bluuebunny/crossref_metadata_2025 huggingface dataset:
Whither neurosurgery?
Authors: Alberstone Cary D. , Benzel Edward C. , Garcia Deborah
Published: January 2008

Although trends in the marketplace demand for neurosurgeons should be of interest to neurosurgeons and prospective neurosurgeons, little data are available that accurately document these trends. A recent report published in the general medical journal Journal of the American Medical Association (JAMA) used the Conference Board help-wanted index to evaluate trends in physician marketplace demand. The authors of the JAMA study concluded that over the past 5 years there has been a significant fall in demand for specialist physicians. Because the discipline of neurosurgery was not included in the JAMA study, the authors of the present report attempt to evaluate the trend in the marketplace demand for neurosurgeons, using the same methodology of the JAMA study. The authors' data suggest that the conclusion of the JAMA study of steep declines in the demand for specialist physicians does not accurately reflect the job market for neurosurgeons, which in fact appears to be relatively stable. The present study attempts to document the stability of the neurosurgery market and outline the steps necessary to protect this market from existing threats.
The Current Procedural Terminology and the Medicare Resource Based Relative Value Scale in neurosurgical practice
Authors: Roski Richard A.
Published: January 2008

Changes in healthcare have made it increasingly more important for neurosurgeons to understand the economic pressures that effect their reimbursement. Two fundamental concepts that are of the greatest importance are the Current Procedural Terminology coding and the Medicare Resource Based Relative Value Scale. The impact of these two entities on neurosurgical reimbursement in analyzed in this review.
Clinical practice guidelines and their role in quality of care assessments
Authors: Gerszten Peter C.
Published: January 2008

Clinical practice guidelines may be defined as systematically developed statements to assist practitioner and patient decisions about appropriate healthcare for specific clinical conditions. The practice guideline is a management plan that enables healthcare providers to make sequential decisions about testing or therapy in a given clinical situation. Given the heterogeneity of disease presentations and the complexity of making therapeutic decisions, the development of guidelines in neurosurgery presents unique problems and challenges. Clinical practice guidelines were developed in part as a method for the assessment of quality of medical care processes. Practice guidelines serve as a tool for comparisons to be made within and between healthcare delivery systems. The implementation of guidelines also allows for the acquisition of clinical and financial data that provide for outcomes analysis and other types of information. The characterization of patterns of care in different institutions and the relationship between patterns of care and outcomes will in the future allow for quality improvement, enable physicians to offer predictability and accountability to third-party interests, and contribute to an understanding of how to offer the best care to neurosurgical patients.

The author provides an overview of clinical practice guidelines and illustrates their role in the assessment of quality of patient care, demonstrates how they fit into the methodology of quality assessments, and underscores the importances of practice quidelines for the development of disease management systems.
The influence of secondary gain on surgical outcome: a comparison between cervical and lumbar discectomy
Authors: Kaptain George J. , Shaffrey Christopher I. , Alden Tord D. , Young Jacob N. , Whitehill Richard
Published: January 2008

Although the expectation of monetary compensation has been associated with failures in lumbar discectomy, the issue has not been investigated in patients undergoing cervical disc surgery. The authors analyzed the relationship between economic forms of secondary gain and surgical outcome in a group of patients with a common pay scale, retirement plan, and disability program.

All procedures were performed at the Portsmouth Naval Medical Center between 1993 and 1995; active-duty military servicepersons treated for cervical radiculopathy were prospectively included. Clinical, demographic, and financial factors were analyzed to determine which were predictive of outcome. Financial data were used to create a compensation incentive, which is proportional to the patient's rank, years of service, potential disability, retirement eligibility, and base pay and reflects the monetary incentive of disability. The results of cervical surgery were compared to a previously reported companion population of patients treated for lumbar disc disease. A good outcome was defined as a return to active duty, whereas a referral for disability was considered a poor surgical result. A 100% follow-up rate was obtained for 269 patients who underwent 307 cervical operations. Only 16% (43 of 269) of patients who underwent cervical operation received disability, whereas 24.7% (86 of 348) of patients who underwent lumbar discectomy obtained a poor result (p = 0.0082). Although economic forms of secondary gain were not associated with a poor outcome in cervical disease, both the rank (p = 0.002) and duration (p = 0.03) of an individual's military career were significant factors (p = 0.02). Of the medical variables tested, multilevel surgery (p = 0.03) and revision operations at the same level (p = 0.03) were associated with referral for medical discharge.

Secondary gain in the form of economic compensation influences outcome in lumbar but not cervical disc surgery patients; the increased rate of disability referral in patients who underwent lumbar discectomy may reflect an expectation of economic compensation. Social factors that are independent of the anticipation of economic compensation seem to influence the outcome in cervical disc surgery patients.
Outcomes after gamma knife radiosurgery in solitary acoustic tumors and neurofibromatosis Type 2
Authors: Kondziolka Douglas , Subach Brian R. , Lunsford L. Dade , Bissonette David J. , Flickinger John C.
Published: January 2008

Surgeons perform stereotactic radiosurgery as the main alternative to acoustic tumor (vestibular schwannoma) resection. The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. Longer-term outcomes are not well documented for patients with solitary tumors or those with neurofibromatosis Type 2 (NF2).

