Canine model of infertility after spinal cord injury: time course of acute changes in semen quality and spermatogenesis.

PURPOSE: We established a canine model of subfertility after spinal cord injury and examined the time course of acute changes in semen quality and spermatogenesis after spinal cord injury. MATERIALS AND METHODS: Seven dogs underwent surgical T7 spinal cord injury. Six dogs were used as controls. Electroejaculation and testicular fine needle aspiration were performed at baseline and twice weekly for 3 weeks after spinal cord injury. Semen quality change was examined by standard semen analysis. Spermatogenesis was assessed by flow cytometry of testicular fine needle aspiration in all dogs as well as by testicular histology at study conclusion in 4 controls and 4 spinal cord injured dogs. RESULTS: No significant changes in spinal cord injured dogs were noted before 3 weeks after injury. From baseline to 3 weeks after injury certain changes were evident in spinal cord injured dogs. Mean antegrade sperm motility decreased from 62.9% to 20.1% (p = 0.008), mean total sperm (antegrade plus retrograde total sperm) decreased from 423 to 294 x 106 which was not statistically significant, and the incidence of testicular haploid cells decreased from 75.6% to 48.3% (p = 0.028). No significant change in any parameter was present in control dogs. The mean number of mature spermatids per cross-sectional tubule on final testicular histology was significantly decreased in spinal cord injured dogs compared with controls (13.6 versus 43.9, p = 0.02). CONCLUSIONS: In the canine model tested the dogs readily survived spinal cord injury, electroejaculation was effective for obtaining ejaculate and fine needle aspiration allowed serial examination of spermatogenesis. Three weeks after spinal cord injury but not before 3 weeks sperm motility and spermatogenesis were significantly decreased. However, at the same point this decrease in spermatogenesis was not yet reflected in the total ejaculated sperm count.

Stereotactic navigation for placement of pedicle screws in the thoracic spine.

OBJECTIVE: Pedicle screw fixation in the lumbar spine has become the standard of care for various causes of spinal instability. However, because of the smaller size and more complex morphology of the thoracic pedicle, screw placement in the thoracic spine can be extremely challenging. In several published series, cortical violations have been reported in up to 50% of screws placed with standard fluoroscopic techniques. The goal of this study is to evaluate the accuracy of thoracic pedicle screw placement by use of image-guided techniques. METHODS: During the past 4 years, 266 image-guided thoracic pedicle screws were placed in 65 patients at the University of Michigan Medical Center. Postoperative thin-cut computed tomographic scans were obtained in 52 of these patients who were available to enroll in the study. An impartial neuroradiologist evaluated 224 screws by use of a standardized grading scheme. All levels of the thoracic spine were included in the study. RESULTS: Chart review revealed no incidence of neurological, cardiovascular, or pulmonary injury. Of the 224 screws reviewed, there were 19 cortical violations (8.5%). Eleven (4.9%) were Grade II (< or =2 mm), and eight (3.6%) were Grade III (>2 mm) violations. Only five screws (2.2%), however, were thought to exhibit unintentional, structurally significant violations. Statistical analysis revealed a significantly higher rate of cortical perforation in the midthoracic spine (T4-T8, 16.7%; T1-T4, 8.8%; and T9-T12, 5.6%). CONCLUSION: The low rate of cortical perforations (8.5%) and structurally significant violations (2.2%) in this retrospective series compares favorably with previously published results that used anatomic landmarks and intraoperative fluoroscopy. This study provides further evidence that stereotactic placement of pedicle screws can be performed safely and effectively at all levels of the thoracic spine.

Emergency magnetic resonance imaging of cervical spinal cord injuries: clinical correlation and prognosis.

