bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlesional central lobule seizures: use of awake cortical mapping and subdural grid monitoring for resection of seizure focus
Authors: Cohen-Gadol Aaron A. , Britton Jeffrey W. , Collignon Frederic P. , Bates Lisa M. , Cascino Gregory D. , Meyer Fredric B.
Published: May 2009

Object. Surgical treatment options for intractable seizures caused by a nonlesional epileptogenic focus located in the central sulcus region are limited. The authors describe an alternative surgical approach for treating medically refractory nonlesional perirolandic epilepsy.

Methods. Five consecutive patients who were treated between 1996 and 2000 for nonlesional partial epilepsy that had originated in the central lobule were studied. The patients' ages ranged from 16 to 56 years (mean 28.6 years; there were four men and one woman). The duration of their epilepsy ranged from 8 to 39 years (mean 20.2 years), with a mean seizure frequency of 19 partial seizures per week. Preoperative assessment included video electroencephalography (EEG) and subtracted ictal—interictal single-photon emission computerized tomography coregistered with magnetic resonance imaging (SISCOM). Patients underwent an awake craniotomy stereotactically guided by the ictal EEG and SISCOM studies. Cortical stimulation was used to identify the sensorimotor cortex and to reproduce the patient's aura. A subdural grid was then implanted based on these results. Subsequent postoperative ictal electrocorticographic recordings and cortical stimulation further delineated the site of seizure onset and functional anatomy. During a second awake craniotomy, a limited resection of the epileptogenic central lobule region was performed while function was continuously monitored intraoperatively. One resection was limited to the precentral gyrus, two to the postcentral gyrus, and in two the excisions involved regions of both the pre- and postcentral gyri.

In three patients a hemiparesis occurred postsurgery but later resolved. In the four patients whose resection involved the postcentral gyrus, transient cortical sensory loss and apraxia occurred, which completely resolved in three. Two patients are completely seizure free, two have experienced occasional nondisabling seizures, and one patient has benefited from a more than 75% reduction in seizure frequency. The follow-up period ranged from 2 to 5.5 years (mean 3.5 years).

Conclusions. A limited resection of the sensorimotor cortex may be performed with acceptable neurological morbidity in patients with medically refractory perirolandic epilepsy. This procedure is an alternative to multiple subpial transections in the surgical management of intractable nonlesional epilepsy originating from the sensorimotor cortex.
Treatment and outcome in 30 patients with posterior cerebral artery aneurysms
Authors: Taylor Christopher L. , Kopitnik Thomas A. , Samson Duke S. , Purdy Phillip D.
Published: May 2009

Object. The records of 30 patients with posterior cerebral artery (PCA) aneurysms treated during a 12-year period were reviewed to determine outcome and the risk of visual field deficit associated with PCA sacrifice.

Methods. Clinical data and treatment summaries for all patients were maintained in an electronic database. The Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores were determined by an independent registrar. Visual field changes were determined by review of medical records. Twenty-eight patients were treated with open surgery, one of them after an attempt at detachable coil embolization failed. Two patients underwent successful endovascular PCA sacrifice.

The mean GOS and mRS scores in 18 patients with unruptured aneurysms were 4 and 2, respectively, at discharge. Subarachnoid hemorrhage (SAH) from other aneurysms and neurological deficits caused by the PCA lesion or underlying disease contributed to poor outcomes in this group. The mean GOS and mRS scores in 12 patients with ruptured aneurysms were 4 and 4, respectively, at discharge. One patient died of severe vasospasm. Neurological deficits secondary to SAH and, in one patient, treatment of a concomitant arteriovenous malformation contributed to poor outcomes in the patients with ruptured aneurysms. Seven patients with normal visual function preoperatively underwent PCA occlusion. One patient (14%) developed a new visual field deficit.

Conclusions. Optimal treatment of PCA aneurysms is performed via one of several surgical approaches or by endovascular therapy. The approach is determined, in part, by the anatomical location and size of the aneurysm and the presence of underlying disease and neurological deficits.
Mutational analysis of 206 families with cavernous malformations
Authors: Laurans Maxwell S. H. , DiLuna Michael L. , Shin Dana , Niazi Faheem , Voorhees Jennifer R. , Nelson-Williams Carol , Johnson Eric W. , Siegel Adrian M. , Steinberg Gary K. , Berg Michel J. , Scott R. Michael , Tedeschi Gioacchino , Enevoldson T. Peter , Anson John , Rouleau Guy A. , Ogilvy Christopher , Awad Issam A. , Lifton Richard P. , Gunel Murat
Published: May 2009

Object. A gene contributing to the autosomal-dominant cerebral cavernous malformation (CCM) phenotype, KRIT1 (an acronym for Krev Interaction Trapped 1), has been identified through linkage analysis and mutation screening. The authors collected blood samples from 68 patients with familial CCM and 138 patients with apparently sporadic CCM as well as from their families, in an effort to characterize the prevalence and spectrum of disease-causing sequence variants in the KRIT1 gene.