To define outcomes, the authors evaluated 462 consecutive patients with solitary acoustic tumors and 40 patients with NF2 (total of 45 tumors treated) who underwent radiosurgery between 1987 and 1998.

Serial imaging studies, clinical evaluations, and a patient survey were performed. The average tumor margin dose was 15 Gy, and the mean transverse tumor diameter was 22 mm. In patients with solitary tumors, prior resection had been performed in 111 patients (24%); 27 patients experienced tumor recurrence after a “total resection.”

The clinical tumor control rate (no resection required) was 98%. In non-NF2 patients followed for at least 5 years, 100 tumors (61.7%) were smaller, 53 (32.7%) remained unchanged in size, and nine (5.6%) were slightly larger. Resection was performed in four patients (2.4%). Neurological deficits after radiosurgery all occurred within the first 28 months. The rates of facial and trigeminal neuropathy varied with radiosurgery technique. In patients with NF2, 16 tumors were smaller, 28 remained unchanged, and one enlarged (overall 98% control rate at median 3-year follow up). Resection was performed in three patients (7%). Useful hearing was preserved in six (43%) of 14 NF2 patients who had useful hearing before radiosurgery.

Radiosurgery provided long-term tumor control associated with high rates of neurological function preservation. No further tumor surgery was necessary in 98% of patients with solitary tumors followed for a minimum of 5 years.
Combining endovascular and neurosurgical treatments of high-risk dural arteriovenous fistulas in the lateral sinus and the confluence of the sinuses
Authors: Goto Katsuya , Sidipratomo Prijo , Ogata Noboru , Inoue Toru , Matsuno Haruo
Published: January 2008

The authors describe their experience in treating dural arteriovenous fistulas (DAVFs) in the lateral sinus and the confluence of sinuses in 17 patients who presented with signs and symptoms related to intracranial hemorrhage, infarction, and diffuse brain swelling. Angiographic examination revealed three different types of DAVFs in these high-risk patients: 1) extremely high flow DAVF not associated with sinus occlusion or leptomeningeal retrograde venous drainage (LRVD); 2) localized DAVF with exclusive LRVD and without sinus occlusion; and 3) diffuse DAVF with sinus occlusion and LRVD. Because of the complex nature of these lesions, the authors adopted a staged protocol in which they combined endovascular and surgical treatments.

The authors believe that by close collaboration between endovascular therapists and vascular neurosurgeons, high-risk DAVFs in the lateral sinus and the confluence of sinuses can be successfully treated without treatment-related morbidity and mortality.
Percutaneous transluminal angioplasty of intracranial artery stenosis: clinical results in 24 patients
Authors: Berg-Dammer Elisabeth , Henkes Hans , Weber Werner , Berlit Peter , Kühne Dietmar
Published: January 2008

Circumscribed stenotic lesions of the intracranial arteries can cause cerebral ischemia by hemodynamic and/or thromboembolic mechanisms. Anticoagulation therapy, antiplatelet therapy, and bypass surgery are treatment strategies that have no direct impact on the underlying lesion. This study summarizes the experience of a single institution at which percutaneous transluminal angioplasty (PTA) of intracranial atherosclerotic stenoses was performed.

The authors performed a retrospective analysis of 24 consecutive patients. Their medical histories (cardiovascular risk factors, current clinical signs and symptoms and their duration, previous stroke[s], and medical treatment) were evaluated together with findings from previous imaging studies. The site and degree of the stenoses to be treated (target lesion) were identified with the use of ultrasound and angiography studies. Additional vascular stenoses were noted. Percutaneous transluminal angioplasty was performed using single-lumen balloon microcatheters with appropriate diameters. The results of PTA were correlated with angiographic and ultrasound findings and the clinical outcome.

Significant cardiovascular risk factors and clinical signs and symptoms related to the target lesion that persisted despite medical treatment were identified in all patients except one. The duration of symptoms varied from several days to 8 months. Previous stroke had occurred in four patients. The degree of stenosis was classified as “high grade” in 10 patients and as “subtotal” in 14. The target lesion (stenosis) was located in the anterior circulation in eight patients (four in the internal carotid and four in the middle cerebral arteries). Stenoses of posterior circulation vessels were treated in 16 patients (nine vertebral, six basilar, and one posterior cerebral arteries). Recanalization was rated “complete” in 15 patients and sufficient in six patients. In three patients residual stenosis remained. Complications were encountered in seven patients: two asymptomatic dissections, one transient vessel occlusion, one vessel occlusion with subsequent stroke, and three ischemic lesions likely due to thromboembolism, two of which caused only transient neurological symptoms.

