bluuebunny/crossref_metadata_2025 huggingface dataset:
Sacral preservation in cauda equina syndrome from inferior vena cava thrombosis
Authors: Widge Alik S. , Tomycz Nestor D. , Kanter Adam S.
Published: February 2011

Acute cauda equina syndrome can occur due to a variety of causes. Inferior vena cava (IVC) thrombosis has been reported as the causal source of this phenomenon twice in the relevant literature, both cases of which presented in a form complete with a component of bowel and/or bladder dysfunction. The authors report an atypical case of cauda equina syndrome in a patient in a hypercoagulable state with an extensive IVC thrombosis, resulting in acute paraparesis in the absence of incontinence or perineal anesthesia. An increasing number of prophylactic and/or therapeutic IVC filters placed in the perioperative period should engender an increased clinical suspicion for IVC thrombosis in patients presenting with acute paraparesis.
Foot drop due to lumbar degenerative conditions: mechanism and prognostic factors in herniated nucleus pulposus and lumbar spinal stenosis
Authors: Iizuka Yoichi , Iizuka Haku , Tsutsumi Satoshi , Nakagawa Yumi , Nakajima Takashi , Sorimachi Yasunori , Ara Tsuyoshi , Nishinome Masahiro , Seki Takayuki , Shida Kosuke , Takagishi Kenji
Published: February 2011

Object

The aim of this study was to analyze the mechanism and prognostic factors of foot drop caused by lumbar degenerative conditions.

Methods

The authors retrospectively reviewed the charts of 28 patients with foot drop due to a herniated nucleus pulposus (HNP) or lumbar spinal stenosis (LSS), scoring between 0 and 3 on manual muscle testing for the tibialis anterior muscles. They analyzed the mechanism of foot drop and whether the duration before the operation, preoperative tibialis anterior and extensor hallucis longus strength, age, gender, and diabetes mellitus were all found to be prognostic factors for postoperative tibialis anterior recovery. They also investigated whether the diagnosis had any influence on the prognosis.

Results

The compression of double roots and a sequestrated fragment were observed, respectively, in 9 and 13 of 16 patients with HNP. Multiple levels including the L4–5 segment were decompressed in 8 of 12 patients with LSS. Analysis did not demonstrate any prognostic factor in surgically treated HNP, but significant associations with prognosis were observed with respect to preoperative tibialis anterior (p = 0.033) and extensor hallucis longus (p = 0.020) strength in patients with LSS. In addition, the postoperative muscle recovery in patients with HNP was significantly superior to that in patients with LSS (p = 0.011).

Conclusions

Double root compression was the most common condition associated with foot drop due to HNP. The diagnosis and preoperative tibialis anterior and extensor hallucis longus strength in LSS were factors that influenced recovery following an operation.
Are high-intensity zones and Modic changes mutually exclusive in symptomatic lumbar degenerative discs?
Authors: Marshman Laurence A. G. , Metcalfe Andrew V. , Krishna Manoj , Friesem Tai
Published: February 2011

Object

Modic changes (MCs) and high-intensity zones (HIZs) potentially serve as variably sensitive markers for discogenic chronic low-back pain (CLBP). No study has hitherto assessed the phenomenon of MC-HIZ coexistence at a single level, and the goal in this study was to assess the nature and frequency of this phenomenon.

Methods

One hundred twenty consecutive patients with discogenic CLBP in whom lumbar MR imaging studies had demonstrated an HIZ, an MC, or both were included.

Results

This cohort (120 consecutive patients with 193 degenerative discs) had discogenic CLBP in at least 1 lumbar level associated with either an HIZ (77 discs), an MC (67 discs), or both (16 patients); there were 55 coexistent non-HIZ/non-MC degenerative discs. Painful MC-HIZ coexistence at 1 level occurred in 6 patients (5 of whom were female). If HIZs and MCs were random, independent entities, then MC-HIZ coexistence at 1 level would have been expected in 67 × 77/193 (that is, 27) discs. The observed frequency was therefore significantly lower (χ2 = 41, p < 0.001). There were no significant demographic differences between groups. The HIZ disc height (8 ± 0.2 mm) was significantly greater than the MC (6.6 ± 0.2 mm) or MC-HIZ (6.7 ± 0.2 mm) disc heights (p < 0.001).

Conclusions

In patients with discogenic CLBP associated with HIZ or MC lesions, MC-HIZ coexistence at 1 level was significantly rarer than expected even by chance; thus, despite both being manifestations of a seemingly common degenerative process, HIZ and MC more closely represent “either/or” phenomena. Because HIZ disc height was significantly greater, HIZs may develop earlier in the disc degenerative ontogeny. If any degenerative disc may only display an HIZ first, yet may ultimately display an MC instead, then HIZs must invariably regress as MCs supervene (or even vice versa). The MC-HIZ coexistence would therefore represent either a rare stable state (possibly more common in females) or a transitory state, as one lesion gradually replaces the other. Longitudinal studies would confirm or refute these hypotheses, although significantly larger sample sizes would be required.
Coincidence of cervical spondylotic myelopathy and intramedullary ependymoma: a potential diagnostic pitfall
Authors: Kurzbuch Arthur R. , Rilliet Benedict , Vargas Maria-Isabel , Boex Colette , Tessitore Enrico
Published: February 2011

