bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain Vasospasm After Head Injury
Authors: Bor-Seng-Shu Edson , Teixeira Manoel Jacobsen 
Published: January 2008

Object.
The purpose of this prospective study was to evaluate the cumulative incidence, duration, and time course of cerebral vasospasm after traumatic brain injury (TBI) in a cohort of 299 patients.

Methods.
Transcranial Doppler (TCD) ultrasonography studies of blood flow velocity in the middle cerebral and basilar arteries (VMCA and VBA, respectively) were performed at regular intervals during the first 2 weeks posttrauma in association with 133Xe cerebral blood flow (CBF) measurements. According to current definitions of vasospasm, five different criteria were used to classify the patients: A (VMCA > 120 cm/second); B (VMCA > 120 cm/second and a Lindegaard ratio [LR] > 3); C (spasm index [SI] in the anterior circulation > 3.4); D (VBA > 90 cm/second); and E (SI in the posterior circulation > 2.5). Criteria C and E were considered to represent hemodynamically significant vasospasm. Mixed-effects spline models were used to analyze the data of multiple measurements with an inconsistent sampling rate.
Overall 45.2% of the patients demonstrated at least one criterion for vasospasm. The patients in whom vasospasm developed were significantly younger and had lower Glasgow Coma Scale scores on admission. The normalized cumulative incidences were 36.9 and 36.2% for patients with Criteria A and B, respectively. Hemodynamically significant vasospasm in the anterior circulation (Criterion C) was found in 44.6% of the patients, whereas vasospasm in the BA—Criterion D or E—was found in only 19 and 22.5% of the patients, respectively. The most common day of onset for Criteria A, B, D, and E was postinjury Day 2. The highest risk of developing hemodynamically significant vasospasm in the anterior circulation was found on Day 3. The daily prevalence of vasospasm in patients in the intensive care unit was 30% from postinjury Day 2 to Day 13. Vasospasm resolved after a duration of 5 days in 50% of the patients with Criterion A or B and after a period of 3.5 days in 50% of those patients with Criterion D or E. Hemodynamically significant vasospasm in the anterior circulation resolved after 2.5 days in 50% of the patients. The time course of that vasospasm was primarily determined by a decrease in CBF.

Conclusions.
The incidence of vasospasm after TBI is similar to that following aneurysmal subarachnoid hemorrhage. Because vasospasm is a significant event in a high proportion of patients after severe head injury, close TCD and CBF monitoring is recommended for the treatment of such patients.
Endoscope or Microscope?
Authors: Couldwell William T. 
Published: January 2008

Object.
The authors compare the views afforded by the operating microscope and the endoscope in the direct endonasal extended transsphenoidal approach to the sellar, suprasellar, and parasellar regions.

Methods.
Five formalin-fixed, silicone-injected adult cadaveric heads were studied. A direct endonasal transsphenoidal approach was performed via the right nostril, pushing aside the nasal septum. The approach was performed with the microscope first, then with the endoscope. For each step (sellar, suprasellar, and clival), the exposure afforded by direct microscopic view was measured and then compared with that obtained using the endoscope. The direct endonasal approach provides a slightly off-midline view. Although the microscope provides an adequate view of the midline structures and part of the contralateral parasellar areas, the addition of the endoscope allows for a more panoramic view and permits widening of the approach in all directions.

Conclusions.
An adequate exposure of the sellar, suprasellar, and infrasellar/upper clival regions can be achieved via a simple, direct endonasal approach. From a direct endonasal route, there is a preferential visualization of the structures contralateral to the approach. The endoscope affords a more panoramic view that extends the area covered by the operating microscope.
Balloon-Assisted Coil Embolization
Authors: Gonzalez L. Fernando , McDougall Cameron G. , Albuquerque Felipe C. , Kim Louis J. , Spetzler Robert F. 
Published: January 2008

Object.
The aim of this study was to assess the incidence, indications, complications, and angiography results associated with balloon-assisted coil embolization (BACE) of intracranial aneurysms and to compare these factors with those for conventional coil embolization (CE).

