle of its path, resulting in twisted condition.

Conclusions

The 3D MR/CT fusion imaging technique enhances visualization of pathoanatomy in cervical hidden area that is composed of the root and intervertebral foramen. This technique provides two distinct advantages for diagnosis of cervical radiculopathy. First, the isolation of individual vertebra clarifies the deformities of the whole root groove, including both the uncinate process and superior articular process in the cervical spine. Second, the tortuous or twisted condition of a compressed root can be visualized.

The surgeon can identify the narrowest face of the root if they view the MR/CT fusion image from the posterolateral-inferior direction. Surgeons use MR/CT fusion images as a pre-operative map and for intraoperative navigation. The MR/CT fusion images can also be used as educational materials for all hospital staff and for patients and patients’ families who provide informed consent for treatments.

Comparison of posterior foraminotomy and anterior foraminotomy with fusion for treating spondylotic foraminal stenosis of the cervical spine: study protocol for a randomized controlled trial (ForaC)

Background

Cervical radiculopathy caused by spondylotic foraminal stenosis may require surgical treatment. Surgical options include anterior cervical foraminotomy and fusion or posterior cervical foraminotomy. Controversy remains regarding the preferable surgical approach. Pertinent clinical evidence is limited to low-quality observational reports. Therefore, treatment decisions are predominantly based on the individual surgeon’s preference and skill. The study objective is to evaluate the efficacy and safety of posterior foraminotomy in comparison to anterior foraminotomy with fusion for the treatment of spondylotic foraminal stenosis.

Methods/design

This is a multicenter randomized, controlled, parallel group superiority trial. A total of 88 adult patients are allocated in a ratio of 1:1. Sample size and power calculations were performed to detect the minimal clinically important difference of 14 points, with an expected standard deviation of 20 in the primary outcome parameter, Neck Disability Index, with a power of 80%, based on an assumed maximal dropout rate of 20%. Secondary outcome parameters include the Core Outcome Measures Index, which investigates pain, back-specific function, work disability, social disability and patient satisfaction. Changes in physical and mental health are evaluated using the Short Form-12 (SF-12) questionnaire. Moreover, radiological and health economic outcomes are evaluated. Follow-up is performed 3, 6, 12, 24, 36, 48 and 60 months after surgery. Major inclusion criteria are cervical spondylotic foraminal stenosis causing radiculopathy of C5, C6 or C7 and requiring decompression of one or two neuroforaminae. Study data generation (study sites) and data storage, processing and statistical analysis (Department of Medical Statistics, Informatics and Health Economics) are clearly separated. Data will be analyzed according to the intention-to-treat principle.

Discussion

The results of the ForaC study will provide surgical treatment recommendations for spondylotic foraminal stenosis and will contribute to the understanding of its short- and long-term clinical and radiological postoperative course. This will hopefully translate into improvements in surgical treatment and thus, clinical practice for spondylotic foraminal stenosis.

Trial registration

Current Controlled Trials: ISRCTN82578069.

Electronic supplementary material

The online version of this article (doi:10.1186/1745-6215-15-437) contains supplementary material, which is available to authorized users.

Clinical relevance of neuroforaminal patency after anterior cervical discectomy and fusion

BACKGROUND

We sought to investigate the clinical relevance of neuroforaminal patency and facet degeneration one year after anterior cervical discectomy and fusion (ACDF). Previous studies were characterized by imprecise techniques and fragmentary measurements, and most lacked reliable clinical data and correlation analyses.

METHODS

Patients with cervical mono- or bi-level degenerative pathology were prospectively included. Neuroforaminal size and segmental height were determined quantitatively, and the degree of facet degeneration was assessed qualitatively before and one year after the operation, by computed tomography. Clinical data, such as the severity of neck and arm pain, were assessed on a visual analogue scale (VAS) from 0 to 10, and neck disability index (NDI) was recorded before and one year after the operation. Their correlation with radiological data was investigated.