Methods. The authors used single-strand conformational polymorphism analysis to identify genomic variants in KRIT1, which were sequenced to determine the specific mutation. Among 43 Hispanic-American kindreds who immigrated to the southwestern US from northern Mexico, 31 share an identical founder mutation. This Q455X mutation is found in 18 (86%) of 21 persons with a positive family history and in 13 (59%) of 22 persons with apparently sporadic CCM. This mutation was not found among 13 persons with CCM who were recruited from Mexico. These findings establish the key role of a recent founder mutation in Hispanic persons with CCM who live in the US.

Although nearly all Hispanic families in the US in which there are multiple CCM cases linked to the CCM1 locus, only 13 of 25 non-Hispanic CCM-carrying families have displayed evidence of linkage to the CCM1 locus. Among these 13 families, the authors identified eight independent mutations in nine kindreds. They identified four additional mutations among 22 familial CCM kindreds with no linkage information, bringing the total number of independent mutations to 12. Inherited KRIT1 mutations were not detected among 103 non-Hispanic persons in whom a family history of CCM was rigorously excluded.

Conclusions. All mutations were nonsense mutations, frame-shift mutations predicting premature termination, or splicesite mutations located throughout the KRIT1 gene, suggesting that these are genetic loss-of-function mutations. These genetic findings, in conjunction with the clinical phenotype, are consistent with a two-hit model for the occurrence of CCM.
Efficacy of moderate hypothermia in patients with severe head injury and intracranial hypertension refractory to mild hypothermia
Authors: Shiozaki Tadahiko , Nakajima Yoshikazu , Taneda Mamoru , Tasaki Osamu , Inoue Yoshiaki , Ikegawa Hitoshi , Matsushima Asako , Tanaka Hiroshi , Shimazu Takeshi , Sugimoto Hisashi
Published: May 2009

Object. This study was performed to determine whether moderate hypothermia (31°C) improves clinical outcome in severely head injured patients whose intracranial hypertension cannot be controlled using mild hypothermia (34°C).

Methods. Twenty-two consecutive severely head injured patients who fulfilled the following criteria were included in this study: an intracranial pressure (ICP) that remained higher than 40 mm Hg despite the use of mild hypothermia combined with conventional therapies; and a Glasgow Coma Scale score of 8 or less on admission. After the failure of mild hypothermia in combination with conventional therapies; patients were exposed to moderate hypothermia as quickly as possible. As brain temperature was reduced from 34 to 31°C, the volume of intravenous fluid infusion was increased significantly from 1.9 ± 0.9 to 2.6 ± 1.2 mg/kg/hr (p < 0.01), and the dose of dopamine infusion increased significantly from 4.3 ± 3.1 to 8.2 ± 4.4 µg/kg/min (p < 0.01). Nevertheless, mean arterial blood pressure and heart rate decreased significantly from 97.1 ± 13.1 to 85.1 ± 10.5 mm Hg (p < 0.01) and from 92.2 ± 13.8 to 72.2 ± 14.3 beats/minute at (p < 0.01) at 34 and 31°C, respectively. Arterial base excess was significantly aggravated from −3.3 ± 4 at 34°C to −5.6 ± 5.4 mEq/L (at 31°C; p < 0.05). Likewise, serum potassium concentration, white blood cell counts, and platelet counts at 31°C decreased significantly compared with those at 34°C (p < 0.01).

In 19 (86%) of 22 patients, elevation of ICP could not be prevented using moderate hypothermia. In the remaining three patients, ICP was maintained below 40 mm Hg by inducing moderate hypothermia; however, these three patients died of multiple organ failure. These results clearly indicate that moderate hypothermia induces complications more severe than those induced by mild hypothermia without improving outcomes.

Conclusions. The authors concluded that moderate hypothermia is not effective in improving clinical outcomes in severely head injured patients whose ICP remains higher than 40 mm Hg after treatment with mild hypothermia combined with conventional therapies.
Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used
Authors: Hanlo Patrick W. , Cinalli Giuseppe , Vandertop W. Peter , Faber Joop A. J. , Bøgeskov Lars , Børgesen Svend E. , Boschert Jürgen , Chumas Paul , Eder Hans , Pople Ian K. , Serlo Willy , Vitzthum Eckehard
Published: May 2009

Object. The goal of this study was to evaluate the long-term results of a flow-regulating shunt (Orbis Sigma Valve [OSV] II Smart Valve System; Integra NeuroSciences, Sophia Antipolis, France) in the treatment of hydrocephalus, whether it was a first insertion procedure or surgical revision of another type of shunt, in everyday clinical practice in a multicenter prospective study.

Methods. Patients of any age who had hydrocephalus underwent implantation of an OSV II system. The primary end point of the study was defined as any shunt-related surgery. The secondary end point was a mechanical complication (shunt obstruction, overdrainage, catheter misplacement, migration, or disconnection) or infection. The overall 5-year shunt survival rates and survival as it applied to different patient subgroups were assessed.

