bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.