RESULTS

Seventy-nine patients aged 53.3 ± 11.3 years were included. One year after surgery, median VAS pain intensity was still significantly improved (neck, from 5 to 1; right arm, from 2 to 1; left arm, from 4 to 1) as was NDI (from 40 to 20). Neuroforaminal size showed a reduction on both sides (left, 0.0289 ± 0.09 cm(2); right, 0.0149 ± 0.08 cm(2)). One year after the operation, segmental height decreased and facet degeneration increased from measures taken before the operation. No correlations were found between neuroforaminal stenosis or the degree of facet degeneration and various clinical outcome parameters.

CONCLUSIONS

The decrease in segmental height one year after ACDF leads in turn to secondary neuroforaminal stenosis and progressive facet degeneration. Of the various neuroforaminal variables used, none revealed a threshold value indicative of the presence or severity of radicular arm pain. This absence of correlation between imaging and clinical information is important and should be considered when allocating patients for surgical interventions.

Anatomy and clinical significance of the uncinate process and uncovertebral joint: A comprehensive review

INTRODUCTION

The uncinate process and its associated uncovertebral articulation are features unique to the cervical spine. This review examines the morphology of these unique structures with particular emphasis on the regional anatomy, development and clinical significance.

MATERIALS AND METHODS

Five electronic databases were utilized in the literature search and additional relevant citations were retrieved from the references. A total of 74 citations were included for review.

RESULTS

This literature review found that the uncinate processes and uncovertebral articulations are rudimentary at birth and develop and evolve with age. With degeneration they become clinically apparent with compression of related structures; most importantly affecting the spinal nerve root and vertebral artery. The articulations have also been found to precipitate torticollis when edematous and be acutely damaged in severe head and neck injuries. The uncinate processes are also important in providing stability and guiding the motion of the cervical spine.

CONCLUSION

This review is intended to re-examine an often overlooked region of the cervical spine as not only an interesting anatomical feature but also a clinically relevant one.

MRI features of cervical articular process degenerative joint disease in Great Dane dogs with cervical spondylomyelopathy

Cervical spondylomyelopathy or Wobbler syndrome commonly affects the cervical vertebral column of Great Dane dogs. Degenerative changes affecting the articular process joints are a frequent finding in these patients; however, the correlation between these changes and other features of cervical spondylomyelopathy are uncertain. We described and graded the degenerative changes evident in the cervical articular process joints from 13 Great Danes dogs with cervical spondylomyelopathy using MR imaging, and evaluated the relationship between individual features of cervical articular process joint degeneration and the presence of spinal cord compression, vertebral foraminal stenosis, intramedullary spinal cord changes, and intervertebral disc degenerative changes. Degenerative changes affecting the articular process joints were common, with only 13 of 94 (14%) having no degenerative changes. The most severe changes were evident between C4-C5 and C7-T1 intervertebral spaces. Reduction or loss of the hyperintense synovial fluid signal on T2-weighted MR images was the most frequent feature associated with articular process joint degenerative changes. Degenerative changes of the articular process joints affecting the synovial fluid or articular surface, or causing lateral hypertrophic tissue, were positively correlated with lateral spinal cord compression and vertebral foraminal stenosis. Dorsal hypertrophic tissue was positively correlated with dorsal spinal cord compression. Disc-associated spinal cord compression was recognized less frequently.

The prevalence cervical facet arthrosis: an osseous study in a cadveric population

BACKGROUND CONTEXT

Cervical facet arthrosis has been implicated as a cause for neck pain, radiculopathy, occipital headache, and ear pain.

PURPOSE

The objective of this study was to examine the occurrence of facet arthrosis in the cervical spine.

STUDY DESIGN/SETTING

This study examined cadaveric specimens from the Hamann Todd Collection.

PATIENT SAMPLE

None.

OUTCOMES MEASURES

None.