Five hundred fifty-seven patients (48% of whom were adults and 52% of whom were children) were selected for OSV II shunt implantation; 196 patients reached the primary end point. Shunt obstruction occurred in 75 patients (13.5%), overdrainage in 10 patients (1.8%), and infection in 46 patients (8.2%). The probability of having experienced a shunt failure—free interval at 1 year was 71% and at 2 years it was 67%; thereafter the probability remained quite stable in following years (62% at the 5-year follow-up examination). No difference in shunt survival was observed between the overall pediatric (≤ 16 years of age) and adult populations. In the pediatric age group, however, there was a significantly lower rate of shunt survival in children younger than 6 months of age (55% at the 5-year follow-up examination).

Conclusions. In this prospective study the authors demonstrate the effectiveness of flow regulation in the treatment of hydrocephalus both in children and in adults. Flow-regulating shunts limit the incidence of overdrainage and shunt-related complications. The overall 5-year shunt survival rate (62%) compares favorably with rates cited in other recently published series.
A waitlist control-group study of cognitive, mood, and quality of life outcome after posteroventral pallidotomy in Parkinson disease
Authors: Carr Jason A. R. , Honey Christopher R. , Sinden Marci , Phillips Anthony G. , Martzke Jeffrey S.
Published: May 2009

Object. The aim of this study was to examine neuropsychological outcome from unilateral posteroventral pallidotomy (PVP) in Parkinson disease while controlling for confounding factors such as test practice and disease progression.

Methods. Participants underwent baseline and 2-month follow-up assessments of cognition, quality of life, mood, and motor functioning. The surgery group (22 patients) underwent PVP (15 left, seven right) after baseline assessment. The waitlist group (14 patients) underwent PVP after follow up. At follow up, the left PVP group exhibited a decline on verbal measures of learning, fluency, working memory, and speeded color naming. The incidence of significant decline on these measures after left PVP ranged from 50 to 86%. The right PVP group did not exhibit a significant cognitive decline, but fluency did decline in 71% of patients who underwent right PVP. Participants who underwent PVP reported better bodily pain and social functioning at follow up than participants in the waitlist group. Improved bodily pain was evident for 62% of the surgery group, and social functioning improved for 19%. Surgery did not alter reported physical functioning or mood. Dyskinesia improved after surgery, but there were no improvements in “on-state” manual dexterity or handwriting.

Conclusions. Most patients who underwent left PVP exhibited declines in learning, fluency, working memory, and speeded color naming. Accounting for retesting effects altered the magnitude of these declines by up to one quarter of a standard deviation, but did not increase the breadth of postsurgical neuropsychological decline beyond that typically reported in the literature. It was found that PVP improved dyskinesia, bodily pain, and social functioning, but did not lead to improvement on other objective and self-reported measures of motor functioning.
Subarachnoid hemorrhage—induced upregulation of the 5-HT1B receptor in cerebral arteries in rats
Authors: Hansen-Schwartz Jacob , Hoel Natalie Løvland , Xu Cang-Bao , Svendgaard Niels-Aage , Edvinsson Lars
Published: May 2009

Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture—induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH.

Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription—polymerase chain reaction (PCR).

In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed.

Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.
Microscopic measurement of the facial nerve root exit zone from central glial myelin to peripheral Schwann cell myelin
Authors: Tomii Masato , Onoue Hisashi , Yasue Masaharu , Tokudome Shogo , Abe Toshiaki
Published: May 2009

Object. The authors have attempted to define the exact borders of the root exit zone (RExZ) of the facial nerve, measure the distribution of myelin histologically, and examine the relationship between contact vessels and the RExZ.

Methods. Seventy-five facial nerves were obtained from brainstems excised from 44 adult patients at autopsy. The arteries and veins associated with the facial nerve were counted and measured. The facial nerves, associated vasculature, and adjoining portions of the brainstem were then removed en bloc. These tissues were serially sectioned and stained, and a photomicrograph of each section was obtained. The distribution of myelin on each section was measured from the upper edge of the supraolivary fossette, and the relationship between contact vessels and the RExZ was examined.

The lateral transitional zone of the facial nerve began 8 mm distal to the upper edge of the supraolivary fossette (root exit point [RExP]) and had a mean length of 1.9 mm. The root detachment point (RDP) of the facial nerve at the medial side was located very close to the beginning of the medial transitional zone. In more than 80% of the nerves that were examined, vascular structures compressed the central glial myelin of the nerve.

Conclusions. The authors propose the use of the terms “RExP,” “RDP,” and “transitional zone,” instead of RExZ, which cannot be well defined. The RDP appears to be a good landmark for use during microvascular decompression.
Spinal cord stimulation reducing infarct volume in a model of focal cerebral ischemia in rats
Authors: Sagher Oren , Huang Dah-Luen , Keep Richard F.
Published: May 2009

Object. The authors previously showed that spinal cord stimulation (SCS) increases cerebral blood flow in rats, indicating that this technique may be useful in the treatment of focal cerebral ischemia. In the present study, the neuroprotective potential of SCS in the setting of middle cerebral artery occlusion (MCAO) was investigated.