OBJECTIVE: The goal of this study was to determine the prognostic and clinical value of magnetic resonance imaging (MRI) performed within hours after cervical spinal cord injuries in human patients. METHODS: Fifty-five patients with acute cervical vertebral column and spinal cord injuries underwent MRI as part of their initial treatment at the University of Michigan Medical Center. All images were obtained within 21 hours after injury (mean, 7.8 h) and were interpreted by an attending neuroradiologist who was blinded to the clinical status of the patients. Neurological function at presentation and in long-term follow-up examinations was compared with MRI characteristics assessed immediately after the injury. RESULTS: The presence and rostrocaudal length of intra-axial hematoma, the rostrocaudal length of spinal cord edema, the presence of spinal cord compression, and spinal cord compression by extra-axial hematoma were each significantly associated with poor neurological function at presentation and in long-term follow-up examinations. Although the best single predictor of long-term improvement in neurological function was the neurological function at presentation, four MRI characteristics, i.e., the presence of intra-axial hematoma, the extent of spinal cord hematoma, the extent of spinal cord edema, and spinal cord compression by extra-axial hematoma, provided significant additional prognostic information. MRI data demonstrated spinal cord compression for 27 of 55 patients (49%), leading to emergency surgery. Among patients who underwent imaging after restoration of normal vertebral alignment using closed cervical traction, 13 of 26 (50%) underwent emergency surgery for treatment of persistent, MRI-demonstrated, spinal cord compression. CONCLUSION: Emergency MRI after spinal cord injury provides accurate prognostic information regarding neurological function and aids in the diagnosis and treatment of persistent spinal cord compression after vertebral realignment.

Correlation of intraluminal thrombosis in brain tumor vessels with postoperative thrombotic complications: a preliminary report.

OBJECT: Thrombotic complications (deep vein thrombosis and/or pulmonary embolization [DVT/PE]) occur in 18 to 50% of patients harboring brain tumors who undergo neurosurgical procedures. Such patients are at risk for DVT/PE because of immobility, paresis, hypovolemia, and lengthy surgery. The present study was undertaken to see whether tumor patients at highest risk for DVT/PE could be identified so that augmentation of prophylactic measures might be used to reduce the incidence of thrombotic complications. METHODS: The authors conducted a retrospective analysis of 488 patients enrolled in their brain tumor registries between 1988 and 1995, identifying 57 patients (12%) with recorded symptomatic DVT, PE, or both postoperatively. In 24 of these 57 cases histological specimens were retrievable for review, allowing an in-depth analysis. Forty-five patients were lost to follow-up review, and the remaining 386 patients had no record of systemic thrombosis. Slides of pathological specimens were retrievable in 50 cases in which there was no DVT/PE. From these 50 cases, 25 were selected at random to represent the control group by a blinded observer. Seventeen (71%) of the 24 brain tumor specimens obtained in patients with DVT/PE stained positively for intraluminal thrombosis (ILT) after hematoxylin and eosin had been applied. The odds ratio associated with the presence of ILT was 17.8, with a confidence interval ranging from 4 to 79.3. No evidence of ILT was found in 22 patients (88%) within the control group (p < 0.0001, Fisher's exact test). Other factors that may predispose patients with brain tumors to DVT/PE-limb paresis, extent of tumor removal, and duration of the surgery-were also analyzed and found not to be statistically significant. Therefore, these factors were not the basis for differences seen between the study and control groups. CONCLUSIONS: These preliminary observations suggest that the presence of ILT within malignant glioma or glioblastoma tumor vessels may represent a marker of tumor-induced hypercoagulability.

Computer-assisted measurement of lumbar spine radiographs.

RATIONALE AND OBJECTIVES: The authors evaluated a method for obtaining reproducible, reliable measurements from standard lumbar spine radiographs for determining the degree of spondylolisthesis, vertebral body height, intervertebral disk space height, disk space angle, and degree of vertebral body wedging. MATERIALS AND METHODS: Four to six easily defined points were identified on each vertebral body on anteroposterior and lateral plain radiographs of the lumbosacral spine of patients. From these points, the degree of spondylolisthesis, the vertebral body height, the intervertebral disk space height, the disk space angle, and the degree of vertebral body wedging were easily calculated by using well-known geometric relationships. This method requires the use of a personal computer and a standard spreadsheet program but does not require the use of any other specialized radiographic equipment, computer hardware, or custom software. RESULTS: Calculations of intra- and interobserver variability for the measurement of spondylolisthesis, disk space height, disk space angle, and vertebral body height measurement showed that the technique is extremely reproducible. CONCLUSION: This technique may prove useful in the prospective evaluation of potential candidates for lumbar spinal stenosis surgery.

