bluuebunny/crossref_metadata_2025 huggingface dataset:
Organization of language areas in bilingual patients: a cortical stimulation study
Authors: Roux Franck-Emmanuel , Trémoulet Michel
Published: May 2009

Object. In an attempt to gain a better understanding of how multiple languages are represented in the human brain, the authors studied bilingual patients who underwent surgery for brain tumors, during which the authors mapped cortical language sites by using electrostimulation.

Methods. Reading, counting, and word retrieval tasks were studied in 12 right-handed bilingual patients with no language deficit. All bilingual patients were native to France. One patient spoke four languages. The patients constituted a nonhomogeneous group in terms of language proficiency or age of acquisition. Languages were evaluated and classified into three major groups, depending on proficiency and date of acquisition. Strict conditions of language site validation were applied, separating typical anomia sites from speech arrest or other language sites (such as hesitation sites). A total of 30 speech arrest sites, 16 anomia sites, and three sites of language difficulties (not typically classified as speech arrest) were found throughout the 26 language studies performed.

Strict overlapping of language areas (for all language tasks) was found in five patients, whereas the remaining seven had at least one area that was language-specific and sometimes task-specific. Specific areas for a particular language were found for word retrieval tasks (anomia) in eight sites (50%) but also in six (20%) of the reading or counting sites (speech arrest), either in frontal (three patients) or in temporoparietal (four patients) regions. Among the four early bilingual patients tested (languages acquired before the age of 7 years), three had language-specific cortical areas. Interestingly, six patients in this series who had a discrepancy between two languages did not have more cortical areas devoted to the less proficient language (with acknowledgment of the limit in cortical exposure available for testing by the craniotomy).

Conclusions. In this series, the authors found that bilingual patients could have common but also different cortical areas for both languages in temporoparietal areas and in frontal areas. In some cases, the authors found that language tasks such as counting, reading, or word retrieval in different languages can be sustained by language- and task-specific cortical areas. In bilingual patients, cortical mapping should ideally be performed using different language tasks in all languages in which the patient is fluent.
Evaluation of the microvasculature and cerebral ischemia after experimental subarachnoid hemorrhage in dogs
Authors: Perkins Eddie , Kimura Hitoshi , Parent Andrew D. , Zhang John H.
Published: May 2009

Object. Whether cerebral vasospasm occurs only in surface vessels or also in parenchymal arterioles is debatable. The present study was undertaken to evaluate comprehensively the microvasculature of the brainstem after experimental subarachnoid hemorrhage (SAH).

Methods. Nine mongrel dogs of either sex, each weighing between 18 and 24 kg, underwent double blood injections spaced 48 hours apart; the injections were infused into the cisterna magna immediately after angiography of the basilar arteries (BAs). Three additional dogs assigned to a control group received no blood injections. The dogs were killed on Day 7. Axial sections obtained from the midpontine region of both control dogs and animals subjected to SAH were evaluated with respect to the morphological characteristics of vessels and neurons, and for ultrastructural changes.

Severe vasospasm occurred in the BAs of all dogs subjected to SAH. Nevertheless, in these animals, the luminal areas and vessel perimeter in parenchymal arterioles, but not in parenchymal venules, were observed to have increased when compared with those of control dogs (p < 0.01, t-test). No corrugation of the internal elastic lamina was observed and smooth-muscle and endothelial cells remained normal at the ultrastructural level in the dogs with SAH.

Conclusions. In this model, vasospasm of the BAs did not extend into the region of the pons to affect the intraparenchymal arterioles. Dilation of the parenchymal arterioles might serve as compensation for reduced blood flow. Thus, no neuronal ischemia or infarction resulted in the pontine region of the brain.
Comparison of different infratentorial—supracerebellar approaches to the posterior and middle incisural space: a cadaveric study
Authors: Ammirati Mario , Bernardo Antonio , Musumeci Angelo , Bricolo Albino
Published: May 2009

Object. The purpose of this investigation was to describe and compare through cadaveric dissection the microsurgical exposure afforded by the median, paramedian, and extreme-lateral infratentorial—supracerebellar approaches to the posterior and middle incisural space.

Methods. The median, paramedian, and extreme-lateral infratentorial—supracerebellar approaches were performed in 10 embalmed cadaveric heads by using standard microneurosurgical methods; each approach was executed a minimum of five times. The dissections were performed in a stepwise fashion, comparing the exposure afforded by each surgical route and highlighting the relationships among the targeted neurovascular structures. Exposure of the dural sinuses and transection of the tentorium were also evaluated in relation to the degree of exposure achieved.

The median infratentorial—supracerebellar route provides direct exposure of the posterior incisural space, although the culmen represents a relative obstacle to exposure of the lower quadrigeminal plate. The paramedian variant allows a more lateral perspective on the posterolateral brainstem surface at the level of the middle incisural space, in addition to exposing the homolateral collicular plate. The extreme-lateral corridor widens the exposure of the paramedian approach to include the anterolateral brainstem surface, offering a complete view of the cisternal space surrounding the middle incisural space. Complete, constant exposure and retraction of the dural sinuses facilitated the surgical exposure.

