bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thalamic stimulation and functional magnetic resonance imaging: localization of cortical and subcortical activation with implanted electrodes
Authors: Rezai Ali R. , Lozano Andres M. , Crawley Adrian P. , Joy Michael L. G. , Davis Karen D. , Kwan Chun L. , Dostrovsky Jonathan O. , Tasker Ronald R. , Mikulis David J. 
Published: January 2008

The utility of functional magnetic resonance (fMR) imaging in patients with implanted thalamic electrodes has not yet been determined. The aim of this study was to establish the safety of performing fMR imaging in patients with thalamic deep brain stimulators and to determine the value of fMR imaging in detecting cortical and subcortical activity during stimulation.
Functional MR imaging was performed in three patients suffering from chronic pain and two patients with essential tremor. Two of the three patients with pain had undergone electrode implantation in the thalamic sensory ventralis caudalis (Vc) nucleus and the other had undergone electrode implantation in both the Vc and the periventricular gray (PVG) matter. Patients with tremor underwent electrode implantation in the ventralis intermedius (Vim) nucleus. Functional MR imaging was performed during stimulation by using a pulse generator connected to a transcutaneous extension lead. Clinically, Vc stimulation evoked paresthesias in the contralateral body, PVG stimulation evoked a sensation of diffuse internal body warmth, and Vim stimulation caused tremor arrest.
Functional images were acquired using a 1.5-tesla MR imaging system. The Vc stimulation at intensities provoking paresthesias resulted in activation of the primary somatosensory cortex (SI). Stimulation at subthreshold intensities failed to activate the SI. Additional stimulation-coupled activation was observed in the thalamus, the secondary somatosensory cortex (SII), and the insula. In contrast, stimulation of the PVG electrode did not evoke paresthesias or activate the SI, but resulted in medial thalamic and cingulate cortex activation. Stimulation in the Vim resulted in thalamic, basal ganglia, and SI activation.
An evaluation of the safety of the procedure indicated that significant current could be induced within the electrode if a faulty connecting cable (defective insulation) came in contact with the patient. Simple precautions, such as inspection of wires for fraying and prevention of their contact with the patient, enabled the procedure to be conducted safely. Clinical safety was further corroborated by performing 86 MR studies in patients in whom electrodes had been implanted with no adverse clinical effects.
This is the first report of the use of fMR imaging during stimulation with implanted thalamic electrodes. The authors' findings demonstrate that fMR imaging can safely detect the activation of cortical and subcortical neuronal pathways during stimulation and that stimulation does not interfere with imaging. This approach offers great potential for understanding the mechanisms of action of deep brain stimulation and those underlying pain and tremor generation.
Workforce demand for neurosurgeons in the United States of America: a 13-year retrospective study
Authors: Friedlich Daniel L. , Feustel Paul J. , Popp A. John 
Published: January 2008

Object
The workforce demand for neurosurgeons was quantified by a review and an analysis of journal recruitment advertisements published over the past 13 years.

Methods
A retrospective analysis of recruitment advertisements from July 1985 through June 1998 was performed by examining issues of the Journal of Neurosurgery and Neurosurgery. Advertisement information that appeared in each journal during the last 3 years was collected from alternating months (July to May); information that appeared prior to that time was collected from alternating recruitment years back to 1985. The authors examined the following workforce parameters: practice venue, subspecialization, and practice size.
They found no significant decrease in neurosurgical recruitment advertisements. There was an average of 102.7 ± 22.4 (standard deviation) advertised positions per year during the most recent 3 years compared with 92.6 ± 17.9 advertised positions per year during the preceding decade. Similarly, there has been no decline in advertised positions either in academic (33 ± 6.1/year for the most recent 3 years compared with 32.8 ± 5.9/year for 1985–1995) or private practice (69.7 ± 21.6/year for the most recent 3 years compared with 59.8 ± 13.4/year for 1985–1995). A shift in demand toward subspecialty neurosurgery was observed. During the past 3 years, 31.2 ± 5.9% of advertised positions called for subspecialty expertise, compared with 18.5 ± 2.8% for the preceding decade (p < 0.05). The largest number of subspecialty advertisements designated positions for spine and pediatric neurosurgeons. Private practice advertisements increasingly sought to add neurosurgeons to group practices.