Comparative mechanical properties of spinal cable and wire fixation systems.

STUDY DESIGN: Surgical spinal cable and wire fixation systems were tested mechanically using standardized methodologies. OBJECTIVES: To compare the relative mechanical properties and biomechanical performances of the different commercially available spinal wire and cable fixation devices, and to provide information that will help in selecting different cables for different clinical applications. SUMMARY OF BACKGROUND DATA: Spinal cables have become extensively used for spinal fixation; however, there are few published accounts delineating their mechanical properties. No reports have compared the relative properties of different cable systems. METHODS: Nine spinal cable and wire fixation systems were mechanically tested to compare their static tensile strength, stiffness, fatigue strength, creep, conformance, and abrasion properties. Titanium and stainless steel Codman cable, Danek cable, and AcroMed cable, polyethylene Smith & Nephew cable, and 20- and 22-gauge stainless steel monofilament Ethicon wire were tested using identical methodologies. The cable or wire was connected into loops with methods that simulated in vivo clinical applications. RESULTS: Under static tensile testing, titanium cables had 70% to 90% of the ultimate tensile strength of the comparable steel cables; the different cables were 100% to 600% stronger than monofilament wire; the ultimate strength of the polyethylene cable was similar to that of the strongest available steel cable. Fatigue testing delineated important differences among the different materials. For a given manufacturer, titanium cables were always more susceptible to fatigue than stainless steel cables of comparable diameter. Polyethylene cable withstood cyclical loading without breaking better than all of the metal cables and wires. The mechanisms of failure differed substantially among materials and types of tests. Polyethylene cables exhibited significant stretching or "creep" at loads that were much lower than the static failure loads. In contrast, no wire cable demonstrated creep. Monofilament wires demonstrated little creep. Polyethylene cables failed by elongating and loosening; wire cables failed by breaking. Monofilament wire and cables conformed least to a solid surface; polyethylene cable conformed the most and flattened out against solid surfaces. Abrasion properties depended on the surface characteristics of the implants. Polyethylene cable was abraded by (and eventually failed by wearing against) the simulated bone, a result that did not occur with any metal cables or wires. The steel and titanium cables and the monofilament wires all had an ability to abrade through simulated bone. CONCLUSIONS: Titanium, steel, and polyethylene cable systems all behave substantially differently mechanically compared with monofilament wire. The relative advantages and disadvantages of each particular products should be considered when selecting an implant for a specific clinical use.

Consequences of high-dose steroid therapy for acute spinal cord injury.

OBJECTIVE: High-dose Solu-Medrol (Upjohn, Kalamazoo, Mich) therapy has become standard care in the management of acute spinal cord injury (ASCI). This study attempts to define the adverse effects that Solu-Medrol therapy has on these patients. DESIGN: Retrospective review with historical control. MATERIALS AND METHODS: From May 1990 to April 1994, all patients with ASCI admitted within 8 hours of injury received high-dose Solu-Medrol per the National Acute Spinal Injury Study (NASCIS-2) protocol. Their demographic and outcome parameters were compared with those of a group admitted from March 1986 to December 1993 with an associated ASCI who received no steroid therapy. MEASUREMENTS AND MAIN RESULTS: Steroid therapy was associated with a 2.6-fold increase in the incidence of pneumonia and an increase in ventilated and intensive care days. However, it was associated with a decrease in duration of rehabilitation and had no significant impact on other outcome parameters, including mortality. CONCLUSIONS: Although the NASCIS-2 protocol may promote early infectious complications, it has no adverse impact on long-term outcome in patients with ASCIs.

Kinetic evaluation of positron-emitting muscarinic receptor ligands employing direct intracarotid injection.

