bluuebunny/crossref_metadata_2025 huggingface dataset:
Defining future directions in spinal cord tumor research
Authors: Claus Elizabeth B. , Abdel-Wahab May , Burger Peter C. , Engelhard Herbert H. , Ellison David W. , Gaiano Nicholas , Gutmann David H. , Heck Daniel A. , Holland Eric C. , Jallo George I. , Kruchko Carol , Kun Larry E. , Maria Bernard L. , Rumboldt Zoran , Seminara Daniela , Spinella Giovanna M. , Stophel Linda , Wechsler-Reya Robert , Wrensch Margaret , Gilbertson Richard J.
Published: February 2011

The relative rarity of spinal cord tumors has hampered the study of these uncommon nervous system malignancies. Consequently, the understanding of the fundamental biology and optimal treatment of spinal cord tumors is limited, and these cancers continue to inflict considerable morbidity and mortality in children and adults. As a first step to improving the outcome of patients affected with spinal cord tumors, the National Institutes of Health Office of Rare Diseases Research in cooperation with the National Cancer Institute and the National Institute of Neurological Disorders and Stroke convened a workshop to discuss the current status of research and clinical management of these tumors. The overall goal of this meeting was to initiate a process that would eventually translate fundamental basic science research into improved clinical care for this group of patients. Investigational priorities for each of these areas were established, and the opportunities for future multidisciplinary research collaborations were identified.
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.
Surgery for cervical dystonia: the emergence of denervation and myotomy techniques and the contributions of early surgeons at The Johns Hopkins Hospital
Authors: Vogel Todd D. , Pendleton Courtney , Quinoñes-Hinojosa Alfredo , Cohen-Gadol Aaron A.
Published: February 2011

Cervical dystonia is a psychologically and physically disabling disease that has intrigued clinicians since the early history of surgery. Because of its elusive etiology, its operative treatment has had an extended evolutionary voyage. Early surgical approaches involved resection of the sternocleidomastoid muscle. Later recognition of more diffuse involvement of the posterior neck muscles led to the introduction of new techniques with more effective results. A review of available surgical patient records at The Johns Hopkins Hospital from around the turn of the 20th century provided a glimpse of the early history of the operative treatment for torticollis through the work of some of the leaders of surgery, including Halsted, Cushing, and specifically Finney. Here, the authors present a segment of history on the surgical treatment of this disease as it relates to the introduction of myotomy and denervation techniques.
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.
Management of neurotrauma by surgeons and orthopedists in a military operational setting
Authors: Mauer Uwe Max , Kunz Ulrich
Published: February 2011

There is a considerable discrepancy between the potential demand for neurosurgeons and the actual availability of such specialists not only in civilian settings but even more so in military operational environments.

For this reason, the Department of Neurosurgery at the German Armed Forces Hospital in Ulm conducts courses for surgeons and orthopedists on the management of patients with neurotrauma. Twelve such courses have already taken place. Each course lasts 1 week. Participants can expect to gain the theoretical knowledge and practical skills they need to provide initial surgical care for patients with traumatic brain injuries and/or spinal trauma. Surgical techniques are practiced above all in pig and human cadavers. At the end of the course, participants with previous surgical knowledge should be able to independently perform a craniotomy, from the planning of the procedure to the closure of the wound. Former course participants have successfully used their neurosurgical knowledge in countries of deployment where they managed patients during teleconsultation sessions and helped repatriate, or even provided surgical treatment to, patients with traumatic brain injuries. In these situations, it was particularly helpful when the physician deployed abroad and the neurosurgeon in Germany knew each other personally. In the future, efforts will be made to combine telemedicine and neuronavigation in an attempt to further improve direct support for physicians under military deployment conditions.
Resident learning curve for minimal-access transforaminal lumbar interbody fusion in a military training program
Authors: Neal Chris J. , Rosner Michael K.
Published: February 2011

Object

Minimal-access transforaminal lumbar interbody fusion (TLIF) has gained popularity as a method of achieving interbody fusion via a posterior-only approach with the aim of minimizing injury to adjacent tissue. While many studies have reported successful outcomes, questions remain regarding the potential learning curve for successfully completing this procedure. The goal of this study, based on a single resident's experience at the only Accreditation Council for Graduate Medical Education–approved neurosurgical training center in the US military, was to determine if there is in fact a significant learning curve in performing a minimal-access TLIF.