Percutaneous balloon dilation proved effective in the treatment of intracranial atherosclerotic stenosis. There are, however, potential complications and experience with this procedure is only limited. Long-term results need to be determined. The authors conclude from their preliminary results that PTA may be an alternative to bypass surgery and conservative management and may be considered for patients in whom ischemic neurological symptoms persist despite medical treatment.
Carotid angioplasty and stenting for recurrent and radiation-induced stenosis: preliminary experience
Authors: Benitez Ronald P. , Armonda Rocco A. , Harrop James , Thomas Jeffrey E. , Rosenwasser Robert H.
Published: January 2008

Carotid endarterectomy for atherosclerotic occlusive disease has become the standard of care for the treatment of symptomatic and asymptomatic occlusive disease of the carotid bifurcation, based on the results of the North American Symptomatic Carotid Endarterectomy Trial, as well as the Asymptomatic Carotid Atherosclerosis Study. For surgical treatment to be of benefit, the perioperative complication rate for neurological events should be 6% or less in the symptomatic population and 3% or less in the asymptomatic group. The performance of carotid endarterectomy for recurrent stenosis and radiation-induced stenosis has reported neurological events ranging from 4 to 10%. It is in this particular population that carotid angioplasty and stent placement may play a role.

The authors performed a retrospective analysis of 11 patients who underwent carotid angioplasty and stent placement for recurrent or radiation-induced stenosis. One patient in whom endarterectomy was performed by the vascular surgery service had a critical stenosis distal to the endarterectomy site and awoke with a neurological deficit. This patient underwent reexploration and placement of a stent in the artery distal to the arteriotomy site.

The follow-up period ranged from 7 to 12 months. Patient age ranged from 65 to 77 years (mean 75 years). Five of eight patients underwent angioplasty and stent placement for recurrent atherosclerotic disease. Two patients had radiation-induced stenosis, and one patient had a stent placed intraoperatively. All patients, with the exception of the one who underwent intraoperative stent placement, had posttreatment stenoses of less than 15%. The surgical patient had a 30% residual stenosis distally. There were no intra- or postoperative transient ischemic attacks, major or minor strokes, or deaths.

Patients who have recurrent or radiation-induced stenosis are potential candidates for angioplasty and stent placement. Before this can be recommended as an alternative to surgical correction, a longer follow-up period is required.
Endovascular embolization of 150 basilar tip aneurysms with Guglielmi detachable coils: results of the Food and Drug Administration multicenter clinical trial
Authors: Eskridge Joseph M. , Song Joon K. , _ _
Published: January 2008

To assess the safety and efficacy of aneurysm embolization performed using Guglielmi detachable coils (GDCs), the authors reviewed the results of a cohort of 150 patients with either ruptured (83 patients) or unruptured (67 patients) basilar tip aneurysms treated with these detachable platinum coil devices in the early part of the United States multicenter GDC clinical trial that led to Food and Drug Administration approval for the device.

The most common presentation in this cohort of patients was headache (53%). All patients were entered into the trial after neurosurgical assessment excluded them as candidates for surgical clipping of their aneurysms. Greater than 90% coil packing was achieved in 75% of the patients. For those patients in whom follow-up information was available, the mean angiographic and clinical evaluation follow-up time for 61 patients with ruptured aneurysms was 13.7 months (range 0-43 months) and that for the 49 patients with unruptured aneurysms was 9.8 (range 0-40 months). Conservative mortality rates included up to 23% for the ruptured aneurysm group and up to 12% for the unruptured aneurysm group; the rebleeding rate for treated ruptured aneurysms was up to 3.3% and the bleeding rate for unruptured aneurysms up to 4.1%. Permanent deficits due to stroke in patients with ruptured or unruptured aneurysms occurred in up to 5% and 9%, respectively. Vasospasm occurred in 8% of the patients; it was associated with two deaths. Periprocedural mortality was 2.7% (four patients with ruptured aneurysms).

Detachable platinum coil embolization is a promising treatment for ruptured basilar tip aneurysms that are not surgically clippable; in selected patients it offers lower incidences of morbidity and mortality compared with conservative medical management. The role of this procedure in unruptured basilar tip aneurysms is unclear with less supportive results. More long-term follow-up evaluation is necessary and results are expected to improve.
Intravascular stents for intracranial internal carotid and vertebral artery aneurysms: preliminary clinical experience
Authors: Lanzino Giuseppe , Wakhloo Ajay K. , Fessler Richard D. , Mericle Robert A. , Guterman Lee R. , Hopkins L. Nelson
Published: January 2008

Results of previous in vitro and in vivo experimental studies have suggested that the placement of a porous stent within the parent artery across the aneurysm neck may hemodynamically uncouple the aneurysm from the parent vessel, leading to thrombosis of the aneurysm. For complex wide-necked aneurysms, a stent may also aid the packing of the aneurysm with Guglielmi detachable coils (GDCs) by acting as a rigid scaffold that prevents coil herniation into the parent vessel. Recently, improved stent system delivery technology has allowed access to the tortuous vascular segments of the intracranial system. The authors report here the intracranial stenting of aneurysms involving different segments of the internal carotid artery (ICA) and the vertebral artery (VA).

Four patients with intracranial aneurysms located at the petrous, cavernous, and paraclinoid segments of the ICA and at the VA proximal to the origin of the posterior inferior cerebellar artery, respectively, were treated since January 1998. In three of these patients, stent placement across the aneurysm neck was followed by GDC placement, accomplished via a microcatheter through stent mesh. In one patient, the aneurysm was treated solely by stenting.

