bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased choline signal coinciding with malignant degeneration of cerebral gliomas: a serial proton magnetic resonance spectroscopy imaging study
Authors: Tedeschi Gioacchino , Lundbom Nina , Raman Ramesh , Bonavita Simona , Duyn Jeff H. , Alger Jeffrey R. , Di Chiro Giovanni
Published: January 2008

The authors tested the hypothesis that proton magnetic resonance spectroscopic (1H-MRS) imaging can be used as a supportive diagnostic tool to differentiate clinically stable brain tumors from those progressing as a result of low- to high-grade malignant transformation or posttherapeutic recurrence. Twenty-seven patients with cerebral gliomas verified on histological examination were studied repeatedly with 1H-MRS imaging over a period of 3.5 years. At the time of each 1H-MRS imaging study, clinical examination, MR imaging, positron emission tomography with 18F-fluorodeoxyglucose, and biopsy findings (when available) were used to categorize each patient as having either stable or progressive disease. Measures of the percentage changes in the choline (Cho) 1H-MRS imaging signal intensity between studies, which were obtained without knowledge of the clinical categorization, allowed the investigators to segregate the groups with a high degree of statistical significance. All progressive cases showed a Cho signal increase between studies of more than 45%, whereas all stable cases showed an elevation of less than 35%, no change, or even a decreased signal. The authors conclude that increased Cho levels coincide with malignant degeneration of cerebral gliomas and therefore may possibly be used as a supportive indicator of progression of these neoplasms.
Treatment of high-grade spinal cord astrocytoma of childhood with “8-in-1” chemotherapy and radiotherapy: a pilot study of CCG-945
Authors: Allen Jeffrey C. , Aviner Shraga , Yates Allan J. , Boyett James M. , Cherlow Joel M. , Turski Patrick A. , Epstein Fred , Finlay Jonathan L. , _ _
Published: January 2008

The purpose of this study was to devise an improved method of treating high-grade gliomas of the spinal cord in children who have a dismal prognosis following conventional treatment. Eighteen children with newly diagnosed high-grade astrocytomas arising in the spinal cord were enrolled in the Children's Cancer Group (CCG) protocol 945. Following surgery, they were all assigned to receive two courses of “8-drugs-in-1-day” (8-in-1) chemotherapy prior to radiotherapy and eight additional courses thereafter. A centralized neuropathology review was used to confirm the diagnosis of high-grade astrocytoma in 13 of the 18 children: anaplastic astrocytoma, (eight patients), glioblastoma multiforme (four patients), and mixed malignant glioma (one patient). Diagnoses were discordant in five patients. There were eight boys and five girls in the group with confirmed diagnoses, with a median age of 7 years (range 1-15 years). The extent of resection was confirmed by computerized tomography or magnetic resonance (MR) evaluation in five of 13 patients. There were six gross-total or near-total resections (>90%), four partial or subtotal resections (10-90%), and three biopsies. Six patients showed evidence of leptomeningeal metastases at diagnosis based on staging MR examinations. Eight of the 13 patients completed at least eight of the prescribed 10 courses of chemotherapy; five received craniospinal radiotherapy and five spinal radiotherapy. The 5-year progression-free and total survival rates for the 13 children were 46 ± 14% and 54 ± 14%, respectively. Seven patients suffered a relapse at the primary site, four of whom also had leptomeningeal metastases. Seven of the 13 patients (54%) remain alive at the time of this report at a median of 76 months (range 51-93 months) from study entry. Six patients died between 8 and 38 months after diagnosis, all with active disease. Intensification of therapy may further improve outcome in this high-risk population.
Hydrocephalus and craniosynostosis
Authors: Cinalli Giuseppe , Sainte-Rose Christian , Kollar Eve Marie , Zerah Michel , Brunelle Francis , Chumas Paul , Arnaud Eric , Marchac Daniel , Pierre-Kahn Alain , Renier Dominique
Published: January 2008

Object

A retrospective study of 1727 cases of craniosynostosis was undertaken to determine the interrelationship between abnormal cerebrospinal fluid (CSF) hydrodynamics and craniosynostosis.