Methods

The authors retrospectively reviewed all minimal-access TLIFs performed by a single neurosurgical resident between July 2006 and January 2008. Minimal-access TLIFs were performed using a tubular retractor inserted via a muscle-dilating exposure to limit approach-related morbidity. The accuracy of screw placement and operative times were assessed.

Results

A single resident/attending team performed 28 minimal-access TLIF procedures. In total, 65 screws were placed at L-2 (1 screw), L-3 (2 screws), L-4 (18 screws), L-5 (27 screws), and S-1 (17 screws) from the resident's perspective. Postoperative CTs were reviewed to determine the accuracy of screw placement. An accuracy of 95.4% (62 of 65) properly placed screws was noted on postoperative imaging. Two screws (at L-5 in the patient in Case 17 and at S-1 in the patient in Case 9) were lateral, and no revision was needed. One screw (at L-4 in Case 24) was 1 mm medial without symptoms or the need for revision. In evaluating the operative times, 2 deformity cases (Grade III spondylolisthesis) were excluded. The average operating time per level in the remaining 26 cases was 113.25 minutes. The average time per level for the first 13 cases was 121.2 minutes; the amount of time decreased to 105.3 minutes for the second group of 13 cases (p = 0.25).

Conclusions

In summary, minimal-access TLIF can be safely performed in a training environment without a significant complication rate due to the expected learning curve.
Multilevel cervical arthroplasty with artificial disc replacement
Authors: Cardoso Mario J. , Rosner Michael K.
Published: February 2011

Object

In this study, the authors review the technique for inserting the Prestige ST in a contiguous multilevel cervical disc arthroplasty in patients with radiculopathy and myelopathy. They describe the preoperative planning, surgical technique, and their experience with 10 patients receiving a contiguous Prestige ST implant. They present contiguous multilevel cervical arthroplasty as an alternative to multilevel arthrodesis.

Methods

After institutional board review approval was obtained, the authors performed a retrospective review of all contiguous multilevel cervical disc arthroplasties with the Prestige ST artificial disc between August 2007 and November 2009 at a single institution by a single surgeon. Clinical criteria included patients who had undergone a multilevel cervical disc arthroplasty performed for radiculopathy and myelopathy without the presence of a previous cervical fusion. Between August 2007 and November 2009, 119 patients underwent cervical arthroplasty. Of the 119 patients, 31 received a Hybrid construct (total disc resection [TDR]–anterior cervical decompression and fusion [ACDF] or TDR-ACDF-TDR) and 24 received a multilevel cervical arthroplasty. The multilevel cervical arthroplasty group consisted of 14 noncontiguous and 10 contiguous implants. This paper examines patients who received contiguous Prestige ST implants.

Results

Ten men with an average age of 45 years (range 25–61 years) were treated. Five patients presented with myelopathy, 3 presented with radiculopathy, and 2 presented with myeloradiculopathy. Twenty-two 6 × 16–mm Prestige ST TDRs were implanted. Six patients received 2-level Prestige ST implants. Five patients received TDRs at C5–6 and C6–7, and 1 patient received TDRs at C3–4 and C4–5. One patient received a TDR at C3–4, C5–6, and C6–7 where C4–5 was a congenital block vertebra. Three patients (2 with 3-level disease and 1 with 4-level disease) received contiguous Prestige ST implants as well as a Prevail ACDF as part of their constructs. The mean clinical and radiographic follow-up was 12 months. There has been no case of screw backout, implant dislodgment, progressive kyphosis, formation of heterotopic bone, evidence of pseudarthrosis at the Prevail levels, or development of symptomatic adjacent level disease.

Conclusions

Multilevel cervical arthroplasty with the Prestige ST is a safe and effective alternative to fusion for the management of cervical radiculopathy and myelopathy.
Does the Wilson frame assist with optimizing surgical exposure for minimally invasive lumbar fusions?
Authors: Cardoso Mario J. , Rosner Michael K.
Published: February 2011

Object

Minimally invasive lumbar spine surgery has dramatically evolved over the last decade. Minimally invasive techniques and transforaminal lumbar interbody fusion (TLIF) often require a steep learning curve. Surgical techniques require pre-positioning the patient in maximal kyphosis to optimize visualization of the disc space and prevent unnecessary retraction of neural structures. The authors describe their experience in validating the surgical technique recommendation of Wilson frame–induced kyphosis.