MATERIALS AND METHODS

Four hundred sixty-five skeletally mature human cervical spines from the Hamann Todd Collection in the Cleveland Museum of Natural History were obtained for analysis. We analyzed the facets for arthrosis. We graded no arthrosis as Grade 0. Facets with peripheral osteophytic reaction, but with no lateral mass distortion were graded as Grade 1. Facets with peripheral osteophytic reaction and lateral mass distortion were graded as Grade 2. Facets that were ankylosed were graded as Grade 3. Each specimen was examined bilaterally at levels from C2-C3 through C6-C7, yielding 4,650 specimen assessments. The data were analyzed to compare cervical levels, gender, facet side, age groups, and race. Proportion analysis, using the Fisher exact test, was used to assess for statistical difference between various groupings.

RESULTS

In the entire population of 465 specimens, the upper cervical specimens appeared to be affected by facet arthrosis more frequently than the lower levels; 12.37% of the specimens had bony evidence of arthrosis at the C2-C3 level; 13.33% of the specimens had arthrosis occur at the C3-C4 level; 14.62% at the C4-C5 level; 7.85% at the C5-C6 level, and 4.84% at the C6-C7 level. The large majority of all cervical facet arthrosis was found to be Grade 1 at all levels. In the older population, the prevalence of facet arthrosis is as high as 29.87% for the C4-C5 level. C4-C5 level appears to be affected the most frequently, followed by the C3-C4 level, then C2-C3, C5-C6, and C6-C7.

CONCLUSION

The prevalence of cervical facet arthrosis increases with age, and occurs more commonly in the upper cervical spine.

Multiple spinal extradural meningeal cysts presenting as acute paraplegia

✓Multiple spinal extradural meningeal cysts are rare. To the authors' knowledge, there have been only four reported cases in the world literature. The authors report a case of multiple spinal extradural meningeal cysts in a 31-year-old woman presenting with acute paraplegia. Magnetic resonance imaging of the thoracolumbar spine revealed multiple extradural cystic lesions extending from T-7 to T-8 and from T-12 to L-3. Intraoperative findings demonstrated a white, fibrous, and tense cyst filled with cerebrospinal fluid–like colorless fluid. Excision of the posterior wall of the symptomatic cyst was followed by immediate neurological improvement. The examination of the pathological specimen showed a thick duralike layer of collagen and an inner membrane of arachnoid that is often not found in these lesions. The final diagnosis was based on combined imaging, intraoperative, and histopathological findings. The authors review the literature and discuss the etiological, diagnostic, and therapeutic aspects of this lesion.

Surgical outcome of posterior decompression for cervical spondylosis with unilateral upper extremity amyotrophy

STUDY DESIGN

Case studies of patients with cervical spondylosis with unilateral upper extremity amyotrophy.

OBJECTIVE

To clarify the surgical outcome of posterior decompression for this amyotrophy.

SUMMARY OF BACKGROUND DATA

Cervical spondylosis sometimes causes a characteristic severe muscular atrophy without sensory disturbance or lower-extremity dysfunction, which is the so-called "cervical spondylotic amyotrophy." However, response to treatment, especially to posterior decompression, has not been well understood.

METHOD

This study included 32 patients. All underwent posterior cervical laminoplasty, and 22 patients had an additional foraminotomy. Preoperative and postoperative muscle power and results of imaging and electrophysiologic studies were evaluated. The follow-up period averaged 78 months. Whether impingement was against the ventral nerve root (VNR) or anterior horn (AH) in the spinal cord was assessed according to these findings. These cases were divided into proximal type and distal type according to the most severely atrophic muscle and compared statistically.

RESULTS

Severe preoperative muscle atrophy was observed in the deltoid and biceps muscles of 24 patients (proximal type) and in the forearm and hand muscles of 8 patients (distal type). Impingements against the VNR and AH were observed in 21 and 28 cases, respectively, and 17 cases had impingement of both the VNR and AH. Improvements in muscle atrophy after surgery were observed in 25 cases. In proximal-type patients, muscle power improved in 92% of cases but was improved in only 38% of the distal-type cases.