Methods

The patients were divided intwo two groups: nonsyndromic craniosynostosis and syndromic craniosynostosis. Cases of occipital plagiocephaly without suture synostosis and cases of shunt-induced craniosynostosis were excluded from the study. The majority of patients (1297) were treated surgically for their cranial deformity; 95% of these patients had a postoperative follow-up review lasting 5 years. Clinical and radiographic charts covering the time from presentation through the follow-up period were reviewed.

Conclusions

Abnormal intracranial CSF hydrodynamics was found in 8.1% of the patients (3.4% of whom had received shunts and 4.5% of whom had not). Three types of CSF hydrodynamic disturbance were observed: progressive hydrocephalus with ventricular dilation, nonprogressive ventriculomegaly, and dilation of the subarachnoid spaces. Hydrocephalus occurred much more frequently in patients with syndromic craniosynostosis (12.1%) than in those with isolated craniosynostosis (0.3%). In fact, patients with kleeblattschädel exhibited hydrocephalus as a constant feature and patients with Crouzon's syndrome were far more likely to have hydrocephalus than those with other syndromes. In Apert's syndrome, ventricular dilation occurred very frequently, but it was almost always nonprogressive in nature. In most cases of syndromic craniosynostosis, venous sinus obstruction and/or chronic tonsillar herniation were found. Their role in the pathophysiology of hydrocephalus in craniosynostosis is discussed.
Role of surgical resection in the treatment of hypothalamic hamartomas causing precocious puberty
Authors: Stewart Laura , Steinbok Paul , Daaboul Jorge
Published: January 2008

Hypothalamic hamartomas (HHs) are benign tumors that are often associated with central precocious puberty. Resection of HHs has been recommended as a treatment option for selected cases of pedunculated lesions, especially in young children. The role of surgery has to be evaluated in the light of the availability of effective medical treatment with gonadotropin-releasing hormone analogs (GnRHas). The authors report the long-term results of total resection of HHs in two children with central precocious puberty and compare it with medical management in four children.

The two surgically treated patients underwent total resection of pedunculated HHs at 1.75 (Case 1) and 3.25 years (Case 2) and have received follow-up care for 9 and 8 years, respectively. There were no postoperative complications and computerized tomography scanning confirmed complete tumor removal in both patients. Both patients subsequently experienced some regression of secondary sexual characteristics. The response of luteinizing hormone to GnRH became prepubertal in one patient and was diminished in the other. However, the growth velocity remained elevated (gt 7 cm/year), bone age remained advanced (gt +2 standard deviations) 5 years after surgery, decreasing adult height prediction. In one child, GnRHa therapy was initiated 7 years postsurgery.

Four children were treated solely with GnRH agonists and have received follow-up care for 2.3, 6, 9, and 9 years, respectively. These patients have had a complete regression of endocrinological abnormalities, including a normalization of growth velocity and reduction in the rate of skeletal maturation. No side effects were noted with decapeptyl treatment, and one child developed sterile abscesses while receiving Lupron-Depot.

The proven efficacy of GnRHa in suppressing puberty and reducing bone age advancement leads the authors to advise against surgery as the initial management of central precocious puberty caused by HHs.
Surgical treatment of craniopharyngiomas. Part II. Endocrine results
Authors: Honegger Jürgen , Buchfelder Michael , Fahlbusch Rudolf
Published: January 2008

This study aimed to elucidate the endocrine outcome of craniopharyngioma surgery. In particular, endocrine results were analyzed in relation to the surgical approach. The study includes 161 patients who underwent pre- and postoperative endocrine assessment, 143 of whom had not previously undergone surgery.

Diabetes insipidus was the most common postoperative deficiency in both the transcranial and transsphenoidal groups. In the case of primary surgery (surgery as initial therapy), the overall percentage of patients with diabetes insipidus increased from 16.1% preoperatively to 59.4% postoperatively. After transcranial surgery, the rate of anterior pituitary deficiency also increased. However, normal preoperative anterior pituitary function was maintained in more than 50% of patients for each endocrine axis. Similar results were attained in the group of patients undergoing complete tumor removal. The best result was achieved for gonadal function: the incidence of hypogonadism increased only slightly from 77.4 to 79.8%. During transsphenoidal surgery, anterior pituitary function was generally preserved. An additional deficient axis was encountered postoperatively in only four (11.4%) of 35 primary surgery cases. Endocrine results were not inferior in patients with a ventrally displaced pituitary. This variant required midline incision of the gland for exposure of the craniopharyngioma. Panhypopituitarism was encountered in only one of eight patients in whom the pituitary stalk was partially resected because of tumor infiltration. None of the 88 patients who remained recurrence-free demonstrated endocrine deterioration during follow-up review, compared with the early postoperative assessment 3 months postsurgery. On the other hand, complete recovery of one endocrine axis was observed in nine of these patients during later follow-up evaluations. In five of them, diabetes insipidus had regressed.

