bluuebunny/crossref_metadata_2025 huggingface dataset:
Multislice computed tomography angiography screening for new aneurysms in patients with previously clip-treated intracranial aneurysms: feasibility, positive predictive value, and interobserver agreement
Authors: van der Schaaf Irene C. , Velthuis Birgitta K. , Wermer Marieke J. H. , Frenkel Nanne J. , Majoie Charles B. L. M. , Witkamp Theo D. , de Kort Gerard , Freling Nicole J. , Rinkel Gabriel J. E. , _ _
Published: January 2008

Object

Multislice computed tomography (CT) angiography may be useful for screening patients with intracranial aneurysms that are treated with clip occlusion. However, cobalt clips produce much more artifact on CT scans than titanium clips, which may hamper the evaluation of the image obtained at the clip site.

Methods

The authors screened 415 patients with previously ruptured aneurysms that had been treated using cobalt clips. Screening was performed using multislice CT angiography. The feasibility of this modality for screening these patients (based on the complication risk, CT angiography quality, and artifact avoidance) and interobserver agreement were evaluated. Patients in whom the presence of an aneurysm was suspected based on results of CT angiography studies underwent digital subtraction (DS) angiography. False-negative and false-positive findings were recorded, and the positive predictive value (PPV) was calculated.

Eight patients (1.9%) had allergies to the contrast material. The quality of the CT angiography image was suboptimal in 14%. In 52%, clip artifacts hampered evaluation of the clip site. In 65 patients who underwent DS angiography, there were nine false-positive and eight false-negative reports related to aneurysms that were either small, located at the clip site, or were infundibula. The PPV on a per-patient basis was 86% (95% confidence interval [CI] 75–94%); for aneurysms at the clip site it was 83% (95% CI 61–95%); and for aneurysms at different locations it was 91% (95% CI 81–97%). The interobserver agreement was good (κ = 0.69; 95% CI 0.60–0.78).

Conclusions

Except for the evaluation of images from the clip site, CT angiography has good feasibility with good PPV and interobserver agreement. Drawbacks are that very small aneurysms can be missed and that visualization is poor at the clip site in patients in whom cobalt clips have been placed for occlusion. This second problem can be expected to resolve with the increasing use of titanium clips.
Split facial nerve course in vestibular schwannomas
Authors: Strauss Christian , Prell Julian , Rampp Stefan , Romstöck Johann
Published: January 2008

Object

The facial nerve in vestibular schwannomas (VSs) is located on the ventral tumor surface in more than 90% of cases; other courses are rare. A split facial nerve course with two distinct bundles has thus far been described exclusively for medial extrameatal tumors.

Methods

Between 1996 and 2005, 16 consecutive cases of 241 surgically treated VSs were observed to have distinct splitting of the facial nerve. The mean tumor size measured 27 mm. In one third of the cases, intrameatal tumor extension with obliteration of the fundus was documented. All patients underwent extensive intraoperative neurophysiological monitoring using multichannel electromyography recordings. Patients were reevaluated 12 months after surgery.

In all 16 patients, distinct splitting of the facial nerve was demonstrated. The major portion of the facial nerve followed a typical course on the ventral tumor surface. The smaller nerve portion in all cases ran parallel to the brainstem up to the level of the trigeminal root exit zone and crossed on the cranial tumor pole to the internal auditory canal. The two nerve portions rejoined at the level of the porus acusticus. The smaller portion carried fibers exclusively to the orbicularis oris muscle, whereas the major portion supplied all three branches of the facial nerve.

Conclusions

In VSs, an aberrant course with distinct splitting of the facial nerve adds considerably to the surgical challenge. Long-term facial nerve results are excellent with extensive neurophysiological monitoring, which allows the differentiation and identification of aberrant facial nerve fibers and avoids additional risks to facial nerve preservation.
Intrasaccular combination of metallic coils and Onyx liquid embolic agent for the endovascular treatment of cerebral aneurysms
Authors: Cekirge H. Saruhan , Saatci Isil , Geyik Serdar , Yavuz Kivilcim , Öztürk Halil , Pamuk Gülsün
Published: January 2008

Object

The aim of this study was to report on a novel technique in which metallic embolization coils were combined with the Onyx liquid embolic agent in the aneurysm sac to achieve a more durable result after endovascular treatment. This therapeutic procedure was performed in selected cases in which, based on the authors’ experiences, either coil embolization or Onyx alone would likely have failed. The authors report long-term clinical and angiographic follow-up results in 20 consecutive intracranial aneurysms treated using this combination for defined indications.

Methods

Twenty aneurysms in 20 patients were treated with a combination of embolic coils and Onyx. Four aneurysms were giant; 13, large; and three, small. This new technique was used when standard Onyx or coil treatment with balloon assistance was determined to involve a higher possibility of recanalization, because either an adjunctive stent insertion could not be performed or the Onyx technique could not be used due to an unsuccessful seal test or intraaneurysm balloon prolapse. In one case, an adjunctive stent was placed before coil placement and Onyx deposition to control the material in the sac of the aneurysm, which had a fusiform neck.

All aneurysms were completely occluded after using this technique. No clinical or technical adverse events occurred in any of the cases. Follow-up angiography was performed in all patients: 3-year studies in six patients, 2-year studies in five, and 1-year studies in nine. None of these studies demonstrated aneurysm regrowth or parent artery occlusion.