The development and characterization of new receptor ligands for in vivo binding assays are often both lengthy and expensive. It is therefore desirable to predict the suitability of a ligand early in the process of its evaluation. In the present study, compartmental analysis following intracarotid ligand injection in the monkey is used to evaluate the in vivo kinetics of the muscarinic cholinergic receptor antagonists [11C]tropanyl benzilate ([11C]TRB) and [11C]N-methylpiperidyl benzilate ([11C]NMPB). Animals were implanted with chronic subcutaneous access ports and indwelling catheters with tips located in the common carotid artery, just proximal to its bifurcation. The external carotid artery was ligated to ensure selective tracer delivery through the internal carotid artery to the brain. Positron emission tomography was used to measure brain tissue time-activity curves following tracer injections. CBF was estimated from the clearance of [15O]H2O, and receptor ligand distributions were analyzed according to a physiologic model consisting of an intravascular compartment and nonspecific plus free and receptor-bound tissue ligand compartments. In [11C]TRB studies, marked reductions in the forward ligand-receptor binding rate and in both the total and the specific binding tissue-to-plasma volumes of ligand distribution were observed after scopolamine receptor blockade or with low administered specific activity. Conversely, neither the distribution volume of the nonspecific plus free ligand compartment nor the rate of ligand dissociation from receptor sites was affected. In [11C]NMPB studies, tissue compartments describing specific binding and nonsaturable components could not be reliably separated. The receptor-related term in this case, the total tissue-to-plasma distribution volume, demonstrated reduction after low specific activity ligand injection. Comparison of the two ligands suggests that NMPB interacts more rapidly with the receptors and has a lower apparent volume of distribution than does TRB. Thus, NMPB may be the more suitable ligand if accurate estimates of binding dissociation rate are limited by temporal constraints or if simplified, one-tissue-compartment analyses are used. The carotid injection method appears promising for the initial evaluation of ligand kinetics, permitting physiologic compartmental analyses without measurement of input functions or chromatography of blood samples.

Threaded steinmann pin fusion of the craniovertebral junction.

STUDY DESIGN: In a clinical retrospective study, the authors review long-term results of occipitocervical fusion using a wide diameter, contoured, threaded Steinmann pin. OBJECTIVES: To evaluate the clinical and radiographic results of occipitocervical fusion using this technique in a variety of abnormalities including rheumatoid arthritis. SUMMARY OF BACKGROUND DATA. The various surgical techniques and hardware developed for occipitocervical fusion have been associated with mixed results, particularly in patients with rheumatoid arthritis or basilar invagination. METHODS: Thirty-nine patients with occipitocervical instability were internally fixed with a wide diameter, contoured, threaded Steinmann pin wired to the occiput and cervical laminae or facets. Fusion was facilitated using autologous iliac crest bone graft and a cervical orthosis. Instability resulted from rheumatoid arthritis (n = 12), congenital anomalies (n = 12), trauma (n = 10), tumor (n = 4), or osteogenesis imperfecta (n = 1). Fifteen patients had radiographic evidence of basilar invagination. Long-term outcome (mean follow-up period, 38.9 months; range, 12-78 months) was based on clinical and radiographic review. RESULTS: Thirty-seven patients (97%) had a stable postoperative occipitocervical construct: there were 35 osseous unions, two fibrous unions, and one nonunion. There was on postoperative death from pulmonary complications. No patient developed evidence of new, recurrent, or progressive basilar invagination. CONCLUSION: The authors concluded that rigid segmental fixation of the craniovertebral junction using a wide diameter, contoured, threaded Steinmann pin and supplemental autograft creates excellent fusion with minimal complications. This technique is appropriate for a variety of abnormalities including rheumatoid arthritis.

Internal fixation of the spine using a braided titanium cable: clinical results and postoperative magnetic resonance imaging.