The authors report the case of a 58-year-old man presenting with a 3-year history of clinical signs of progressive cervical spondylotic myelopathy (CSM). Magnetic resonance imaging showed a severe stenosis of the cervical spinal canal at C3–4 and C5–6 levels due to multiple discopathies. High signal intensities on T2-weighted MR images of the spinal cord and low signal intensities on T1-weighted images at the C2–6 levels were noted, as was contrast enhancement at the C3–4 level. The patient underwent a bilateral decompressive laminectomy at C3–6. The patient did not show any clinical improvement. Thus, further cervical MR imaging was performed and the differential diagnosis of an intramedullary tumor was considered in view of the persisting intramedullary enhancement. This diagnosis prompted a second operation involving a posterior midline myelotomy and excision of an intramedullary ependymoma at the C3–4 level. Intramedullary tumors should be considered in the differential diagnosis of CSM with an atypical pattern of MR imaging features.
Reliability and validity of the M. D. Anderson Symptom Inventory–Spine Tumor Module
Authors: Armstrong Terri S. , Gning Ibrahima , Mendoza Tito R. , Vera-Bolanos Elizabeth , Gilbert Mark R. , Rhines Laurence D. , Weinberg Jeffrey S. , Sanchez-Williams Gisela , Levin Victor , Burton Allen W. , Cleeland Charles
Published: February 2011

Object

Tumors involving the spine have unique associated neurological symptoms. The occurrence of spine-related symptoms has been shown to predict treatment course and survival in several studies conducted in patients with solid tumors and consequent spinal cord dysfunction. Currently, no instrument that measures both neurological and cancer-related symptoms exists for patients with spine tumors. The objective of this study was to develop a reliable and valid self-reporting instrument for patients with spine tumors.

Methods

Patients with diagnosed tumors involving the spine (both primary and metastatic) participated in this study. Data collection tools included a patient-completed demographic data sheet, an investigator-completed clinician checklist, and the core M. D. Anderson Symptom Inventory to which were added 16 neurological symptoms (M. D. Anderson Symptom Inventory–Spine Tumor Module [MDASI-SP]). The authors evaluated the reliability and validity of the MDASI-SP in patients with spine tumors.

Results

One hundred twenty-six patients participated in the study. Participants were primarily white (73%) males (53%) with metastatic spine tumors (76%). They ranged in age from 18–81 years (median 56 years). Cognitive debriefing of the MDASI-SP was conducted showing the instrument was clear, concise, and easily understood by patients. The most severe core symptoms were pain, fatigue, numbness, disturbed sleep, and distress. The most severe spine module symptoms were spine pain, numbness, weakness in the legs, neck stiffness, and changes in bowel or sexual function. The mean symptom severity of items as well as a cluster analysis was used to reduce the number of total items to 18 (5 spine module items). Regression analysis showed that 57.4% of the variability in symptom interference with daily function was explained by the final instrument. Factor analysis was performed to determine the underlying constructs being evaluated by the symptom items. The 18-item MDASI-SP measures 4 underlying constructs including a disease, an autonomic, a constitutional/treatment, and an emotional factor. The internal consistency (reliability) of the MDASI-SP was 0.946, and the instrument was sensitive to disease severity based on the Karnofsky Performance Scale (KPS). The mean symptom severity was 1.52 for those with good KPS scores (80–100) versus 2.46 for those with poor scores (p < 0.01). The instrument was also sensitive to neurological status according to the Frankel grade (p < 0.001) and inpatient status (p < 0.01).

Conclusions

The 18-item MDASI-SP demonstrated validity and reliability in patients with spine tumors as a composite measure of disease-related symptoms. This instrument can be used to describe symptom occurrence throughout the disease trajectory and to evaluate interventions designed for symptom management.
Solitary intradural extramedullary lymphoma of the cervical spine
Authors: Yamashita Tomoya , Sakaura Hironobu , Oshima Kazuya , Iwasaki Motoki , Yoshikawa Hideki
Published: February 2011

The authors report on the case of a 64-year-old man with solitary intradural extramedullary non-Hodgkin lymphoma of the cervical spine. The lesion mimicked the appearance of meningioma on MR imaging. Positron emission tomography showed increased accumulation of fluorine-18–labeled fluorodeoxyglucose only in the cervical lesion. Serum levels of C-reactive protein and soluble interleukin-2 receptor were mildly elevated. At surgery, the intradural tumor in the subarachnoid space was totally extirpated. Based on histopathological findings, diffuse, large B-cell type non-Hodgkin lymphoma was diagnosed. Postoperatively, the patient was treated with 2 courses of chemotherapy by intrathecal injection of methotrexate, cytarabine, and prednisolone and 4 courses of intravenous rituximab, an antibody binding to CD20 on the surface of B cells. All preoperative symptoms completely resolved after surgery. Two years postoperatively, the patient was faring well with no evidence of local recurrence or new lesions at any other site. To the best of the authors' knowledge, this case is the first reported instance of solitary intradural extramedullary non-Hodgkin lymphoma of the cervical spine.
Techniques for anterior cervical decompression for radiculopathy
Authors: Matz Paul G. , Ryken Timothy C. , Groff Michael W. , Vresilovic Edward J. , Anderson Paul A. , Heary Robert F. , Holly Langston T. , Kaiser Michael G. , Mummaneni Praveen V. , Choudhri Tanvir F. , Resnick Daniel K.
Published: February 2011