Methods

Over the past 6 months, data obtained in 20 consecutive patients (40 total levels) undergoing minimally invasive TLIF were reviewed. In each patient, preincision intraoperative radiographs were reviewed at L4–5 and L5–S1 with the patient on a Wilson frame in maximal lordosis and then in maximal kyphosis. The change in disc space angle at L4–5 and L5–S1 after changing from maximal lordosis to maximal kyphosis was reviewed. Descriptive statistics were calculated for sagittal plane angular measures at L4–5 and L5–S1 in lordosis and kyphosis, including absolute differences and percentage of change between positions. Inferential statistics were calculated using paired t-tests with α= 0.05.

Results

Twenty patients underwent single- or multilevel minimally invasive TLIF. Inducing kyphosis with the Wilson frame aided in optimizing exposure and decreasing the need for neural structure retraction. Both L4–5 and L5–S1 showed statistically significant (p < 0.001) and clinically meaningful changes with increased segmental flexion in the kyphotic position. At L4–5 the mean increase in flexion was 4.5° (95% CI 2.9–6.0°), representing an average 47% change. The mean increase in flexion at L5–S1 was 3.2° (95% CI 2.3–4.2°), representing an average 20.8% change. In lordosis the mean angle at L4–5 was 10.6 ± 4.4° and at L5–S1 was 17 ± 7.0°. In kyphosis the mean angle at L4–5 was 6.1 ± 4.5° and at L5–S1 was 13.8 ± 6.5°. Additionally, there was a statistically significant difference (p < 0.05) in percentage of change between the 2 levels, with L4–5 showing a greater change (27% more flexion) between positions, but the absolute mean difference between the levels was small (1.3°).

Conclusions

Minimally invasive TLIF is challenging and requires a significant learning curve. The recommended surgical technique of inducing kyphosis with the Wilson frame prior to incision significantly optimizes exposure. The authors' experience demonstrates that this technique is essential when performing minimally invasive lumbar spinal fusions.
The French mobile neurosurgical unit
Authors: Dulou Renaud , Dagain Arnaud , Delmas Jean-Marc , Lambert Evelyne , Blondet Eric , Goasguen Olivier , Pouit Bruno , Dutertre Guillaume , de Soultrait François , Pernot Philippe
Published: February 2011

The authors present the French concept of a mobile neurosurgical unit (MNSU) as used to provide specific support to remote military medicosurgical units deployed in Africa, South America, Central Europe, and Afghanistan. From 2001 to 2009, 15 missions were performed, for 16 patients. All but 3 of these missions (those in Kosovo, French Guyana, and Afghanistan) concerned Africa. Eleven patients were French soldiers, 3 were civilians, and 2 were Djiboutian soldiers. The conditions that MNSUs were requested for included craniocerebral wounds (2 cases), closed head trauma (7 cases), spinal trauma (5 cases), and spontaneous intracranial hemorrhage (2 cases). In 5 of the 16 cases, neurosurgical treatment was provided on site. All French soldiers and 2 civilians were evacuated to France. The MNSU can be deployed for timely treatment when some delay in neurosurgical management is acceptable.
Use of neurosurgical decision-making and damage-control neurosurgery courses in the Iraq and Afghanistan conflicts: a surgeon's experience
Authors: Teff Richard J.
Published: February 2011

A shortage of Coalition neurological surgeons in the Iraq conflict prompted a creative approach to standardized neurosurgical care in 2007. After formulation of theater-wide clinical pathway guidelines, a need for standardized triage and neurological resuscitation was identified. The object was to establish a simple, reproducible course for medics, forward surgical and emergency room personnel, and other critical care providers to quickly standardize the ability of all deployed health care personnel to provide state-of-the-art neurosurgical triage and damage-control interventions. The methods applied were Microsoft PowerPoint presentations and hands-on learning. The year-long project resulted in more than 100 individuals being trained in neurosurgical decision making and in more than 15 surgeons being trained in damage-control neurosurgery. At the year's conclusion, hundreds of individuals received exceptional neurosurgical care from nonneurosurgical providers and a legacy course was left for future deployed providers to receive ongoing education at their own pace.
Intercontinental aeromedical evacuation of patients with traumatic brain injuries during Operations Iraqi Freedom and Enduring Freedom
Authors: Fang Raymond , Dorlac Gina R. , Allan Patrick F. , Dorlac Warren C.
Published: February 2011

Traumatic brain injury contributes significantly to military combat morbidity and mortality. No longer maintaining comprehensive medical care facilities throughout the world, the US military developed a worldwide trauma care system making the patient the moving part of the system. Life-saving interventions are performed early, and essential care is delivered at forward locations. Patients then proceed successively through increasingly capable levels of care culminating with arrival in the US. Proper patient selection and thorough mission preparation are crucial to the safe and successful intercontinental aeromedical evacuation of critical brain-injured patients during Operations Iraqi Freedom and Enduring Freedom.
Battlefield neurosurgical care in the current conflict in southern Afghanistan
Authors: Eisenburg Markus F. , Christie Martin , Mathew Peter
Published: February 2011