Conclusions. The infratentorial—supracerebellar approaches allow safe circumferential exposure of the posterior and middle incisural space. Choosing among different variants allows the surgeon to reach selected areas, with the midline variant being best for exposure of the posterior incisural space, and the paramedian and extreme-lateral variants being best for reaching the posterior and the anterior part of the middle incisural space, respectively. The more lateral the approach, the more anterior and multiangled the exposure gained. Complete, constant exposure and retraction of the dural sinuses improves the exposure. Accurate knowledge of the regional anatomy is mandatory.
Neural and marrow—derived stromal cell sphere transplantation in a rat model of traumatic brain injury
Authors: Lu Dunyue , Li Yi , Mahmood Asim , Wang Lei , Rafiq Tahir , Chopp Michael
Published: May 2009

Object. This study was designed to investigate the effect of treatment with a novel composite material consisting of embryonic neurospheres and bone marrow—derived stromal cell spheres (NMSCSs) in a rat model of traumatic brain injury (TBI).

Methods. The NMSCS composite was injected into the TBI contusion site 24 hours after injury, and all rats were killed on Day 14 after the transplantation. The Rotarod test and the neurological severity score were used to evaluate neurological function. The transplanted NMSCS was analyzed in recipient rat brains by using histological staining and laser scanning confocal microscopy. The lesion volumes in the brains were also calculated using computer image analysis.

Conclusions. Rats that received NMSCS transplants had reduced lesion volume and showed improved motor and neurological function when compared with control groups 14 days after the treatment. These results suggest that transplantation of this novel biological material (NMSCS) may be useful in the treatment of TBI.
Origin of surface potentials evoked by electrical stimulation of oculomotor nerves: are they related to electrooculographic or electromyographic events?
Authors: Sasaki Tatsuya , Suzuki Kyouichi , Matsumoto Masato , Sato Taku , Kodama Namio , Yago Keiko
Published: May 2009

Object. Evoked potentials elicited by electrical stimulation of the oculomotor nerve and recorded from surface electrodes placed on the skin around the eyeball reportedly originate in the eye and are represented on electrooculograms. Because evoked potentials recorded from surface electrodes are extremely similar to those of extraocular muscles, which are represented on electromyograms, the authors investigated the true origin of these potentials.

Methods. Evoked potentials elicited by electrical stimulation of the canine oculomotor nerve were recorded from surface electrodes placed on the skin around the eyeball. A thread sutured to the center of the cornea was pulled and the potentials that were evoked during the resultant eye movement were recorded. These potentials were confirmed to originate in the eye and to be represented on electrooculograms because their waveforms were unaffected by the administration of muscle relaxant. To eliminate the influence of this source, the retina, a main origin of standing potentials of the eyeball, was removed. This resulted in the disappearance of electrooculography (EOG) waves elicited by eye movement. Surface potentials elicited by oculomotor nerve stimulation were the same before and after removal of the retina. Again the oculomotor nerve was electrically stimulated and electromyography (EMG) response of the extraocular muscles was recorded at the same time that potentials were recorded from the surface electrodes. In their peak latencies, amplitudes, and waveforms, the evoked potentials obtained from surface electrodes were almost identical to EMG responses of extraocular muscles.

Conclusions. Evoked potentials elicited by electrical stimulation of the oculomotor nerves and obtained from surface electrodes originated from EMG responses of extraocular muscles. These evoked potentials do not derive from the eye.
Reversal of attenuation of cerebrovascular reactivity to hypercapnia by a nitric oxide donor after controlled cortical impact in a rat model of traumatic brain injury
Authors: Zhang Fangyi , Sprague Shane M. , Farrokhi Farrokh , Henry Matthew N. , Son Minnette G. , Vollmer Dennis G.
Published: May 2009

Object. Traumatic brain injury (TBI) attenuates the cerebral vasodilation to hypercapnia. Cortical spreading depression (CSD) also transiently reduces hypercapnic vasodilation. The authors sought to determine whether the CSD elicited by a controlled cortical impact (CCI) injury masks the true effect of TBI on hypercapnic vasodilation, and whether a nitric oxide (NO) donor can reverse the attenuation of hypercapnic vasodilation following CCI.

Methods. Anesthetized rats underwent moderate CCI. Cerebral blood flow was monitored with laser Doppler flowmetry and the response to hypercapnia was determined for injured and sham-injured animals. The effect of the NO donor, S-nitroso-N-acetylpenicillamine (SNAP), on this response was also assessed.

At an uninjured cortical site ipsilateral to the CCI, a single wave of CSD was recorded and the CO2 response at this location was significantly attenuated for up to 30 minutes (seven rats, p < 0.05). At the injured cortex, hypercapnic vasodilation continued to be attenuated for 7 hours. The cerebral vasodilation to CO2 was 37 ± 5% in injured rats (six) compared with 84 ± 10% in the sham-injured group (five rats, p < 0.05). After 30 minutes of topical superfusion with SNAP, hypercapnic vasodilation was restored to 74 ± 7% (nine rats, p > 0.1 compared with that in the sham-injured group). In contrast, papaverine, an NO-independent vasodilator, failed to reverse the attenuation of the CO2 response to CCI.