The authors conclude that it is worth preserving the pituitary stalk and gland at surgery because anterior pituitary function is more often maintained than is generally believed. Postoperative diabetes insipidus must be accepted as a consequence of complete removal of the pituitary. However, pituitary function may recover and diabetes insipidus in particular may abate with time.
Recent results of primary transnasal surgery for infradiaphragmatic craniopharyngioma
Authors: Abe Takumi , Lüdecke Dieter K.
Published: January 2008

Results of primary transnasal surgery were evaluated in 35 patients (18 males and 17 females) with intrasellar and suprasellar craniopharyngiomas treated between 1985 and 1996 when more refined surgical and diagnostic techniques were available. Patients ranged in age from 8 to 72 years (mean 27 years); 14 patients were younger than 18 years of age. The transnasal approach was chosen because of sellar enlargement and presence of infradiaphragmatic tumor. The paramedian portion of the normal pituitary gland was incised vertically to reach a dorsally located tumor in 25 patients. Complete tumor resection was achieved in 15 patients and subtotal removal in 19; in one patient, only aspiration of cyst contents was performed. Tumor regrowth was seen in three patients after subtotal removal; in two, total tumor removal was achieved by a second transnasal surgery, whereas radiotherapy was administered in the other. In a single patient, total tumor removal was achieved by a second transcranial surgery after cyst aspiration. The duration of the clinical follow-up period was at least 1 year. Persistent diabetes insipidus appeared after total tumor resection in five patients. Cerebrospinal fluid leakage occurred in three patients, with two requiring revision. Among 29 patients with preoperatively normal pituitary functions, 20 (69%) were preserved after primary total resection, whereas six (19.4%) of 31 previously disturbed functions were normalized. After subtotal removal including cyst aspiration, 39 (88.6%) of 44 normal functions were preserved, whereas nine (24.3%) of 37 disturbed functions were normalized. The transnasal approach should be the first choice in infradiaphragmatic craniopharyngiomas with sellar enlargement in cases in which the extrasellar portion is mostly cystic and is accessible. The concept of subtotal removal with preservation of pituitary functions, especially when treating craniopharyngioma in children, seems to be justified.
Experience in the surgical management of 82 symptomatic herniated thoracic discs and review of the literature
Authors: Stillerman Charles B. , Chen Thomas C. , Couldwell William T. , Zhang Wei , Weiss Martin H.
Published: January 2008

Object

The authors aimed to develop management strategies for the treatment of herniated thoracic discs and to define indications for selection of surgical approaches. Symptomatic thoracic discs requiring surgery are rare. Between 1971 and 1995, 71 patients with 82 herniated thoracic discs were surgically treated by the authors. The treated group included 34 men and 37 women whose ages ranged from 19 to 75 years, with a mean age of 48 years. The most common sites of disc herniation requiring surgery were from T-8 to T-11. Evidence of antecedent trauma was present in 37% of the patients. Preoperative symptoms included pain (localized, axial, or radicular) in 54 (76%) of the 71 patients, evidence of myelopathy that is, motor impairment in 43 (61%), hyperreflexia and spasticity in 41 (58%), sensory impairment 43 (61%), and bladder dysfunction in 17 (24%).

Methods

Radiological diagnosis for the patients in this series was accomplished by means of myelography, computerized tomography myelography, or magnetic resonance imaging. Classification of the disc location into two groups reveals that 94% were centrolateral and 6% were lateral. Evidence of calcification was present in 65% of patients, and in 7% intradural extension was noted at surgery. Ten patients (14%) were found to have multiple herniations. Four surgical approaches were used for the removal of these 82 disc herniations: transthoracic in 49 (60%), transfacet pedicle-sparing in 23 (28%), lateral extracavitary in eight (10%), and transpedicular in two (2%). Postoperative evaluation revealed improvement or resolution of pain in 47 (87%) of 54, hyperreflexia and spasticity in 39 (95%) of 41, sensory changes in 36 (84%) of 43, bowel/bladder dysfunction in 13 (76%) of 17, and motor impairment in 25 (58%) of 43. Complications occurred in a total of 12 (14.6%) of 82 discs treated surgically. Major complications were seen in three patients and included perioperative death from cardiopulmonary compromise, instability requiring further surgery, and an increase in the severity of a preoperative paraparesis.