Methods. The authors induced permanent, focal cerebral ischemia by using either suture-induced occlusion or direct division of the MCA in Sprague—Dawley rats. Electrical stimulation of the cervical spinal cord was performed during cerebral ischemia. Cerebral blood flow was assessed using both laser Doppler flowmetry (LDF) and quantitative radiotracer analysis. Stroke volumes were analyzed after 6 hours of ischemia.

Spinal cord stimulation resulted in a 52.7 ± 13.3% increase in LDF values (nine animals). Following MCAO, LDF values decreased by 64.1 ± 3.6% from baseline values (10 animals). Spinal cord stimulation subsequently increased LDF values to 30.9 ± 13.5% below original baseline values. These findings were corroborated using radiotracer studies. Spinal cord stimulation in the setting of transcranial MCAO significantly reduced stroke volumes as well (from 203 ± 33 mm3 [control] to 32 ± 8 mm3 [MCAO plus SCS], seven animals in each group, p < 0.001). Similarly, after suture-induced MCAO, SCS reduced stroke volumes (from 307 ± 29 mm3 [control] to 78 ± 22 mm3 [MCAO plus SCS], 10 animals in each group, p < 0.001).

Conclusions. A strategy of performing SCS for the prevention of critical ischemia is feasible and may have the potential for the treatment and prevention of stroke.
Accessory intraventricular prominence of the occipital horn of the lateral ventricle
Authors: Vandewalle Giovani , Beuls Emile , Vanormelingen Linda , Vandersteen Marjan
Published: May 2009

Object. Knowledge of normal variations in ventricular morphological features is important in endoscopic neurosurgery. Classically, two elevations are described on the medial wall of the occipital horn of the lateral ventricle: an upper bulb and a lower calcar avis. Nevertheless, a third, as yet unreported elevation may be present at the junction of the medial wall and the floor of the occipital horn. The authors report the frequency with which this third elevation was found in a series of cadaveric brains.

Methods. The medial wall of the occipital horn of the lateral ventricle was studied in the three orthogonal planes in 45 formalin-fixed cadaveric hemispheres. The underlying structures responsible for the observed intraventricular prominences were exposed by microdissection.

A third elevation was present, lying ventrorostral to the calcar avis, in seven (47%) of the 15 single hemispheres, and bilaterally in six (40%) of the 15 whole brains. After microdissection, a fiber bundle from the splenium of the corpus callosum was seen emerging in the occipital horn at the angle between the tail of the hippocampus and the bulb of the occipital horn. The most rostral fibers fanned out inferolaterally along the floor of the collateral trigone. The larger, posterior part protruded into the medial wall along the ventral border of the calcar avis as far as the tip of the occipital horn.

Conclusions. Besides its importance as a variation of normal ventricular morphological features, the close relationship of this accessory intraventricular prominence to the tail of the hippocampus should be kept in mind when intervening neurosurgically so that damage to the underlying commissural fibers can be avoided.
Application of shock waves as a treatment modality in the vicinity of the brain and skull
Authors: Nakagawa Atsuhiro , Kusaka Yasuko , Hirano Takayuki , Saito Tsutomu , Shirane Reizo , Takayama Kazuyoshi , Yoshimoto Takashi
Published: May 2009

Object. Shock waves have not previously been used as a treatment modality for lesions in the brain and skull because of the lack of a suitable shock wave source and concerns about safety. Therefore, the authors have performed experiments aimed at developing both a new, compact shock wave generator with a holmium:yttrium-aluminum-garnet (Ho:YAG) laser and a safe method for exposing the surface of the brain to these shock waves.

Methods. Twenty male Sprague—Dawley rats were used in this study. In 10 rats, a single shock wave was delivered directly to the brain, whereas the protective effect of inserting a 0.7-mm-thick expanded polytetrafluoroethylene (ePTFE) dural substitute between the dura mater and skull before applying the shock wave was investigated in the other 10 rats. Visualizations on shadowgraphy along with pressure measurements were obtained to confirm that the shock wave generator was capable of conveying waves in a limited volume without harmful effects to the target. The attenuation rates of shock waves administered through a 0.7-mm-thick ePTFE dural substitute and a surgical cottonoid were measured to determine which of these materials was suitable for avoiding propagation of the shock wave beyond the target.

Conclusions. Using the shock wave generator with the Ho:YAG laser, a localized shock wave (with a maximum overpressure of 50 bar) can be generated from a small device (external diameter 15 mm, weight 20 g). The placement of a 0.7-mm-thick ePTFE dural substitute over the dura mater reduces the overpressure of the shock wave by 96% and eliminates damage to surrounding tissue in the rat brain. These findings indicate possibilities for applying shock waves in various neurosurgical treatments such as cranioplasty, local drug delivery, embolysis, and pain management.
Simultaneous use of bilateral subthalamic nucleus stimulators and an implantable cardiac defibrillator
Authors: Rosenow Joshua M. , Tarkin Howard , Zias Elias , Sorbera Carmine , Mogilner Alon
Published: May 2009