Conclusions. The authors conclude that CSD elicited by CCI can mask the true effect of TBI on hypercapnic vasodilation for at least 30 minutes. Exogenous NO, but not papaverine, can reverse the attenuation of cerebrovascular reactivity to CO2 caused by TBI. This result supports the hypothesis that NO production is reduced after TBI and that the NO donor has a potential beneficial role in the clinical management of head injury.
Intracerebral Whipple disease: unusual location and bone destruction
Authors: Akar Ziya , Tanriover Necmettin , Tüzgen Saffet , Canbaz Bülent , Erman Haldun , ÖZ Büge , Kuday Cengiz
Published: May 2009

✓ Whipple disease is a rare systemic bacterial infection characterized by migratory polyarthralgia and chronic diarrhea. In 5 to 20% of patients with Whipple disease, the infection may present initially with or eventually develop symptoms related to the central nervous system (CNS). Although CNS involvement is a known feature of systemic Whipple disease, intracerebral mass lesions are uncommon. Mass lesions in these cases are typically deep seated and multifocal. Corticosubcortical regions are unusual sites of CNS involvement in cases of Whipple disease. In the present paper, the authors describe the first case of Whipple disease to feature a single corticosubcortical solid frontoparietal mass lesion that displayed homogeneous contrast enhancement on neuroimaging and was associated with bone destruction of the calvaria. Although CNS involvement has been observed in the form of deep-seated mass lesions in cases of systemic Whipple disease, unusual manifestations should be kept in mind during diagnosis and follow-up review in these patients.
Ventriculoperitoneal shunt failure as a secondary complication of ovarian hyperstimulation syndrome
Authors: Lee Gabriel Yin Foo , Daniel Roy T. , Jones Nigel R.
Published: May 2009

✓ The authors report on a patient who presented with shunt failure due to ovarian hyperstimulation syndrome (OHSS) following in vitro fertilization treatment. Shunt dysfunction was attributed to intraabdominal hypertension as a consequence of ascites. At surgery, the shunt was found to be patent. The peritoneal catheter was externalized and subsequently revised to become a ventriculoatrial shunt system. This led to clinical improvement in the patient and restoration of ventricular size. Such a shunt complication has not previously been reported. Neurosurgeons should be alerted to this possibility in view of the increasing use of assisted conception in many developed countries.
Tonsillectomy without craniectomy for the management of infantile Chiari I malformation
Authors: Lazareff Jorge A. , Galarza Marcelo , Gravori Tooraj , Spinks Theodore J.
Published: May 2009

Object. The authors report their experience with 15 pediatric patients who underwent resection or shrinkage of the cerebellar tonsils without craniectomy or laminectomy, for the management of Chiari I malformation.

Methods. The procedure was performed in six boys and nine girls with a mean age of 10 years. Thirteen patients presented with the congenital form of this disorder and two patients with Chiari I malformation caused by lumboperitoneal shunting. Clinical complaints included headaches (seven patients), scoliosis (four patients), numbness of the extremities (four patients), and upper-limb weakness (two patients). Two patients presented with failure to thrive and one with vocal cord palsy. Eight patients (six girls and two boys) had syringomyelia. The patients' symptoms had developed within a mean time period of 21 months (range 1–70 months). In all patients the cerebellar tonsils were exposed through a dura mater—arachnoid incision at the occipitoatlantal space. In seven patients the tonsils were resected and in the remaining eight patients the tonsils were shrunk by coagulating their surfaces.

All patients improved postoperatively. Gliosis with cortical atrophy was observed in the resected neural tissue. Syringomyelia was reduced in seven of eight patients. The mean length of the follow-up period was 7 months.

Conclusions. Removal of herniated cerebellar tonsils can be sufficient for alleviating symptoms in patients with Chiari I malformations.
Intracranial saccular aneurysm enlargement determined using serial magnetic resonance angiography
Authors: Phan Thanh G. , Huston John , Brown Robert D. , Wiebers David O. , Piepgras David G.
Published: May 2009

Object. The goal of this study was to determine the frequency of enlargement of unruptured intracranial aneurysms by using serial magnetic resonance (MR) angiography and to investigate whether aneurysm characteristics and demographic factors predict changes in aneurysm size.

Methods. A retrospective review of MR angiograms obtained in 57 patients with 62 unruptured, untreated saccular aneurysms was performed. Fifty-five of the 57 patients had no history of subarachnoid hemorrhage. The means of three measurements of the maximum diameters of these lesions on MR source images defined the aneurysm size. The median follow-up period was 47 months (mean 50 months, range 17–90 months).