Conclusions

The combination of the embolic coils and the Onyx liquid embolic agent provides very durable aneurysm occlusion for defined indications.
Using endothelial nitric oxide synthase gene polymorphisms to identify intracranial aneurysms more prone to rupture in Japanese patients
Authors: Krischek Boris , Kasuya Hidetoshi , Akagawa Hiroyuki , Tajima Atsushi , Narita Akira , Onda Hideaki , Hori Tomokatsu , Inoue Ituro
Published: January 2008

Object

Recent investigators found that the presence of three tandem polymorphisms of the endothelial nitric oxide synthase (eNOS) gene—promoter single nucleotide polymorphism (SNP) T-786C, intron-4 27-bp variable number of tandem repeats, and the G894T SNP in exon 7—was indicative of intracranial aneurysms more prone to rupture in a Caucasian patient sample. In the present study, the authors sought to determine whether the presence of these eNOS polymorphisms could indicate which Japanese patients with aneurysms were more endangered by a subarachnoid hemorrhage (SAH).

Methods

The three eNOSpolymorphisms were genotyped in 297 patients with ruptured aneurysms (RAs), 108 patients with unruptured aneurysms (UAs), and 176 healthy volunteers by using polymerase chain reaction.

The distribution of the variant alleles did not differ significantly (p > 0.05) between the RA group and the UA group. The frequency of the corresponding genotypes between the two groups and a haplotype analysis did not show any significant differences. Further comparisons of the RA and UA groups with the control group did not yield any significant allele or genotype frequency differences.

Conclusions

These data show that the examined set of eNOS polymorphisms were not indicative of which Japanese patients with intracranial aneurysms would suffer an SAH. The presence of eNOS polymorphisms is not useful in identifying intracranial aneurysms that are more prone to rupture in a Japanese patient sample.
Oncocytic meningiomas: cases with benign histopathological features and a favorable clinical course
Authors: Gallina Pasquale , Buccoliero Anna Maria , Mariotti Furio , Mennonna Pasquale , di Lorenzo Nicola
Published: January 2008

Object

Oncocytic meningioma has recently been recognized as a distinct morphological variant of intracranial meningothelial neoplasms, and only a few cases have been reported in the literature. The first description of this lesion, which was based on data in six cases, revealed a potentially aggressive nature with a tendency to infiltrate the brain and to recur. However, the true behavior of, and the long-term follow-up data for, such lesions must still be outlined.

Methods

The authors report on five cases of intracranial oncocytic meningiomas. On neuroimaging, the lesions showed the characteristic features of common meningiomas. All patients underwent gross-total removal of the mass together with the adjacent dura mater. No additional treatments were administered. Histologically, the tumors were composed of sheets, nests, and cords of large polygonal neoplastic cells with finely granular cytoplasm. Necrosis was absent in all cases. Mitosis was also absent or exceedingly rare, and no brain cortex infiltration was observed. The follow up ranged from 6 to 54 months (mean 32.4 months). At the last follow-up evaluation, all patients were asymptomatic and magnetic resonance imaging examinations demonstrated no evidence of tumor recurrence.

Conclusions

Data in the presented cases did not confirm a previously described propensity to aggressiveness in this meningioma subtype. In fact, the histological features as well as the long-term favorable clinical course may suggest benign behavior of such neoplasms, as in the common forms of meningiomas.
Expanded polytetrafluoroethylene graft for bypass surgery using the excimer laser–assisted nonocclusive anastomosis technique
Authors: Reinert Michael , Verweij Bon H. , Schaffner Thomas , Mihalache George , Schroth Gerhard , Seiler Rolf W. , Tulleken Cornelis A. F.
Published: January 2008

Object

Patients with complex craniocerebral pathophysiologies such as giant cerebral aneurysms, skull base tumors, and/or carotid artery occlusive disease are candidates for a revascularization procedure to augment or preserve cerebral blood flow. However, the brain is susceptible to ischemia, and therefore the excimer laser–assisted nonocclusive anastomosis (ELANA) technique has been developed to overcome temporary occlusion. Harvesting autologous vessels of reasonable quality, which is necessary for this technique, may at times be problematic or impossible due to the underlying systemic vascular disease. The use of artificial vessels is therefore an alternative graft for revascularization. Note, however, that it is unknown to what degree these grafts are subject to occlusion using the ELANA anastomosis technique. Therefore, the authors studied the ELANA technique in combination with an expanded polytetrafluoroethylene (ePTFE) graft.

Methods

The experimental surgeries involved bypassing the abdominal aorta in the rabbit. Ten rabbits were subjected to operations representing 20 ePTFE graft–ELANA end-to-side anastomoses. Intraoperative blood flow, follow-up angiograms, and long-term histological characteristics were assessed 75, 125, and 180 days postoperatively. Angiography results proved long-term patency of ePTFE grafts in all animals at all time points studied. Data from the histological analysis showed minimal intimal reaction at the anastomosis site up to 180 days postoperatively. Endothelialization of the ePTFE graft was progressive over time.