CONCLUSIONS

Laminoplasty and foraminotomy were effective in the treatment of most patients with this syndrome, although the outcome in the distal type was inferior to that in the proximal type.

Dynamic intervertebral foramen narrowing during simulated rear impact

STUDY DESIGN

A biomechanical study of intervertebral foraminal narrowing during simulated automotive rear impacts.

OBJECTIVES

To quantify foraminal width, height, and area narrowing during simulated rear impact, and evaluate the potential for nerve root and ganglion impingement in individuals with and without foraminal spondylosis.

SUMMARY OF BACKGROUND DATA

Muscle weakness and paresthesias, documented in whiplash patients, have been associated with neural compression within the cervical intervertebral foramen. To our knowledge, no studies have comprehensively examined dynamic changes in foramen dimensions.

METHODS

There were 6 whole cervical spine specimens (average age 70.8 years) with muscle force replication and surrogate head that underwent simulated rear impact at 3.5, 5, 6.5, and 8 g, following noninjurious baseline 2 g acceleration. Peak dynamic narrowing of foraminal width, height, and area were determined during each impact and statistically compared to baseline narrowing.

RESULTS

Significant increases (P < 0.05) in average peak foraminal width narrowing above baseline were observed at C5-C6 beginning with 3.5 g impact. No significant increases in average peak foraminal height narrowing were observed, while average peak foraminal areas were significantly narrower than baseline at C4-C5 at 3.5, 5, and 6.5 g.

CONCLUSIONS

Extrapolation of the present results indicated that the highest potential for ganglia compression injury was at the lower cervical spine, C5-C6 and C6-C7. Acute ganglia compression may produce a sensitized neural response to repeat compression, leading to chronic radiculopathy following rear impact.

The effect of posterior cervical distraction on foraminal dimensions utilizing a screw-rod system

STUDY DESIGN

Cadaveric human cervical spine anatomic study using posterior lateral mass screw-rod instrumentation to assess foraminal enlargement via distraction techniques.

OBJECTIVES

To determine the role of posterior cervical distraction on foraminal dimensions and to ascertain the impact of this technique on segmental kyphosis.

SUMMARY OF BACKGROUND DATA

Management of cervical spondylotic radiculopathy includes removal of offending compressive structures and enlarging the neuroforamen via anterior discectomy with interbody fusion or posterior laminoforaminotomy.

METHODS

Six human cervical spines were prepared and posterior exposure performed. Lateral mass screws were inserted from C5 to C7 and a longitudinal rod attached. Distraction was applied between the screw heads at 2 mm intervals and accuracy confirmed with digitized calipers. Pre- and postdistraction computed tomography was performed including axial and reformatted images. Foraminal area, height, and width and sagittal alignment and disc heights were evaluated.

RESULTS

The results suggest that minimal posterior distraction of 4 to 6 mm at C5-C6 and C6-C7 may enlarge the neuroforamen by 10 to 18 mm. Foraminal height and width increased minimally from baseline to maximum distraction; however, these measurements did not reach statistical significance at either level. A decrease of segmental lordosis at C5-C6 was noted from baseline to 8 mm of distraction. Statistically significant kyphosis from baseline was present at 6 mm of distraction leading to overall 5.2 +/- 1.4degrees change in alignment. At C6-C7, statistically significant kyphosis was not present until 8 mm of distraction (4.62 +/- 2.23degrees).

CONCLUSIONS

This study suggests that posterior cervical instrumented distraction in the setting of foraminal stenosis is a reasonable supplement to direct laminoforaminotomy and nerve root decompression. Distraction leads to minimal segmental kyphosis, allowing this technique to serve as an adjunct for additional foraminal enlargement.