Conclusions
Contrary to previous reports and a prevailing myth, our data show no decrease in workforce demand for neurosurgeons in the United States over the past 3 years compared with the prior decade. A shift toward subspecialist recruitment, particularly for spine neurosurgeons, has been demonstrated in both academic and private practice venues.
Neuroendoscopic approach to tectal tumors: a consecutive series
Authors: Oka Kazunari , Kin Yoshiaki , Go Yoshinori , Hirakawa Katsuyuki , Tomonaga Masamichi , Inoue Tohru , Yoshioka Susumu 
Published: January 2008

The authors report a consecutive series of 10 patients who presented with signs and symptoms caused by tectal tumors. Clinical findings, radiographic features, neuroendoscopic management strategies, and histological findings are reported and discussed.
Since January 1990, 11 neuroendoscopic procedures were performed in 10 patients who harbored tectal tumors. The patients were followed for an average of 5 years (range 2 months to 12 years), and a retrospective study was conducted in which case notes, radiological findings, operative notes, and histopathological findings were assessed. Magnetic resonance (MR) imaging was performed, and the images were used to classify patients into three groups: those with hypertrophy of the tectum in whom isointensity appeared on T1-weighted images (Group 1); those with a tectal tumor occupying the cerebral aqueduct in whom decreased signal intensity appeared on T1-weighted images, as well as no enhancement after gadolinium administration (Group 2); and those with a tectal tumor in whom mixed signal intensity appeared on T1-weighted images and conspicuous evidence of contrast enhancement (Group 3). The results of histological examination were consistent with MR imaging features: in Group 1, glial tissue or gliosis; in Group 2, benign astrocytoma; and in Group 3, malignant astrocytoma. Cerebrospinal fluid diversion was the only surgical treatment that provided relief from obstructive hydrocephalus. One patient in Group 3 underwent radiotherapy and subsequent partial tumor removal under neuroendoscopic guidance. Thereafter, the tumor remained in decline. All patients had normal intellectual status after undergoing surgery in which a neuroendoscope was used.
Neuroendoscopic procedures can provide histological diagnosis, define the tumor-midbrain interrelationship, and be highly effective in treating obstructive hydrocephalus and in removing tectal tumors. This procedure may receive clinical application as a new management strategy for tectal glioma.
Endoscopy of the posterior fossa and endoscopic dissection of acoustic neuroma
Authors: Göksu Nebil , Bayazit Yildirim , Kemaloglu Yusuf 
Published: January 2008

The objective of this study was to evaluate the importance of endoscopes in eliminating the disadvantage of posterior fossa approach--that is, the lack of adequate visualization obtained of the lateral aspect of the internal acoustic canal (IAC).
Over a 10-year period 32 patients underwent removal of acoustic neuroma (AN) via a combined retrosigmoid retrolabyrinthine approach (CRSRL). Endoscopes were used at different stages of the operation, and their use was evaluated with regard to elimination of the disadvantages of the posterior fossa approach.
All patients in whom AN had been diagnosed underwent surgery. A standard combined retrosigmoid retrolabyrinthine approach was performed. Standard sinus endoscopes of 0, 30, and 70° were introduced into the cerebellopontine angle before debulking the tumor, and the IAC was inspected at the end of the operation. Neurovascular integrity as well as the relationship between AN and surrounding structures were evaluated. The IAC was inspected for residual tumor, and if any was found, endoscopic tumor dissection was performed.
Endoscopes have facilitated the understanding of the relationship between AN and neighboring neurovascular structures. The disadvantage of posterior fossa approach can be eliminated by using endoscopes.
In surgery in which the posterior fossa approach is performed, endoscopes can be used to make operations safer. In addition to allowing inspection of the fundus, it is possible to perform tumor dissection within the IAC by using the endoscopes.
Fatal subarachnoid hemorrhage after endoscopic third ventriculostomy
Authors: Schroeder Henry W. S. , Warzok Rolf W. , Assaf Jamal A. , Gaab Michael R. 
Published: January 2008