Object

The objective of this systematic review was to use evidence-based medicine to identify the best techniques for anterior cervical nerve root decompression.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to techniques for the surgical management of cervical radiculopathy. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). 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

Both anterior cervical discectomy (ACD) and anterior cervical discectomy with fusion (ACDF) are equivalent treatment strategies for 1-level disease with regard to functional outcome (Class II). Anterior cervical discectomy with fusion may achieve a more rapid reduction of neck and arm pain compared to ACD with a reduced risk of kyphosis, although functional outcomes may be similar. Anterior cervical discectomy with fusion is not a lasting means of increasing foraminal or disc height compared to ACD. Anterior cervical plating (ACDF with instrumentation) improves arm pain (but not other clinical parameters) better than ACDF in the treatment of 2-level disease (Class II). With respect to 1-level disease, plating may reduce the risk of pseudarthrosis and graft problems (Class III) but does not necessarily improve clinical outcome alone (Class II). Cervical arthroplasty is recommended as an alternative to ACDF in selected patients for control of neck and arm pain (Class II).

Conclusions

Anterior cervical discectomy, ACDF, and arthroplasty are effective techniques for addressing surgical cervical radiculopathy.
Cervical laminoforaminotomy for the treatment of cervical degenerative radiculopathy
Authors: Heary Robert F. , Ryken Timothy C. , Matz Paul G. , Anderson Paul A. , Groff Michael W. , Holly Langston T. , Kaiser Michael G. , Mummaneni Praveen V. , Choudhri Tanvir F. , Vresilovic Edward J. , Resnick Daniel K.
Published: February 2011

Object

The objective of this systematic review was to use evidence-based medicine to examine the efficacy of posterior laminoforaminotomy in the treatment of cervical radiculopathy.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to posterior laminoforaminotomy and cervical radiculopathy. Abstracts were reviewed, and 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 which 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

Posterior laminoforaminotomy improves clinical outcome in the treatment of cervical radiculopathy resulting from soft lateral cervical disc displacement or cervical spondylosis with resulting narrowing of the lateral recess. All studies were Class III. The most frequent design flaw involved the lack of utilization of validated outcomes measures. In addition, few historical studies included a detailed preoperative analysis of the patients. As such, the vast majority of studies that included both pre- and postoperative assessments with legitimate outcomes measures have been performed since 1990.

Conclusions

Posterior laminoforaminotomy is an effective treatment for cervical radiculopathy.
Techniques for cervical interbody grafting
Authors: Ryken Timothy C. , Heary Robert F. , Matz Paul G. , Anderson Paul A. , Groff Michael W. , Holly Langston T. , Kaiser Michael G. , Mummaneni Praveen V. , Choudhri Tanvir F. , Vresilovic Edward J. , Resnick Daniel K.
Published: February 2011

Object

The objective of this systematic review was to use evidence-based medicine to determine the efficacy of interbody graft techniques.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical interbody grafting. Abstracts were reviewed and studies that met the 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 Surgerons/Congress of Neurological Surgeons.

Results

Autograft bone harvested from the iliac crest, allograft bone from either cadaveric iliac crest or fibula, or titanium cages and rectangular fusion devices, with or without the use of autologous graft or substitute, have been successful in creating arthrodesis after 1- or 2-level anterior cervical discectomy with fusion (Class II). Alternatives to autograft, allograft, or titanium cages include polyetheretherketone cages and carbon fiber cages (Class III). Polyetheretherketone cages have been used successfully with or without hydroxyapatite for anterior cervical discectomy with fusion. Importantly, recombinant human bone morphogenic protein-2 carries a complication rate of up to 23–27% (especially local edema) compared with 3% for a standard approach.

Conclusions

Current evidence does not support the routine use of interbody grafting for cervical arthrodesis. Multiple strategies for interbody grafting have been successful with Class II evidence supporting the use of autograft, allograft, and titanium cages.
Thoracolumbar spinal deformity: Part II. Developments from 1990 to today
Authors: Lam Fred C. , Kanter Adam S. , Okonkwo David O. , Ogilvie James W. , Mummaneni Praveen V.
Published: February 2011

In the first part of this 2-part historical review, the authors outlined the early diagnostic and therapeutic strategies used in the management of spinal deformity. In this second part, they expand upon those early innovations and further detail the advances from 1990 to the modern era.
Management of delayed esophageal perforations after anterior cervical spinal surgery
Authors: Dakwar Elias , Uribe Juan S. , Padhya Tapan A. , Vale Fernando L.
Published: February 2011

Object

Delayed esophageal perforation is an uncommon but well-known complication after anterior cervical spine surgery. To the authors' knowledge there is no consensus to the optimal management of these patients in the literature.

Methods

The authors performed a retrospective review of 5 cases involving patients who were referred to their institution for the management of delayed esophageal perforations after undergoing anterior cervical spine surgery for a variety of reasons.