✓ Bilateral electrical stimulation of the subthalamic nucleus is being used with increasing frequency as a treatment for severe Parkinson disease (PD). Implantable cardiac defibrillators improve survival in certain high-risk patients with coronary artery disease and ventricular arrhythmias. Because of concern about possible interaction between these devices, deep brain stimulation (DBS) systems are routinely disconnected before defibrillators are implanted in patients with PD and arrhythmia. The authors report on a patient with bilateral subthalamic stimulators who underwent successful placement of an implantable defibrillator. Testing of the devices over a wide range of settings revealed no interaction. The patient subsequently underwent multiple episodes of cardioversion when the ventricular lead became dislodged. There was no evidence of adverse neurological effects, and interrogation of the DBS devices after cardioversion revealed no changes in stimulus parameters. The outcome in this case indicates that DBS systems may be safely retained in selected patients who require implantable cardiac defibrillators.
Osler and the “medico-chirurgical neurologists”: Horsley, Cushing, and Penfield
Authors: Feindel William
Published: May 2009

✓ Sir Victor Horsley's lecture “On the Technique of Operations on the Central Nervous System,” delivered in Toronto in 1906, set the stage for an appraisal of Sir William Osler as a protagonist for the emerging specialty of neurosurgery.

During his time at McGill University from 1871 to 1884, Osler performed more than 1000 autopsies. His pathological reports covered the topics of cerebral aneurysm, apoplectic hemorrhage, vascular infarction, subdural hematoma, meningitis, multiple sclerosis, cerebral abscess, and brain tumor. He wrote about cerebral localization and anatomy and the relationships between the morphological characteristics of the brain and intelligence and criminality. During his continuing career at Philadelphia and Baltimore, Osler published widely on problems in clinical neurology, including monographs on cerebral palsies and chorea as well as chapters on disorders of the nervous system in the first five editions of his popular textbook, The Principles and Practice of Medicine. He became familiar with many of the outstanding figures in medical neurology of his time.

Regarding neurosurgery, Osler commended the pioneer operation for a brain tumor in 1884 by Rickman Godlee and the surgery for epilepsy in 1886 by Horsley. In 1907, in discussing the state of brain surgery as reviewed by Horsley, William Macewen, and others, Osler made a plea for “medico-chirurgical neurologists, properly trained in the anatomical, physiological, clinical and surgical aspects of the subject.” He played a significant role as a referring physician, mentor, and friend to his young colleague Harvey Cushing (later to become Osler's Boswell), who was breaking new ground in neurosurgery at Johns Hopkins Hospital. Beyond that Osler became an inspiring hero figure for his Oxford student Wilder Penfield, who a few decades later would establish a neurological institute at McGill University where medico-chirurgical neurology would flourish.
Unruptured paraclinoid aneurysms: a management strategy
Authors: Iihara Koji , Murao Kenichi , Sakai Nobuyuki , Shindo Atsushi , Sakai Hideki , Higashi Toshio , Kogure Shuji , Takahashi Jun C. , Hayashi Katsuhiko , Ishibashi Toshihiro , Nagata Izumi
Published: May 2009

Object. To elucidate an optimal management strategy for unruptured paraclinoid aneurysms, the authors retrospectively reviewed their experience in the treatment of 100 patients who underwent 112 procedures for 111 paraclinoid aneurysms performed using direct surgery and/or endovascular treatment.

Methods. Between 1997 and 2002, 111 unruptured paraclinoid aneurysms categorized according to a modified al-Rodhan classification (Group Ia, 30 anterior wall lesions; Group Ib, 25 ventral paraclinoid lesions; Group II, 18 true ophthalmic artery lesions; Group III, 37 carotid cave lesions; and Group IV, one transitional lesion) were treated by direct surgery (35 lesions) and/or endovascular treatment (77 lesions) (one aneurysm was treated by both procedures). In lesions in Groups Ia, Ib, II, and III that were treated by endovascular treatment, complete aneurysm obliteration was achieved in 50, 65, 50, and 78%, respectively, and the combined transient and permanent morbidity rates due to cerebral embolic events were 20, 25, 20, and 13.9%, respectively. Overall, the transient morbidity rate after endovascular treatment was 14.3% and the permanent morbidity rate was 6.5%. Notably, permanent visual deficits caused by retinal embolism occurred after endovascular treatment in two patients with Group II aneurysms. Direct surgery was mainly performed in Groups Ia (20 lesions), Ib (five lesions), and II (eight lesions), with complete neck clip occlusion achieved in 80, 80, and 71.4%, respectively; the transient and permanent morbidity rates associated with aneurysms treated by surgery were 8.6 and 2.9%, respectively.

Conclusions. Endovascular therapy for superiorly projecting paraclinoid aneurysms (Groups Ia and II) is associated with lower rates of complete obliteration than direct surgery, and with rates of cerebral embolic events comparable to those of endovascular treatment in the other groups. Furthermore, endovascular treatment for Group II aneurysms entails additional risks of retinal embolism. Therefore, direct surgery is recommended for the treatment of paraclinoid aneurysms projecting superiorly. For other groups, especially for Group III, endovascular treatment is the acceptable first line of therapy.
Smaller cerebral aneurysms producing more extensive subarachnoid hemorrhage following rupture: a radiological investigation and discussion of theoretical determinants
Authors: Russell Stephen M. , Lin Ke , Hahn Sigrid A. , Jafar Jafar J.
Published: May 2009

Object. The goal of this study was to determine the relationship between aneurysm size and the volume of subarachnoid hemorrhage (SAH).