Conclusions

The ELANA technique in combination with the ePTFE graft seems to have favorable attributes for end-to-side anastomoses and may be suitable for bypass procedures.
Endovascular surgery for very small ruptured intracranial aneurysms
Authors: Suzuki Sachio , Kurata Akira , Ohmomo Taketomo , Sagiuchi Takao , Niki Jun , Yamada Masaru , Oka Hidehiro , Fujii Kiyotaka , Kan Shinichi
Published: January 2008

✓Application of endovascular surgery for very small aneurysms is controversial because of technical difficulties and high complication rates. The aim in the present study was to assess treatment results in a series of such lesions at one institution.

Since 1997, endovascular surgery has been advocated for very small ruptured aneurysms (<3 mm in maximum diameter) that fulfill the criterion of a fundus/neck ratio greater than 1.5. Twenty-one patients were treated, for whom the World Federation of Neurosurgical Societies classification before treatment was Grade I in 10, Grade II in two, Grade III in two, Grade IV in five, and Grade V in two. The aneurysm location was the internal carotid artery in four, the anterior communicating artery in 11, the middle cerebral artery in one, and the vertebrobasilar system in five. In all patients, endovascular surgery was performed using Guglielmi detachable coils after induction of general anesthesia. Initially, the presumed volume of the lesions was calculated for each aneurysm. Thereafter, the appropriate coil length was decided according to the volume embolization ratio, as 30 to 40%. In all attempts to obliterate aneurysms a single coil was used.

All aneurysms were completely obliterated as confirmed by postembolization angiography, without procedure-related complications. During the follow-up period only one patient needed additional coil embolization for a growing aneurysm. Final outcomes were good recovery in 15 patients, moderate disability in five, and severe disability in one.

Appropriate selection of patients and coils, and use of sophisticated techniques allow a good outcome for patients with very small aneurysms.
Wrap-clipping with polytetrafluoroethylene for ruptured blisterlike aneurysms of the internal carotid artery
Authors: Kubo Yoshitaka , Ogasawara Kuniaki , Tomitsuka Nobuhiko , Otawara Yasunari , Watanabe Mikio , Ogawa Akira
Published: January 2008

✓ A technique combining wrapping and clip occlusion of aneurysms by using polytetrafluoroethylene (PTFE) for treatment of ruptured blisterlike aneurysms of the supraclinoid internal carotid artery (ICA) is described. The diameter of the abnormal arterial lesion along the long axis of the ICA and the distance between the origin of the ophthalmic artery and the origin of the posterior communicating artery (PCoA), or the origin of the PCoA and the origin of the anterior choroidal artery are measured intraoperatively; a strip of PTFE membrane is then trimmed with scissors to match this diameter and distance. After temporarily occluding the cervical ICA, the intracranial ICA that includes the lesion is wrapped with the strip of PTFE, and one or more aneurysm clips are applied parallel to the ICA. This procedure was successfully accomplished in six patients, all of whom had an uneventful postoperative course with no recurrent subarachnoid hemorrhage during the follow-up period. “Wrap-clipping” using PTFE is a useful procedure for management of ruptured blisterlike aneurysms of the ICA.
Meeting the challenges of neurosurgery
Authors: Wirth Fremont P.
Published: January 2008

✓The challenges faced by neurosurgery in 2006 are many. There are five principal challenges that have received a great deal of attention from the Board of Directors of the American Association of Neurological Surgeons this past year. These are the challenge of maintaining a modern, efficient, and responsive educational program for neurosurgery; the challenge of maintaining the boundaries of neurosurgical practice and preventing the incursion of subspecialty groups into the performance of neurosurgical procedures; the challenge of responding to the changing demands of society; the challenge of influencing increased reimbursement; and the challenge of creating meaningful medical liability reform. Each of these issues are discussed.
Use of clinical signs and computed tomography myelography findings in detecting and excluding nerve root avulsion in complete brachial plexus palsy
Authors: Bertelli Jayme Augusto , Ghizoni Marcos Flávio
Published: January 2008

Object

The purpose of this study was to investigate the usefulness of preoperative evaluation based on clinical testing and computed tomography (CT) myelography in differentiating root rupture (that is, graftable root) from root avulsion in total brachial plexus palsy.

Methods

Thirty-two patients with total brachial plexus palsy were clinically tested for the presence of phrenic nerve palsy, supraclavicular Tinel sign, shoulder protraction, Bernard–Horner syndrome, and hand pain. The patients underwent CT myelography and then underwent surgery. The combination of a positive Tinel sign and a positive shoulder protraction test accurately predicted the presence of a graftable root in 93.7% of the cases. A 96.8% rate of accuracy was attained if the results of the CT myelography were considered together with the clinical signs. The presence of Bernard–Horner syndrome and hand pain accurately indicated avulsion of the lower roots in 93.7% of the patients. Computed tomography myelography accurately predicted the condition of the lower roots in 100% of the cases. Total avulsion injury was observed in five cases (16%). The lower roots were avulsed in 94% of the cases. The C-5 and C-6 roots were grafted 40 times, and a suitable root stump for grafting lay in a retroscalenic position in 18 (45%) of the 40 cases.

Conclusions

Preoperative assessment based on clinical examination and CT myelography allowed correct surgical planning in more than 90% of the cases.
Effectiveness and handling characteristics of a three-layer polymer dura substitute: a prospective multicenter clinical study
Authors: Messing-Jünger A. Martina , Ibáñez Javier , Calbucci Fabio , Choux Maurice , Lena Gabriel , Mohsenipour Iradj , Van Calenbergh Frank
Published: January 2008

Object

The goal of this study was to assess the effectiveness and handling characteristics of a dura substitute composed of two outer layers of expanded polytetrafluoroethylene (PTFE) and a middle layer consisting of an elastomeric fluoropolymer.