No periprocedural complications were observed, and at follow up, no patient was found to have suffered symptoms referable to aneurysm growth or thromboembolic complications. More than 90% occlusion of the aneurysm was achieved in the three cases treated by stenting and GDC placement. One of these patients underwent 6-month follow-up angiography that did not reveal any in-stent stenosis. In the case treated solely by stent placement, no evidence of aneurysm thrombosis was observed either immediately postprocedure or on follow-up angiography performed 24 hours later.

A new generation of flexible stents can be used to treat intracranial aneurysms in difficult-to-access areas such as the proximal intracranial segments of the ICA or the VA. The stent allows tight coil packing even in the presence of a wide-necked, irregularly shaped aneurysm and may provide an endoluminal matrix for endothelial growth. Although convincing experimental evidence suggests that stent placement across the aneurysm neck may by itself promote intraluminal thrombosis, the role of this phenomenon in clinical practice may be limited at present by the high porosity of currently available stents.
Safety and efficacy of transluminal balloon angioplasty in the prevention of vasospasm in patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study
Authors: Muizelaar J. Paul , Zwienenberg Marike , Mini Nancy A. , Hecht Stephen T.
Published: January 2008

Recent advances in neuroradiology have made it possible to dilate human cerebral arteries that show vasospasm following aneurysmal subarachnoid hemorrhage (SAH), but the time window is short and the success rate for reversal of delayed ischemic neurological deficit (DIND) varies between 31% and 77%. In a canine model of vasospasm, transluminal balloon angioplasty (TBA) performed on Day 0 (the day of aneurysm rupture) has been shown to completely prevent the development of angiographically demonstrated narrowing by Day 7; this effect is better than any pharmacological treatment for vasospasm thus far described.

The authors conducted a pilot trial to assess the safety and efficacy of TBA performed within 3 days post-SAH. Twelve patients with a very high probability of developing vasospasm (Fisher Grade 3) were included. Target vessels for prophylactic TBA were the internal carotid artery, A1 segment, M1 segment, and P1 segment bilaterally, the basilar artery, and the vertebral artery.

No patient developed DIND or more than mild vasospasm, according to transcranial Doppler criteria. At 3 months, seven patients made a good recovery, two patients were moderately disabled, and three patients died; one patient died because of a vessel rupture during TBA and two older patients died of medical complications associated with an already poor clinical condition at admission.

Compared with the results of large series reported in literature of patients with aneurysmal SAH, the results of this pilot study indicate an extremely low incidence of vasospasm and DIND after patients underwent prophylactic TBA. A larger, randomized study, however, is required to determine whether prophylactic TBA is efficacious enough to justify the risks.
Microvascular decompression of cranial nerves: lessons learned after 4400 operations
Authors: McLaughlin Mark R. , Jannetta Peter J. , Clyde Brent L. , Subach Brian R. , Comey Christopher H. , Resnick Daniel K.
Published: January 2008

Object

Microvascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and other cranial nerve rhizopathies. The senior author (P.J.J.) began performing this procedure in 1969 and has performed more than 4400 operations. The purpose of this article is to review some of the nuances of the technical aspects of this procedure.

Methods

A review of 4415 operations shows that numerous modifications to the technique of microvascular decompression have occurred during the last 29 years. Of the 2420 operations performed for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia before 1990, cerebellar injury occurred in 21 cases (0.87%), hearing loss in 48 (1.98%), and cerebrospinal fluid (CSF) leakage in 59 cases (2.44%). Of the 1995 operations performed since 1990, cerebellar injuries declined to nine cases (0.45%), hearing loss to 16 (0.8%), and CSF leakage to 37 (1.85%) (p < 0.01, test for equality of distributions). The authors describe slight variations made to maximize surgical exposure and minimize potential complications in each of the six principal steps of this operation. These modifications have led to decreasing complication rates in recent years.

Conclusions

Using the techniques described in this report, microvascular decompression is an extremely safe and effective treatment for many cranial nerve rhizopathies.
Moyamoya syndrome associated with cocaine abuse
Authors: Schwartz Marc S. , Scott R. Michael
Published: January 2008

The authors report the case of a 30-year-old woman who was a long-term intranasal cocaine abuser and who presented with transient ischemic attacks and multiple cerebral infarctions that were associated with moyamoya syndrome. The authors suggest that, because of its sympathomimetic effects, chronic cocaine use may promote intracranial arterial stenosis, distal ischemia, and subsequent formation of moyamoya-like vessels. The patient has remained clinically stable with no new episodes of stroke 6 years after undergoing “pial synangiosis” (modified encephaloduroarteriosynangiosis) to revascularize both hemispheres. Cocaine abuse may lead to moyamoya syndrome and may represent a chronic effect on the cerebral vasculature.
Magnetoencephalographic mapping of the language-specific cortex
Authors: Papanicolaou Andrew C. , Simos Panagiotis G. , Breier Joshua I. , Zouridakis George , Willmore L. James , Wheless James W. , Constantinou Jules E. C. , Maggio William W. , Gormley William B.
Published: January 2008

Object

In this paper the authors introduce a novel use of magnetoencephalography (MEG) for noninvasive mapping of language-specific cortex in individual patients and in healthy volunteers.