Methods. One hundred consecutive patients who presented with acute SAH, which was diagnosed on the basis of a computerized tomography (CT) scan within 24 hours postictus and, subsequently, confirmed to be aneurysmal in origin by catheter angiography, were included in this study. The data were collected prospectively in 32 patients and retrospectively in 68. The volume of SAH on the admission CT scan was scored in a semiquantitative manner from 0 to 30, according to a previously published method.

The mean aneurysm size was 8.3 mm (range 1–25 mm). The mean SAH volume score was 15 (range 0–30). Regression analysis revealed that a smaller aneurysm size correlated with a more extensive SAH (r2 = 0.23, p < 0.0001). Other variables including patient sex and age, intraparenchymal or intraventricular hemorrhage, multiple aneurysms, history of hypertension, and aneurysm location were not statistically associated with a larger volume of SAH.

Conclusions. Smaller cerebral aneurysm size is associated with a larger volume of SAH. The pathophysiological basis for this correlation remains speculative.
Dose—volume prediction of radiation-related complications after proton beam radiosurgery for cerebral arteriovenous malformations
Authors: Barker Fred G. , Butler William E. , Lyons Sue , Cascio Ethan , Ogilvy Christopher S. , Loeffler Jay S. , Chapman Paul H.
Published: May 2009

Object. The use of radiosurgery for the treatment of cerebral arteriovenous malformations (AVMs) and other lesions demands an accurate understanding of the risk of radiation-related complications. Some commonly used formulas for predicting risk are based on extrapolation from small numbers of animal experiments, pilot human treatment series, and theoretical radiobiological considerations. The authors studied the incidence of complications after AVM radiosurgery in relation to dose, volume, and other factors in a large patient series.

Methods. A retrospective review was conducted in 1329 patients with AVM treated by Dr. Raymond Kjellberg at the Harvard Cyclotron Laboratory (HCL) between 1965 and 1993. Dose and volume were obtained from HCL records, and information about patient follow up was derived from concurrent clinical records, questionnaires, and contact with referring physicians. Multivariate logistic regression with bootstrapped confidence intervals was used.

Follow up was available in 1250 patients (94%); the median follow-up duration was 6.5 years. The median radiation dose was 10.5 Gy and the median treatment volume was 33.7 cm3. Twenty-three percent of treated lesions were smaller than 10 cm3. Fifty-one permanent radiation-related deficits occurred (4.1%). Of 1043 patients treated with a dose predicted by the Kjellberg isoeffective centile curve to have a less than 1% complication risk, 1.8% suffered radiation-related complications. Actual complication rates were 4.7% for 128 patients treated at Kjellberg risk centile doses of 1 to 1.8%, and 34% for 61 patients treated at risk centile doses of 2 to 2.5%. The fitted logistic model showed that complication risk was related to treatment dose and volume, thalamic or brainstem location, and patient age.

Conclusions. The Kjellberg isoeffective risk centile curve significantly underpredicted actual risks of permanent complications after proton beam radiosurgery for AVMs. Actual risks were best predicted using a model that accounted for treatment dose and volume, lesion location, and patient age.
Cocaine use as a predictor of outcome in aneurysmal subarachnoid hemorrhage
Authors: Howington Jay U. , Kutz Scott C. , Wilding Gregory E. , Awasthi Deepak
Published: May 2009

Object. The goal of this study was to analyze the relationship between cocaine use and outcomes of aneurysmal subarachnoid hemorrhage (SAH).

Methods. A retrospective review was performed of the medical records of patients with intracranial aneurysms treated at a single institution between January 1996 and December 2001. Only patients who presented with SAH were included in the study. The covariates chosen for the statistical analysis included the following: patient age, sex, and race; systolic and mean arterial blood pressure measurements on hospital admission; Hunt and Hess and Fisher grades; preexistent major systemic disease; and history of alcohol, tobacco, or cocaine use. The Glasgow Outcome Scale (GOS) was used to standardize outcome and was dichotomized such that a score between 1 and 3 was considered a poor outcome and a score of 4 or 5 was considered a favorable outcome.

The records of 151 patients were reviewed and 108 of these presented with aneurysmal SAH. Of these 108 patients, 36 (33.3%) had used cocaine within 24 hours before presentation. A Hunt and Hess grade of IV or V was assigned to 20 (55.6%) of 36 patients who used cocaine, compared with eight (11.1%) of 72 patients who did not; this difference was found to be statistically significant (p < 0.0001). Twenty-eight patients (77.8%) in the cocaine user group and 20 patients (27.8%) in the non—cocaine user group experienced clinically significant, angiographically confirmed vasospasm during their hospital course (p < 0.0001). Cocaine use was associated with a 2.8-fold greater risk of developing vasospasm (95% confidence interval [CI] 1.86–4.22). A GOS score of 1, 2, or 3 was assigned to 33 patients (91.7%) in the cocaine user group and to 20 patients (27.8%) in the non—cocaine user group (p < 0.0001). Cocaine use was associated with a 3.3-fold greater risk of poor outcome (95% CI 2.24–4.85). This association was found to be independent of Hunt and Hess grade as well as of vasospasm.