Methods

In a prospective multicenter study, the dura substitute was implanted using a standard technique in 119 patients undergoing cranial or spinal surgery requiring duraplasty. Intraoperative assessments of the dura patch consisted of testing for cerebrospinal fluid (CSF) leakage employing the Valsalva maneuver and a surgeon’s standard evaluation of the handling characteristics of the device. Postoperative assessments conducted during a mean follow-up time of 15.7 months (range 0.3–45.6 months) consisted of physical examinations, routine computed tomography (CT) or magnetic resonance (MR) imaging studies, and histological studies of any removed dura patches.

The mean age of the 119 patients was 40 years (range < 1–81 years). The dura substitute was implanted cranially in 102 patients and spinally in 17. Intraoperative assessment including the Valsalva maneuver led to application of additional sutures in 17 patients. Handling features were rated very good to excellent. Postoperative clinical evaluation resulted in 79 excellent and 18 good results. Imaging studies (MR imaging studies in 69 patients and CT studies in 34 patients) showed no adhesions in 87 patients and minimal adhesions in seven patients (the dura was not visualized in nine patients). Postoperative complications occurred in 12 patients. There were six cases of CSF leakage, three cases of extradural hematoma, one case of arachnoid fibrosis after decompression of a Chiari malformation Type I, and two cases of infection. Eight (7%) of these complications were potentially related to the dura patch.

Conclusions

In a large, multicenter clinical study of the use of an expanded-PTFE–containing dura substitute, the device was found to be easy to handle and implant. No serious dura patch–related intraoperative adverse events were observed. Postoperatively, there were no major sealing problems or long-term complications. In two cases the patch had to be removed due to fibrosis and infection. The three-layer polymer dura substitute appears to be safe and effective in minimizing CSF leakage and adhesion formation, and its use avoids any risk of prion disease transmission.
Boron neutron capture therapy for recurrent malignant meningioma
Authors: Tamura Yoji , Miyatake Shin-Ichi , Nonoguchi Naosuke , Miyata Shirou , Yokoyama Kunio , Doi Atsushi , Kuroiwa Toshihiko , Asada Masahiro , Tanabe Hideki , Ono Koji
Published: January 2008

✓ Malignant meningioma is a rare brain tumor with a high risk of recurrence. If this tumor recurs after complete resection and adjuvant radiotherapy, there is no optimal treatment to control it. The authors report the first case of recurrent malignant meningioma treated using boron neutron capture therapy (BNCT). This 25-year-old pregnant woman presented with a large frontal tumor. After her baby was born, she underwent gross-total resection of the tumor. A second resection and three Gamma Knife surgeries could not control progression of the enhancing mass; therefore, the authors applied BNCT based on their experience with it in the treatment of malignant gliomas. The minimum tumor dose and maximum brain tissue dose were estimated as 39.7 Gy-Eq and less than 9.0 Gy-Eq, respectively. Before BNCT the patient was mobile by wheelchair only, whereas 1 week after therapy she was able to walk. Twenty-two weeks later she underwent a second BNCT for tumor regrowth on the contralateral side, and the lesion was subsequently reduced. The tumor volume was markedly decreased from 65.6 cm3 at the time of the first BNCT to 31.8 cm3 at 26 weeks thereafter. The treatment of recurrent malignant meningioma is difficult and has been discouraging thus far. Data in the present case indicate that BNCT may be a promising treatment option for this challenging tumor.
Using an end-to-side interposed sural nerve graft for facial nerve reinforcement after vestibular schwannoma resection
Authors: Samii Madjid , Koerbel Andrei , Safavi-Abbasi Sam , Di Rocco Federico , Samii Amir , Gharabaghi Alireza
Published: January 2008

✓ Increasing rates of facial and cochlear nerve preservation after vestibular schwannoma surgery have been achieved in the last 30 years. However, the management of a partially or completely damaged facial nerve remains an important issue. In such a case, several immediate or delayed repair techniques have been used.

On the basis of recent studies of successful end-to-side neurorrhaphy, the authors applied this technique in a patient with an anatomically preserved but partially injured facial nerve during vestibular schwannoma surgery. The authors interposed a sural nerve graft to reinforce the facial nerve whose partial anatomical continuity had been preserved. On follow-up examinations 18 months after surgery, satisfactory cosmetic results for facial nerve function were observed.

The end-to-side interposed nerve graft appears to be a reasonable alternative in cases of partial facial nerve injury, and might be a future therapeutic option for other cranial nerve injuries.
Comparison between motor evoked potential recording and fiber tracking for estimating pyramidal tracts near brain tumors
Authors: Mikuni Nobuhiro , Okada Tsutomu , Nishida Namiko , Taki Junya , Enatsu Rei , Ikeda Akio , Miki Yukio , Hanakawa Takashi , Fukuyama Hidenao , Hashimoto Nobuo
Published: January 2008

Object

The utility of subcortical electrical stimulation and fiber tracking were compared to estimate the pyramidal tract near brain tumors.