No aneurysm ruptured during the follow-up period. Four patients (7%) harbored aneurysms that had increased in size. No aneurysms smaller than 9 mm in diameter grew larger, whereas four (44%) of the nine aneurysms with initial diameters of 9 mm or larger increased in size. Factors that predicted aneurysm growth included the size of the lesion (p < 0.001) and the presence of multiple lobes (p = 0.021). The location of the aneurysm did not predict an increased risk of enlargement.

Conclusions. Patients with medium-sized or large aneurysms and patients harboring aneurysms with multiple lobes may be at increased risk for aneurysm growth and should be followed up with MR imaging if the aneurysm is left untreated.
Effectiveness of neurosurgical clip application in patients with aneurysmal subarachnoid hemorrhage
Authors: Brilstra Eva H. , Algra Ale , Rinkel Gabriel J. E. , Tulleken Cornelis A. F. , van Gijn Jan
Published: May 2009

Object. Neurosurgical clip application is the standard method used to prevent rebleeding in patients with aneurysmal subarachnoid hemorrhage (SAH). The authors assessed the magnitude of the reduction in poor outcomes that accompanies a strategy aimed at surgery.

Methods. Three hundred forty-six consecutive patients with aneurysmal SAH were studied. The authors estimated the number of surgically treated patients with good outcomes who would have had poor outcomes as a consequence of rebleeding if clip application had not been performed (A). They also assessed the number of patients whose poor outcomes were exclusively caused by operative complications (B). Without an operation some of these patients would have had poor outcomes because of rebleeding (C). The authors represented the number of patients in whom poor outcome was prevented by surgery with the following formula: A − B + C. They assessed the relationships between baseline characteristics of patients and aneurysms and the likelihood that a patient underwent surgery, the risk of operative complications, and the risk of rebleeding.

The absolute reduction in the risk of poor outcome found in patients who undergo surgery was 9.7%. This implies that to prevent a poor outcome in one patient, surgery had to be performed in 10. The relative risk of poor outcome following surgery compared with that after conservative treatment was estimated to be 0.81. Logistic regression analysis showed a statistically significant relationship between patient age older than 65 years and the occurrence of operative complications (odds ratio [OR] 2.49; 95% confidence interval [CI] 1.03–6.03), between age older than 65 years and the likelihood of undergoing surgery (OR 0.12; 95% CI 0.07–0.2), and between a poor clinical condition at admission and the likelihood of undergoing surgery (OR 0.26; 95% CI 0.14–0.47). The authors did not identify any predictive factors for rebleeding when the Cox proportional hazard model was used.

Conclusions. The beneficial effect of a treatment strategy in which the goal is surgery is substantial. If new treatment modalities such as embolization with coils are explored, these should carefully be compared with surgery before they are generally introduced.
The facial nerve in medial acoustic neuromas
Authors: Strauss Christian
Published: May 2009

Object. Functional results after surgery for acoustic neuromas that have little or no growth within the internal auditory canal are controversial, because these medial tumors can grow to a considerable size within the cerebellopontine angle (CPA) before symptoms occur.

Methods. A prospective study was designed to evaluate the surgical implications of the course of the facial nerve within the CPA on medial acoustic neuromas. This study included a consecutive series of 22 patients with medial acoustic neuromas (mean size 32 mm, range 17–52 mm) who underwent surgery via a suboccipitolateral approach between 1997 and 2001. All patients underwent pre- and postoperative magnetic resonance imaging and preoperative electromyography (EMG). Evaluation was based on continuous intraoperative EMG monitoring and video recordings of the procedure. All patients were reevaluated at a mean of 19 months (6–50 months) postsurgery.

Preoperative evaluation of facial nerve function revealed House—Brackmann Grade I in six, Grade II in 14, and Grade III in two patients. During surgery a distinct splitting of the nerve at the root exit zone through its intracisternal course was seen in eight patients and documented by selective electrical stimulation. The facial nerve was separated into a smaller portion that ran cranially and parallel to the trigeminal nerve, and a larger portion on the anterior tumor surface. Both components joined anterior to the porus without major spreading of the nerve bundle. In two cases the nerve was found on the posterior surface of the cranial tumor. In one case the facial nerve entered the porus of the canal at its lower part, obtaining the expected anatomical position proximally within the middle portion of the canal. An anterior cranial, middle (five cases each), or caudal course (two cases) was seen in the remaining patients. After surgery, facial nerve function deteriorated in most cases; on follow-up evaluation House—Brackmann Grade I was found in 11, Grades II and III in 10, and Grade V in one patient.

Conclusions. The facial nerve requires special attention in surgery for medial acoustic neuromas, because an atypical course of the nerve can be expected in the majority of cases. A split course of the nerve was found in 36% of the cases presented. Meticulous use of intraoperative facial nerve stimulation and continuous monitoring ensures facial nerve integrity and offers good functional results in patients with medial acoustic neuromas.
Functional outcome after gamma knife surgery or microsurgery for vestibular schwannomas
Authors: Régis Jean , Pellet William , Delsanti Christine , Dufour Henry , Roche Pierre Hughes , Thomassin Jean Marc , Zanaret Michel , Peragut Jean Claude
Published: May 2009

Object. Microsurgical excision is an established treatment for vestibular schwannoma (VS). In 1992 the authors used a patient questionnaire to evaluate the functional outcome and quality of life in a series of 224 consecutive patients. In addition, starting with gamma knife surgery (GKS) in 1992, the authors decided to use the same methodology to evaluate prospectively the results of this modality to compare the two alternatives.