An international military campaign involving large numbers of troops is ongoing in Afghanistan. To support the military efforts in the conflict zone, a network of military medical services of varying levels has been established. The largest and busiest multinational military hospital in southern Afghanistan is located at Kandahar Air Field where the only neurosurgeon is based. This report outlines the contribution of multinational military health services and the workload of the neurosurgical service in Kandahar.
A systematic review of randomized trials on the effect of cervical disc arthroplasty on reducing adjacent-level degeneration
Authors: Botelho Ricardo Vieira , Moraes Osmar José dos Santos , Fernandes Gustavo Alberto , Buscariolli Yuri dos Santos , Bernardo Wanderley Marques
Published: February 2011

Object

Anterior cervical discectomy and fusion had been considered a safe and effective procedure for radiculopathy and myelopathy in the cervical spine, but degeneration in adjacent spinal levels has been a problem in some patients after fusion. Since 2002, cervical disc arthroplasty has been established as an alternative to fusion. The objective of this study was to review data concerning the role of cervical arthroplasty in reducing adjacent-level degeneration.

Methods

A systematic review was performed using the MEDLINE, EMBASE, Cochrane, and LILACS databases, focusing on a structured question involving the population of interest, types of intervention, types of control, and outcomes studied.

Results

No study has specifically compared the results of arthroplasty with the results of fusion with respect to the rate of postoperative development of adjacent-segment degenerative disease. One paper described a rate for adjacent-level surgery. The level of evidence of that paper was classified 2b, and although its authors found a statistically significant between-groups difference (arthroplasty vs fusion) using log-rank analysis, re-analysis according to number needed to treat (in the current paper) did not reveal statistical significance.

Conclusions

Adjacent-level degeneration has not been adequately studied in a review of the available randomized controlled trials on this topic, and there is no clinical evidence of reduction in adjacent-level degeneration with the use of cervical arthroplasty.
The predictive value of the baseline Oswestry Disability Index in lumbar disc arthroplasty
Authors: Deutsch Harel
Published: February 2011

Object

The goal of the study was to determine patient factors predictive of good outcome after lumbar disc arthroplasty. Specifically, the paper examines the relationship of the preoperative Oswestry Disability Index (ODI) to patient outcome at 1 year.

Methods

The study is a retrospective review of 20 patients undergoing a 1-level lumbar disc arthroplasty at the author's institution between 2004 and 2008. All data were collected prospectively. Data included the ODI, visual analog scale scores, and patient demographics.

Results

All patients underwent a 1-level disc arthroplasty at L4–5 or L5–S1. The patients were divided into 2 groups based on their baseline ODI. Patients with an ODI between 38 and 59 demonstrated better outcomes with lumbar disc arthroplasty. Only 1 (20%) of 5 patients with a baseline ODI higher than 60 reported a good outcome. In contrast, 13 (87%) of 15 patients with an ODI between 38 and 59 showed a good outcome (p = 0.03). The negative predictive value of using ODI > 60 is 60% in patients who are determined to be candidates for lumbar arthroplasty.

Conclusions

Lumbar arthroplasty is very effective in some patients. Other patients do not improve after surgery. The baseline ODI results are predictive of outcome in patients selected for lumbar disc arthroplasty. A baseline ODI > 60 is predictive of poor outcome. A high ODI may be indicative of psychosocial overlay.
Bulgarian military neurosurgery: from Warsaw Pact to the North Atlantic Treaty Organization
Authors: Enchev Yavor , Eftimov Tihomir
Published: February 2011

After 45 years as a closest ally of the Soviet Union in the Warsaw Pact, founded mainly against the US and the Western Europe countries, and 15 years of democratic changes, since 2004 Bulgaria has been a full member of NATO and an equal and trusted partner of its former enemies. The unprecedented transformation has affected all aspects of the Bulgarian society. As a function of the Bulgarian Armed Forces, Bulgarian military medicine and in particular Bulgarian military neurosurgery is indivisibly connected with their development. The history of Bulgarian military neurosurgery is the history of the transition from the Union of Soviet Socialist Republics military system and military medicine to NATO standards in every aspect. The career of the military neurosurgeon in Bulgaria is in many ways similar to that of the civilian neurosurgeon, but there are also many peculiarities. The purpose of this study was to outline the background and the history of Bulgarian military neurosurgery as well as its future trends in the conditions of world globalization.
Efficacy and limitations of intraoperative spinal cord monitoring using nasopharyngeal tube electrodes
Authors: Yamamoto Naoya , Kobashi Hiroe , Shiba Masahiro , Itoh Tatsuo
Published: February 2011