Methods.
Between 1995 and 2005, 827 intracranial aneurysms in 757 consecutive patients were packed with coils. Balloon-assisted coil embolization was used in 8.6% (71 of 827) of the coil insertion procedures and was more frequently used in large aneurysms, un-ruptured lesions, and those located on the vertebrobasilar system and carotid artery. Procedure-related complications leading to death or dependency were significantly higher in BACEs (14.1%) compared with those in CEs (3%). Packing densities and the results of 6-month follow-up angiography studies did not differ significantly between the two types of treatments. There was a strong trend for a higher retreatment rate in the aneurysms treated with BACE.

Conclusions.
Balloon-assisted coil embolization of intracranial aneurysms is associated with a high complication rate and should only be used if conventional CE of these lesions is impossible or has failed and if anticipated surgical risks are too high. The BACE procedure does not improve the occlusion rates of the aneurysms on follow-up evaluation.
Meningiomas of the Superior Sagittal Sinus
Authors: Chernov Mikhail 
Published: January 2008

Object.
Radical removal of meningiomas involving the major dural sinuses remains controversial. In particular, whether the fragment invading the sinus must be resected and whether the venous system must be reconstructed continue to be issues of debate. In this paper the authors studied the effects, in terms of tumor recurrence rate as well as morbidity and mortality rates, of complete lesion removal including the invaded portion of the sinus and the consequences of restoring or not restoring the venous circulation.

Methods.
The study consisted of 100 consecutive patients who had undergone surgery for meningiomas originating at the superior sagittal sinus in 92, the transverse sinus in five, and the confluence of sinuses in three. A simplified classification scheme based on the degree of sinus involvement was applied: Type I, lesion attachment to the outer surface of the sinus wall; Type II, tumor fragment inside the lateral recess; Type III, invasion of the ipsilateral wall; Type IV, invasion of the lateral wall and roof; and Types V and VI, complete sinus occlusion with or without one wall free, respectively. Lesions with Type I invasion were treated by peeling the outer layer of the sinus wall. In cases of sinus invasion Types II to VI, two strategies were used: a nonreconstructive (coagulation of the residual fragment or global resection) and a reconstructive one (suture, patch, or bypass). Gross-total tumor removal was achieved in 93% of cases, and sinus reconstruction was attempted in 45 (65%) of the 69 cases with wall and lumen invasion. The recurrence rate in the study overall was 4%, with a follow-up period from 3 to 23 years (mean 8 years). The mortality rate was 3%, all cases due to brain swelling after en bloc resection of a Type VI meningioma without venous restoration. Eight patients—seven of whom harbored a lesion in the middle third portion of the superior sagittal sinus—had permanent neurological aggravation, likely due to local venous infarction. Six of these patients had not undergone a venous repair procedure.

Conclusions.
The relatively low recurrence rate in the present study (4%) favors attempts at complete tumor removal, including the portion invading the sinus. The subgroup of patients without venous reconstruction displayed statistically significant clinical deterioration after surgery compared with the other subgroups (p = 0.02). According to this result, venous flow restoration seems justified when not too risky.
Gamma Knife surgery for trigeminal schwannoma
Authors: Sheehan Jason , Yen Chun Po , Arkha Yasser , Schlesinger David , Steiner Ladislau 
Published: January 2008

Object
Trigeminal schwannomas are rare intracranial tumors. In the past, resection and radiation therapy were the mainstays of their treatment. More recently, neurosurgeons have begun to use radiosurgery in the treatment of trigeminal schwannomas because of its successful use in the treatment of vestibular schwannomas. In this article the authors evaluate the radiological and clinical outcomes in a series of patients in whom Gamma Knife surgery (GKS) was used to treat trigeminal schwannomas.

Methods
Twenty-six patients with trigeminal schwannomas underwent GKS at the University of Virginia Lars Lek-sell Gamma Knife Center between 1989 and 2005. Five of these patients had neurofibromatosis and one patient was lost to follow up. The median tumor volume was 3.96 cm3, and the mean follow-up period was 48.5 months. The median prescription radiation dose was 15 Gy, and the median prescription isodose configuration was 50%. There was clinical improvement in 18 patients (72%), a stable lesion in four patients (16%), and worsening of the disease in three patients (12%). On imaging, the schwannomas shrank in 12 patients (48%), remained stable in 10 patients (40%), and increased in size in three patients (12%). These results were comparable for primary and adjuvant GKSs. No tumor growth following GKS was observed in the patients with neurofibromatosis.