Conclusions. Cocaine adversely affects both the presentation of and outcome in patients with aneurysmal SAH who are undergoing treatment for this disease. The vasoactive properties of the drug appear to aggravate the already tenuous situation of SAH and increase both the occurrence and influence of cerebral vasospasm. Statistical analysis demonstrates that cocaine directly affects both presentation and outcome in a significant manner. It is the authors' interpretation of the results of this retrospective review that cocaine use negatively affects outcome to such an extent that it should be considered equal to the presence of a major systemic illness when determining Hunt and Hess grade.
Efficacy of aprotinin in children undergoing craniofacial surgery
Authors: D'Errico Celia C. , Munro Hamish M. , Buchman Steven R. , Wagner Deborah , Muraszko Karin M.
Published: May 2009

Object. This prospective, randomized, placebo-controlled, double-blind trial was undertaken to assess the efficacy of aprotinin in reducing the need for blood transfusions in 39 children undergoing reconstructive craniofacial surgery.

Methods. Two demographically similar groups—a total of 39 patients with a mean age of 1.2 ± 1.2 years—were studied. The efficacy of aprotinin (240 mg/m2 administered intravenously over 20 minutes, followed by infusions of 56 mg/m2/hr) was compared with that of an equal infusion of 0.9% saline (placebo).

Patients in the aprotinin group received less blood per kilogram of body weight than patients in the placebo group (32 ± 25 ml/kg compared with 52 ± 34 ml/kg, respectively; p = 0.04). Those patients in whom aprotinin was administered experienced less change in their hematocrit levels during surgery (aprotinin −33 ± 13% compared with placebo −44 ± 9%, p = 0.01). Each patient underwent a transfusion as per study protocol, and there was no significant change in hematocrit levels from the beginning to the end of surgery. The surgical faculty judged blood loss in patients in the aprotinin group to be significantly less than usual (p = 0.03). The use of aprotinin was also associated with reduced blood transfusion requirements during the first 3 postoperative days (p = 0.03). There was no adverse event reported in either the aprotinin or placebo group.

Conclusions. Aprotinin decreased blood transfusion requirements in pediatric patients undergoing craniofacial reconstruction, thereby reducing the risks associated with exposure to banked blood components.
Surgical experience in 130 pediatric patients with Chiari I malformations
Authors: Tubbs R. Shane , McGirt Matthew J. , Oakes W. Jerry
Published: May 2009

Object. The aim of this study was to present the long-term findings of a surgical series of pediatric patients with Chiari I malformations.

Methods. One hundred thirty symptomatic pediatric patients with Chiari I malformations underwent posterior fossa decompression. The age in this group of patients ranged from 2 months to 20 years (mean 11 years). The length of the hospital stay extended from 2 to 7 days (mean 2.7 days), and follow up was from 3 months to 15 years (mean 4.2 years). Patients most often presented with headache/neck pain (38%) and scoliosis (18%). Examples of associated diagnoses included neurofibromatosis Type 1 (5.5%), hydrocephalus (11%), idiopathic growth hormone deficiency (5.5%), and Klippel—Feil anomaly (5%). Syringes were present in 58% of patients. Seventeen percent of patients had caudal displacement of the brainstem and fourth ventricle. Postoperative relief of preoperative pathologies was experienced in 83% of patients. Of the most common presenting symptoms—headache/neck pain and scoliosis—12 and 17%, respectively, were not alleviated postoperatively. Complications occurred in 2.3% of this group and included the development of acute hydrocephalus postoperatively and severe life-threatening signs of brainstem compression that necessitated a transoral odontoidectomy. Nine patients have had to undergo repeated operations for continued symptoms or persistent large syringes. During surgery 10 patients (7.7%) were found to have arachnoid veils occluding the fourth ventricular outlet, and nine of these had syringomyelia. In our experience almost all syringes will stabilize or improve with posterior fossa decompression and duraplasty.

Conclusions. The authors believe this to be the largest reported series of pediatric patients who have undergone posterior fossa decompression for Chiari I malformations.
Shared oligodendrocyte lineage gene expression in gliomas and oligodendrocyte progenitor cells
Authors: Bouvier Corinne , Bartoli Catherine , Aguirre-Cruz Lucinda , Virard Isabelle , Colin Carole , Fernandez Carla , Gouvernet Joany , Figarella-Branger Dominique
Published: May 2009

Object. Gliomas (astrocytic and oligodendroglial) are the most frequently occurring primary neoplasms in the central nervous system (CNS). Histological classification, which can be performed to distinguish astrocytomas from oligodendrogliomas, is essentially based on pathological features and has great prognostic and therapeutic value but lacks reproducibility. Specific markers of cell lineage, especially those for oligodendrogliomas, are still lacking. The oligodendrocyte lineage (OLIG) genes, transcriptional factors of the basic helix-loop-helix family, have been recently identified in oligodendrocyte progenitor cells (OPCs) in the CNS of developing and adult rodents. Data from a few studies have shown in a small series of brain tumors that OLIG genes characterize oligodendrogliomas. To search for a differential expression of the OLIG genes in subgroups of brain tumors, the authors investigated OLIG1 and OLIG2 gene expression.