Object

Motor evoked potentials are widely used for intraoperative spinal cord monitoring. However, there are problems with anesthetic constraints and high trial-by-trial variability of compound muscle action potential amplitude in muscle motor evoked potential monitoring. It is difficult to determine when to warn the surgeon of an occurrence of spinal cord risk. A method of estimation for motor function in the spinal cord has not been established. To monitor spinal cord function with reliable evoked potentials, including the upper cervical spinal cord and the ventral spinal cord, the authors developed a nasopharyngeal tube electrode that can be placed in front of the upper and ventral cervical spinal cord. The purpose of this study was to investigate the origins and pathways of descending or ascending spinal cord evoked potentials (SCEPs) elicited with this electrode, and the usefulness and limitations of this method.

Methods

A nasopharyngeal tube electrode was inserted into the nostril. A catheter electrode was placed in the epidural or subarachnoid space at the thoracic spine. Ventral SCEP was recorded from the thoracic spinal cord after transpharyngeal stimulation, and dorsal SCEP was recorded with the nasopharyngeal electrode after thoracic spinal cord stimulation. There was no restriction of anesthetic technique in recording. When the amplitude of either of the SCEPs declined to 80% of the baseline, a warning was provided to the surgeon during the observed operative procedure. At the end of surgery, less than 50% or more than 30% of the baseline amplitude was considered a significant change in both SCEPs. The sensitivity and specificity for both SCEPs to detect neurological deterioration were calculated.

Results

The electrode provided noninvasive access to the ventral cervicomedullary junction. The SCEPs showed stable responses. A response change was only observed in situations involving a risky procedure for the spinal cord. Ventral SCEPs showed high sensitivity (73.1%) for identifying patients with new neurological deficits or an exacerbation of preexisting neurological deficits after surgery, but dorsal SCEPs showed lower sensitivity (46.1%) in the total number of cases. Both SCEPs showed high specificities. The sensitivities of ventral SCEP, dorsal SCEP, and either SCEP were 100.0%, 50.0%, and 100.0% for the upper cervical spinal cord, 33.3%, 0%, and 55.6% for the lower cervical spinal cord, and 77.8%, 64.7%, and 88.2% for the thoracic spinal cord.

Conclusions

Combined recording of both SCEPs estimated the ventral and dorsal white matter function in the spinal cord. Measuring the SCEPs with the nasopharyngeal electrode can be another useful approach for upper cervical and thoracic spinal cord monitoring. Ventral SCEP was more reliable for monitoring postoperative spinal cord function than dorsal SCEP. Ventral SCEP does not estimate the gray matter and spinal root functions in the lower cervical spinal cord.
Complications in spine surgery
Authors: Nasser Rani , Yadla Sanjay , Maltenfort Mitchell G. , Harrop James S. , Anderson D. Greg , Vaccaro Alexander R. , Sharan Ashwini D. , Ratliff John K.
Published: February 2011

Object

The overall incidence of complications or adverse events in spinal surgery is unknown. Both prospective and retrospective analyses have been performed, but the results have not been critically assessed. Procedures for different regions of the spine (cervical and thoracolumbar) and the incidence of complications for each have been reported but not compared. Authors of previous reports have concentrated on complications in terms of their incidence relevant to healthcare providers: medical versus surgical etiology and the relevance of perioperative complications to perioperative events. Few authors have assessed complication incidence from the patient's perspective. In this report the authors summarize the spine surgery complications literature and address the effect of study design on reported complication incidence.

Methods

A systematic evidence-based review was completed to identify within the published literature complication rates in spinal surgery. The MEDLINE database was queried using the key words “spine surgery” and “complications.” This initial search revealed more than 700 articles, which were further limited through an exclusion process. Each abstract was reviewed and papers were obtained. The authors gathered 105 relevant articles detailing 80 thoracolumbar and 25 cervical studies. Among the 105 articles were 84 retrospective studies and 21 prospective studies. The authors evaluated the study designs and compared cervical, thoracolumbar, prospective, and retrospective studies as well as the durations of follow-up for each study.