Conclusions
Gamma Knife surgery affords a favorable risk-to-benefit profile for patients harboring trigeminal schwannomas. Larger studies with open-ended follow-up review will be necessary to determine the long-term results and complications of GKS in the treatment of trigeminal schwannomas.
Neurokinin-1 receptor antagonism in a rat model of subarachnoid hemorrhage: prevention of upregulation of contractile ETB and 5-HT1B receptors and cerebral blood flow reduction
Authors: Ansar Saema , Svendgaard Niels-Aage , Edvinsson Lars 
Published: January 2008

Object
Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced cerebral blood flow (CBF) and to cerebral ischemia, in some cases even producing infarction and long-term disability. The goal of the present study was to investigate the hypothesis that inhibition of neurokinin-1 receptors (NK1Rs) by administration of L-822429 blunts the decrease in CBF as well as cerebrovascular receptor upregulation in an animal model of SAH.

Methods
Subarachnoid hemorrhage was induced in rats by injection of 250 μl of blood into the prechiasmatic cistern. The NK1R inhibitor L-822429 was injected intracisternally 30 minutes and 24 hours after the induction of SAH. Two days after SAH induction, the basilar arteries were harvested, and contractile responses to endothelin-1 (ET-1, an ETA- and ETB-receptor agonist) and 5-carboxamidotryptamine (a 5-hydroxytryptamine-1 [5-HT1]-receptor agonist) were investigated using sensitive myographs. To determine whether NK1R inhibition had an influence on local CBF after post-SAH, a quantitative autoradiographic technique was used.
After SAH, the vascular receptor phenotype was changed in cerebral arteries through upregulation of contractile ETB and 5-HT1B receptors, while regional and total CBF were markedly reduced. Treatment with the selective NK1R inhibitor L-822429 prevented both the receptor upregulation and the reduction in regional and global CBF.

Conclusions
The data reveal the coregulation of vascular receptor changes and blood flow effects, and also show that interaction with a small-molecule NK1R antagonist is a promising area of focus for the development of specific treatments for SAH.
Surgical anatomy and landmarks for the basal vein of Rosenthal
Authors: Tubbs R. Shane , Loukas Marios , Louis Robert G. , Shoja Mohammadali M. , Askew Cameron S. , Phantana-Angkool April , Salter E. George , Oakes W. Jerry 
Published: January 2008

Object
The basal vein of Rosenthal (BV) courses from the premesencephalic cistern, through the ambient cistern, and terminates in the quadrigeminal cistern. The aim of this study was to describe and quantitate the surgical anatomy of this structure and specifically to provide landmarks for identifying this vessel along its course. These data may be of use, for example, to surgeons using subtemporal operative approaches through regions where this vessel is concealed.

Methods
The authors examined 15 latex-injected adult cadaveric brains (30 sides) to delineate the morphological characteristics of the BV. Dissections of the BV were then performed and measurements were made between this structure and the tentorial incisura at the anterior, middle, and posterior borders of the lateral midbrain.
All specimens were found to have a left and right BV with varying morphological characteristics. The mean distance between the BV and posterior cerebral artery at the midpoint of the lateral midbrain was 16 mm. The BV was always found superomedial to the posterior cerebral artery along the lateral aspect of the midbrain, and the BV ranged in diameter from 1 to 5 mm. The BV drained into the vein of Galen in all but two specimens. The mean distances from the tentorial edge to the BV at the anterior, middle, and posterior borders of the lateral midbrain were 11, 13, and 4 mm, respectively. No statistically significant differences were found when comparing left and right sides or male and female specimens.

Conclusions
The authors hope that these data will help the neurosurgeon operating near the BV to avoid injury to this important structure.
Safety and efficacy of the porcine small intestinal submucosa dural substitute: results of a prospective multicenter study and literature review
Authors: Bejjani Ghassan K. , Zabramski Joseph , _ _ 
Published: January 2008

Object
Dural substitutes are often needed after neurosurgical procedures to expand or replace dura mater resected during surgery. A new dural repair material derived from porcine small intestinal submucosa (SIS) was evaluated in a prospective multicenter clinical study.