Methods

The authors describe a series of six experiments in which normative MEG data were collected and the reliability, validity, and topographical accuracy of the data were assessed in patients who had also undergone the Wada procedure or language mapping through intraoperative cortical stimulation.

Conclusions

Findings include: 1) receptive language-specific areas can be reliably activated by simple language tasks and this activation can be readily recorded in short MEG sessions; 2) MEG-derived maps of each individual are reliable because they remain stable over time and are independent of whether auditory or visual stimuli are used to activate the brain; and 3) these maps are also valid because they concur with results of the Wada procedure in assessing hemispheric dominance for language and with the results of cortical stimulation in identifying the precise topography of receptive language regions within the dominant hemisphere.

Although the MEG mapping technique should be further refined, it has been shown to be efficacious by correctly identifying the language-dominant hemisphere and specific language-related regions within this hemisphere. Further development of the technique may render it a valuable adjunct for routine presurgical planning in many patients who harbor tumors or have epilepsy.
Moyamoya disease in the midwestern United States
Authors: Wetjen Nicholas M. , Garell P. Charles , Stence Nicholas V. , Loftus Christopher M.
Published: January 2008

There have been few investigations of moyamoya disease in the United States and no systematic description of the management practices or outcome from this population. The authors reviewed their experience with this disease to gain a better understanding and improve the treatment of patients with moyamoya disease in the United States. Over a 25-year period 30 patients with moyamoya disease have been treated at the University of Iowa. The cases were divided into patients who had classic, probable, and akin moyamoya disease.

Results indicated that there was a bimodal age distribution and a female predominance of cases. In estimating the referral pattern of our institution, the authors determined that there were greater numbers of epidemiological characteristics than previously anticipated. Patients were treated either surgically or nonsurgically, and different management strategies were utilized in each of the major groups: superficial temporal artery to middle cerebral artery anastomosis and encephalodurosynangiosis in the surgical group; or antiplatelet, anticoagulation, or nonpharmacological intervention in the nonsurgical group.

The authors conclude that there is a higher prevalence and incidence of moyamoya disease in the United States than previously reported and that there are some clinical characteristics of this disease that differ from the cases reported in southeast Asia. These differences may be due to genetic or environmental factors but can also be partly explained by the lower index of suspicion for this disease and, thus, a delay in or complete absence of the correct diagnosis.
Surgical decompression for traumatic brain swelling: indications and results
Authors: Guerra Waltraud Kleist-Welch , Gaab Michael R. , Dietz Hermann , Mueller Jan-Uwe , Piek Jürgen , Fritsch Michael J.
Published: January 2008

Object

Decompressive craniectomy has been performed since 1977 in 57 patients with traumatic brain injury. The authors assess the efficacy of this treatment and the indications for its use.

Methods

The clinical status of the patients, their computerized tomography (CT) scans, and intracranial pressure (ICP) levels were documented prospectively in a standard protocol. At the beginning of the study, all patients older than 30 years were excluded. As of 1989 patients older than 40 years were excluded until 1991; since that time patients older than 50 years have been excluded. Primary brain or brainstem injury with fully developed bulbar brain syndrome, loss of auditory evoked potentials (AEPs), and/or oscillation flow in a transcranial Doppler ultrasound examination were contraindications to decompressive craniectomy. A positive indication for decompression was given in the case of progressive therapy-resistant intracranial hypertension in correlation with clinical (Glasgow Coma Scale [GCS] score, decerebrate posturing, dilating of pupils) and electrophysiological (electroencephalography, somatosensory evoked potentials, and AEPs) parameters and with findings on CT scans. Unilateral decompressive craniectomy was performed in 31 patients and bilateral craniectomy in 26 patients. In all cases, a wide frontotemporoparietal craniectomy was followed by a dura enlargement covered with temporal muscle fascia.

The outcomes of the treatment were surprisingly good. Only 11 patients (19%) died, three of whom died of acute respiratory disease syndrome. Five patients (9%) survived, but remained in a persistent vegetative state; six patients (11%) survived with a severe permanent neurological deficit, and 33 patients (58%) attained social rehabilitation. Two patients (3.5%) did not have a follow-up examination. The GCS score on the 1st day posttrauma and the mean ICP turned out to be the best predictors for a good prognosis. The results demonstrate the importance of decompressive craniectomy in the treatment of traumatic brain swelling.