Results

The primary presenting symptom in all 5 patients was dysphagia. All patients initially underwent primary closure of the perforation with a sternocleidomastoid muscle flap. One patient required multiple surgeries to correct the perforation and ultimately required a free flap.

Conclusions

The authors recommend a multidisciplinary approach that involves otolaryngological surgeons as well as spine surgeons. They recommend removal of all anterior hardware and believe that it is essential to the treatment of esophageal perforations. If the patient does not have evidence of fusion at the time of presentation, then posterior cervical instrumentation is a viable alternative.
Complications in the management of Charcot spinal arthropathy
Authors: Hong Joseph , Sanfilippo James A. , Rihn Jeffrey , Fernandez Carmella , Winegar Corbett D. , Friel Brian , Ludwig Steven , Gelb Daniel , Vaccaro Alexander R.
Published: February 2011

Charcot spinal arthropathy is a relatively rare, destructive process characterized by a cycle of progressive deformity, destruction, and worsening instability as a result of repetitive trauma and inflammation. It may result from nontraumatic as well as traumatic causes. Historically, patients with severe symptomatic instability have been successfully treated with combined anterior and posterior fusion techniques. The long-term outcomes and potential complications, however, have not been well reported. The authors report on 2 such cases of Charcot spinal arthropathy treated surgically, one with a traumatic and one with a nontraumatic etiology. They include the unique pitfalls encountered while treating these patients, as well as their surgical treatments, complications, and long-term results.
Radiographic assessment of cervical subaxial fusion
Authors: Kaiser Michael G. , Mummaneni Praveen V. , Matz Paul G. , Anderson Paul A. , Groff Michael W. , Heary Robert F. , Holly Langston T. , Ryken Timothy C. , Choudhri Tanvir F. , Vresilovic Edward J. , Resnick Daniel K.
Published: February 2011

Object

The objective of this systematic review was to use evidence-based medicine to identify the best methodology for radiographic assessment of cervical subaxial fusion.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and keywords relevant to cervical fusion. Abstracts were reviewed and 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

Pseudarthrosis is best assessed through the absence of motion detected between the spinous processes on dynamic radiographs (Class II). The measurement of interspinous distance on dynamic radiographs of ≥ 2 mm is a more reliable indicator for pseudarthrosis than angular motion of 2° based on Cobb angle measurements (Class II). Similarly, it is also understood that the pseudarthrosis rate will increase as the threshold for allowable motion on dynamic radiographs decreases. The combination of interspinous distance measurements and identification of bone trabeculation is unreliable when performed by the treating surgeon (Class II). Identification of bone trabeculation on static radiographs should be considered a less reliable indicator of cervical arthrodesis than dynamic films (Class III).

Conclusions

Consideration should be given to dynamic radiographs and interspinous distance when assessing for pseudarthrosis.
Biomechanics of C-7 transfacet screw fixation
Authors: Horn Eric M. , Reyes Phillip M. , Baek Seungwon , Senoglu Mehmet , Theodore Nicholas , Sonntag Volker K. H. , Crawford Neil R.
Published: February 2011

Object

The small diameter of the pedicle can make C-7 pedicle screw insertion dangerous. Although transfacet screws have been studied biomechanically when used in pinning joints, they have not been well studied when used as part of a C7–T1 screw/rod construct. The authors therefore compared C7–T1 fixation using a C-7 transfacet screw/T-1 pedicle screw construct with a construct composed of pedicle screws at both levels.

Methods

Each rigid posterior screw/rod construct was placed in 7 human cadaveric C6–T2 specimens (14 total). Specimens were tested in normal condition, after 2-column instability, and once fixated. Nondestructive, nonconstraining pure moments (maximum 1.5 Nm) were applied to induce flexion, extension, lateral bending, and axial rotation while recording 3D motion optoelectronically. The entire construct was then loaded to failure by dorsal linear force.

Results

There was no significant difference in angular range of motion between the 2 instrumented groups during any loading mode (p > 0.11, nonpaired t-tests). Both constructs reduced motion to < 2° in any direction and allowed significantly less motion than in the normal condition. The C-7 facet screw/T-1 pedicle screw construct allowed a small but significantly greater lax zone than the pedicle screw/rod construct during lateral bending, and it failed under significantly less load than the pedicle screw/rod construct (p < 0.001).

Conclusions

When C-7 transfacet screws are connected to T-1 pedicle screws, they provide equivalent stability of constructs formed by pedicle screws at both levels. Although less resistant to failure, the transfacet screw construct should be a viable alternative in patients with healthy bone.
Measurements and mapping of 282,420 nerve fibers in the S1–5 nerve roots
Authors: Hauck Erik F. , Schwefer Markus , Wittkowski Werner , Bothe Hans W.
Published: February 2011

Object

The study aims to analyze nerve fiber types in the sacral nerve roots as a prerequisite for stimulation.

Methods

One-micrometer cross-sections of human ventral and dorsal S1–5 roots were stained with osmium and toluidine blue. The total fiber diameter and myelin sheath were measured in 282,420 nerve fibers.