Methods. Among the 500 patients who were included prospectively, the authors only evaluated patients in whom GKS was the primary treatment for unilateral VS. Four years of follow up was available for the first 104 consecutive patients. Statistical analysis of the GKS and microsurgery populations has shown that only a comparison of Stage II and III (according to the Koos classification) was meaningful in terms of group size and preoperative risk factor distribution. Objective results and questionnaire answers from the first 97 consecutive patients were compared with the 110 patients in the microsurgery group who fulfilled the inclusion criteria.

Questionnaire answers indicated that 100% of patients who underwent GKS compared with 63% of patients who underwent microsurgery had no new facial motor disturbance. Forty-nine percent of patients who underwent GKS (17% in the microsurgery study) had no ocular symptoms, and 91% of patients treated with GKS (61% in the microsurgery study) had no functional deterioration after treatment. The mean hospitalization stay was 3 days after GKS and 23 days after microsurgery. All the patients who underwent GKS who had been employed, except one, had kept the same professional activity (56% in the microsurgery study). The mean time away from work was 7 days for GKS (130 days in the microsurgery study). Among patients whose preoperative hearing level was Class 1 according to the Gardner and Robertson scale, 70% preserved functional hearing after GKS (Class 1 or 2) compared with only 37.5% in the microsurgery group.

Conclusions. Functional side effects happen during the first 2 years after radiosurgery. Findings after 4 years of follow up indicated that GKS provided better functional outcomes than microsurgery in this patient series.
Intracranial navigation by using low-field intraoperative magnetic resonance imaging: preliminary experience
Authors: Kanner Andrew A. , Vogelbaum Michael A. , Mayberg Marc R. , Weisenberger Joseph P. , Barnett Gene H.
Published: May 2009

Object. Intracranial navigation by using intraoperative magnetic resonance (iMR) imaging allows the surgeon to reassess anatomical relationships in near—real time during brain tumor surgery. The authors report their initial experience with a novel neuronavigation system coupled to a low-field iMR imaging system.

Methods. Between October 2000 and December 2001, 70 neurosurgical procedures were performed using the mobile 0.12-tesla PoleStar N-10 iMR imaging system. The cases included 38 craniotomies, 15 brain biopsies, nine transsphenoidal approaches, and one drainage of a subdural hematoma. Tumor resection was performed using the awake method in seven of 38 cases.

Of the craniotomies, image-confirmed complete or radical tumor resection was achieved in 28 cases, subtotal resection in eight cases, and open biopsies in two cases. Tumor resection was controlled with the use of image guidance until the final intraoperative images demonstrated that there was no residual tumor or that no critical brain tissue was at risk of compromise. In each stereotactic biopsy the location of the biopsy needle could be verified by intraoperative imaging and diagnostic tissue was obtained. Complications included a case of aseptic meningitis after a biopsy and one case of temporary intraoperative failure of the anesthesia machine. Awake craniotomies were performed successfully with no permanent neurological complications.

Conclusions. Intraoperative MR image—based neuronavigation is feasible when using the Odin PoleStar N-10 system for tumor resections that require multiple other surgical adjuncts including awake procedures, cortical mapping, monitoring of somatosensory evoked potentials, or electrocorticography. Use of the system for brain biopsies offers the opportunity of immediate verification of the needle tip location. Standard neurosurgical drills, microscopes, and other equipment can be used safely in conjunction with this iMR imaging system.
Movement-related neurons of the subthalamic nucleus in patients with Parkinson disease
Authors: Abosch Aviva , Hutchison William D. , Saint-Cyr Jean A. , Dostrovsky Jonathan O. , Lozano Andres M.
Published: May 2009

Object. The subthalamic nucleus (STN) is a target in the surgical treatment of Parkinson disease (PD). Little is known about the neurons within the human STN that modulate movement. The authors' goal was to examine the distribution of movement-related neurons within the STN of humans by using microelectrode recording to identify neuronal receptive fields.

Methods. Data were retrospectively collected from microelectrode recordings that had been obtained in 38 patients with PD during surgery for placement of STN deep brain stimulation electrodes. The recordings had been obtained in awake, nonsedated patients. Antiparkinsonian medications were withheld the night before surgery. Neuronal discharges were amplified, filtered, and displayed on an oscilloscope and fed to an audio monitor. The receptive fields were identified by the presence of reproducible, audible changes in the firing rate that were time-locked to the movement of specific joint(s).