Conclusions

Surgical decompression should be routinely performed when indicated before irreversible ischemic brain damage.
Carotid endarterectomy compared with angioplasty and stenting: the status of the debate
Authors: Albuquerque Felipe C. , Teitelbaum George P. , Larsen Donald W. , Giannotta Steven L.
Published: January 2008

Endarterectomy is the treatment of choice for patients with symptomatic stenosis of the internal carotid artery. Recently, debate has arisen over the potential benefits of endovascular techniques. Although retrospective analyses of angioplasty and stenting procedures suggest comparable clinical efficacy to endarterectomy, prospective evaluation is pending. The authors review the status of the debate and discuss those issues on both sides that are particularly contentious and clinically relevant.
Surgical treatment for acute spinal cord injury study pilot study #2: evaluation of protocol for decompressive surgery within 8 hours of injury
Authors: Ng Wai Pui , Fehlings Michael G. , Cuddy Brian , Dickman Curtis , Fazl Mahmood , Green Barth , Hitchon Patrick , Northrup Bruce , Sonntag Volker , Wagner Frank , Tator Charles H.
Published: January 2008

Acute spinal cord injury (SCI) is a major public health problem for which there is still only limited treatment available. The National Acute Spinal Cord Injury Study-2 (NASCIS-2) and -3 clinical trials demonstrated that the use of acute pharmacotherapy with methylprednisolone can attenuate the secondary injury cascade if administered within 8 hours of acute SCI. However, no trial has been performed to examine whether acute surgical decompressive procedures within this critical 8-hour time window can improve patients' neurological outcome. The purpose of the current prospective Surgical Treatment for Acute Spinal Cord Injury Study (STASCIS) pilot study was to determine the feasibility of obtaining a radiological diagnosis of spinal canal compromise of 25% or more and to perform spinal cord (C3-T1) decompressive procedures by 8 hours postinjury. One of the following three decompressive methods was used: 1) traction alone; 2) traction and surgery; or 3) surgery alone. Twenty-six patients from eight North American centers were entered into the study between 1996 and 1997. Significant difficulties were encountered in many centers in performing immediate magnetic resonance imaging examination in patients with acute SCI. Fewer than 10% of acute cervical SCI patients could be enrolled into this protocol mainly because the combination of the required time for rescue, resuscitation, transport, imaging study, and surgical preparation exceeded the 8-hour injury-to-decompressive surgery window. Eleven patients underwent decompressive procedures initially by being placed in traction at a mean time of 10.9 hours postinjury. Those patients not undergoing this procedure underwent decompressive surgery at a mean time of 40.1 hours. However, the surgical decompressive procedure was completed within 12 hours in seven patients. As a result of these findings, several major changes have been made to the STASCIS protocol for early decompressive therapy.
The fate of the compressed deformed spinal cord after decompressive surgery: MR imaging and histopathological findings in experimental studies
Authors: Tanaka Hisato , Nagata Kensei , Inoue Akio , Yoshizuka Mitsuaki
Published: January 2008

The authors conducted a study in which they applied the spinal cord compression-decompression model in rabbits to investigate the morphological changes and histopathological findings in the deformed spinal cord over a long-term period after performing decompressive surgery.

Throughout the experimental period, mangnetic resonance (MR) images were obtained frequently; after obtaining a final MR image, the spinal cord was dissected and underwent histological examination.

Immediately after decompressive surgery, axial T1-wieighted MR imaging revealed an increase in the cross-sectional area of the spinal cord during the 1st and 2nd weeks. The spinal cord area achieved a peak at an average of 5.9 weeks after decompressive surgery, when it displayed isointensity on T1- and high-intensity on T2-weighted images. The main histological findings were spongy changes in the white matter, which persisted for 4 months postsurgery. There was a significant correlation between the presurgical spinal cord area and the postsurgical decreased number of motor neuron cells.

Based on the MR imaging and histopathological studies, although the deformed spinal cord that underwent compression for 3 months was immediately restored morphologically after decompressive surgery, the change in quality in the spinal cord persisted at least 4 months.
Neural network analysis of preoperative variables and outcome in epilepsy surgery
Authors: Arle Jeffrey E. , Perrine Kenneth , Devinsky Orrin , Doyle Werner K.
Published: January 2008

Because appropriate patient selection is essential for achieving successful outcomes after epilepsy surgery, the need for more robust methods of predicting postoperative seizure control has been created. Standard multivariate techniques have been only 75 to 80% accurate in this regard. Recent use of artificial intelligence techniques, including neural networks, for analyzing multivariate clinical data, has been successful in predicting medical outcome. The authors applied neural network techniques to 80 consecutive patients undergoing epilepsy surgery in whom demographic, seizure, operative, and clinical variables to predict postoperative seizures data were obtained.

Neural networks were able to predict postoperative seizures in up to 98% of cases. Student's t tests or chi-square analysis performed on individual variables revealed that only the preoperative medication index was significantly different (p = 0.02) between the two outcome groups. Six different combinations of input variables were used to train the networks. Neural network accuracies differed in their ability to predict seizures using all data (96%); all data minus electroencephalography concordance and operative side (93%); all data except intra- or postoperative variables such as tissue pathology (98%); all data excluding pathology, intelligence quotient (IQ) data, and Wada results (84%); only using demographics and tissue pathology (65%); and only using IQ data (63%).