Results

The analysis revealed the following 3 main nerve fiber types: Aα fibers (diameter 6–14 μm), Aγ fibers (diameter 2–4 μm), and B fibers (diameter < 2 μm). The B fibers were absent in S-1, present in some S-2 fascicles, and abundant from S-3 to S-5. The Aα fibers dominated the S-1 roots and most fascicles of S-2 roots. In the S3–5 roots, only a few Aα fibers were present. The relative occurrence of Aγ fibers increased from S-1 to S-5. In dorsal roots, Aγ fibers represented ~ 70% of all nerve fibers in every root and fascicle.

Conclusions

The B fibers represented efferent parasympathetic fibers. These fibers were concentrated in certain areas of the nerve roots, not randomly distributed. The Aα fibers innervate lower-extremity muscles and sphincters. The inverse correlation of Aα and Aγ fibers in the ventral roots from S-1 to S-5 is surprising. In dorsal roots, Aγ fibers may conduct pain, touch, and temperature signals. Highly selective fiber stimulation specific for type, location, and direction may improve sacral nerve stimulation for a spastic bladder in paraplegic individuals.
Traumatic spondylolisthesis of the axis: a biomechanical comparison of clinically relevant anterior and posterior fusion techniques
Authors: Chittiboina Prashant , Wylen Esther , Ogden Alan , Mukherjee Debi P. , Vannemreddy Prasad , Nanda Anil
Published: February 2011

Object

Surgical management of unstable traumatic spondylolisthesis of the axis includes both posterior and anterior fusion methods. The authors performed a biomechanical study to evaluate the relative stability of anterior fixation at C2–3 and posterior fixation of C-1 through C-3 in hangman's fractures.

Methods

Fresh-frozen cadaveric spine specimens (occipital level to T-2) were subjected to stepwise destabilization of the C1–2 complex, replicating a Type II hangman's fracture. Intact specimens, fractured specimens, and fractured specimens with either anterior screw and plate or posterior screw and rod fixation were each tested for stability. Each spine was subjected to separate right and left rotation, bending, flexion, and extension testing.

Results

Anterior fixation restored stiffness in flexion and extension movements to values greater than those for intact specimens. For other movement parameters, the values approximated those for intact specimens. Posterior fixation increased the stiffness to above those values seen for anterior fixation specimens.

Conclusions

In cadaveric spine specimens subjected to a Type II hangman's fracture, both anterior fixation at C2–3 and posterior fixation with C-1 lateral mass screws and C-2 and C-3 pedicle screws resulted in a consistent increase in stiffness, and hence in stability, over intact specimens.
The effects of punctured nucleus pulposus on lumbar radicular pain in rats: a behavioral and immunohistochemical study
Authors: Zhang Kui-Bo , Zheng Zhao-Min , Liu Hui , Liu Xian-Guo
Published: February 2011

Object

Application of the nucleus pulposus (NP) to the nerve root has been developed as a model of lumbar radicular pain. The relationship between disc degeneration and the induction of radicular pain, however, has not yet been fully explored. The authors of this study investigated pain-related behaviors and expression of tumor necrosis factor–α (TNF-α) in the dorsal root ganglion (DRG) to evaluate the effects of punctured NP on lumbar radiculopathy.

Methods

An anular needle puncture model of intervertebral disc degeneration in a rat tail was established. Normal and previously punctured NP tissues were obtained and placed on the L-5 nerve root following a hemilaminectomy. Behavioral tests including assessment of motor function, mechanical threshold, and thermal withdrawal latency were performed before and after surgery. The TNF-α immunoreactivity in L-5 DRG specimens was examined through immunohistochemical study.

Results

The punctured discs showed significant degeneration 2 weeks after intervention. Application of both normal and punctured NP induced mechanical hyperalgesia in the ipsilateral paw for 10 days after surgery, but hyperalgesia was more severe in the punctured NP group. No statistically significant within-group changes in thermal withdrawal latency over time were found. A significant increase in the expression of TNF-α–positive neurons in DRG specimens was observed in both NP graft groups.

Conclusions

Needle puncture led to degenerative changes in the rat tail disc, and the degenerated NP enhanced mechanical hyperalgesia induced by application of the NP to the lumbar nerve root. This model of disc degeneration and lumbar radicular pain is appropriate for evaluating the efficacy of biological treatments for degenerative disc diseases.
Intramedullary bronchogenic cyst of the conus medullaris
Authors: Yilmaz Cem , Gulsen Salih , Sonmez Erkin , Ozger Ozkan , Unlukaplan Muge , Caner Hakan
Published: February 2011

Spinal bronchogenic cysts are rare congenital lesions. The authors describe their experience in the treatment of a 17-year-old boy who presented with back pain and paresthesia in both lower extremities. Lumbar MR imaging revealed the presence of an intramedullary cystic lesion at the conus medullaris and histopathological analysis revealed a bronchogenic cyst. To the best of the authors' knowledge, this is the first report of an intramedullary spinal bronchogenic cyst arising at the conus; all previously reported spinal bronchogenic cysts were either intradural extramedullary or not located at the conus.
Intradural cervical root adjacent interconnections in the normal, prefixed, and postfixed brachial plexus
Authors: Tubbs R. Shane , El-Zammar Diala , Loukas Marios , Cömert Ayhan , Cohen-Gadol Aaron A.
Published: February 2011

Object

Intradural intercommunications between adjacent nerve roots have received scant attention in the literature. Moreover, the pattern of these connections among individuals harboring normal, pre-, and postfixed brachial plexuses, to the authors' knowledge, has not been explored.