Conclusions

Review of this series, with the attendant complications, together with evaluation of several contemporary thoracic disc series, has facilitated the authors' decision-making process when considering the comprehensive management of these patients, including the selection of a surgical approach.
Endoscopic microscopic transpedicular thoracic discectomy
Authors: Jho Hae-Dong
Published: January 2008

In an effort to make thoracic discectomy simple and less invasive while using direct visualization, a 70š-angled lens endoscope has been adopted to visualize the ventral aspect of the spinal cord dura mater during microsurgical thoracic discectomy via a transpedicular approach. The patient is positioned in a 60š forwardly inclined lateral position with the side of the lesion facing upward. After radiographic corroboration of the correct level, a transpedicular approach is made using a 1.5-cm-diameter tubular retractor through a 2-cm-long paramedian transverse skin incision. With the aid of an operating microscope, the ipsilateral facet joint, including the upper portion of the pedicle, is removed using a high-speed drill, thus exposing the neural foramen, intervertebral disc, and upper portion of the pedicle leading to the vertebral bodies. When the herniated disc and bone spur have been removed laterally in relation to the spinal cord, creating a cavity under the operating microscope, a 4-mm-diameter rigid endoscope with a 70š-angled lens is mounted to an endoscope holder so that the ventral aspect of the spinal cord dura mater can be visualized directly. With the aid of direct endoscopic visualization, the disc and bone spur, which compress the spinal cord anteriorly, are pushed away toward a cavity created at the intervertebral space and are removed using a downward-biting long-armed curette. Patients with myelopathy are kept overnight in the hospital; however, those with radiculopathy are discharged home on the same day as their operation. The surgical technique and two illustrative cases are reported.
Minimally invasive techniques in spinal surgery: current practice
Authors: Kambin Parviz , Gennarelli Thomas , Hermantin Frank
Published: January 2008

Minimally invasive spinal surgery under arthroscopic or endoscopic magnification and illumination is emerging as an alternative, reliable method of treatment in a variety of spinal disorders. The operative techniques being used for discectomy and retrieval of herniated disc fragments or stabilization of unstable spinal motion segments are being utilized for visual diagnosis and debridement of infectious discitis and osteomyelitis transpedicular and transforaminal vertebral body biopsy, temporary diagnostic fixation of unstable lumbar motion segments, and transforaminal epidural steroid therapy.
Intraoperative chymopapain in lumbar laminotomy for disc disease: a less invasive technique
Authors: Alden Tord D. , Kaptain George J. , Jane John A. , Jane John A.
Published: January 2008

The use of chymopapain in the treatment of lumbar disc herniation has been widely studied since Smith first described its use in humans in 1963. The authors describe the use of chymopapain intraoperatively in open lumbar microdiscectomy in 63 patients. When combined with the results of a previous study performed at the same institution, the authors found that this technique significantly reduces the rate of recurrent disc herniation when compared with traditional laminotomy with discectomy. This procedure maximizes the benefits of each approach taken separately, allowing for decompression of the nerve root from a free fragment or sequestered disc and preventing recurrence through dissolution of the nucleus pulposus. Overall, outcome was good or excellent immediately postoperatively in 73% of the 63 patients and in 64% at last follow-up evaluation. Additionally, this procedure is safe with no complications noted in the immediate perioperative period or at follow-up evaluation.
Endoscopic foraminotomy using a microendoscopic discectomy system in cadaveric specimens
Authors: Roh Sung Woo , Kim Daniel H. , Cardoso Alberto C. , Fessler Richard G.
Published: January 2008