Methods

In 22 patients, the white matter at the bottom of a tumor was electrically stimulated near the fiber tracking of the pyramidal tract shown on a neuronavigation system. The distance between the center of the fiber tracking of these tracts and the stimulated region was measured and defined as the motor evoked potential (MEP) response. The MEP was consistently produced at distances less than 7 mm (six patients), but was consistently absent at distances more than 13 mm (seven patients) from the fiber tracking of the pyramidal tracts. In the nine patients in whom the distance was between 8 and 12 mm, an MEP was elicited when stimulation was applied at the level of the corona radiata. Motor function was preserved or even improved with appropriate tumor resection in all patients.

Conclusions

The anteroposteriorly running superior longitudinal fasciculus could cause complications in the fiber tracking of upper-extremity motor pathways at the level of the corona radiata. During resection of tumors located near the corona radiata, subcortical electrical stimulation should be applied at some distance from the pyramidal tract, as estimated by fiber tracking.
Selective subtemporal amygdalohippocampectomy for refractory temporal lobe epilepsy: operative and neuropsychological outcomes
Authors: Hori Tomokatsu , Yamane Fumitaka , Ochiai Taku , Kondo Shinji , Shimizu Satoru , Ishii Kenji , Miyata Hajime
Published: January 2008

Object

The authors evaluated operative, neuropathological, and neuropsychological results after selective subtemporal amygdalohippocampectomy for refractory temporal lobe epilepsy in patients who were observed for at least 2 years after surgery.

Methods

Twenty-six consecutive patients underwent selective subtemporal amygdalohippocampectomy for nonlesional, medically refractory temporal lobe epilepsy. Neuropsychological evaluation using the Wechsler Adult Intelligence Scale was done before surgery in all patients, 2 months after surgery in 24 patients, and at 2-year follow up in 19 patients. A verbal paired associates learning test was administered before surgery and 2 months after surgery in 19 patients. The data were compared between the 13 patients in whom the language-dominant hemisphere was surgically treated and the six patients in whom the language-nondominant hemisphere was treated.

After surgery, 84% of the patients attained either Engel Class I or II seizure outcome. There were no permanent subjective complications except postoperative memory impairment in one patient. Neuropathological examination confirmed hippocampal sclerosis in 19 patients. No significant differences in IQ and verbal memory test scores were observed between the patients in whom the language-dominant hemisphere was treated and those in whom the language-nondominant hemisphere was treated. Significant postoperative increases in verbal IQ, performance IQ, and full-scale IQ were observed over time. No significant differences were found between pre- and postoperative verbal memory test scores, and no subjective visual field loss was marked in any patient.

Conclusions

Subtemporal selective amygdalohippocampectomy provides favorable surgical and neuropsychological outcomes and does not cause significant postoperative decline of verbal memory if performed on the language-dominant side.
A microsurgical study of the anatomy and course of the ophthalmic artery and its possibly dangerous anastomoses
Authors: Perrini Paolo , Cardia Andrea , Fraser Kenneth , Lanzino Giuseppe
Published: January 2008

Object

The authors studied the microsurgical anatomy of the ophthalmic artery (OphA), paying particular attention to its possibly dangerous anastomoses with the middle meningeal artery (MMA).

Methods

The microsurgical anatomy of the OphA and its anastomoses with the MMA were studied in 14 vessels from seven adult cadaveric heads. The origination order of the OphA branches varies in relation to whether the artery, along its intraorbital course, crosses above or below the optic nerve (ON). The central retinal artery is the first branch to course from the OphA when it crosses over the ON, and it is the second branch to course from the OphA when the artery crosses under the ON. Anastomoses between branches of the MMA and the OphA were present in the majority of the specimens examined.

Conclusions

Detailed knowledge of the microanatomy of the OphA and recognition of anastomoses between the external carotid artery and the OphA are critically important in avoiding disastrous complications during endovascular procedures.
Anatomical study of the pterygopalatine fossa using an endoscopic endonasal approach: spatial relations and distances between surgical landmarks
Authors: Solari Domenico , Magro Francesco , Cappabianca Paolo , Cavallo Luigi M. , Samii Amir , Esposito Felice , Paternò Vincenzo , de Divitiis Enrico , Samii Madjid
Published: January 2008

Object

The pterygopalatine fossa is an area that lies deep within the skull base. The recent extensive use of the endoscopic endonasal approach has provided neurosurgeons with a method to reach various areas of the skull base through a less invasive approach than traditional transcranial or transfacial approaches. This study aims to provide neurosurgeons with new data concerning direct endoscopic measurements and precise anatomical topography features of the pterygopalatine fossa.

Methods

An anatomical dissection of six fixed cadaver heads (12 pterygopalatine fossae) was performed to analyze spatial relationships and distances between the most important neurovascular structures in this region, and to estimate the size of the endoscopic surgical field for operations in this area. The endoscopic endonasal approach offers direct access to the pterygopalatine fossa through its anteromedial walls.