Methods

Sixty adult cadavers were evaluated for the presence of a normal, prefixed, or postfixed brachial plexus. Next, with the cadaver placed prone, laminectomies of all cervical and the upper thoracic vertebrae were performed. The dura mater was opened and observations were made for the presence of neural intercommunications between the roots of adjacent spinal levels. Any correlations between such root communications and pre- and postfixed brachial plexuses were explored.

Results

Among the cadavers, 28% harbored prefixed and 5% harbored postfixed brachial plexuses. Intercommunications between adjacent dorsal roots were more or less equally distributed between left and right sides. A total of 134 interconnections were identified between C-1 and T-2 levels. No interconnection spanned more than one spinal segment. When all sides were included, in ascending order based on the number of interconnections present, interconnections between roots were found between T-1 and T-2, C-1 and C-2, C-8 and T-1, C-2 and C-3, C-3 and C-4, C-4 and C-5, C-7 and C-8, C-6 and C-7, and C-5 and C-6. In this same order, the percent of total connections for each of these levels was 0, 0.8, 2, 7, 13, 15, 16, 20, and 25%. For left and right sides, a total of 73 and 61 interconnections were identified, respectively. This order of concentration was found to have no statistical difference between cadavers that had a normal arrangement of the brachial plexus, a prefixed brachial plexus, or a postfixed brachial plexus. No specimen was found to have interconnections between adjacent ventral roots.

Conclusions

Such variations as intradural interconnections may lead to misinterpretation of spinal levels harboring pathological entities of the spinal axis and should be considered during surgical procedures of this region such as rhizotomy. However, the present study did not find a correlation between the level of these interconnections and whether the brachial plexus was pre- or postfixed (that is, there were no observable shifts intradurally that corresponded to the extradural segmental contributions to the brachial plexus).
Achondroplasia and cervical laminoplasty
Authors: Yoshii June , Traynelis Vincent C.
Published: February 2011

Achondroplasia is associated with short pedicles that predispose individuals with this trait to develop symptomatic spinal canal stenosis. Laminoplasty is an excellent means of treating cervical myelopathy due to stenosis in selected individuals. Laminoplasty preserves segmental motion and stability, both of which are of benefit to all individuals. The authors report the successful surgical treatment of an achondroplastic adult woman with laminoplasty. This procedure alleviated her symptoms, and she was doing well at 2-year follow-up.
Low-dose kaolin-induced feline hydrocephalus and feline ventriculostomy: an updated model
Authors: Lollis S. Scott , Hoopes P. Jack , Kane Susan , Paulsen Keith , Weaver John , Roberts David W.
Published: February 2011

Object

Intracisternal injection of kaolin is a well-described model of feline hydrocephalus. Its principal disadvantage is a high rate of procedure-related morbidity and mortality. The authors describe a series of modifications to a commonly used protocol, intended to ameliorate animal welfare concerns without compromising the degree of ventricular enlargement.

Methods

In 11 adult cats, hydrocephalus was induced by injection of kaolin into the cisterna magna. Kaolin doses were reduced to 10 mg, compared with historical doses of ~ 200 mg, and high-dose dexamethasone was used to reduce the severity of meningeal irritation. A control cohort of 6 additional animals received injections of isotonic saline into the cisterna magna.

Results

The mean ventricular volume increased from a baseline of 0.183 ± 0.068 ml to 1.43 ± 0.184 ml. Two animals were killed prior to completion of the study. Of the remaining animals, all were ambulatory by postinjection Day 1, and all had resumed normal oral intake by postinjection Day 3. Two animals required subcutaneous fluid supplementation. Ventriculostomy using anatomical landmarks was performed to ascertain intraventricular pressure. The mean intraventricular pressure after hydrocephalus was 15 cm H2O above the ear (range 11–20 cm H2O).

Conclusions

Reduction in kaolin dosage and the postoperative administration of high-dose corticosteroid therapy appear to reduce morbidity and mortality rates compared with historical experiences. Hydrocephalus is radiographically evident as soon as 3 days after injection, but it does not substantially interfere with feeding and basic selfcare. To the extent that animal welfare concerns may have limited the use of this model in recent years, the procedures described in the present study may offer some guidance for its future use.
Exacerbation of spinal cord injury due to static compression occurring early after onset
Authors: Swartz Karin R. , Scheff Nicole N. , Roberts Kelly N. , Fee Dominic B.
Published: February 2011

Object

The authors used a rat model to assess spinal cord compression following an incomplete spinal cord injury (SCI).

Methods

Incomplete SCI was created in the thoracic spinal cord in a novel application of a rodent spinal cord compression model. A moderate impaction force was applied instantaneously to the spinal cord and was followed by 0 seconds, 10 seconds, 30 seconds, or 5 minutes of continued compression (termed “dwell”). The different groups were assessed by behavioral testing with the Basso, Beattie, Bresnahan locomotor rating scale, and with histological injury quantification and morphometrical analysis.

Results

Compression after the SCI resulted in worsened Basso, Beattie, Bresnahan scale scores; however, the duration of compression was not significant. Compression did not significantly affect the percentage of spared total tissue, percent spared total white matter, or percent spared total gray matter. Percent spared tissue at the epicenter of injury was statistically worsened by compression but not in a time-dependent manner.

Conclusions

The authors' results suggest that spinal cord compression after the initial injury is an additional mechanism by which SCI worsens, and that the mechanism of this injury occurs rapidly. These data, however, do not support duration of compression as a significant variable.
Occipital condyle fractures: clinical decision rule and surgical management
Authors: Maserati Matthew B. , Stephens Bradley , Zohny Zohny , Lee Joon Y. , Kanter Adam S. , Spiro Richard M. , Okonkwo David O.
Published: February 2011

Object

Occipital condyle fractures (OCFs) are rare injuries and their treatment remains controversial. Several classification systems have been proposed, first by Anderson and Montesano and more recently by Tuli and colleagues and Hanson and associates, who sought to stratify these fractures in a manner that would guide treatment that has typically ranged from semirigid collar immobilization to halo fixation or occipitocervical fusion. It has been the authors' impression, based on experience with OCFs at their institution, that classification is cumbersome and contributes little to the clinical decision-making process, while the identification of craniocervical misalignment and neural element compromise is paramount, and sufficient, for the planning of treatment.

Methods

The authors performed a retrospective review of 24,745 consecutive trauma presentations to a single Level I trauma center (UPMC Presbyterian Hospital) over a 6-year period, identifying 100 patients with 106 OCFs. All patients were evaluated by the spine trauma service and underwent imaging of the craniocervical junction using reconstructed CT scans. Patient characteristics, fracture characteristics (including fracture classification according to the 2 major classification systems), initial management, and status at follow-up were recorded.

Results

The incidence of OCF in this trauma population was 0.4%. Two patients had evidence of craniocervical misalignment on reconstructed CT imaging at the time of admission; both patients underwent occipitocervical fusion. One patient underwent occipitocervical fusion for unrelated C1–2 fractures. The remainder of those surviving to discharge, whose fractures represented all fracture subtypes, received treatment with a rigid cervical collar or counseling alone. No patients, including 4 patients with bilateral OCFs, were found to have developed delayed craniocervical instability or misalignment on follow-up, or to require further neurosurgical intervention for an OCF. Neural element compression was not identified in any of the patients, and there were no cases of delayed cranial neuropathy.

Conclusions

Beyond the identification of craniocervical misalignment on reconstructed CT scans at admission, further classification of OCFs is unnecessary. Management should consist of up-front occipitocervical fusion or halo fixation in cases demonstrating occipitocervical misalignment, or of immobilization in a rigid cervical collar followed by delayed clinical and radiographic evaluation in a spine trauma clinic if misalignment is not present.
Role of the blood-spinal cord barrier in posttraumatic syringomyelia
Authors: Hemley Sarah J. , Biotech B. , Tu Jian , Stoodley Marcus A.
Published: February 2011

Object

Posttraumatic syringomyelia produces a significant burden of pain and neurological deficits in patients with spinal cord injury. The mechanism of syrinx formation is unknown and treatment is often ineffective. A possible explanation for syrinx formation is fluid leakage from the microcirculation in the presence of a compromised blood-spinal cord barrier (BSCB). The aim of this study was to investigate the structural and functional integrity of the BSCB in a model of posttraumatic syringomyelia.

Methods

The excitotoxic amino acid and arachnoiditis model of syringomyelia was used in 27 Sprague-Dawley rats. Structural integrity of the BSCB was assessed using immunoreactivity to endothelial barrier antigen (EBA), and loss of functional integrity was assessed by extravasation of intravascular horseradish peroxidase. Animals were studied after 3 days, or at 1, 3, 6, or 12 weeks after surgery. There were laminectomy-only and saline injection control animals for comparison at each time point.

Results

Syrinxes formed in 16 of the 17 animals injected with excitotoxic amino acid. Loss of structural and functional integrity of the BSCB in syrinx animals was noted at all time points. Disruption of the BSCB was most dramatic in tissue adjacent to the syrinx, and in the central and dorsal gray matter. Changes in EBA expression generally corresponded with altered vascular permeability, although in the acute stages, widespread vascular permeability occurred without a corresponding decrease in EBA expression. At the later time points (3–12 weeks) EBA expression was often absent, although no vascular leakage was observed.

Conclusions

This study demonstrated a prolonged structural and functional disruption of the BSCB in this model of posttraumatic syringomyelia. Loss of functional integrity of the BSCB, with fluid entering the interstitial space of the spinal cord, may contribute to initial cyst formation after spinal cord injury and subsequent enlargement of the cyst, to produce posttraumatic syringomyelia.
High-grade intramedullary astrocytomas: 30 years' experience at the Neurosurgery Department of the University of Rome “Sapienza”
Authors: Raco Antonino , Piccirilli Manolo , Landi Alessandro , Lenzi Jacopo , Delfini Roberto , Cantore Giampaolo
Published: February 2011

Object

The goal in this study was to review a series of patients who underwent surgical removal of intramedullary high-grade gliomas, focusing on the functional outcome, recurrence rates, and technical problems continually debated in neurosurgical practice.