Results

In the 105 articles reviewed, there were 79,471 patients with 13,067 reported complications for an overall complication incidence of 16.4% per patient. Complications were more common in thoracolumbar (17.8%) than cervical procedures (8.9%; p < 0.0001, OR 2.23). Prospective studies yielded a higher incidence of complications (19.9%) than retrospective studies (16.1%; p < 0.0001, OR 1.3). The complication incidence for prospective thoracolumbar studies (20.4%) was greater than that for retrospective series (17.5%; p < 0.0001). This difference between prospective and retrospective reviews was not found in the cervical studies. The year of study publication did not correlate with the complication incidence, although the duration of follow-up did correlate with the complication incidence (p = 0.001).

Conclusions

Retrospective reviews significantly underestimate the overall incidence of complications in spine surgery. This analysis is the first to critically assess differing complication incidences reported in prospective and retrospective cervical and thoracolumbar spine surgery studies.
Impact of cordectomy as a treatment option for posttraumatic and non-posttraumatic syringomyelia with tethered cord syndrome and myelopathy
Authors: Ewelt Christian , Stalder Susanne , Steiger Hans-Jakob , Hildebrandt Gerhard , Heilbronner Raoul
Published: February 2011

Object

Spinal cordectomy has recently become more important in the treatment of end-stage posttraumatic or postoperative syringomyelia and arachnopathy as a last resort to manage ascending neurological dysfunction, spasticity, and pain in paraplegic patients. The aim in this study was to confirm a clinical benefit in strict indications for cordectomy.

Methods

Between February 2000 and September 2007, 15 spinal cordectomies were performed at the Department of Neurosurgery, Cantonal Hospital, St. Gallen. Indications for treatment were end-stage myelopathies caused by syringomyelia, tethered cord syndrome, and arachnopathy with progressive spasticity and pain or progressive upper-level neurological deficits related to the tethered cord syndrome. All patients had severe motor and sensory deficits with no residual voluntary function below the affected level.

Results

Fourteen of 15 patients showed stabilization or even an improvement in motor and sensory function. Four patients suffered from progressive spasticity and 3 from deterioration due to pain. There were no other adverse surgical events.

Conclusions

Cordectomy can be a useful instrument to preserve functions of the upper extremities and to improve spasticity and pain in patients with severe myelopathy and tethered cord, syringomyelia, or arachnopathy of various etiologies.
Potentiation of neurite outgrowth and reduction of apoptosis by immunosuppressive agents: implications for neuronal injury and transplantation
Authors: Sheehan Jason , Eischeid Anne , Saunders Randi , Pouratian Nader
Published: February 2011

Object

Immunosuppressive agents are believed to play a role in recovery from spinal cord injury, but the underlying mechanisms by which neuronal function is improved by these agents are poorly understood. In this study, the authors evaluate the effect of immunosuppressive medications on neurite outgrowth and cell survival after a pharmacologically induced injury.

Methods

Differentiated human neuroblastoma SH-SY5Y cells were injured using the calcium agonist thapsigargin. After cellular injury, neurite outgrowth in the presence or absence of immunosuppressive agents was measured. Apoptosis was quantified with the aid of a terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling assay.

Neurite outgrowth was severely restricted following thapsigargin injury. Outgrowth was potentiated, however, by the addition of concentrations of 1 and 10 μM cyclosporin A in a dose-dependent fashion. Similarly, addition of 10 nM FK506 increased the percentage of neurites in the 20- to 40-micron range. A low dose (1 μM) of dexamethasone did not have a significant effect on neurite outgrowth, but a higher dose (10 μM) increased the percentage of neurites in the 10- to 45-micron range. These agents also lessened the degree of thapsigargin-induced apoptosis.

Conclusions

Immunosuppressive agents such as cyclosporin A, FK506, and dexamethasone can potentiate neurite outgrowth and protect against apoptotic cell death in a human postmitotic neuronal cell line. Such effects may have implications for lessening neuronal injury after neurotrauma, stroke, or neurodegeneration.
Unilateral intraputaminal glial cell line–derived neurotrophic factor in patients with Parkinson disease: response to 1 year each of treatment and withdrawal
Authors: Slevin John T. , Gash Don M. , Smith Charles D. , Gerhardt Greg A. , Kryscio Richard , Chebrolu Himachandra , Walton Ashley , Wagner Renee , Young A. Byron
Published: February 2011

Object

Glial cell line–derived neurotrophic factor (GDNF) infused unilaterally into the putamen for 6 months was previously shown to improve motor functions and quality of life measures significantly in 10 patients with Parkinson disease (PD) in a Phase I trial. In this study the authors report the safety and efficacy of continuous treatment for 1 year or more. After the trial was halted by the sponsor, the patients were monitored for an additional year to evaluate the effects of drug withdrawal.