Methods
Between 2000 and 2003, 59 patients at five different institutions underwent dural reconstruction with the SIS dural substitute, with a minimum follow up of 6 months. The primary goals of the study were to assess the efficacy and safety of the SIS dural substitute according to the rate of cerebrospinal fluid (CSF) leakage, infection, and meningitis.
Chiari malformation Type I decompression (32 patients) and tumor resection (18 patients) were the most common procedures performed, with 81% of SIS grafts implanted in the posterior fossa or spine. There was one case of a CSF leak (1.7%), two cases of wound infection (3.4%), and no cases of bacterial meningitis (0%) in the 58 patients available for follow up. In both cases of wound infection, the SIS graft acted as a barrier to infection and was not removed. Intraoperatively, a watertight seal was achieved in all 59 cases. On follow-up imaging available in 27 patients there was no evidence of any adverse reaction to the graft or of cerebral inflammation.

Conclusions
The SIS dural substitute demonstrated substantial efficacy in these patients after a mean follow up of 7.3 ± 2.2 months. Rates of infection, CSF leakage, and meningitis were comparable to those reported for other dural substitute materials. A lack of adverse reactions to the graft, favorable safety profile, and clinical efficacy all point to the utility of this material as an alternative for dural repair.
In vivo transcranial brain surgery with an ultrasonic time reversal mirror
Authors: Pernot Mathieu , Aubry Jean-Francois , Tanter Mickael , Boch Anne-Laure , Marquet Fabrice , Kujas Michele , Seilhean Danielle , Fink Mathias 
Published: January 2008

Object
High-intensity focused ultrasonography is known to induce controlled and selective noninvasive destruction of tissues by focusing ultrasonic beams within organs, like a magnifying glass concentrating enough sunlight to burn a hole in paper. Such a technique should be highly interesting for the treatment of deep-seated lesions in the brain. Nevertheless, ultrasonic tissue ablation in the brain has long been hampered by the defocusing effect of the skull bone.

Methods
In this in vivo study, the authors used a high-power time-reversal mirror specially designed for noninvasive ultrasonic brain treatment to induce thermal lesions through the skulls of 10 sheep. The sheep were divided into three groups and, depending on group, were killed 1, 2, or 3 weeks after treatment. The thermal lesions were confirmed based on findings of posttreatment magnetic resonance imaging and histological examinations.
After treatment, the basic neurological functions of the animals were unchanged: the animals recovered from anesthesia without any abnormal delay and did not exhibit signs of paralysis or coma. No major behavioral change was observed.

Conclusions
The results provide striking evidence that noninvasive ultrasonographic brain surgery is feasible. Thus the authors offer a novel noninvasive method of performing local brain ablation in animals for behavioral studies. This technique may lead the way to noninvasive and nonionizing treatment of brain tumors and neurological disorders by selectively targeting intracranial lesions. Nevertheless, sheep do not represent a good functional model and extensive work will need to be conducted preferably on monkeys to investigate the effects of this treatment.
Pain and Craniotomy
Authors: Kincaid M. Sean , Lam Arthur M. 
Published: January 2008

Object
Opioid administration after major intracranial surgery is often limited by a presumed lack of need and a concern that opioids will adversely affect the postoperative neurological examination. The authors conducted a prospective study to evaluate the incidence, severity, and treatment of postoperative pain in patients who underwent major intracranial surgery.

Methods
One hundred eighty-seven patients (77 men and 110 women, mean age 52 ± 15 years, mean weight 78.1 ± 19.9 kg) underwent either supratentorial (129 patients) or infratentorial (58 patients) procedures. Sixty-nine percent of the patients reported experiencing moderate to severe pain (≥ 4 on a 0–10 scale) during the 1st postoperative day. Pain scores greater than or equal to 4 persisted in 48% on the 2nd postoperative day. Approximately 80% of patients were treated with acetaminophen on the 1st postoperative day, whereas opioids (primarily intravenous fentanyl) were administered to 58%. Compared with patients who underwent supratentorial procedures, those who underwent infratentorial procedures reported more severe pain at rest (mean score 4.9 ± 2.2 compared with 3.8 ± 2.6; p = 0.015) and with movement (mean score 6.3 ± 2.6 compared with 4.5 ± 2.7; p <0.001) on the 1st postoperative day. On both the 1st and 2nd postoperative days, patients who underwent infratentorial procedures received greater quantities of opioid (p ≤ 0.019) and nonopioid (p ≤ 0.013) analgesics than those who underwent supratentorial procedures. Patients' dissatisfaction with analgesic therapy was significantly associated with elevated pain levels on the first 2 postoperative days (p <0.001).