The median number of electrode tracks per patient was six (range two–nine). The receptive fields were identified in 278 (55%) of 510 STN neurons studied. One hundred one tracks yielded receptive field data. Fourteen percent of 64 cells tested positive for face receptive fields, 32% of 687 cells tested positive for upper-extremity receptive fields, and 21% of 242 cells tested positive for lower-extremity receptive fields. Sixty-eight cells (24%) demonstrated multiple-joint receptive fields. Ninety-three cells (65%) with movement-related receptive fields were located in the dorsal half of the STN, and 96.8% of these were located in the rostral two thirds of the STN. Analysis of receptive field locations from pooled data and along individual electrode tracks failed to reveal a consistent somatotopic organization.

Conclusions. Data from this study demonstrate a regional compartmentalization of neurons with movement-related receptive fields within the STN, supporting the existence of specific motor territories within the STN in patients suffering from PD.
Administration of interleukin-12 and -18 enhancing the antitumor immunity of genetically modified dendritic cells that had been pulsed with Semliki Forest virus—mediated tumor complementary DNA
Authors: Yamanaka Ryuya , Yajima Naoki , Tsuchiya Naoto , Honma Junpei , Tanaka Ryuichi , Ramsey Jay , Blaese Michael , Xanthopoulos Kleanthis G.
Published: May 2009

Object. Immunogene therapy for malignant gliomas was further investigated in this study to improve its therapeutic efficacy.

Methods. Dendritic cells (DCs) were isolated from bone marrow and pulsed with phosphate-buffered saline or Semliki Forest virus (SFV)—mediated 203 glioma complementary (c)DNA with or without systemic administration of interleukin (IL)-12 and IL-18 to treat mice bearing the 203 glioma. To study the immune mechanisms involved in tumor regression, the authors investigated tumor growth of an implanted 203 glioma model in T cell subset—depleted mice and in interferon (IFN) γ—neutralized mice. To examine the protective immunity produced by tumor inoculation, a repeated challenge of 203 glioma cells was given by injecting the cells into the left thighs of surviving mice and the growth of these cells was monitored.

The authors demonstrated that the combined administration of SFV-cDNA, IL-12, and IL-18 produced significant antitumor effects against the growth of murine glioma cells in vivo and also can induce specific antitumor immunity. The synergic effects of the combination of SFV-cDNA, IL-12, and IL-18 in vivo were also observed to coincide with markedly augmented IFNγ production. The antitumor effects of this combined therapy are mediated by CD4+ and CD8+ T cells and by NK cells. These results indicate that the use of IL-18 and IL-12 in DC-based immunotherapy for malignant glioma is beneficial.

Conclusions. Immunogene therapy combined with DC therapy, IL-12, and IL-18 may be an excellent candidate in the development of a new treatment protocol. The self-replicating SFV system may therefore provide a novel approach for the treatment of malignant gliomas.
The internal acoustic meatus and its meningeal layers: a microanatomical study
Authors: Lescanne Emmanuel , Velut Stéphane , Lefrancq Thierry , Destrieux Christophe
Published: May 2009

Object. The authors studied the cadaveric heads of 22 adults to describe the internal acoustic meatus (IAM) and its contents. Special attention was paid to the length of the arachnoidal and dural sheaths surrounding the neural structures, including the vestibular ganglion. An additional goal of this study was to verify anatomically the concept of arachnoidal duplication, which is reputedly induced by medial growth of vestibular neuromas and helpful in atraumatic dissection.

Methods. Twelve cadaveric heads (24 IAMs) were injected with colored latex and fixed in formalin. Cautious removal of the skull vault and the brain or the skull base allowed superior and anteroinferior views of the IAM, respectively. Photographs were obtained after removal of the bone canal and dissection of the meninges with the aid of optic magnification. Ten IAMs were prepared for histological study and the osteological anatomy of the fundus was endoscopically described for the remaining 10.

The dura mater covered the bone structures of the IAM, and the arachnoidal membrane of the cerebellopontine cistern invaginated into this dural cul-de-sac as a “muff.” The entire neurovascular content of the IAM, including the vestibular ganglion, was surrounded by this arachnoidal sheath in which cerebrospinal fluid circulated. The length of this arachnoidal sheath was the same ventrally and dorsally and, in all specimens, the entrance of the cochleovestibulofacial complex into the subarachnoid space was located at the fundus level.

Conclusions. In this study the authors demonstrated the existence of an acousticofacial cistern containing every nerve of the vestibulocochleofacial complex, including the vestibular ganglion from which acoustic neuromas develop. These findings clearly contradict the theory of the duplication of arachnoidal layers during medial growth of vestibular neuromas and may explain some of the intraoperative difficulties encountered in the atraumatic dissection of these tumors.
The voice of art and the art of medicine
Authors: Pelofsky Stan , Pelofsky Raina
Published: May 2009

✓ Vincent van Gogh's life, letters, and art are the framework for this existential speech about the nature of alienation, as well as its threat to humanity and to the artful practice of medicine. The honest, human voice expressed in van Gogh's art stands in opposition to alienation, which occurs when we divide the world into two parts: the “perfect” world of science versus the “flawed” world of human experience. Bridging this divide allows for an “authentic” life, one which honestly defines itself and faces difficult human truths. The most difficult truth relates to our own mortality, but it must be faced if we are to understand the value of existence. Film clips from Woody Allen's Hannah and Her Sisters illustrate how an artist's portrayal of these issues can be both profound and humorous, and how art brings us closer to our own humanity and to the essence of medicine. Neurosurgeons are warned about the lure of science and technology as a substitute for purpose and meaning, both as physicians and as human beings. The role of the American Association of Neurological Surgeons is explored and found to offer neurosurgeons a bridge away from alienation and toward a neurosurgical community. Neurosurgeons are urged to find meaning through service to their profession and to find the voice and art of medicine.