Methods. Using semiquantitative reverse transcription—polymerase chain reaction (RT-PCR), the authors analyzed a series of 89 tumors (71 astrocytic and oligodendroglial tumors, eight ependymomas, three medulloblastomas, four meningiomas, and three schwannomas) and normal human brain tissue samples. It was demonstrated that OLIG gene expression was largely limited to glial tumors, that is, astrocytomas and oligodendrogliomas. A very low level was detected in ependymomas, whereas other tumors lacked OLIG gene expression altogether. Surprisingly, OLIG1 and OLIG2 expression was not limited to oligodendroglial tumors, but was observed in astrocytic lesions as well, independent of tumor grade. Interestingly, these genes were expressed at the highest level in pilocytic astrocytomas according to semiquantitative RT-PCR results, which were confirmed on dot blot analysis. In situ hybridization showed that the OLIG2 gene was expressed by tumor cells in pilocytic astrocytomas as well as those in oligodendrogliomas.

Conclusions. The OLIG genes are additional markers shared by all gliomas and OPCs. These markers may help to classify gliomas, to improve understanding of their histogenesis, and to identify new therapeutic targets.
Neural—dural transition at the medial anterior cranial base: an anatomical and histological study with clinical applications
Authors: Dare Amos O. , Balos Lucy L. , Grand Walter
Published: May 2009

Object. Few anatomical studies have been focused on the morphological features and microscopic anatomy of the transition from the intracranial space to the medial anterior cranial base. The authors of the current study performed histological analyses to define the structure of the transition from neural foramina to the cranial base (neural—dural transition) at the cribriform plate, particularly as related to cerebrospinal fluid (CSF) fistula formation and surgical intervention in the region.

Methods. The medial anterior cranial base was resected in six cadaveric specimens. Histological methods were used to study the anatomy of the region on the microscopic level. Results of these examinations revealed a multilayered neural—dural transition at the cribriform plate, which consisted of an arachnoid membrane and a potential subarachnoid space as well as dura mater, periosteum, ethmoid bone, and associated layers of submucosa and mucosa of the paranasal air spaces. A subarachnoid space was identified around the olfactory nerves as they exited the neural foramina of the cribriform plates. The dura mater eventually thinned out and became continuous with the periosteum in the ethmoid bone. The dura, arachnoid membrane, and associated potential subarachnoid space were obliterated at a place 1 to 2 mm into the olfactory foramen. The authors present a case of recurrent CSF rhinorrhea successfully treated using a technique of multilayered reconstruction with pericranium, fat, and bone.

Conclusions. The findings provide an anatomical basis for CSF fistula formation in the region of the cribriform plate and help to explain the unusual presentations in patients who have CSF rhinorrhea and meningitis. These results may facilitate the treatment of CSF fistulas, repair of defects in the medial anterior cranial base, and approaches to tumors and other pathological entities in the region.
The sphenopetroclival venous gulf: a microanatomical study
Authors: Iaconetta Giorgio , Fusco Mario , Samii Madjid
Published: May 2009

Object. The sphenopetroclival area is the border zone between the middle and posterior cranial fossa. Several authors have studied the microsurgical anatomy of this region and have furnished sometimes contradictory descriptions of this area, which still represents a great challenge for the neurosurgeon. On the basis of previous anatomical data reported in the literature, the authors undertook a new microanatomical analysis of the sphenopetroclival region and report their findings.

Methods. Twenty human cadaveric heads were used to reproduce, in the laboratory, different skull base approaches to expose the petroclival area. Measurements were taken in 40 specimens.

From this study has emerged the finding that the sphenopetroclival area is a venous space, which the authors have named the “sphenopetroclival venous gulf” (SPCVG). The SPCVG is filled anteriorly by blood from the cavernous sinus (lateral sellar compartment [LSC], medially by blood from the basilar plexus, and laterally by blood from the superior petrosal sinus; this venous gulf is drained by the inferior petrosal sinus. The SPCVG is comparable in shape to an irregular hedron figure. It contains the Dorello canal, the venous segment of the abducent nerve, and the superior sphenopetrosal (Gruber) ligament, the fibers of which are in anatomical continuity with those of the inferior sphenopetrosal (petrolingual) ligament, forming a “falciform ligament.”

Conclusions. The structures defining the posterior surface of the SPCVG may represent a helpful surgical corridor through which it is possible to approach the LSC via the posterior fossa. This conceptualization of the SPCVG is an attempt to define univocally the microanatomy of the sphenopetroclival region in its entirety.