Analysis of the results reveals that several networks that are trained with the usual accepted variables characterizing the typical evaluation of epilepsy patients can predict postoperative seizures with greater than 95% accuracy.
Comparative localization of auditory comprehension using functional magnetic resonance imaging and cortical stimulation
Authors: Schlosser Michael J. , Luby Marie , Spencer Dennis D. , Awad Issam A. , McCarthy Gregory
Published: January 2008

The authors have previously described a functional magnetic resonance (fMR) imaging procedure for the localization of auditory comprehension in which focal activation of posterior temporal and inferior frontal regions of the left hemisphere was reliably demonstrated. Because this past study was conducted in neurologically normal volunteers, it was not possible to determine whether the activated regions were critical to the performance of language tasks; that is, whether the fMR imaging activations provided a rate measure of language processing. A direct comparison of fMR imaging language activation with cortical stimulation must be completed before the tool can be used with confidence in presurgical planning.

Here the authors report a series of 33 consecutive patients who underwent dominant hemisphere resection in which fMR image mapping of auditory comprehension was performed at the Yale neurosurgical program.

In 23 of the 33 patients reliable fMR imaging activation was shown. In 16 of these 23 patients language mapping was performed using either intra- or extraoperative cortical stimulation. Cortical stimulation failed to localize language areas in two of the 16 patients. Electrical stimulation that was performed in close proximity to the fMR image activations interfered with auditory comprehension, object naming, or speech production in 12 of the remaining 14 patients. Five of the 10 cases in which evocation reliable fMR imaging activation failed were attributable to technical problems and/or patient head movement.

Cortical stimulation results and fMR imaging findings were consistent in all but two patients. However, the spatial extent of the activation produced by fMR imaging and the spatial extent of stimulation-induced language disruption that was caused by direct cortical stimulation did not always correspond. Problems in defining the extent of activation by both methods are discussed.
Functional neuronavigation with magnetoencephalography: outcome in 50 patients with lesions around the motor cortex
Authors: Ganslandt Oliver , Fahlbusch Rudolf , Nimsky Christopher , Kober Helmut , Möller Martin , Steinmeier Ralf , Romstöck Johann , Vieth Jürgen
Published: January 2008

The authors conducted a study to evaluate the clinical outcome in 50 patients with lesions around the motor cortex who underwent surgery in which functional neuronavigation was performed.

The sensorimotor cortex was identified in all patients with the use of magnetoencephalography (MEG). The MEG-source localizations were superimposed onto a three-dimensional magnetic resonance image, and the image data set was then implemented into a neuronavigation system. Based on this setup, the surgeon chose the best surgical strategy. During surgery, the pre- and postcentral gyrus were identified by neuronavigation, and in addition, the central sulcus was localized using intraoperative recording of somatosensory evoked potentials. In all cases MEG localizations of the sensory or motor cortex were correct. In 30% of the patients preoperative paresis improved, in 66% no additional deficits occurred, and in only 4% (two patients) deterioration of neurological function occurred. In one of these patients the deterioration was not related to the method.

The method of incorporating functional data into neuronavigation systems is a promising tool that can be used in more radical surgery to cause less morbidity around eloquent brain areas.
Error analysis for a free-hand three-dimensional ultrasound system for neuronavigation
Authors: Hartov Alexander , Eisner Symma D. , David  , Roberts W. , Paulsen Keith D. , Platenik Leah A. , Miga Michael I.
Published: January 2008

Image-guided neurosurgery that is directed by a preoperative imaging study, such as magnetic resonance (MR) imaging or computerized tomography (CT) scanning, can be very accurate provided no significant changes occur during surgery. A variety of factors known to affect brain tissue movement are not reflected in the preoperative images used for guidance. To update the information on which neuronavigation is based, the authors propose the use of three-dimensional (3-D) ultrasound images in conjunction with a finite-element computational model of the deformation of the brain. The 3-D ultrasound system will provide real-time information on the displacement of deep structures to guide the mathematical model. This paper has two goals: first, to present an outline of steps necessary to compute the location of a feature appearing in an ultrasound image in an arbitrary coordinate system; and second, to present an extensive evaluation of this system's accuracy. The authors have found that by using a stylus rigidly coupled to the 3-D tracker's sensor, they were able to locate a point with an overall error of 1.36 ± 1.67 mm (based on 39 points). When coupling the tracker to an ultrasound scanhead, they found that they could locate features appearing on ultrasound images with an error of 2.96 ± 1.85 mm (total 58 features). They also found that when registering a skull phantom to coordinates that were defined by MR imaging or CT scanning, they could do so with an error of 0.86 ± 0.61 mm (based on 20 coordinates). Based on their previous finding of brain shifts on the order of 1 cm during surgery, the accuracy of their system warrants its use in updating neuronavigation imaging data.
Endoscopic management of cysticercal cysts within the lateral and third ventricles
Authors: Bergsneider Marvin , Holly Langston T. , Lee Jae Hong , King Wesley A. , Frazee John G.
Published: January 2008

In this report the authors review their 3-year experience with the endoscopic management of patients with hydrocephalus who harbored cysticercal cysts within the third and lateral ventricles. The management plan was to utilize an endoscopic approach to remove the cysts and to incorporate techniques useful in treating obstructive hydrocephalus. The ultimate goals were to avoid having to place a complication-prone cerebrospinal fluid shunt and to eliminate the risk of complications related to cyst degeneration.