Methods

During the extended study, patients received unilateral intraputaminal infusion of 30 μg/day GDNF at a basal infusion rate supplemented with pulsed boluses every 6 hours at a convection-enhanced delivery rate to increase tissue penetration of the protein. When the study was stopped, the delivery system was reprogrammed to deliver sterile saline at the basal infusion rate of 2 μl/hour.

The Unified PD Rating Scale (UPDRS) total scores after 1 year of therapy were improved by 42 and 38%, respectively, in the “off” and “on” states. Motor UPDRS scores were also improved: 45 and 39% in the off and on conditions, respectively. Benefits from treatment were lost by 9 to 12 months after GDNF infusion was halted. At that time, the patients had returned to their baseline UPDRS scores and required higher levels of conventional antiparkinsonian drugs to treat symptoms. After 11 months of treatment, the delivery system had to be removed in one patient because of the risk of infection. In seven patients antibodies to GDNF developed, with no evidence of clinical sequelae. There was also no evidence of GDNF-induced cerebellar toxicity, as evaluated using magnetic resonance imaging analysis and clinical testing.

Conclusions

Unilateral administration of GDNF results in significant, sustained bilateral benefits. These improvements are lost within 9 months after drug withdrawal. Safety concerns with GDNF therapy can be closely monitored and managed.
Platform technologies to support brain–computer interfaces
Authors: Sclabassi Robert J. , Liu Qiang , Hackworth Steven A. , Justin Gusphyl A. , Sun Mingui
Published: February 2011

✓There is a lack of adequate and cost-effective treatment options for many neurodegenerative diseases. The number of affected patients is in the millions, and this number will only increase as the population ages. The developing areas of neuromimetics and stimulative implants provide hope for treatment, as evidenced by the currently available, but limited, implants. New technologies are emerging that are leading to the development of highly intelligent, implantable sensors, activators, and mobile robots that will provide in vivo diagnosis, therapeutic interventions, and functional replacement. Two key platform technologies that are required to facilitate the development of these neuromimetic and stimulative implants are data communication channels and the devices' power supplies. In the research reported in this paper, investigators have examined the use of novel concepts that address these two needs. These concepts are based on ionic volume conduction (VC) to provide a natural communication channel to support the functioning of these devices, and on biofuel cells to provide a continuously rechargeable power supply that obtains electrons from the natural metabolic pathways. The fundamental principles of the VC communication channels, including novel antenna design, are demonstrated. These principles include the basic mechanisms, device sensitivity, bidirectionality of communication, and signal recovery. The demonstrations are conducted using mathematical and finite element analysis, physical experiments, and animal experiments. The fundamental concepts of the biofuel cells are presented, and three versions of the cells that have been studied are discussed, including bacteria-based cells and two white cell–based experiments. In this paper the authors summarize the proof or principal experiments for both a biomimetic data channel communication method and a biofuel cell approach, which promise to provide innovative platform technologies to support complex devices that will be ready for implantation in the human nervous system in the next decade.
Limits of brain–computer interface
Authors: Bakay Roy A. E.
Published: February 2011

✓Most patients who are candidates for brain–computer interface studies have an injury to their central nervous system and therefore may not be ideal for rigorous testing of the full abilities and limits of the interface. This is a report on a quadriplegic patient who appeared to be a reasonable candidate for intracranial implantation of neurotrophic electrodes. He had significant cortical atrophy in both the motor and parietal cortical areas but was able to generate signal changes on functional magnetic resonance images by thinking about hand movements. Only a few low-amplitude action potentials were obtained, however, and he was unable to achieve single-unit control. Despite this failure, the use of field potentials offered an alternative method of control and allowed him some limited computer interactions. There are clearly limits to what can be achieved with brain–computer interfaces, and the presence of cortical atrophy should serve as a warning for future investigators that less invasive techniques may be a more prudent approach for this type of patient.
A technique for minimally altering anatomically based subthalamic electrode targeting by microelectrode recording
Authors: Senatus Patrick B. , Teeple David , McClelland Shearwood , Pullman Seth L. , Yu Qiping , Ford Blair , McKhann Guy M. , Goodman Robert R.
Published: February 2011

Object

Implantation of a subthalamic nucleus (STN) deep brain stimulation (DBS) electrode is increasingly recognized as an effective treatment for advanced Parkinson disease (PD). Despite widespread use of microelectrode recording (MER) to delineate the boundaries of the STN prior to stimulator implantation, it remains unclear to what extent MER improves the clinical efficacy of this procedure. In this report, the authors analyze a series of patients who were treated at one surgical center to determine to what degree final electrode placement was altered, based on readings obtained with MER, from the calculated anatomical target.