Conclusions
In contrast to prevailing assumptions, the study findings reveal that most patients undergoing elective major intracranial surgery will experience moderate to severe pain for the first 2 days after surgery and that this pain is often inadequately treated.
How does the participation of a resident surgeon in procedures for small intracranial aneurysms impact patient outcome?
Authors: Morgan Michael K. , Assaad Nazih N. , Davidson Andrew S. 
Published: January 2008

Object
In this paper the authors' goal was to evaluate whether resident neurosurgeons participating in entry-level aneurysm surgery have a negative impact on patient outcomes.

Methods
The authors searched the database for entry-level aneurysm surgeries (that is, those ≤ 10 mm and located in the internal carotid artery [beyond the paraclinoid segment] and middle cerebral artery) performed in 1991 through 2005. The presence or absence of an advanced resident (in his/her last 3 years of residency) was noted. The analysis was examined in 3-year quintiles.
A total of 355 cases (196 with resident participation and 159 without) were evaluated. Permanent adverse outcomes were seen in 11 patients (3.1% of the total study population), all due to branch artery occlusion. The incidence of permanent adverse outcomes in the first 3 years was 10.7% and 2.4% thereafter. This difference was statistically significant (p = 0.015). There was no difference in the incidence of adverse outcomes when comparing surgery performed with and without participation of an advanced resident.

Conclusions
In this study the authors have demonstrated a learning curve in this series of patients. This study also suggests that involving residents in the repair of small unruptured aneurysms will not compromise patient care. In addition, patients can be informed that the team approach to their surgery is at least as good as having the experienced surgeon performing all aspects of the surgery.
Hemorrhage after particle embolization of hemangioblastomas: comparison of outcomes in spinal and cerebellar lesions
Authors: Cornelius Jan Frédérick , Saint-Maurice Jean Pierre , Bresson Damien , George Bernard , Houdart Emmanuel 
Published: January 2008

Object
In this study the authors compare the clinical outcomes after particle embolization of hemangioblastomas in the cerebellum and spinal cord. They also review the literature of similar cases.

Methods
Seven patients with hemangioblastomas in the spinal cord (four patients) and cerebellum (three patients) underwent preoperative embolization at the authors' center. Magnetic resonance imaging and selective angiography studies as well as histological diagnoses were available in all patients. Embosphere particles (trisacryl gelatin microspheres) were used in all cases. The smallest particle diameter ranged from 100 to 300 μm at the beginning of embolization in all patients.
The outcome of embolization was favorable in patients with spinal cord hemangioblastomas, but it was unfavorable for those with cerebellar hemangioblastomas; acute tumor bleeding and death occurred in all of the latter cases. The outcomes following embolization are very different for these two locations possibly because of the different capillary sizes.

Conclusions
The authors no longer use particle embolization to treat cerebellar hemangioblastomas.
Comparison of anterior- and posterior-approach instrumented lumbar interbody fusion for spondylolisthesis
Authors: Min Jun-Hong , Jang Jee-Soo , Lee Sang-Ho 
Published: January 2008

Object
The purpose of this study was to compare the imaging and clinical outcomes obtained in patients with lumbar spondylolisthesis who have undergone either instrumented anterior lumbar interbody fusion (ALIF) or instrumented posterior LIF (PLIF), especially with regard to the development of adjacent-segment degeneration (ASD).

Methods
Forty-eight patients with preoperative spondylolisthesis and minimal ASD who underwent instrumented L4–5 fusion were divided into two groups according to the surgical approach. After ensuring the two groups' comparability, the following variables were evaluated: postoperative segmental and lumbar lordosis, postoperative percentage of vertebral slippage, reduction rate, incidence of ASD, and clinical outcomes.

Results
Adjacent-segment degeneration was found in 44.0% of the patients in the ALIF group and in 82.6% of those in the PLIF group (p = 0.008). Clinical success rates were 92.0 and 87.0% in the ALIF and PLIF groups, respectively. There were no statistically significant intergroup differences in the postoperative segmental and lumbar lordosis, postoperative percentage of slippage, reduction rate, Japanese Orthopaedic Association score, and success rate.

Conclusions
Both ALIF and PLIF can produce good outcomes in treating lumbar spondylolisthesis, but ALIF is more advantageous in preventing the development of ASD.