Segmental spinal fixation using sublaminar or interspinous stainless steel wire has been successfully used for many years. Stainless steel cables have been developed that are stronger and more flexible, allowing for shorter operative time and decreased risk of neurological deficit. However, stainless steel implants create significant artifact on magnetic resonance imaging (MRI), reducing the postoperative usefulness of this imaging modality. Titanium instrumentation has the advantage of producing minimal MRI artifact. Recently, a braided titanium cable has been developed that has the advantages of strength and flexibility as well as minimal production of MRI artifact. We present a series of 50 patients who underwent internal fixation of the spine using a braided titanium cable either alone or in combination with supplementary titanium instrumentation. No instrument failures have occurred to date. Postoperative MRI scans have revealed minimal implant-related artifact, allowing for high-resolution, noninvasive postoperative imaging of the neuraxis. We conclude that braided titanium cable has significant advantages over stainless steel cable or monofilament wire and is a valuable instrument for segmental spine fixation.

Acetylcholine induces contraction in vergebral arteries from treated hypertensive patients.

Endothelium-dependent vasodilatation to acetylcholine is abnormal in animal models of hypertension. This abnormality reflects a change in the balance of relaxing and contracting factors produced in the vascular wall. In human cerebral arteries, endothelin has been implicated in the abnormal vasoconstrictor response following subarachnoid hemorrhage. This study tests the hypothesis that cerebral arteriolar dilatation to acetylcholine reduced in clinical hypertension due to an overproduction of endothelin. Our results show that at high concentrations of muscarinic agonist (0.3-3 microM), human vertebral arteries from hypertensive patients contract whereas those from normotensive patients remain maximally dilated. We conclude that the normal dilator response to acetylcholine is abrogated in vertebral arteries from treated hypertensive patients but endothelin-1 does not contribute to the abnormal responsiveness.

Primary osseous amyloidoma causing spinal cord compression.

The myelographic, CT, and MR findings of a rare localized primary bone amyloidoma causing upper thoracic spinal cord compression are presented. Imaging showed a large, calcified mass centered in the posteromedial portion of the left second rib that invaded the second thoracic vertebra and the spinal canal.

Vertebral artery dissection related to basilar impression: case report.

A 50-year-old man with myelopathy secondary to basilar impression developed bilateral vertebral artery dissection after undergoing treatment with 8 pounds of cervical traction. The vertebral artery dissection resulted in vertebrobasilar insufficiency and posterior circulation stroke. In this report, the current management philosophies in the treatment of basilar impression are discussed, and the pertinent neurovascular anatomy is illustrated. This report suggests that vertebral artery injury may result from attempted reduction of severe basilar impression. Regardless of the cause of cranial settling, the risk of vertebral artery injury with cervical traction should be considered in patients with severe basilar impression.

Products of cells from gliomas: IX. Evidence that two fundamentally different mechanisms change extracellular matrix expression by gliomas.

Four human astrocytic gliomas of high grade of malignancy were each evaluated in tissue and in vitro for percentages of cells expressing glial fibrillary acidic protein (GFAP), collagen type IV, laminin and fibronectin assessed by immunofluorescence with counterstaining of nuclear DNA. Percentages of cells with reticulin and cells binding fluorescein-labeled Ulex europaeus agglutinin were also assessed. In tissue, each extracellular matrix (ECM) component was associated with cells in the walls of abnormal proliferations of glioma vessels, and all four tumors had the same staining pattern. Two strikingly different patterns of conversion of gene product expression emerged during in vitro cultivation. (1). In the most common pattern, percentages of all six markers consistently shifted toward the exact phenotype of mesenchymal cells in abnormal vascular proliferations: increased reticulin, collagen type IV, laminin and fibronectin; markedly decreased glial marker GFAP and absent endothelial marker Ulex europaeus agglutinin. The simplest explanation of this constellation of changes coordinated toward expression of vascular ECM markers is that primary glioma cell cultures are overgrown by mesenchymal cells from the abnormal vascular proliferations of the original glioma. These cell cultures were tested for in situ hybridization (ISH) signals of chromosomes 7 and 10. Cells from one glioma had diploid signals. Cells from the other glioma had aneuploid signals indicating they were neoplastic; however, their signals reflected different numerical chromosomal aberrations than those common to neoplastic glia. (2). The second pattern was different. Cells with ISH chromosomal signals of neoplastic glia retained GFAP, and gained collagen type IV. Their laminin and fibronectin diminished, but persisted among a lower percentage of cells. Cloning and double immunofluorescence confirmed the presence of individual cells with glial and mesenchymal markers. A cell expressing GFAP in addition to either fibronectin, reticulin or collagen type IV is not a known constituent of glioblastoma tissue. This provides evidence of a second mechanism of conversion of gene expression in gliomas.

Outcome after laminectomy for lumbar spinal stenosis. Part I: Clinical correlations.

All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metropolitan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient questionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore necessary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy.

Outcome after laminectomy for lumbar spinal stenosis. Part II: Radiographic changes and clinical correlations.

The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels. This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.

Nonunion of a type II odontoid fracture after an apparent radiographic fusion: case report.

The type II odontoid fracture, initially described by Anderson and D'Alonzo, is the most common axis fracture. Several factors that predict the need for operative intervention have been discussed in the literature; however, the initial treatment remains somewhat controversial. We present the case of a 20-year-old woman who suffered a Type II odontoid fracture during a skiing accident. She was managed initially with halo-vest immobilization, and after 12 weeks, bony fusion was documented by plain spine radiographs and tomography. Routine follow-up cervical spine films at 8 months after her injury revealed no union at the previous fracture site and resultant atlantoaxial instability. A posterior C1-C2 fusion was therefore performed, leading to a long-term solid bony fusion. There are no previous reports in the literature describing a nonunion after radiographically documented healing of a Type II odontoid fracture. We present this case in order to emphasize the importance of scheduled follow-up examinations, including cervical spine films, for at least 12 months after a documented fusion. Further reports of similar cases may generate a more thorough understanding of the pathogenesis of delayed nonunion and may elicit factors that will predict its development.

Endothelium dependency of contractile activity differs in infant and adult vertebral arteries.

Contractions to serotonin (5-HT) and endothelin-1 (ET-1) in infant (0-2 yr) and adult (38-71 yr) vertebral arteries were examined in the presence of either the cyclooxygenase inhibitor indomethacin or NG-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide production. In addition, endothelium-dependent relaxations to acetylcholine were characterized in arteries contracted with agonist. The results showed that: (a) Contractions of infant arteries to 5-HT or ET-1 decreased to 44 +/- 8% and 27 +/- 13%, respectively, within 10 min. Indomethacin or removal of endothelium abolished this decreased response, whereas L-NMMA had no effect. (b) Adult arteries produced sustained contractions to 5-HT or ET-1 that were unaffected by indomethacin, endothelium denudation, or L-NMMA. (c) Endothelium-dependent relaxations to acetylcholine were greater in infant than adult arteries and were abolished by indomethacin (but not L-NMMA) in infants and L-NMMA (but not indomethacin) in adults. Thus, endothelium-dependent responses in infant arteries are attenuated because of increased prostaglandin activity not observed in adult tissues. Additionally, there is an age-dependent change in the primary mechanism responsible for acetylcholine-induced vasodilation. Apparently, endothelium dependency of acetylcholine-induced relaxation is highly dependent on cyclooxygenase activity in the infant vertebral artery, but in the adult artery, nitric oxide is linked to the vasodilator response.

Metastatic epidural spinal cord compression: current concepts and treatment.

Metastatic epidural spinal cord compression (MESCC) is a medical emergency complicating the course of 5-10% of patients with cancer [1]. When diagnosis and treatment is early with the patient ambulatory prognosis for continued ambulation is good [2]. If the patient is nonambulatory or paraplegic, prognosis for meaningful recovery of motor and bladder function is markedly decreased. In the last decade, significant advances in the understanding, management and treatment of metastatic epidural spinal cord compression have occurred. Recent pathophysiological and pharmacological animals studies have afforded insights into disease mechanisms [3-9]. The audit of standard methods of investigation and magnetic resonance imaging have resulted in revision of guidelines for patient evaluation [10-17]. Finally, new surgical philosophies and technical advances have generated interest and controversy [18-25]. With improved clinical awareness, new imaging modalities will help us diagnose epidural spinal cord compression earlier and institute appropriate treatment.