[Note: Actual film clips were used when this address was delivered. Unofficial transcripts of the clips have been included in this article so that the integrity of the speech would not be compromised.]
Reliability of the oral glucose tolerance test in the early postoperative assessment of acromegaly remission
Authors: Kristof Rudolf A. , Neuloh Georg , Redel Lioba , Klingmüller Dietrich , Schramm Johannes
Published: May 2009

Object. The suppression of growth hormone (GH) to less than 1 µg/L during the oral glucose tolerance test (OGTT) is generally considered to be the standard for the assessment of biochemical remission of GH excess following surgery for GH-secreting pituitary adenomas. In this study the authors examine the reliability of the results of the early postoperative OGTT (epOGTT) in indicating remission or persistence of active acromegaly.

Methods. Data from the case files of 67 consecutive patients who underwent surgery for the first time for GH-secreting pituitary adenomas were reviewed retrospectively. Definitive remission of acromegaly was considered to be present if, without adjuvant therapy and at the most recent follow-up examination, GH was suppressed to less than 1 µg/L during the OGTT, the level of insulin-like growth factor—I (IGF-I) was within normal limits, and there was no clinical or magnetic resonance imaging evidence of persisting disease. The results of the epOGTT (obtained during the 2nd postoperative week) and the 3-month-postoperative OGTT (3mpOGTT) were compared with the patient's outcome at the most recent follow-up examination. A highly sensitive (≤ 0.3 µg/L) immunoradiometric assay for GH and a highly sensitive (≤ 32 µg/L) radioimmunoassay for IGF-I were used.

Correct epOGTT findings were noted in 83.6% of the patients: correct normal results (definitive remission of acromegaly) in 55.2% and correct pathological results (persisting acromegaly) in 28.3% of the patients. The rate of false findings was 16.4%: false normal results in 1.5% and false pathological results in 14.9% of the patients. The rate of correct 3mpOGTT findings increased to 98.5%: correct normal results in 68.6% and correct pathological ones in 29.8% of the patients. A false (false pathological) 3pmOGTT result occurred in only one patient (1.5%). At the most recent follow-up examinations (median 3.6 years) all OGTT findings were correct: correct normal results in 70.1% and correct pathological results in 29.9% of the patients. An intact adenopituitary function was associated (p = 0.04) with the occurrence of false epOGTT findings.

Conclusions. The high rate of false results, 16.4% for the epOGTT, declined significantly to 1.5% 3 months postoperatively and to 0% at the most recent follow-up examination. The OGTT appears to be more reliable at 3 months postoperatively. Unless there is obvious evidence of persisting disease following surgery for GH-secreting pituitary adenomas, adjuvant therapy should be delayed for 3 months postoperatively to avoid subjecting the patient to superfluous treatment.
Plasma endothelin and big endothelin concentrations and serum endothelin-converting enzyme activity following aneurysmal subarachnoid hemorrhage
Authors: Juvela Seppo
Published: May 2009

Object. Pathogenesis of delayed ischemia after aneurysmal subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET)-1 with its powerful and long-lasting vasoconstricting activity. In this prospective study the author investigated the correlations between serial plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 molar concentration ratio and serum endothelin-converting enzyme (ECE)-1 activity, and ischemic complications after SAH.

Methods. To measure plasma ET-1 (51 patients), big ET-1 immunoreactivity (22 patients), and serum ECE-1 activity (13 patients), blood samples were obtained on admission, in the morning after aneurysm surgery, and during the 2nd week after hemorrhage in 51 consecutive patients (28 men and 23 women, with a mean age of 50.8 years) with aneurysmal SAH. Mean plasma concentrations of ET-1 in patients with SAH (mean ± standard deviation: on admission, 4.2 ± 2 pg/ml; after surgery, 4.3 ± 2.2 pg/ml; and during the 2nd week after SAH, 3.7 ± 1.9 pg/ml) differed from those in healthy volunteers (2.9 ± 1.2 pg/ml; p < 0.01). Plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 ratio did not change significantly with elapsed time following SAH; however, serum ECE-1 activity during the 2nd week after SAH was higher in patients with SAH than that in controls (162 ± 43 compared with 121 ± 56 pg/ml, respectively; p = 0.028). Plasma ET-1 concentrations (p < 0.05) and the ET-1/big ET-1 ratios (p = 0.063) were higher but plasma big ET-1 concentrations were lower (p < 0.05) in patients who experienced symptomatic delayed cerebral ischemia, compared with other patients with SAH. In addition, in cases in which follow-up computerized tomography scans or magnetic resonance images demonstrated permanent ischemic lesions attributable to vasospasm, patients had higher ET-1 concentrations than did other patients with SAH.