A retrospective analysis of 10 endoscopically managed patients with hydrocephalus and cysticercal cysts within the third or lateral ventricles was performed. A general description of the instrumentation and the technique used for removal of the intraventricular cysts is given. At presention, neuroimaging revealed findings suggestive of obstructive hydrocephalus in eight patients.

Seven of the 10 patients treated endoscopically were spared the necessity of shunt placement. Three successful third ventriculostomies and one therapeutic septum pellucidotomy were performed. Despite frequent rupture of the cyst walls during removal of the cyst, there were no cases of ventriculitis. The endoscopic approach successfully allowed removal of a cyst situated in the roof of the anterior third ventricle. One patient suffered from recurrent shunt obstructions secondary to a shunt-induced migration of cysts from the posterior fossa to the lateral ventricles.

The endoscopic removal of third and lateral ventricle cysticercal cysts, combined with a third ventriculostomy or septum pellucidotomy in selected cases, is an effective treatment in patients with hydrocephalus and should be considered the primary treatment for this condition.
Endoscopic removal of cysticercal cysts within the fourth ventricle: technique and results
Authors: Bergsneider Marvin
Published: January 2008

There is no consensus as to the optimum management of patients who harbor cysticercal cysts within the fourth ventricle. Compared with the alternative treatment options of anthelmintic medication and/or cerebrospinal fluid shunting, the surgical removal of the cyst has the advantage of eliminating the inflammatory nidus and potentially obviating the need for a complication-prone shunt. Here, an endoscopic surgical approach is described and proposed as a superior alternative to the suboccipital craniotomy for removal of a fourth ventricle cyst.

A retrospective analysis was conducted to compare five consecutive endoscopic cases with eight previous consecutive cases in which a suboccipital craniotomy was performed to remove fourth ventricle cysticercal cysts. Comparisons are made with regards to success in removing the cyst, length of operation, surgical blood loss, postoperative discomfort, and complications. A detailed description of the endoscopic technique is given.

Endoscopic removal of all cysts within the fourth ventricle was successful in each case. The mean length of operative times was shorter and the blood loss was reduced with the endoscopic procedure compared with the suboccipital craniotomy (2.5 ± 0.8 hours and 5.3 ± 2.2 hours [p = 0.02], 19 ± 4ml and 269 ± 203 ml [p = 0.02], respectively). The endoscopic procedure was safe and associated with less postoperative discomfort in most patients.

In properly selected patients, the endoscopic removal of cysticercal cysts located within the fourth ventricle is superior to the suboccipital craniotomy and should be considered as the primary treatment for this condition.
“Picture-in-picture” endoscopic images in the microscope
Authors: Seki Yojiro , Umezu Hiromichi , Usui Masaaki , Tsumanuma Takashi , Nakatate Ken-ichi
Published: January 2008

The authors describe a new piece of equipment that enables simultaneous monitoring of the endoscopic image and unilateral microscopic image; that is, "picture-in-picture" images for endoscope-assisted microsurgery. The system is simple and purely optical, consisting of light-weight semi-rigid fibers and a special adapter incorporated in the microscope. Throughout the initial neurosurgical procedures in which it was tested, the system proved particularly useful for inspecting the facial nerve behind the acoustic neurinoma and for observing the contact between arteries and the facial nerve during decompressive procedures for hemifacial spasm.
Virtual endoscopic environments in modern neurosurgical practice
Authors: Levy Michael L. , Chen Joseph C. T. , Amar Arun P. , Yamada Shinya , Togo Koji , Iizuka Yoshiro , Assifi Murwarid Mura
Published: January 2008

Modern radiographic techniques have allowed the creation of high-definition planar images that can provide important anatomical as well as physiological data. Planar imaging sets can be reformatted into three-dimensional (3-D) data sets that can then be manipulated to demonstrate important anatomical or gross pathological features. Three-dimensional data sets have been used with success in modern image-guided or frameless stereotactic surgery. Another potential application is so-called "virtual endoscopy" or "scopeless endoscopy," in which a 3-D anatomical data set is reformatted into a volume-rendered image that can then be viewed. By reformatting images in this way, a "surgeon's-eye" view can be obtained, which can aid in presurgical planning and diagnosis. The use of virtual endoscopy has the potential to increase our understanding of the appropriate anatomy and the anatomical relationships most apparent during neurosurgical approaches. In so doing, virtual endoscopy may serve as an important means of planning for therapeutic interventions.

On the other hand, one must always be cognizant of the technical limitations of these studies regardless of the quality of the reconstructed images. Prospective, correlative, clinical studies in which the anatomical advantages of virtual-based endoscopy are evaluated in large cadaver or patient series must be performed. Until then, the only potential ways to compensate for errors that exist in the algorithms and reconstructions of 3-D endoscopic images are based on the surgeon's understanding of the clinical state of the patient and prior experience with the anatomy in the region of question.