Methods

Subthalamic DBS devices were placed bilaterally in nine patients with advanced PD. Frame-based volumetric magnetic resonance images were acquired and then transferred to a stereotactic workstation to determine the anterior and posterior commissure coordinates and plane. The initial anatomical target was 4 mm anterior, 4 mm deep, and 12 mm lateral to the midcommissural point. The MERs defined the STN boundaries along one or more parallel tracks, refining the final electrode placement by comparison of results with illustrations in a stereotactic atlas.

In eight of 18 electrodes, the MER results did not prompt an alteration in the anatomically derived target. In another eight placements, MER altered the target by less than 1 mm and two of 18 electrode positions differed by less than 2 mm. The anterior–posterior difference was 0.53 ± 0.65 mm, whereas the medial–lateral direction differed by 0.25 ± 0.43 mm. The ventral boundary of the STN defined by MER was 2 ± 0.72 mm below the calculated target (all values are the means ± standard deviation). All patients attained clinical improvement, similar to previous reports.

Conclusions

In this series of patients, microelectrode mapping of the STN altered the anatomically based target only slightly. Because it is not clear whether such minor adjustments improve clinical efficacy, a prospective clinical comparison of MER-refined and anatomical targeting may be warranted.
Stereotactic radiosurgery for glioblastoma: a final report of 31 patients
Authors: Masciopinto Jeffery E. , Levin Allan B. , Mehta Minesh P. , Rhode Blair S.
Published: February 2011

✓ From February 1989 to December 1992, 31 patients who presented with an initial pathological diagnosis of glioblastoma multiforme underwent tumor debulking or biopsy, stereotactic radiosurgery, and standard radiation therapy as part of their primary treatment. Presenting characteristics in the 22 men and nine women included a median age of 57 years, Karnofsky Performance Scale score median of 80, and median tumor volume of 16.4 cm3.

Stereotactic radiosurgery delivered a central dose of 15 to 35 Gy with the isocenter location, collimator size, and beam paths individualized by means of three-dimensional software developed at the University of Wisconsin. The peripheral isodose line varied from 40% to 90% with a median of 72.5% and a mode of 80%. The mean follow-up period was 12.84 months with a median of 9.5 months. Statistical analysis was performed using Kaplan—Meier analysis and log-rank comparison of risk factor groups.

The parameters of age, initial Karnofsky Performance Scale score, and biopsy were significantly different in patient survival from debulking; but no difference was noted between single and multiple isocenters and patterns of steroid requirement. Radiographic recurrences were divided by location into the following categories: central (within central stereotactic radiosurgery dose), 0; peripheral (within 2 cm of central dose), 19; and distant (> 2 cm), 4. There is no evidence of recurrence in five surviving patients. Actuarial 12-month survival was 37%, with a median survival of 9.5 months. These values are similar to previous results for surgery and standard radiotherapy alone.22 The results suggest that the curative value of radiosurgery is significantly limited by peripheral recurrences.
Treatment of occipital neuralgia by partial posterior rhizotomy at C1–3
Authors: Dubuisson David
Published: February 2011

✓ To minimize the sensory loss associated with intradural posterior rhizotomy for medically refractory occipital neuralgia, partial sectioning of the upper cervical posterior rootlets was performed in 11 patients. The ventrolateral aspect of each posterior rootlet from C-1 to the upper portion of C-3 was divided at the root entry zone. In three patients with bilateral neuralgia, the procedure was performed on both sides, for a total of 14 partial rhizotomy procedures in the 11 patients. This resulted in satisfactory preservation of scalp sensation in all cases. Pain within the territory of the greater occipital nerve was consistently reduced or abolished by this procedure. The overall degree of pain relief was rated good or excellent after 10 of the 14 procedures. The other four procedures alleviated pain in the territory of the greater occipital nerve, but the results were marred by persistent periorbital or temporal pain. Two patients subsequently underwent complete C1–3 posterior rhizotomy without further improvement. Although partial posterior rhizotomy at C1–3 did not always relieve pain in the periorbital and temporal regions, this procedure did provide consistent long-term relief of severe occipital pain with minimal risk of postoperative vertigo, scalp anesthesia, or deafferentation syndrome.