In recent years, endoscopic third ventriculostomy has become a well-established procedure for the treatment of various forms of noncommunicating hydrocephalus. Endoscopic third ventriculostomy is considered to be an easy and safe procedure. Complications have rarely been reported in the literature. The authors present a case in which the patient suffered a fatal subarachnoid hemorrhage (SAH) after endoscopic third ventriculostomy.
This 63-year-old man presented with confusion and drowsiness and was admitted in to the hospital in poor general condition. Computerized tomography scanning revealed an obstructive hydrocephalus caused by a tumor located in the cerebellopontine angle. An endoscopic third ventriculostomy was performed with the aid of a Fogarty balloon catheter. Some hours postoperatively, the patient became comatose. Computerized tomography scanning revealed a severe perimesencephalic-peripontine SAH and progressive hydrocephalus. Despite emergency external ventricular drainage, the patient died a few hours later.
Although endoscopic third ventriculostomy is considered to be a simple and safe procedure, one should be aware that severe and sometimes fatal complications may occur. To avoid vascular injury, perforation of the floor of the third ventricle should be performed in the midline, halfway between the infundibular recess and the mamillary bodies, just behind the dorsum sellae.
Anterior thoracic intradural arachnoid cysts
Authors: Caruso Gerardo , Germanò Antonino , Caffo Mariella , Belvedere Massimo , La Rosa Giovanni , De Divitiis Oreste , Tomasello Francesco 
Published: January 2008

Anterior thoracic intradural arachnoid cysts (ATIACs) are a rare cause of spinal cord and nerve root compression, for which different treatment strategies have been proposed. Although ATIAC represents a well-known clinical entity, the choice of surgical method has not been uniform, and no study has been specifically designed to compare the results of the different treatment options adopted.
The authors report the case of a 40-year old man with a 1-year history of dorsal pain, weakness in the lower extremities, gait disturbance, and mild sexual and urinary dysfunction. On neurological examination spastic paraparesis, lower-extremity hypertonia, and hypesthesia below T-2 were demonstrated. Magnetic resonance imaging revealed the presence of an ATIAC at the T-2 level. The patient underwent complete microsurgical removal of the cyst.
The authors conducted a Medline search of the relevant literature from 1966 to 1998 and also obtained data on other cases in which patients underwent surgical treatment of ATIAC. The literature search yielded five such cases. Treatment strategies were complete excision and fenestration followed by placement of a shunt. In addition, one case was characterized by intraoperative cyst rupture during retraction of the spinal cord.
Correct preoperative workup coupled with microneurosurgical technique allow for successful removal of the lesion and excellent outcome. Based on the literature review and the results in our case, the complete excision of ATIAC is associated with an excellent outcome, which is different from results achieved using other surgical strategies.
Painful supernumerary phantom arm following motor cortex stimulation for central poststroke pain
Authors: Canavero Sergio , Bonicalzi Vincenzo , Castellano Giancarlo , Perozzo Paula , Massa-Micon Barbara 
Published: January 2008

In this report, the authors describe a case in which the patient began to experience a supernumerary phantom arm after she received motor cortex stimulation for central pain. The patient had a history of right thalamocapsular stroke. It is speculated that the motor cortex activation triggered a response in the patient's parietal lobe, precipitating perception of the phantom limb.
To the authors' knowledge this is the first reported case of its kind.
Endoscopic transpedicular thoracic discectomy
Authors: Jho Hae-Dong 
Published: January 2008

Object
To minimize the invasiveness and maximize the adequacy of the decompressive proceedure in thoracic discectomy, a 70° endoscope was adopted to perform transpedicular thoracic discectomy.

Methods
A posterior transpedicular approach was performed via a 2-cm transverse skin incision, using the operating microscope or a 0°-lens endoscope. Using a 70°-lens endoscope, discectomy was performed after obtaining direct visualization of the ventral aspect of the spinal cord dura mater. This surgical technique has been used in 25 patients. There were 12 men and 13 women whose age ranged from 29 to 70 years (median 46 years). Thirteen patients experienced myelopathy, with or without radiculopathy, 10 presented with radiculopathy, and two patients suffered from segmental pain. The follow-up period ranged from 4 to 60 months (median 27 months). In 12 of the 13 patients with myelopathy, excellent improvement was shown postoperatively. In the remaining patient, symptoms recurred when she was injured in a motor vehicle accident 3 months postsurgery. In nine of 10 patients with radiculopathy pain resolved completely. In the one patient with right-sided hypochondral pain and in the two patients with segmental pain no relief was obtained despite excellent discectomy results that were demonstrated on postoperative magnetic resonance images. The average length of hospital stay was overnight.