Conclusions. The plasma ET-1 concentration correlates with delayed cerebral ischemia after SAH, suggesting that an increased ET conversion rate in the endothelium predicts ischemic symptoms. Increased serum ECE-1 activity during the 2nd week may reflect the severity of endothelial injury to cerebral arteries.
Cerebral hemodynamics and metabolism in patients with cerebral arteriovenous malformations: an evaluation using positron emission tomography scanning
Authors: Iwama Toru , Hayashida Kohei , Takahashi Jun C. , Nagata Izumi , Hashimoto Nobuo
Published: May 2009

Object. The purpose of this study was to evaluate cerebral hemodynamic and metabolic features in patients with arteriovenous malformations (AVMs) by using positron emission tomography (PET) scanning.

Methods. Twenty-four patients with supratentorial cerebral AVMs participated in PET studies in which 15O inhalation steady-state methods were used. The authors recorded the values of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), the regional oxygen extraction fraction (rOEF), and the regional cerebral metabolic rate of O2 (rCMRO2) at three designated regions of interest (ROIs) in each patient. These ROIs included perilesional (ROI-p), ipsilateral remote (ROI-i), and contralateral symmetrical (ROI-c) brain regions. To identify the factors that exert a direct effect on the hemodynamics of brains affected by AVM, we also separated the lesions according to their size and flow type shown on angiograms, and grouped the patients according to the presence or absence of progressive neurological deficits. We then compared the PET parameters at different ROIs in individual patients and evaluated the mean values obtained for all 24 patients according to AVM flow type and size, and the presence or absence of progressive neurological deficits.

Conclusions. Overall, mean rCBV and rOEF values were significantly higher in ROI-p than in ROI-c (p = 0.00046 and p = 0.015, respectively). No significant differences were seen between the ROI-i and ROI-c with respect to rCBF, rCBV, and rOEF. Mean rCMRO2 values were similar in the three ROIs; however, the mean rCBF was significantly lower in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.019), large AVMs (p = 0.017), and progressive neurological deficits (p = 0.021). Furthermore, the mean rOEF values were significantly higher in the ROI-p than in the ROI-c in patients with high-flow AVMs (p = 0.005), large AVMs (p = 0.019), and progressive neurological deficits (p = 0.017). The PET studies revealed hemodynamic impairment characterized by decreased rCBF and increased rOEF and rCBV values in the ROI-p of patients with large, high-flow AVMs regardless of whether they exhibited progressive neurological deficits.
Three-dimensional helical computerized tomography angiography in the diagnosis, characterization, and management of middle cerebral artery aneurysms: comparison with conventional angiography and intraoperative findings
Authors: Villablanca J. Pablo , Hooshi Parizad , Martin Neil , Jahan Reza , Duckwiler Gary , Lim Sylvester , Frazee John , Gobin Y. Pierre , Sayre James , Bentson John , Viñuela Fernando
Published: May 2009

Object. Middle cerebral artery (MCA) aneurysms can be difficult to detect and characterize. The authors describe the utility and impact of helical computerized tomography (CT) angiography for the evaluation of aneurysms in this location, and compare this modality with digital subtraction (DS) angiography and intraoperative findings.

Methods. Two hundred fifty-one patients with suspected cerebral aneurysms underwent CT angiography. Two-dimensional multiplanar reformatted images and three-dimensional CT angiograms were examined by two independent readers in a blinded fashion. Results were compared with findings on DS angiograms to determine the relative efficacy of these modalities in the detection and characterization of aneurysms. Questionnaires completed by neurosurgeons and endovascular therapists were used to determine the impact of CT angiograms on aneurysm management.

Twenty-eight patients harboring 31 MCA aneurysms and 26 patients without aneurysms were identified using CT angiography. The sensitivity of CT angiography and DS angiography for MCA aneurysms was 97%; both techniques showed 100% specificity. In 76% of evaluations, the CT angiography studies provided information not available on DS angiography examinations. For the characterization of aneurysms, CT angiography was rated superior (72%) or equal (20%) to DS angiography in 92% of cases evaluated (p < 0.001). Computerized tomography angiography was evaluated as the only study needed for patient triage in 82% of cases (p < 0.001), and as the only study needed for treatment planning in 89% of surgically treated (p < 0.001) and in 63% of endovascularly treated cases (p < 0.001). The information acquired on CT angiograms changed the initial treatment plan in 24 (67%) of these 36 complex lesions (p < 0.01). The aneurysm appearance intraoperatively was identical or nearly identical to that seen on CT angiograms in 17 (89%) of 19 of the surgically treated cases.

Conclusions. Computerized tomography angiography has unique advantages over DS angiography and is a viable alternative to the latter modality in the diagnosis, triage, and treatment planning in patients with MCA aneurysms.