A new method for lumbar herniated inter-vertebral disc diagnosis based on image analysis of transverse sections

This paper describes an image analysis method that uses automatic algorithms for the evaluation of herniation classification and geometry in the diagnosis of lumbar herniated inter-vertebral disc (HIVD). The method uses boundary approximation that uses a B-spline curve to approximate circle-like disc boundary and excludes the herniation from other normal parts of the disc boundary and, feature recognition that classifies the herniation, and herniation shape reconstruction that infers the 3D geometry from one or more transverse sections. This method can be used as a qualitative and quantitative tool for the diagnosis of lumbar HIVD using transverse sections.

Diagnosis and surgical management of intraspinal synovial cysts: report of 19 cases

OBJECTIVE

Synovial cysts of the vertebral facet joints are a source of nerve root compression. Different surgical procedures are in use, but no consensus has been formed so far as to which method should be used in synovial cysts. To clarify the role of surgical management, the efficacy of operative procedures and factors influencing the outcome in our own series of 19 patients treated between 1994 and 1998 were analysed.

METHODS

Nineteen patients with a mean age of 65 years underwent surgery for medically intractable radicular pain or neurological deficits caused by synovial cysts. The patients' records were retrospectively analysed for neurological deficits, cysts diameter, operative approach, segmental hypermobility, and clinical outcome; CT and MRI were analysed for additional degenerative changes.

RESULTS

In 17 patients an excellent result and in two patients a good postoperative result was achieved. Twelve patients were found to have hypermobility of the facet joints and six had spondylolisthesis. There was no correlation between cyst diameter, operative approach, and outcome. No intraoperative or postoperative complications occurred.

CONCLUSIONS

Age and hypermobility may play a part in the aetiology of facet joint synovial cysts. As all operative strategies showed equally good clinical outcome, total excision via a small flavectomy as the least invasive approach should be considered therapy of choice in patients with cysts causing neurological deficits.

Cervical and thoracic juxtafacet cysts causing neurologic deficits

STUDY DESIGN

Case reports and review of the literature.

OBJECTIVES

To review the clinical features, treatment, and outcome of juxtafacet cysts.

SUMMARY OF BACKGROUND DATA

There have previously been 4 reported cases of thoracic juxtafacet cysts and 19 cases of cervical juxtafacet cysts. Cervical cysts have usually originated from the cruciate ligament and caused myelopathy. Thoracic cysts are usually signaled by myelopathy.

METHODS

The records of the Neurosurgery Department of Royal Adelaide Hospital from 1980 through 1995 were reviewed for cases of intraspinal juxtafacet cysts.

RESULTS

Eight cases of intraspinal juxtafacet cysts were identified; six were in the lumbar spine. One patient had a cervical cyst related to a facet joint and had unilateral radiculopathy. A second patient with a thoracic cyst had the gradual onset of myelopathy. Both patients had surgical excision of the cyst without resection of the adherent dura. The symptoms and neurologic signs improved in each case.

CONCLUSIONS

Cervical and thoracic juxtafacet cysts are rare lesions that are usually signaled by myelopathy. Results of surgery are excellent in most cases, even if the cyst is not completely excised.

Soft cervical disc herniation. Influence of cervical spinal canal measurements on development of neurologic symptoms

STUDY DESIGN

In 100 consecutive patients who underwent surgery because of soft cervical disc herniation, the sagittal and transverse diameters, the area of the bony cervical spinal canal, the sagittal diameter of the hernia, and the minimal bony intervertebral foramen diameter were measured by computed tomography. The data were compared with measurements from a control group of 35 matched healthy individuals.

OBJECTIVES

To evaluate the relation between the severity of concurrent neurologic symptoms and the sagittal and transverse diameters, the cross-sectional area of the bony spinal canal, the sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in patients with soft cervical disc herniation.