Conclusions
The use of a 70°-lens endoscope via a transpedicular route has made thoracic discectomy comparable with cervical or lumbar discectomy in its surgical invasiveness, in the patient's recovery time, and in complexity of surgical procedure.
Thoracoscopic microsurgical excision of herniated thoracic discs
Authors: Rosenthal Daniel , Dickman Curtis A. 
Published: January 2008

Object
The authors began using thoracoscopy to treat pathological conditions of the spine in 1992. In this study they delineate their clinical experience in which this procedure was used to resect herniated thoracic discs.

Methods
Fifty-five patients underwent thoracoscopy for the resection of herniated thoracic discs. Thirty-six patients presented with myelopathies and 19 with incapacitating thoracic radicular pain. Forty-three patients underwent a single-level, 11 a two-level, and one a three-level discectomy. The mean operative time for thoracoscopic microdiscectomy was 3 hours and 25 minutes (range 80-542 minutes) and the mean blood loss was 327 ml (range 124-1500 ml). Compared with thoracotomy, which was performed in 18 patients, thoracoscopy was associated with a mean of 1 hour less operative time and less than one-half of the blood loss, duration of chest tube drainage, usage of pain medication, and length of hospitalization. Compared with costotransversectomy, which was performed in 15 patients, thoracoscopy permitted more complete resection of calcified and midline thoracic discs because it provided a direct view of the entire anterior surface of the dura. Thoracotomy was associated with a significantly greater incidence of prolonged, disabling intercostal neuralgia compared with the mild transient episodes of intercostal neuralgia associated with thoracoscopy (50% compared with 16%). Thoracotomy also was associated with a significantly higher incidence of postoperative atelectasis and pulmonary dysfunction than thoracoscopy (33% compared with 7%). Clinical and neurological outcomes were excellent (mean follow-up period 15 months). Among the 36 myelopathic patients, 22 completely recovered neurologically; five improved functionally but had some residual myelopathic symptoms; and nine stabilized. Among the 19 patients with isolated thoracic radiculopathies, 15 recovered completely; four improved moderately; and none had worsened radicular pain.

Conclusions
Thoracoscopic microdiscectomy is a reliable surgical technique that can be performed safely with excellent clinical and neurological results.
Predicting the probability of meningioma recurrence based on the quantity of peritumoral brain edema on computerized tomography scanning
Authors: Mantle Ross E. , Lach Boleslaw , Delgado Mauricio R. , Baeesa Salleh , Bélanger Gerard 
Published: January 2008

Object
The goal of this study was to determine whether the quantity of peritumoral brain edema displayed on computerized tomography (CT) scanning could be correlated with brain invasion and subsequent recurrence of meningiomas.

Methods
One hundred thirty-five patients who underwent resection of intracranial meningiomas at the Ottawa Civic Hospital were followed during the period 1980 to 1998. A complete resection was defined as one in which tumor, invaded bone, and involved dura were removed. Tumors were examined microscopically for evidence of brain invasion. The mean follow-up period was 9 years (± 4 years, standard deviation [SD]) and the mean time to recurrence was 5 years (± 4 years, SD). The authors used a simple grading system based on the average thickness (in centimeters) of edema seen on an axial CT slice showing the most tumor. Edema grade was linearly related to edema volume determined by digitizing the scans (r = 0.96; 29 cases). The chance of brain invasion increased by 20% for each centimeter of edema (rs = 1, p < 0.0001; 124 cases). The presence of brain invasion was predictive of recurrence after complete resection with an accuracy of 83%, a sensitivity of 89%, and a specificity of 82%. The chance of recurrence within 10 years after complete resection was given by the equation: percentage chance of recurrence = (centimeter of edema)3 X 0.7, which can be used to predict the chance of recurrence based on findings on CT scans (rs = 1.00, p < 0.0001; 86 patients). Statistical significance was confirmed using Kaplan-Meier and univariate and multivariate analyses. Completeness of resection was the most powerful predictor of recurrence (p < 0.00001, r = 0.6), followed by edema grade and brain invasion (both p = 0.02, r = 0.1). Patient age and gender and tumor location, size, and histological subtype were nonsignificant factors.

Conclusions
Brain invasion causes peritumoral edema. Invaded brain tissue is also the source of residual cells in cases of tumor recurrence after gross-total resection.
Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system
Authors: Wilson John A. , Bowen Sam , Branch Charles L. , Meredith J. Wayne 
Published: January 2008

Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system.
Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure.
These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine.