bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereotactic radiosurgery for brainstem arteriovenous malformations: factors affecting outcome
Authors: Maruyama Keisuke , Kondziolka Douglas , Niranjan Ajay , Flickinger John C. , Lunsford L. Dade
Published: May 2009

Object. Management options for arteriovenous malformations (AVMs) of the brainstem are limited. The long-term results of stereotactic radiosurgery for these disease entities are poorly understood. In this report the authors reviewed both neurological and radiological outcomes following stereotactic radiosurgery for brainstem AVMs over 15 years of experience.

Methods. Fifty patients with brainstem AVMs underwent gamma knife surgery between 1987 and 2002. There were 29 male and 21 female patients with an age range of 7 to 79 years (median 35 years). Anatomical locations of these AVMs included the midbrain (39 lesions), pons (20 lesions), and medulla oblongata (three lesions). The radiation dose applied to the margin of the AVM varied from 12 to 26 Gy (median 20 Gy). Forty-five patients were followed up from 5 to 176 months (mean 72 months). The angiographically confirmed actuarial obliteration rate was 66% at the final follow-up examination. Two patients experienced a hemorrhage before obliteration. The annual hemorrhage rate was 1.7% for the first 3 years after radiosurgery and 0% thereafter. Patients who had received irradiation at two or fewer isocenters had higher obliteration rates (80% compared with 44% for > two isocenters, p = 0.006), and this was related to a more spherical nidus shape. The rate of persistent neurological complications in patients treated using magnetic resonance imaging—based dose planning after 1993 was 7%, compared with 20% in patients treated before 1993. An older patient age, a lesion located in the tectum, and a higher radiosurgery-based score were significantly associated with greater neurological complications.

Conclusions. Stereotactic radiosurgery provided complete obliteration of AVMs in two thirds of the patients with a low risk of latency-interval hemorrhage. Better three-dimensional imaging studies and conformal dose planning reduced the risk of adverse radiation effects. Younger patients harboring more spherical AVMs that did not involve the tectal plate had the best outcomes.
Preoperative neuroimaging findings as a predictor of the surgical plane of cleavage: prospective study of 100 consecutive cases of intracranial meningioma
Authors: Alvernia Jorge E. , Sindou Marc P.
Published: May 2009

Object. To understand the cause and prevention of postoperative ischemic and/or venous parenchymal infarcts after intracranial meningioma resection, the authors describe the value of neuroimaging in predicting the surgical plane of cleavage.

Methods. A prospective study of 100 meningiomas was performed, in which tumor size, absence or presence of peritumoral edema, tumor—parenchyma interface, and types of arterial vascularization (that is, dural—meningeal, pial—cortical, or mixed) were correlated with the type of dissection plane (extrapial, subpial, or mixed) encountered at surgery. A direct correlation was found between the tumor size identified on T1-weighted magnetic resonance (MR) imaging sequences and the degree of subpial (nonextrapial) surgical plane of cleavage (p < 0.00001). A similar correlation was found with the grade of peritumoral edema identified on preoperative computerized tomography (CT) scanning (p < 0.0001) or T2-weighted MR imaging sequences (p < 0.00001) and tumor pial vascularization as seen on angiography (p < 0.0001). Nevertheless, the tumor—parenchyma interface on preoperative T2-weighted MR imaging sequences was not predictive of the surgical plane (p > 0.5). The worst clinical outcome was found in the tumors located in eloquent areas and in which a subpial plane was encountered at surgery (p = 0.03).

Conclusions. Peritumoral edema on preoperative CT and MR studies and tumor pial vascularization as seen on selective angiography can be used to predict the surgical plane of cleavage in meningiomas. The association between tumor size and a subpial surgical plane may be explained by a more pial vascularization seen on angiography. Meningiomas with a location in eloquent cortex and a subpial dissection plane should be considered a high-risk group.
The role of transsphenoidal surgery in the treatment of craniopharyngiomas
Authors: Maira Giulio , Anile Carmelo , Albanese Alessio , Cabezas Daniel , Pardi Flaminia , Vignati Andrea
Published: May 2009

Object. The optimal approach for the surgical treatment of craniopharyngiomas is still debated. In all cases involving the sella turcica, the authors have exclusively used transsphenoidal surgery (TSS), assuming that this approach is less traumatic than an intracranial one. Moreover, TSS was also performed in some cases of purely suprasellar craniopharyngiomas. In this study the surgical indications and the results obtained in all patients who had undergone TSS were analyzed.

Methods. In a series of 92 patients who underwent surgery for craniopharyngiomas, TSS was the first choice of approach in 57 cases (62%) consisting of 29 female and 28 male patients with ages ranging from 12 to 79 years (mean 35 years). The follow-up duration ranged from 2 to 20 years. A standard transsphenoidal approach was used in patients with an exclusively intrasellar (11 patients) or an intrasellar and suprasellar tumor (37 patients); in nine cases of tumors located exclusively above the sella turcica, a transsphenoidal presellar approach (seven patients) or a transsellar—transdiaphragmatic approach (two patients) was used. Total removal was performed in 36 patients (63%). All patients had good clinical results. Postoperative cerebrospinal fluid leakage occurred in 10 cases, but only one case required a surgical repair of the sella. Two patients died of late complications (3.5%). There were eight cases (14%) of tumor regrowth.

Conclusions. The authors assert that, when used in appropriately located craniopharyngiomas and by neurosurgeons with extensive experience in pituitary surgery, TSS offers excellent results with minor risks.
Convection-enhanced delivery of paclitaxel for the treatment of recurrent malignant glioma: a Phase I/II clinical study
Authors: Lidar Zvi , Mardor Yael , Jonas Tali , Pfeffer Raphael , Faibel Meir , Nass Dvora , Hadani Moshe , Ram Zvi
Published: May 2009

Object. A minority of patients with recurrent glioblastomas multiforme (GBMs) responds to systemic chemotherapy. The authors investigated the safety and efficacy of intratumoral convection-enhanced delivery (CED) of paclitaxel in patients harboring histologically confirmed recurrent GBMs and anaplastic astrocytomas.

Methods. Fifteen patients received a total of 20 cycles of intratumoral CED of paclitaxel. The patients were observed daily by performing diffusion-weighted (DW) magnetic resonance (MR) imaging to assess the convective process and routine diagnostic MR imaging to identify the tumor response. Effective convection was determined by the progression of the hyperintense signal within the tumor on DW MR images, which corresponded to a subsequent lytic tumor response displayed on conventional MR images. Of the 15 patients, five complete responses and six partial responses were observed, giving a response rate of 73%. The antitumor effect was confirmed by one biopsy and three en bloc resections of tumors, which showed a complete response, and by one tumor resection, which demonstrated a partial response. Lack of convection and a poor tumor response was associated with leakage of the convected drug into the subarachnoid space, ventricles, and cavities formed by previous resections, and was seen in tumors containing widespread necrosis. Complications included transient chemical meningitis in six patients, infectious complications in three patients, and transient neurological deterioration in four patients (presumably due to increased peritumoral edema).

Conclusions. On the basis of our data we suggest that CED of paclitaxel in patients with recurrent malignant gliomas is associated with a high antitumor response rate, although it is associated with a significant incidence of treatment-associated complications. Diffusion-weighted MR images may be used to predict a response by demonstrating the extent of convection during treatment. Optimization of this therapeutic approach to enhance its efficacy and reduce its toxicity should be explored further.
Increase of metabolic activity and disruption of normal contractile protein distribution by bilirubin oxidation products in vascular smooth-muscle cells
Authors: Lyons Melissa A. , Shukla Rakesh , Zhang Kejun , Pyne Gail J. , Singh Meha , Biehle Susan J. , Clark Joseph F.
Published: May 2009

Object. Cerebral vasospasm is a common cause of morbidity and death following aneurysmal subarachnoid hemorrhage (SAH). Previous research has shown that bilirubin oxidation products (BOXes) are present in the cerebral spinal fluid in patients with SAH-induced cerebral vasospasm and can contribute to vasoconstriction and vasospasm in vitro and in vivo. The events leading to cerebral vasospasm are not understood; however, one component of the occlusion may be due to vascular remodeling. In this study the authors have investigated the actions of BOXes, okadaic acid ([OA], a phosphatase inhibitor), and phorbol-12 myristate-13 acetate ([PMA], a protein kinase activator) on vascular smooth-muscle cell (VSMC) morphology and metabolism.

Methods. Immunohistochemical analysis was performed to assess VSMC morphology and α–smooth-muscle actin (αSMA) distribution following the application of BOXes, OA, or PMA. Changes in the level of lactate dehydrogenase (LDH) release and oxidative metabolism were also measured.

The BOXes, OA, or PMA caused VSMCs to change their shape and exhibit altered αSMA distribution. These treatments increased LDH release (p < 0.05), which is an index of increased cell stress. Oxidative metabolism significantly increased at low and high doses of BOXes, that is, 143 ± 8.5% and 180 ± 11.8%, respectively (p < 0.0001). Both PMA and OA also caused a significant increase in metabolism.

Conclusions. The authors concluded that BOXes, OA, and PMA alter VSMC morphology and metabolic activity, events that have been observed during vascular remodeling. Although the mechanism remains unclear, the results indicate that BOXes may play a role in the vascular remodeling that occurs following aneurysmal SAH.
Evaluation of cardiac sympathetic nerve function by myocardial 123I-metaiodobenzylguanidine scintigraphy before and after endoscopic sympathectomy
Authors: Toyota Shingo , Takimoto Hiroshi , Karasawa Jun , Kato Amami , Yoshimine Toshiki
Published: May 2009

Object. The purpose of this study was to analyze the change in cardiac sympathetic function by performing a 123I-metaiodobenzylguanidine (MIBG) imaging study after endoscopic upper thoracic sympathectomy (EUTS) in patients with palmar hyperhidrosis before and after surgery.

Methods. Between February 1999 and February 2002, 135 patients underwent bilateral EUTS to treat palmar hyperhidrosis. Between September 2001 and February 2002, 12 of these consecutively enrolled patients were also included in a 123I-MIBG imaging study. These patients underwent cardiac 123I-MIBG imaging 1 day before and 7 days after they had undergone EUTS. The heart/mediastinum (H/M) ratio and the washout rate were calculated for both early and late phases, and single-photon emission computerized tomography (SPECT) imaging of the early phase was performed.

Excessive perspiration from the palms disappeared immediately after EUTS in all patients, and they showed no symptoms of a circulatory condition following the procedure. On the 123I-MIBG imaging studies, the early H/M ratio before EUTS was 2.35 ± 0.26 and postoperatively it was 2.29 ± 0.23. The delayed H/M ratio before EUTS was 2.59 ± 0.3 and after the procedure it was 2.66 ± 0.27. There was no significant difference between the H/M ratio before and after EUTS. The washout rate after EUTS (14.27 ± 4.71%) was significantly lower than that measured before EUTS (18.36 ± 5.13%; p < 0.01). No apparent local defects of accumulation of MIBG were found on SPECT images obtained post-EUTS.

Conclusions. Endoscopic upper thoracic sympathectomy is a minimally invasive procedure; no local denervation was found after EUTS. Findings on 123I-MIBG imaging studies indicate that EUTS suppresses the activation of the sympathetic nervous system slightly, similar to beta-blocker therapy.
The anatomical basis for surgical preservation of temporal muscle
Authors: Kadri Paulo A. S. , Al-Mefty Ossama
Published: May 2009

Object. Mobilizing the temporal muscle is a common neurosurgical maneuver. Unfortunately, the cosmetic and functional complications that arise from postoperative muscular atrophy can be severe. Proper function of the muscle depends on proper innervation, vascularization, muscle tension, and the integrity of muscle fibers. In this study the authors describe the anatomy of the temporal muscle and report technical nuances that can be used to prevent its postoperative atrophy.

Methods. This study was designed to determine the susceptibility of the temporal muscle to injury during common surgical dissection. The authors studied the anatomy of the muscle and its vascularization and innervation in seven cadavers. A zygomatic osteotomy was performed followed by downward mobilization of the temporal muscle by using subperiosteal dissection, which preserved the muscle and allowed a study of its arterial and neural components.

The temporal muscle is composed of a main portion and three muscle bundles. The muscle is innervated by the deep temporal nerves, which branch from the anterior division of the mandibular nerve. Blood is supplied through a rich anastomotic connection between the deep temporal arteries (anterior and posterior) on the medial side and the middle temporal artery (a branch of the superficial temporal artery [STA]) on the lateral side.

Conclusions. Based on these anatomical findings, the authors recommend the following steps to preserve the temporal muscle: 1) preserve the STA; 2) prevent injury to the facial branches by using subfascial dissection; 3) use a zygomatic osteotomy to avoid compressing the muscle, arteries, and nerves, and for greater exposure when retracting the muscle; 4) dissect the muscle in subperiosteal retrograde fashion to preserve the deep vessels and nerves; 5) deinsert the muscle to the superior temporal line without cutting the fascia; and 6) reattach the muscle directly to the bone.
An investigation of structural degradation of cerebrospinal fluid shunt valves performed using scanning electron microscopy and energy-dispersive x-ray microanalysis
Authors: Sgouros Spyros , Dipple Susan J.
Published: May 2009

Object. Surveys of cerebrospinal fluid (CSF) shunts that have been removed from patients have shown that even when the ventricular catheter is the cause of the obstruction, the valve may be obstructed or underperforming. The aim of this pilot study was to investigate the degradation of shunt valve structure over time due to the deposition of debris. The findings were compared with findings in unused valves.

Methods. Scanning electron microscopy was used to visualize the structures of the valves. The items that were examined included two unused and nine explanted cylindrical medium pressure valves, one unused and six explanted Delta 1.5 valves (PS Medical, Goleta, CA), and one explanted Medos Programmable valve (Codman Johnson & Johnson, LeLocle, Switzerland). The valves were cut open, disassembled, and coated in gold. The areas that were analyzed included the main valve chamber, the diaphragm unit, and the antisiphon device. For areas with abnormal deposits, energy-dispersive x-ray microanalysis was performed to establish the chemical composition of the deposits.

The reference unused valves had smooth surfaces with no deposits in any areas. All explanted valves had extensive deposits in all surveyed areas. The deposits varied from small clusters of crystals to large areas that displayed a cobblestone appearance. In diaphragm valves the deposits extensively affected the surface of the diaphragm and the gap between the diaphragm and the surrounding case, where normally CSF flows; in the Medos valve the deposits affected in the spring and “staircase” unit. Deposits were present as early as 2 weeks after implantation. On some valves there was a complete film covering the entire outlet of the valve, which formed a cast inside the valve stretching from wall to wall. The deposits consisted mostly of sodium and chloride, but occasionally contained calcium. In all infected and some noninfected valves there was a significant peak of carbon, indicating the presence of protein deposits.

Conclusions. It appears that the continuous flow of CSF through shunt valves causes surface deposits of sodium chloride and other crystals on all aspects of the valve, including the outlet pathways. The formation of deposits may be encouraged by the adhesive properties of the materials that constitute the valve parts.
Determining the position and size of the subthalamic nucleus based on magnetic resonance imaging results in patients with advanced Parkinson disease
Authors: Richter Erich O. , Hoque Tasnuva , Halliday William , Lozano Andres M. , Saint-Cyr Jean A.
Published: May 2009

Object. The subthalamic nucleus (STN) is a target in surgery for Parkinson disease, but its location according to brain atlases compared with its position on an individual patient's magnetic resonance (MR) images is incompletely understood. In this study both the size and location of the STN based on MR images were compared with those on the Talairach and Tournoux, and Schaltenbrand and Wahren atlases.

Methods. The position of the STN relative to the midcommissural point was evaluated on 18 T2-weighted MR images (2-mm slices). Of 35 evaluable STNs, the most anterior, posterior, medial, and lateral borders were determined from axial images, dorsal and ventral borders from coronal images. These methods were validated using histological measurements in one case in which a postmortem examination was performed.

The mean length of the anterior commissure—posterior commissure was 25.8 mm. Subthalamic nucleus borders derived from MR imaging were highly variable: anterior, 4.1 to −3.7 mm relative to the midcommissural point; posterior, 4.2 to 10 mm behind the midcommissural point; medial, 7.9 to 12.1 mm from the midline; lateral, 12.3 to 15.4 mm from the midline; dorsal, 0.2 to 4.2 mm below the intercommissural plane; and ventral, 5.7 to 9.9 mm below the intercommissural plane.

The position of the anterior border on MR images was more posterior, and the medial border more lateral, than its position in the brain atlases. The STN was smaller on MR images compared with its size in atlases in the anteroposterior (mean 5.9 mm), mediolateral (3.7 mm), and dorsoventral (5 mm) dimensions.

Conclusions. The size and position of the STN are highly variable, appearing to be smaller and situated more posterior and lateral on MR images than in atlases. Care must be taken in relying on coordinates relative to the commissures for targeting of the STN.
Histological analysis of the location of effective thalamic stimulation for tremor
Authors: Gross Robert E. , Jones Edward G. , Dostrovsky Jonathan O. , Bergeron Catherine , Lang Anthony E. , Lozano Andres M.
Published: May 2009

✓ Chronic electrical stimulation of the thalamus is an effective treatment for essential and parkinsonian tremor. Although the preferred surgical target is generally accepted to lie within the ventral intermediate nucleus (Vim), the relationship between the surgically defined target and the true histologically defined target is addressed in only a few reports, due in large measure to the need for advanced cytoarchitectonic techniques to define the borders of the thalamic nuclei. The authors report on a patient who underwent effective thalamic deep brain stimulation (DBS) for tremor. By defining the boundaries of the thalamic nuclei, they were able to relate effective DBS to electrode location within the anterior region of the ventral posterior lateral nucleus—the proprioceptive shell of the sensory nucleus—and the posteroventral region of the ventral lateral nucleus, which are equivalent to the Vim defined by Hassler, et al.
Intrasellar aneurysm and a growth hormone—secreting pituitary macroadenoma
Authors: Sade Burak , Mohr Gérard , Tampieri Donatella , Rizzo Arthur
Published: May 2009

✓ An aneurysm completely included within a pituitary adenoma that lies inside the sella turcica is rare and challenging from both a diagnostic and treatment viewpoint. A 39-year-old woman presented with symptoms and signs of acromegaly. Magnetic resonance imaging revealed a pituitary macroadenoma, which was associated with an intrasellar aneurysm. Digital subtraction angiography confirmed the presence of the cavernous carotid artery aneurysm. Complete endovascular obliteration of the aneurysm was achieved using Guglielmi Detachable Coils and the patency of the internal carotid artery was maintained. The pituitary adenoma was resected subtotally via a transsphenoidal microsurgical approach 8 months later. Preoperative detection of a coexisting intrasellar aneurysm in a patient with a pituitary adenoma is mandatory to avoid life-threatening hemorrhagic complications. Endovascular coil placement is an effective treatment option when performed before the transsphenoidal removal of the adenoma.
Partial epilepsy presenting as episodic dyspnea: a specific network involved in limbic seizure propagation
Authors: Cohen-Gadol Aaron A. , DiLuna Michael L. , Spencer Dennis D.
Published: May 2009

✓ The authors describe a patient who experienced stereotypical episodes of dyspnea and presyncopal sensation without loss of consciousness during a 4-month period. Further evaluation established intermittent arterial O2 desaturations associated with this dyspnea. After an extensive cardiopulmonary workup was performed for presumptive diagnosis of pulmonary embolism, a brain magnetic resonance image revealed a right medial temporal lobe lesion. The patient's dyspnea was then suspected to be a symptom of a seizure. His shortness of breath and O2 desaturation resolved with administration of phenytoin. This case, to the authors' knowledge, is the first documented example of simple partial seizures presenting with episodic autonomic cardiopulmonary symptoms in the absence of other ictal behavior. This case may also illustrate one specific limbic autonomic network.
Intraoperative stereoscopic QuickTime Virtual Reality
Authors: Balogh Attila , Preul Mark C. , Schornak Mark , Hickman Michael , Spetzler Robert F.
Published: May 2009

Object. The aim of this study was to acquire intraoperative images during neurosurgical procedures for later reconstruction into a stereoscopic image system (QuickTime Virtual Reality [QTVR]) that would improve visualization of complex neurosurgical procedures.

Methods. A robotic microscope and digital cameras were used to acquire left and right image pairs during cranial surgery; a grid system facilitated image acquisition with the microscope. The surgeon determined a field of interest and a target or pivot point for image acquisition. Images were processed with commercially available software and hardware. Two-dimensional (2D) or interlaced left and right 2D images were reconstructed into a standard or stereoscopic QTVR format. Standard QTVR images were produced if stereoscopy was not needed.

Intraoperative image sequences of regions of interest were captured in six patients. Relatively wide and deep dissections afford an opportunity for excellent QTVR production. Narrow or restricted surgical corridors can be reconstructed into the stereoscopic QTVR mode by using a keyhole mode of image acquisition. The stereoscopic effect is unimpressive with shallow or cortical surface dissections, which can be reconstructed into standard QTVR images.

Conclusions. The QTVR system depicts multiple views of the same anatomy from different angles. By tilting, panning, or rotating the reconstructed images, the user can view a virtual three-dimensional tour of a neurosurgical dissection, with images acquired intraoperatively. The stereoscopic QTVR format provides depth to the montage. The system recreates the dissection environment almost completely and provides a superior anatomical frame of reference compared with the images captured by still or video photography in the operating room.
Gamma knife surgery for idiopathic trigeminal neuralgia performed using a far-anterior cisternal target and a high dose of radiation
Authors: Massager Nicolas , Lorenzoni José , Devriendt Daniel , Desmedt Françoise , Brotchi Jacques , Levivier Marc
Published: May 2009

Object. Gamma knife surgery (GKS) has emerged as a suitable treatment of pharmacologically resistant idiopathic trigeminal neuralgia. The optimal radiation dose and target for this therapy, however, remain to be defined. The authors analyzed the results of GKS in which a high dose of radiation and a distal target was used, to determine the best parameters for this treatment.

Methods. The authors evaluated results in 47 patients who were treated with this approach. All patients underwent clinical and magnetic resonance imaging examinations at 6 weeks, 6 months, and 1 year post-GKS. Fifteen potential prognostic factors associated with favorable pain control were studied.

The mean follow-up period was 16 months (range 6–42 months). The initial pain relief was excellent (100% pain control) in 32 patients, good (90–99% pain control) in seven patients, fair (50–89% pain control) in three patients, and poor (< 50% pain control) in five patients. The actuarial curve of pain relief displayed a 59% rate of excellent pain control and a 71% excellent or good pain control at 42 months after radiosurgery. Radiosurgery-induced facial numbness was bothersome for two patients and mild for 18 patients. Three prognostic factors were found to be statistically significant factors for successful pain relief: a shorter distance between the target and the brainstem, a higher radiation dose delivered to the brainstem, and the development of a facial sensory disturbance after radiosurgery.

Conclusions. To optimize pain control and minimize complications of this therapy, we recommend that the nerve be targeted at a distance of 5 to 8 mm from the brainstem.
The role of σ-receptors in levodopa-induced dyskinesia in patients with advanced Parkinson disease: a positron emission tomography study
Authors: Nimura Taro , Ando Tadashi , Yamaguchi Keiichiro , Nakajima Takeshi , Shirane Reizo , Itoh Masatoshi , Tominaga Teiji
Published: May 2009

Object.Levodopa-induced dyskinesia (LID) in patients with Parkinson disease (PD) mimics acute dystonic reactions induced by antipsychotic agents, possibly mediated by σ-receptors; however, there are few reports in which the relationship between σ-receptors and LID in advanced PD is investigated. The binding potential of cerebellar σ-receptors before and after a pallidal surgery for dyskinesia in patients with advanced PD is assessed.

Methods.Six patients with advanced PD (male/female ratio 3:3, age 56.7 ± 9.8 years) underwent stereotactic pallidal surgery (two posteroventral pallidotomy procedures and four deep brain stimulation of the globus pallidus internus, including one bilateral case). Clinical features of patients with PD were assessed using Hoehn and Yahr (H & Y) stages, the Unified Parkinson's Disease Rating Scale (UPDRS), and the Schwab and England Activities of Daily Life Scale (S & E). The LID was evaluated by LID severity score. The binding potential of cerebellar σ-receptors was determined before and after the surgery by11C-nemonapride positron emission tomoraphy, a specific radioligand for σ-receptors in the cerebellum. All clinical scores, especially the LID severity score, were dramatically improved after the surgery (p < 0.05). Preoperatively, contralateral cerebellar binding potential was significantly elevated (p < 0.01), and it was reduced after the surgery, but it was still higher than that of healthy volunteers (p < 0.05). The ipsilateral cerebellar binding potential remained unchanged after the surgery. The level of binding potential did not correlate with H & Y stage, UPDRS, or S & E score, but a strong positive correlation was seen between the binding potential and the preoperative LID severity score when the patients were receiving medication (r = 0.893, p < 0.05).

Conclusions.Cerebellar σ-receptors may potentially involve the genesis of LID in advanced PD.
Transsphenoidal surgery in Cushing disease: 10 years of experience in 34 consecutive cases
Authors: Höybye Charlotte , GrenbäcK Eva , Thorén Marja , Hulting Anna-Lena , Lundblad Lars , von Holst Hans , Änggård Anders
Published: May 2009

Object. Cushing disease is a rare disorder. Because of their small size the adrenocorticotropic hormone (ACTH)—producing tumors are often not detectable on neuroimaging studies. To obtain a cure with transsphenoidal surgery (TSS) may therefore be difficult. In this report the authors present 10 years of experience in the treatment of patients with Cushing disease who were followed up with the same protocol and treated by the same surgeon.

Methods. Thirty-four patients, 26 of them female and eight of them male (mean age 40 years, range 13–74 years) were studied. All had obvious clinical signs and symptoms of Cushing syndrome. Magnetic resonance (MR) imaging was performed in all patients, and inferior petrosal sinus (IPS) sampling was done in 14.

In 12 patients MR imaging indicated a pituitary tumor; 10 were microadenomas and two were macroadenomas. In six patients with no visible tumor, the results of IPS sampling supported the diagnosis. All patients underwent TSS; the mean follow-up duration was 6 ± 0.5 years. Selective adenomectomy was performed in 32 and hemihypophysectomy in the other two patients. A cure was obtained in 31 patients (91%) after one TSS and in two more patients after further TSS; one patient was not cured despite two TSSs and one underwent bilateral adrenalectomy. Disease recurrence was seen in two patients after 3 years, and they were successfully treated with stereotactic gamma knife surgery. Half of the patients had an ACTH deficiency postoperatively, whereas one third had other pituitary hormone insufficiencies. There were no serious complications attributable to the surgical intervention.

Conclusions. Transsphenoidal surgery with selective adenomectomy is an effective and safe treatment for Cushing disease. In the patients presented in this study, the surgical outcome seemed to depend on careful preoperative evaluation and the surgeon's experience. For optimal results in this rare disease the authors therefore suggest that the endocrinological, radiological, and surgical procedures be coordinated in a specialized center.
False localizing sign of C1–2 cerebrospinal fluid leak in spontaneous intracranial hypotension
Authors: Schievink Wouter I. , Maya M. Marcel , Tourje James
Published: May 2009

Object. Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak is an important cause of new daily persistent headaches. Spinal neuroimaging is important in the treatment of these patients, particularly when direct repair of the CSF leak is contemplated. Retrospinal C1–2 fluid collections may be noted on spinal imaging and these are generally believed to correspond to the site of the CSF leak. The authors undertook a study to determine the significance of these C1–2 fluid collections.

Methods. The patient population consisted of a consecutive group of 25 patients (18 female and seven male) who were evaluated for surgical repair of a spontaneous spinal CSF leak. The mean age of the 18 patients was 38 years (range 13–72 years). All patients underwent computerized tomography myelography. Three patients (12%) had extensive retrospinal C1–2 fluid collections; the mean age of this woman and these two men was 41 years (range 39–43 years). The actual site of the CSF leak was located at the lower cervical spine in these patients and did not correspond to the site of the retrospinal C1–2 fluid collection.

Conclusions. A retrospinal fluid collection at the C1–2 level does not necessarily indicate the site of the CSF leak in patients with spontaneous intracranial hypotension. This is an important consideration in the treatment of these patients because therapy may be inadvertently directed at this site.
Bitemporal head crush injuries: clinical and radiological features of a distinctive type of head injury
Authors: Gonzalez Tortosa José , Martínez-Lage Juan F. , Poza Máximo
Published: May 2009

Object. Most craniocerebral injuries are caused by mechanisms of acceleration and/or deceleration. Traumatic injuries following progressive compression to the head are certainly unusual. The authors reviewed clinical and radiological features in a series of patients who had sustained a special type of cranial crush injury produced by the bilateral application of rather static forces to the temporal region. Their aim was to define the characteristic clinical features in this group of patients and to assess the mechanisms involved in the production of the cranial injuries and those of the associated cerebral and endocrine lesions found in this peculiar type of head injury.

Methods. Clinical records of 11 patients were analyzed with regard to the state of consciousness, cranial nerve involvement, findings on neuroimaging studies, endocrine symptoms, and outcome. Furthermore, an experimental model of bitemporal crush injury was developed by compressing a dried skull with a carpenter's vice.

Seven of the 11 patients were 16 years old or younger. All patients presented with a characteristic clinical picture consisting of no loss of consciousness (six patients), epistaxis (nine patients), otorrhagia (11 patients), peripheral paralysis of the sixth and/or seventh cranial nerves (10 patients), hearing loss (five patients), skull base fractures (11 patients), pneumocephalus (11 patients), and diabetes insipidus (seven patients). Ten patients survived the injury and most recovered neurological function.

Conclusions. Static forces applied to the head in a transverse axis produce fractures in the skull base that cross the midline structures without producing significant cerebral damage. Stretching of cranial nerves at the skull base explains the nearly universal finding of paralysis of these structures, whereas an increase in the vertical diameter of the skull accounts for the occurrence of diabetes insipidus in the presence of an intact function of the anterior pituitary lobe. The association of clinical, endocrine, and neuroimaging findings encountered in this peculiar type of head injury supports the idea that this subset of injured patients has a distinctive clinical condition, namely the syndrome of bitemporal crush injury to the head.
Combined treatment of advanced stages of recurrent skin cancer of the head
Authors: Pompucci Angelo , Rea Giancarla , Farallo Eugenio , Salgarello Marzia , Campanella Antonino , Fernandez Eduardo
Published: May 2009

Object.The authors investigated whether skull base resection and primary free-flap reconstruction in a single-stage surgery is oncologically effective for treating advanced stages of recurrent skin cancer (RSC) of the head.

Methods.Eighteen consecutive patients were surgically treated. Twelve of them underwent an anterolateral skull base resection, which was performed using a pterional craniotomy combined with an orbitozygomatic osteotomy. Six patients underwent a posterolateral skull base resection, which was performed using an asterional craniotomy combined with a retrolabyrinthine petrosectomy. The wide postoperative defects were covered with muscular or myocutaneous free flaps.

The main factor influencing survival was the extent of the resection: patients with no or minimal residual disease showed a statistically significant longer survival time than those with consistent residual disease. Basal cell carcinoma had a better prognosis than squamous cell carcinoma. A trend toward improved survival was observed in patients classified as T4M0 with negative lymph nodes (N0), but this trend was not statistically significant. Adjuvant radiotherapy significantly influenced both survival time and the rate of local recurrence. The surgical morbidity rate was 27.8%; there were two transient cerebrospinal fluid leaks and three seventh cranial nerve injuries. Late complications included radionecrosis in one patient and skin erosion requiring a second surgery in another patient. No deaths occurred during a 30-day postoperative period.

Conclusions.Advances in skull base surgery and free-flap reconstruction allowed the authors to treat patients with advanced-stage RSC of the head in a rather satisfactory manner. Only when it is impossible to achieve no or minimal residual disease should aggressive treatment be considered.
Deferoxamine-induced attenuation of brain edema and neurological deficits in a rat model of intracerebral hemorrhage
Authors: Nakamura Takehiro , Keep Richard F. , Hua Ya , Schallert Timothy , Hoff Julian T. , Xi Guohua
Published: May 2009

Object. Previous studies undertaken by the authors have indicated that iron accumulation and oxidative stress in the brain contribute to secondary brain damage after intracerebral hemorrhage (ICH). In the present study the authors investigate whether deferoxamine, an iron chelator, can reduce ICH-induced brain injury.

Methods. Male Sprague—Dawley rats each received an infusion of 100 µl of autologous whole blood into the right basal ganglia and were killed 1, 3, or 7 days later. Iron distribution was examined histochemically (enhanced Perls reaction). The effects of deferoxamine on ICH-induced brain injury were examined by measuring brain edema and neurological deficits. Immunohistochemical analysis was performed to investigate 8-hydroxyl-2′-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and Western blot analysis was performed to measure the amount of apurinic/apyrimidinic endonuclease/redox effector factor—1 (APE/Ref-1), a repair mechanism for DNA oxidative damage.

Iron accumulation was observed in the perihematomal zone from 1 day after ICH. Deferoxamine attenuated brain edema, neurological deficits, and ICH-induced changes in 8-OHdG and APE/Ref-1.

Conclusions. Deferoxamine and other iron chelators may be potential therapeutic agents for ICH. They may act by reducing the oxidative stress caused by the release of iron from the hematoma.
Oligodendroglioma and juvenile pilocytic astrocytoma presenting as synchronous primary brain tumors
Authors: Kan Peter , Gottfried Oren , Blumenthal Deborah T. , Townsend Jeannette J. , Drozd-Borysiuk Ela , Brothman Arthur R. , Jensen Randy L.
Published: May 2009

✓ Multiple metastatic brain tumors and multifocal primary brain tumors of a single histological type are well described in the literature. The concurrent presence of multiple primary brain tumors with different histological characteristics, however, is very rare. The authors describe the first known case in which an oligodendroglioma and a juvenile pilocytic astrocytoma (JPA) presented as synchronous primary brain tumors in the same patient.

This 43-year-old man presented with a 2-month history of progressive headaches, nausea, and vomiting. Magnetic resonance imaging demonstrated an enhancing heterogeneous right medial cerebellar lesion and a larger calcified, nonenhancing, heterogeneous right frontal lesion with surrounding edema and a mass effect. The results of a metastatic workup were unremarkable.

The patient underwent an initial right frontotemporal craniotomy and a subsequent suboccipital craniectomy 2 years later for resection of the posterior fossa lesion. Histological examination revealed the frontal and cerebellar lesions to be an oligodendroglioma and JPA, respectively. A molecular analysis detected a deletion of chromosome 1p36 in the oligodendroglioma, but not in the JPA. After the initial operation, the patient received follow-up care for his oligodendroglioma, but eventually required temozolomide for tumor progression. His condition remains stable both neurologically and according to imaging studies.

The authors describe the first known case in which a low-grade oligodendroglioma and a JPA presented as synchronous primary brain tumors. They review the literature on multiple primary brain tumors with different histological characteristics and discuss potential mechanisms for the development of these lesions.
Complications of preoperative embolization of cerebral arteriovenous malformations
Authors: Taylor Christopher L. , Dutton Kim , Rappard George , Pride G. Lee , Replogle Robert , Purdy Phillip D. , White Jonathan , Giller Cole , Kopitnik Thomas A. , Samson Duke S.
Published: May 2009

Object. Preoperative embolization is viewed by the authors as a useful adjunct in the surgical management of cerebral arteriovenous malformations (AVMs). This study was performed to determine the rate of significant complication in patients undergoing this procedure.

Methods. Demographic, anatomical, and procedure data were collected prospectively. The treating physician reported complications. In addition, a review of medical records including procedure reports, operative reports, and discharge summaries was performed. Univariate statistical analysis was performed to determine if any of the variables was predictive of a poor outcome of embolization (death or permanent neurological deficit).

Endovascular procedures for embolization were performed 339 times in 201 patients during an 11-year period. Female patients comprised 53.7% of the study group and 85.6% of the AVMs were supratentorial. Embolization was performed using polyvinyl alcohol particles, N-butyl cyanoacrylate, detachable coils, and/or the liquid polymer Onyx. Analyzed by procedure, a poor result of embolization occurred in 7.7%. Analyzed by patient, 11% died or had a permanent neurological deficit as a result of the embolization. None of the demographic, anatomical, or procedure variables identified were predictive of a poor outcome.

Conclusions. Preoperative embolization may gradually reduce flow to an AVM, reduce intraoperative blood loss, and reduce operative time. The risks of this procedure, however, are not insignificant and must be considered in planning treatment for patients with AVMs.
Surgical considerations regarding giant dilations of the perivascular spaces
Authors: House Paul , Salzman Karen L. , Osborn Anne G. , MacDonald Joel D. , Jensen Randy L. , Couldwell William T.
Published: May 2009

Object. Dilations of brain perivascular spaces (PVSs), also known as Virchow—Robin spaces, are routinely identified on magnetic resonance imaging studies of the brain and recognized as benign normal variants. Giant dilations occur only rarely and can be easily misdiagnosed as central nervous system tumors. The relevant surgical literature was reviewed to help establish indications for surgical intervention in these typically benign lesions.

Methods. Giant dilations of the PVSs in 12 patients who had undergone surgery for several different indications were identified. Both clinical and radiographic presentations of these patients were reviewed along with the surgical procedures.

Conclusions. Dilations of the PVSs can become giant lesions that may necessitate surgical intervention to relieve mass effect or hydrocephalus. The relationship of these lesions to neurological symptoms such as tremor and seizures remains unclear.
Gamma knife surgery in the management of brain metastases from lung carcinoma: a retrospective analysis of survival, local tumor control, and freedom from new brain metastasis
Authors: Jawahar Ajay , Matthew Ronnie E. , Minagar Alireza , Shukla Deepti , Zhang John H. , Willis Brian K. , Ampil Federico , Nanda Anil
Published: May 2009

Object. The objective of this retrospective study was to analyze the results of stereotactic radiosurgery performed using a gamma knife in the treatment of 44 consecutive patients with brain metastases from lung carcinoma.

Methods. Forty-four patients with lung carcinoma were treated for metastatic brain tumors by performing radiosurgery with a Leksell Gamma Knife. Twenty-one patients (47.7%) were women and 23 were men. The mean age of the patients was 56 years (range 35–77 years). Twenty-two patients (50%) had solitary tumors and the rest had multiple tumors (two—six lesions). Eighteen patients (40.9%) presented with a recurrent and/or progressive brain disease that previously had been treated with other modalities (surgery, external-beam radiotherapy, or both). Fifteen patients had controlled lung disease and 19 patients had systemic metastases (in lymph nodes, liver, and/or bones) at the time of radiosurgery.

The median follow-up period was 18.25 months. All patients were followed up for three different end points: 1) death caused by the disease; 2) clinical and/or radiological evidence of progression of the tumor that had been treated with radiosurgery; and 3) appearance of new lesions. At the last follow-up review, 17 patients (38.6%) were alive and 27 (61.4%) had died. Ten patients (22.7%) died as a result of brain disease (failure of local control or new metastases). Controlled primary disease at the time of detection of metastases and the ability to achieve local tumor control after radiosurgery significantly improved the patient survival (p < 0.01). Control of the treated tumor(s) was achieved in 32 of 44 patients (72 tumors) and 10 patients experienced treatment failure. In addition to the 44 patients comprising the study population, two other patients were treated, but died of lung disease too early in the follow-up period to have been assessed. As of the last follow-up review, no new brain metastasis had occurred in 36 patients (81.8% [includes surviving and nonsurviving patients]). The median duration of overall survival was 7 months, the median period of controlled brain disease was 21 months, and the median period of freedom from new brain metastases was 17 months (95% confidence interval 13–19 months).

Conclusions. Gamma knife surgery has significantly reduced the incidence of mortality from brain disease by effectively accomplishing local tumor control in patients with metastatic lung cancer. Local control and freedom from new brain metastases is not influenced by prior external-beam radiotherapy.