Conclusions

Using an endoscopic endonasal approach makes it possible to identify all of the anatomical landmarks of the pterygopalatine fossa and almost all of the contiguous skull base areas.
Anatomical variations in pneumatization of the anterior clinoid process
Authors: Mikami Takeshi , Minamida Yoshihiro , Koyanagi Izumi , Baba Takeo , Houkin Kiyohiro
Published: January 2008

Object

An anterior clinoidectomy can provide enormous benefits, facilitating the management of paraclinoid and upper basilar artery lesions, but it also carries the potential risk of cerebrospinal fluid leaks. The aim of this study was to assess the variation in the pneumatization of the anterior clinoid process (ACP) in an attempt to reduce the complications associated with an anterior clinoidectomy.

Methods

The authors analyzed the anatomical variations in the pneumatization of the ACP and optical strut (OS) in 600 sides of 300 consecutive patients by using multidetector-row computed tomography (CT). Computed tomography scans with a 0.5-mm thickness were obtained, and coronal and sagittal reconstructions of the images were displayed in all cases. Pneumatization of the ACP was found in 9.2% of all sides. The origin of pneumatization was the sphenoid sinus in 81.8% of all the sides, the ethmoid sinus in 10.9%, and both of these sinuses in 7.3%. Pneumatized patterns were divided into three groups according to the route: 74.5% were Type I, in which pneumatization occurred via the OS; 14.5% were Type II, pneumatization via the anterior root (AR); and 10.9% were Type III, pneumatization via both the OS and the AR. The origin of pneumatization and the pneumatization pattern showed statistical dependence (p < 0.001). Pneumatization of the OS beyond its narrowest point was found in 6.8% of all sides.

Conclusions

An awareness of the different variations in pneumatization can prevent destruction of the mucous membrane and facilitate orientation during reconstruction with cranialization. During an anterior clinoidectomy, preoperative CT assessments are necessary to evaluate pneumatization of the ACP.
Detection of the subthalamic nucleus in microelectrographic recordings in Parkinson disease using the high-frequency (> 500 Hz) neuronal background
Authors: Novak Peter , Daniluk Slawomir , Ellias Samuel A. , Nazzaro Jules M.
Published: January 2008

✓Accurate and fast localization of the subthalamic nucleus (STN) during intraoperative electrophysiological monitoring can improve the outcome of deep brain stimulation surgery. The authors show a simple method of detecting the STN that is based on an analysis of the high-frequency (> 500 Hz) background (HFB) activity of neurons. The HFB reflects multiunit spiking activity close to the recording electrode, and its characteristic profile, which is higher in the STN than in neighboring structures, and facilitates delineation of both the dorsal and ventral STN borders.
Inside and somewhat outside Charity
Authors: Kline David G.
Published: January 2008

✓On August 29, 2005, a hurricane named Katrina struck the Gulf Coast. Many feared the consequences of such a storm, but very few believed that it could ever happen. This article is a narrative written shortly after the evacuation of patients and personnel from the flooded Charity Hospital.

The days at Charity hospital were hot and humid following Katrina, and as time passed the air was permeated by a stench that was inescapable. Rendering care to patients without electricity, and thus light and air conditioning, with a temperature in the 90°s and no running water was a challenge. Trying to cool patients with central fever and providing adequate ventilation for unconscious patients was extremely difficult. Without elevators, climbs up to and down from the 14th floor—where the author and his colleagues had their sleeping rooms—and the 12th (surgical intensive care unit [ICU]), seventh (neuro ICU and step-down units), and sixth (medical ICU) floors were tedious. The descent to check the emergency department and obtain a closer look at flooding in the streets around the hospital, which maintained a 4- to 5-foot water level, became prohibitive because of the contemplation of the necessary return ascent.

There were 21 patients, mostly neurosurgical, in the neuro ICU and step-down units and wards. This is their story.
Radiosurgery for facial schwannoma
Authors: Kida Yoshihisa , Yoshimoto Masayuki , Hasegawa Toshinori
Published: January 2008

Object

The aim of this study was to evaluate the results of radiosurgery in patients with facial schwannoma.

Methods

The study population consisted of 14 patients, six men and eight women, with a mean age of 45.4 years. Most of the patients had presented with facial palsy (11 of 14 patients) and/or hearing disturbance (nine of 14 patients). Prior treatment in nine of the 14 cases consisted of tumor resection or tumor biopsy. Tumor volume ranged from 0.98 to 20.8 cm3, and the mean tumor volume was 5.5 cm3. The mean maximum radiation dose and mean tumor margin dose used for radiosurgery were 24.0 and 12.9 Gy, respectively.

During the mean follow-up period of 31.4 months (range 12–120 months), 10 of the tumors shrank and four remained unchanged. The tumor response and tumor control rates were 57 and 100%, respectively. None of the tumors progressed, and no subsequent resection was required. Facial nerve function improved in five cases, remained unchanged in eight, and became worse in one. There was no change in hearing function in any of the patients. Complications developed in only one patient: the onset of facial palsy immediately after treatment, which subsequently recovered to House–Brackmann Grade III.

Conclusions

In summary, radiosurgery was found to be a very useful method of treating facial schwannoma, for both tumor control and functional control. Radiosurgery should therefore be the treatment of first choice for facial schwannomas.
Patterns of skull base meningioma progression after failed radiosurgery
Authors: Couldwell William T. , Cole Chad D. , Al-Mefty Ossama
Published: January 2008

Object

Stereotactic radiosurgery has been reported to be an effective alternative to surgical removal of small to medium benign meningiomas as well as an adjuvant treatment modality to reduce the risk of tumor progression after subtotal resection. Its efficacy has been proved by excellent short-term radiosurgically demonstrated control rates, which have been reported to approach or exceed 90% in many contemporary studies involving the use of either linear accelerator–based systems or the Gamma Knife. Little is known, however, regarding the growth patterns of meningiomas that fail to stabilize after radiosurgery.

Methods

The authors report 13 cases of benign skull base meningiomas (World Health Organization Grade I) that demonstrated progression after radiosurgical treatment as a primary or an adjuvant therapy. Several tumors demonstrated rapid growth immediately after radiosurgical treatment, whereas other lesions progressed in a very delayed manner in some patients (up to 14 years after treatment). Regardless of the interval after which it occurs, tumor growth can be quite aggressive once it has begun.

Conclusions

Skull base meningioma growth can be aggressive after failed radiosurgery in some patients, and treatment failure can occur at long intervals following treatment. Special attention must be devoted to such significant occurrences given the increasing number of patients undergoing stereotactic radiosurgery for benign tumors, and careful extended (> 10 years) follow up must be undertaken in all patients after radiosurgery.
Collagen matrix duraplasty for cranial and spinal surgery: a clinical and imaging study
Authors: Narotam Pradeep K. , Reddy Kesava , Fewer Derek , Qiao Fan , Nathoo Narendra
Published: January 2008

Object

The repair of dural defects is controversial in contemporary neurosurgery. To date, collagen-based products remain a continued area of interest in the development of dural grafts. The authors conducted a prospective case–control study in which they evaluated collagen matrix in the repair of dural defects following cranial and spinal surgery by using specific clinical and magnetic resonance (MR) imaging outcome measures.

Methods

Enrolled in the study were 79 patients, 36 male (45.6%) and 43 female (54.4%), with a mean age of 53 ± 15.8 years. The pathological diagnosis was brain tumor in 49 cases (62%), vascular conditions in 16 (20.2%), degenerative spine in 10 (12.7%), trauma in two (2.5%), and other in two (2.5%). Most of the patients underwent supratentorial craniotomy (57; 72.2%), whereas 11 patients (13.9%) each underwent posterior fossa and spinal surgery. Sixty-three patients (79.7%) completed the study, which included clinical and MR imaging evaluations at 3 months postsurgery. There were no cerebrospinal fluid (CSF) leaks or delayed hemorrhages. The neurosurgical wound infection rate was 3.8%: superficial wound infection in two cases and deep infection and brain abscess in one case (recurrent brain tumor following radiation therapy).

Among the 63 patients in whom 3-month postsurgery imaging data were available, asymptomatic small pseudomeningoceles were detected on MR imaging in two (3.2%); a minor subgaleal fluid collection, which resolved spontaneously, was apparent in another patient (1.6%). Nonspecific dural enhancement was demonstrated on images obtained in seven patients (11.1%), and asymptomatic spinal epidural enhancement was observed on images obtained in two of three patients who had undergone lumbar laminectomy for spinal stenosis.

Conclusions

When used as a dural onlay graft, collagen matrix had a 100% CSF containment rate but might be associated with occult radiological abnormalities.
Recognition and management of delayed hyponatremia following transsphenoidal pituitary surgery
Authors: Zada Gabriel , Liu Charles Y. , Fishback Dawn , Singer Peter A. , Weiss Martin H.
Published: January 2008

Object

The goal of this study was to assess the incidence of symptomatic and occult hyponatremia in patients who had undergone transsphenoidal pituitary surgery.

Methods

Patients who underwent transsphenoidal surgery at the University of Southern California University Hospital between 1997 and 2004 had serum sodium levels drawn on an outpatient basis on postoperative Day 7. Patient records were retrospectively reviewed to determine the incidence of, and risk factors for, symptomatic and asymptomatic hyponatremia.

Two hundred forty-one patients had routine serum sodium levels drawn as outpatients on postoperative Day 7. Twenty-three percent of these patients were found to be hyponatremic (Na ≤ 135 mEq/L). The overall incidence rate of symptomatic hyponatremia in the 241 patients was 5%. The majority of hyponatremic patients (80%) remained asymptomatic, whereas 20% became symptomatic. In patients with symptomatic hyponatremia, the mean sodium level at diagnosis was 120.5 mEq/L, compared with 128.4 mEq/L in asymptomatic, hyponatremic patients (p < 0.0001). Female patients were more likely to develop hyponatremia than male patients (33% compared with 22%, p < 0.03). Fifty-two percent of patients who had transient diabetes insipidus (DI) early in their postoperative course subsequently developed hyponatremia, compared with 21% of those who did not have DI (p < 0.001). Patient age, tumor type, and tumor size did not correlate with development of delayed hyponatremia. Outpatients with moderately and severely low sodium levels were 5 and 12.5 times more likely, respectively, to be symptomatic than were patients with mild hyponatremia.

Conclusions

Delayed hyponatremia occurs more frequently than was previously suspected in patients who have undergone transsphenoidal surgery, especially in female patients and those who have previously had transient DI. The majority of hyponatremic patients remain asymptomatic. Obtaining a serum sodium value on an outpatient basis 1 week after pituitary surgery is helpful in recognition, risk stratification, and subsequent intervention, and may prevent potentially serious complications.
The diagnostic utility of brain biopsy procedures in patients with rapidly deteriorating neurological conditions or dementia
Authors: Josephson S. Andrew , Papanastassiou Alexander M. , Berger Mitchel S. , Barbaro Nicholas M. , McDermott Michael W. , Hilton Joan F. , Miller Bruce L. , Geschwind Michael D.
Published: January 2008

Object

Obtaining brain biopsy specimens is often the diagnostic test of last resort for patients with unexplained neurological conditions, particularly those with a rapidly deteriorating neurological course. The goals of this analysis were to determine the diagnostic sensitivity of brain biopsy specimens in these types of patients and retrospectively identify features of these disorders that may have enabled an earlier diagnosis, which may prevent the need for diagnostic brain biopsy procedures in the future.

Methods

The authors reviewed the case records of all brain biopsy procedures that had been performed at a single tertiary care institution between January 1993 and April 2002 in 171 patients. Patients with HIV or nonlymphomatous brain tumors were excluded from this analysis because the utility of brain biopsy specimens for these conditions has been determined from previous studies. A subgroup analysis of this cohort was performed in the 64 patients who had comprehensive medical records and a clinical syndrome involving a progressively deteriorating neurological condition of less than 1 year in duration.

The overall sensitivity of brain biopsy procedures for diagnostic purposes in the cohort was 65% (111 of 171 patients). The two most common diagnoses in the subgroup with rapidly deteriorating neurological conditions were primary central nervous system (CNS) B-cell lymphoma in 20.3% (13 patients) and Creutzfeldt–Jakob disease in 15.6% (10 patients), followed by viral encephalitis in 14.1% (nine patients) and CNS vasculitis in 9.4% (six patients). Clinical symptoms and laboratory data were compared among the diagnostic groups.

Conclusions

These results will help guide the evaluation of patients with neurological conditions that are difficult to diagnose and will provide a foundation for further prospective studies.
Thirty-day morbidity and mortality rates for carotid artery intervention by surgeons who perform both carotid endarterectomy and carotid artery angioplasty and stent placement
Authors: Ecker Robert D. , Lau Tsz , Levy Elad I. , Hopkins L. Nelson
Published: January 2008

Object

There is no known standard 30-day morbidity and mortality rate for high-risk patients undergoing carotid artery (CA) angioplasty and stent (CAS) placement. The high-risk registries and the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy, Carotid Revascularization using Endarterectomy or Stenting Systems, and European Long-term Carotid Artery Stenting trials report different rates of morbidity and mortality, and each high-risk cohort has a different risk profile. The applicability of carotid endarterectomy (CEA) results from North American Symptomatic Carotid Endarterectomy Trial/Asymptomatic Carotid Atherosclerosis Study (NASCET/ACAS) remains uncertain, as most clinical CAS placement series reported to date typically included patients who would not have qualified for those studies. At the University at Buffalo, the same neurosurgeons perform triage in patients with CA disease and perform both CEA and CAS insertion. The authors review morbidity and mortality rates in this practice model.

Methods

Diagnosis-related group codes were used to search the authors’ practice database for patients who had undergone a completed CA intervention solely for the indication of atherosclerotic disease. One hundred twenty patients (129 vessels) treated with CAS surgery and 95 patients (100 vessels) treated with CEA met these criteria. In the CAS placement group, 78% of the patients would not have met NASCET/ACAS inclusion criteria. Demographic and clinical data for both groups were recorded on a spreadsheet for analysis.

At 30 days, one patient in the CEA group and two in the CAS group had died. Stroke occurred in one patient in the CAS group and none in the CEA group. Myocardial infarction (MI) occurred in one patient who underwent CAS surgery compared with three undergoing CEA. Composite incidence of stroke/death/MI was 3.3% in the CAS group and 3.2% in the CEA group.

Conclusions

In a practice in which surgeons perform both CEA and CAS surgery, the event rates for the CAS surgery equivalent to NASCET and ACAS rates for CEA can be achieved, even in high-risk NASCET/ACAS-ineligible patients in 78% of the CAS cases.
Trends in the incidence of subarachnoid hemorrhage in Akita Prefecture, Japan
Authors: Kozák Norbert , Hayashi Masato
Published: January 2008

Object

The incidence of subarachnoid hemorrhage (SAH) in Japan has been reported to be among the highest in the world. The aim of this study was to analyze the incidence of SAH and its trends in Akita Prefecture, Japan.

Methods

The incidence rate of SAH between January 1, 1989, and December 31, 1998, was investigated using the prospective Akita Stroke Register. Computed tomography scans were obtained in all suspected cases of SAH. During the study period, 3257 patients with their first SAH were registered. The crude annual incidence rates of SAH in men, women, and both sexes were 20, 33, and 27 per 100,000 population per year, respectively. Age-standardized incidence rates remained stable. Crude incidence rates in women increased. In men the incidence reached a plateau after 55 years of age; in women it peaked in the eighth decade of life. The 28-day case fatality rate was 26.7%, without significant changes. Two diurnal peaks were observed: one at 7 a.m. and another at 5 p.m. The incidence was lowest in summer and highest in spring, in both sexes.

Conclusions

The incidence of SAH in patients in Akita Prefecture is similar to that reported in other Japanese studies. The age-standardized incidence rates are stable. The increasing crude incidence in women is probably attributable to the aging of the Japanese population.