Methods

Between December 1976 and December 2006, 22 patients underwent removal of intramedullary high-grade gliomas. Lesions were located in the cervical spinal cord in 12 patients, and in the thoracic cord in 10.

Results

. Histological examinations showed 10 Grade III astrocytomas and 12 glioblastomas. Only 2 of the 22 high-grade astrocytomas could be completely removed. The clinical postoperative status worsened in 14 patients (63.6%), was unchanged in 7 patients (31.8%), and there was 1 case of intraoperative death (4.5%). None of the 22 patients showed improvement in their neurological status postoperatively. In this series, excluding the 1 intraoperative death, all patients died of progression of the malignancy.

Conclusions

Surgical treatment did not ameliorate the postoperative neurological status; instead, in the majority of cases, it prompted a worsening of the deficit. Radiotherapy and chemotherapy have a little influence on the length of survival. In this series, multimodality treatment of intramedullary high-grade astrocytomas has been shown to increase length of survival without improving the neurological status.
Cervical pedicle screw insertion using a computed tomography cutout technique
Authors: Miyamoto Hiroshi , Uno Koki
Published: February 2011

Object

The pedicle screw has been reported to provide the strongest fixation for the cervical spine, but there is a possibility of malpositioning the screws, which may cause fatal complications such as vertebral artery and neural injuries. Using the conventional freehand technique, between 6.7 and 29% of the screws have been found to be malpositioned. If an accurate entry point and insertion trajectory through the isthmus of the pedicle can be maintained during surgery, safer insertion of the pedicle screw should be achieved. The authors have developed a new pedicle screw insertion method, called the “CT cutout” technique, and report on the technical and clinical aspects of this new technique in terms of accuracy.

Methods

A total of 130 pedicle screws were inserted from C-2 to T-1 in 29 consecutive patients using the new technique. In the CT cutout technique, a CT slice of every vertebra in which the authors intended to insert pedicle screws was captured from 3D CT images of the cervical spine with the gantry parallel to the pedicle. A life-sized CT image was developed for each level, and the desired insertion line, passing through the middle of the isthmus, was drawn on the image. The images were then cut along the insertion line and the posterior margin of the lamina, and sterilized. During surgery, the proper cephalocaudal entry point was determined using a lateral fluoroscopic image, the CT cutout was placed on the posterior surface of the lamina, and the appropriate entry point and trajectory of pedicle screw insertion were chosen with reference to the CT cutout. The percentage of malpositioned pedicle screws and the deviation between the intended entry point and angle of the pedicle screw, and those that were achieved in practice, was investigated using postoperative CT images.

Results

Three perforations (2.3%) in which more than half a screw diameter was exposed outside the pedicle, and 2 penetrations (1.5%) in which a screw diameter was completely exposed, were identified on the postoperative CT images. All breaches were directed laterally. No neural or vascular injuries were observed. The deviation between the intended entry point and angle of the pedicle screw and the actual values was 0.20 ± 0.75 mm and 1.46 ± 4.21°, respectively.

Conclusions

Several techniques for pedicle screw insertion such as computer-assisted navigation, CT-based navigation, and acquisition of fluoroscopic intraoperative pedicle axis views have been used for improving accuracy. However, there remains a possibility of misplacement, and these costly procedures often require delivery of a high x-ray dose to both patients and surgeons, and/or time-consuming configuration of reference points during surgery. The CT cutout technique is an easy, low-cost procedure that can be performed with the aid of single-plane fluoroscopy and without the need of configuration. This new technique shows great promise for safe pedicle screw insertion for the cervical spine.
Spinal meningocele due to iatrogenic dural puncture during epidural analgesia for childbirth: 5-year history of headache with a spinal etiology
Authors: Nurboja Besnik , Rezajooi Kia , Newton Mary C. , Casey Adrian T. H.
Published: February 2011

Patients undergoing epidural injection for labor pains occasionally sustain iatrogenic inadvertent puncture of the dura with or without damage to the underlying neurological structures. This may be associated with CSF leakage, headache, neurological deficit, and infection. Rarely, the headache persists for years. To the authors' knowledge, chronic headache due to acquired spinal meningocele featuring as a duplicated dural sac, as a sequela of traumatic inadvertent dural puncture, has not been previously reported.

The authors report a case of a 20-year-old woman with persistent headaches following an epidural injection. Five years later, the persistent headache was found to be due to a large acquired spinal meningocele. The operative removal of the meningocele led to resolution of headaches.

This report highlights the importance of considering a spinal condition as a culprit for chronic headache and postulates a mechanism for the formation of the acquired spinal meningocele appearing as a duplicated dural sac. The authors recommend early MR imaging of the spine for any persisting headache that has a history of attempted spinal access. If an acquired spinal meningocele collection is found, exploration with a view to complete removal of the sac should be considered.

To the authors' knowledge, this is the first case report depicting a rare, treatable cause of chronic spinal hypotension resulting in headaches.