bluuebunny/crossref_metadata_2025_split huggingface dataset:
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).
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

ObjectThe 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.MethodsBetween 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.ConclusionsSurgical 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.
Dermatomyotomal supply in patients with variations in the number of lumbar vertebrae
Authors: Kottlors Michael , Glocker Franz Xaver 
Published: February 2011

Object
Variation in the number of lumbar vertebrae occurs in a small portion of the population. Either the fifth lumbar vertebra shows assimilation to the sacrum or the first sacral vertebra shows a lumbar configuration, resulting in 4 or 6 lumbar vertebrae, respectively. Etiologically, lumbar nerve root syndrome is diagnosed by comparing the anatomical level of the disc herniation to the compressed nerve root and to the pattern of the peripheral sensory and motor deficit. In case of a variation in the number of lumbar vertebrae, defining the lumbar nerve roots becomes difficult. Variations in the number of lumbar vertebrae make the landmarks (the twelfth rib and the first sacral vertebra) unreliable clues to define the nerve roots. The allocation of the clinically damaged segment to the spinal disorder seen in imaging studies is essential for differential diagnosis and spine surgery.

Methods
A retrospective study was conducted of clinical, electrophysiological, and imaging data among inpatients over a period of 21 months. Eight patients who had isolated monosegmental discogenic nerve root compression and a variation in the number of lumbar vertebrae were selected.

Results
Seven patients presented with 6 lumbar vertebrae, and 1 patient presented with 4 lumbar vertebrae and disc herniation on 1 of the 2 caudal levels. Compression of the second-to-last nerve root in patients with 6 lumbar vertebrae resulted either in clinical L-5 or S-1 syndrome, or a combination of both. Compression of the last caudal nerve root resulted in a clinical S-1 nerve root syndrome.

Conclusions
The findings suggest that the dermatomyotomal supply of the lumbosacral nerve roots can vary in patients with a variation in the number of lumbar vertebrae, and a meticulous clinical, radiological, and electrophysiological examination is essential.
Limited functional recovery in rats with complete spinal cord injury after transplantation of whole-layer olfactory mucosa
Authors: Aoki Masanori , Kishima Haruhiko , Yoshimura Kazuhiro , Ishihara Masahiro , Ueno Masaki , Hata Katsuhiko , Yamashita Toshihide , Iwatsuki Koichi , Yoshimine Toshiki 
Published: February 2011

Object
The olfactory mucosa (OM) consists of 2 layers, the epithelium and the lamina propria. Attempts have been made to restore motor function in rat models of spinal cord injury (SCI) by transplanting olfactory ensheathing cells from the lamina propria, but there has been no attempt to transplant the OM in animal models. To investigate the potential of the OM to restore motor function, the authors developed a rat model of SCI and delayed transplantation of syngenic OM.

Methods
Two weeks after complete transection of the spinal cord at the T-10 level in Wistar rats, pieces of syngenic whole-layer OM were transplanted into the lesion. Rats that underwent respiratory mucosa transplantation were used as controls. The authors evaluated the locomotor activity according to the Basso-Beattie-Bresnahan scale for 8 weeks after transplantation. Obtained spinal cords were analyzed histologically.

Results
The OM transplantation rats showed significantly greater hindlimb locomotor recovery than the respiratory mucosa–transplanted rats. However, the recovery was limited according to the Basso-Beattie-Bresnahan scale. In the histological examination, the serotonergic raphespinal tract was regenerated. The pseudocyst cavity volume in the vicinity of the SCI lesion correlated negatively with the functional recovery.

Conclusions
Transplantation of whole-layer OM in rats contributes to functional recovery from SCI, but the effect is limited. In addition to OM transplantation, other means would be necessary for better outcomes in clinical situations.
Neurological function after total en bloc spondylectomy for thoracic spinal tumors
Authors: Murakami Hideki , Kawahara Norio , Demura Satoru , Kato Satoshi , Yoshioka Katsuhito , Tomita Katsuro 
Published: February 2011

Object
Total en bloc spondylectomy (TES) for thoracic spinal tumors may in theory produce neurological dysfunction as a result of ischemic or mechanical damage to the spinal cord. Potential insults include preoperative embolization at 3 levels, intraoperative ligation of segmental arteries, nerve root ligation, and circumferential dural dissection. The purpose of this study was to assess neurological function after thoracic TES.

Methods
The authors performed a retrospective review of 79 patients with thoracic-level spinal tumors that had been treated with TES between 1989 and 2006. Neurological function was retrospectively analyzed according to the Frankel grading system. Of the 79 cases, 26 involved primary tumors and 53 involved metastatic tumors. The number of excised vertebrae was 1 in 60 cases, 2 in 13, and ≥ 3 in 6. The Frankel grade before surgery was B in 1 case, C in 16, D in 29, and E in 33.

Results
At the follow-up, the Frankel grade was C in 2 cases, D in 24, and E in 53. Of 46 cases with neurological deficits before surgery, neurological improvement of at least 1 Frankel grade was achieved in 25 cases (54.3%). Although the Frankel grade did not change in 21 patients, improvement in neurological symptoms within the same Frankel grade did occur in these patients. There were no cases of neurological deterioration.

Conclusions
There was no neurological deterioration due to preoperative embolization, ligation of segmental arteries, or ligation of thoracic nerve roots. Each of the cases with preoperative neurological deficits showed improvement in neurological symptoms. Data in the current study clinically proved that TES is a safe operation with respect to spinal cord blood flow. In TES, the spinal cord is circumferentially decompressed and the spinal column is shortened. An increase in spinal cord blood flow due to spinal shortening in addition to decompression was considered to have brought about a resolution of neurological symptoms with TES.