SUMMARY OF BACKGROUND DATA

Traumatic injury and spondylotic changes have a far greater impact on the spinal cord and nerve roots if the sagittal diameter of the bony cervical spinal canal is small. However, in the case of soft cervical disc herniation, no computer tomographic measurements are available for sagittal and transverse diameters, cross-sectional area of the bony spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in relation to the severity of concurrent neurologic symptoms.

METHODS

Computed tomography was used to measure sagittal and transverse diameters, cross-sectional area of the bony cervical spinal canal, sagittal diameter of the hernia, and diameter of the minimal bony intervertebral foramen in 100 patients with symptomatic monosegmental cervical soft disc herniation. All patients had undergone an anterior discectomy with removal of the hernia and subsequent interbody fusion using an autologous bone graft taken from the iliac crest.

RESULTS

A mean sagittal diameter of the bony cervical spinal canal of 12.9 mm was found, indicating a certain degree of developmental stenosis. Patients with motor disturbances had a significantly smaller sagittal diameter of the bony spinal canal than did patients without motor disturbances. There was a linear correlation between the sagittal diameter of the bony cervical spinal canal and that of the hernia. The sagittal diameter, the area of the bony spinal canal, and diameter of the minimal bony intervertebral foramen were significantly smaller in patients with soft cervical disc herniation than in the control group.

CONCLUSIONS

Results from this study strongly suggest that the degree and severity of neurologic symptoms accompanying cervical soft disc herniation are inversely related to the sagittal diameter and the area of the bony cervical spinal canal. The latter area is reduced in cases of developmental stenosis or because of soft disc herniation. Moreover, patients with soft cervical disc herniation have a significantly smaller sagittal diameter of the bony spinal canal, a significantly smaller minimal bony intervertebral foramen diameter, and a significantly smaller cross-sectional area of the bony cervical canal than do healthy matched individuals.

A comparison of T2 and gadolinium enhanced MRI with CT myelography in cervical radiculopathy

Two MRI strategies which have been reported to be effective in assessing cervical exit foramina, were prospectively compared with CT myelography in 20 patients with cervical radiculopathy. The first strategy utilized 3D T2* images, the second gadolinium enhanced 2D T1 images. Gadolinium (dimeglumine gadopentetate, Schering Ltd) enhanced images did not confer any benefit in the investigation of this condition, probably due to enhancement of herniated disc material and osteophytes adjacent to the neurocentral joint. Three-dimensional (3D) T2* white cerebrospinal fluid images had an accuracy approaching 90% for the diagnosis of foraminal encroachment, compared with a gold standard. MRI including a 3D T2* sequence is thus an acceptable primary investigation for cervical radiculopathy, but when the findings are incompatible with clinical symptomatology, CT myelography is still indicated.

Cervical disk prolapse

OBJECTIVE

To correlate the findings on computed tomographic myelography (CTM) with surgically and pathologically proven prolapsed cervical disks, mention other pertinent cross-sectional imaging studies, and note the clinical relevance of certain CTM features.

DESIGN

We retrospectively reviewed the medical and radiologic records of Mayo patients with suspected degenerative cervical disk disease during a 4-year period.

MATERIAL AND METHODS

Between January 1986 and December 1989, 734 patients with possible cervical disk disease underwent assessment by CTM. An extruded disk was noted in 297 of these patients. In this study group, magnetic resonance (MR) imaging was also done in 28 patients and plain computed tomography was performed in 14, and we summarized those findings.

RESULTS

Of the 297 study patients, 280 had a cervical radiculopathy and 17 had a myelopathy. CTM identified more than 90% of the extruded cervical disks. CTM could not distinguish between an osteophytic cartilaginous cap and a disk, and CTM could not identify the source of a cervical radiculopathy in 102 patients. Although only a few imaging studies other than CTM were performed, those modalities were less sensitive in the detection of prolapsed disks.

CONCLUSION

Imaging of cervical disk prolapse continues to be difficult, and the results are not always specific. CTM is the most sensitive imaging examination, but the number of MR studies in the current series of patients was insufficient for a reasonable comparison between the two modalities.