Although the anterior approach is more commonly performed for the treatment of cervical disc disease, the posterior approach has distinct advantages in selected cases of foraminal stenosis and posterolateral disc herniation. The authors performed cervical key hole foraminotomies using a microendoscopic discectomy (MED) system in four cadaveric cervical spine specimens to evaluate this minimally invasive surgical approach for cervical disc diseases. The amount of bone decompression achieved by using the MED system was compared with that achieved by using the open foraminotomy procedure in each cadaveric specimen. Three noncontiguous cervical nerve roots were selected between C-3 and C-8 in each specimen and were decompressed using the MED system on one side and using the open foraminotomy procedure on the contralateral side. Postoperative computerized tomography (CT) myelography showed that adequate bone decompression was achieved by using either the MED or open procedure in all specimens. Postoperatively, open dissection was performed to confirm and compare the amount of decompression in both the MED and open procedures. The laminotomy size (vertical and transverse diameter), the length of decompressed nerve root, and the proportion of removed facet joint were measured on every operative level. The average vertical diameter of laminotomy area and the percentage of facet removed were significantly greater in the MED procedure than the open procedure (p < 0.05). The transverse diameter of the laminotomy area and the average decompressed root length were not significantly different between MED and open surgery. The authors conclude that endoscopic cervical foraminotomy using the MED system is a feasible procedure and may be clinically applicable in the treatment of foraminal stenosis and laterally located cervical disc herniation.
Posterolateral approach for decompression with anterior and posterior fusion: a less invasive surgical technique for stabilization of the thoracic spine
Authors: Das Kaushik , Rawanduzy Ahmed , Couldwell William T.
Published: January 2008

The goals of surgery in unstable thoracic fractures or tumors involving the thoracic spine are neural decompression, correction of deformity, and stabilization. Several different approaches can be used to achieve these goals. The anterior, combined anterior and posterior, and more recently thoracoscopic approaches are well described in the literature and are extremely effective in achieving the goals mentioned. However, they do carry with them significant morbidity and mortality rates in patients who are elderly, who have associated medical problems, or for whom there are contraindications to thoracic surgery. The authors believe the posterolateral approach is a viable alternative that is reasonably well tolerated in this select patient population. One can achieve circumferential neural decompression as well as anterior and posterior arthrodesis through a single incision. Most neurosurgeons are familiar with the anatomical landmarks and technical steps in the posterolateral approach, and the authors believe it is a less invasive method that can be especially useful and should not be overlooked in this subgroup of patients.
Thoracoscopic sympathectomy: techniques and outcomes
Authors: Johnson J. Patrick , Ahn Samuel S. , Choi William C. , Masciopinto Jeffery E. , Kim Kee D. , Filler Aaron G. , DeSalles Antonio A. F.
Published: January 2008

Thoracic sympathectomy is an important option in the treatment of palmar hyperhidrosis and pain disorders. Earlier surgical procedures were highly invasive with known morbidity, acceptable outcome, and established recurrence rates that were the limitations to considering surgical treatment. Thoracoscopic sympathectomy is a minimally invasive procedure that allows detailed visualization of the sympathetic ganglia and minimal postoperative morbidity; however, outcome studies of this technique have been limited. The authors treated 39 patients with 60 thoracoscopic procedures, and the outcomes in this small series were equivalent to previously established open surgical techniques; however, operative moribidity rates, hospital stay, and time of return to normal activity were substantially reduced. Complications and recurrence of symptoms were also comparable to previous reports. Overall patient satisfaction and willingness to repeat the operative procedure ranged from 66 to 96% in all patients. Patients and physicians can consider minimally invasive thoracoscopic sympathectomy procedures as an option to treat sympathetically mediated disorders because of the procedure's reduced morbidity and at least equivalent outcome rates in comparison to other treatments.
Surgical treatment of low-grade gliomas in the intraoperative magnetic resonance imager
Authors: Martin Claudia , Alexander Eben , Wong Terry , Schwartz Richard , Jolesz Ferenc , Black Peter McL.
Published: January 2008

Radical resection of low-grade gliomas can decrease the incidence of recurrence, the time to tumor progression, and the incidence of malignant transformation. The authors present a series of 25 patients who underwent craniotomy and resection of low-grade tumor in an intraoperative magnetic resonance (MR) imager. This is an open configuration 0.5-tesla imager developed by The Brigham and Women's Hospital and General Electric, in which a patient can be placed to undergo surgery. Gross-total removal was accomplished under real-time image guidance. These intraoperative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery. The authors consistently found that the extent of abnormality seen on the intraoperatively obtained films of resection was larger than that apparent in the surgical field of view alone. Intraoperative imaging made accurate surgical identification of these abnormal areas and subsequent resection possible. Patients with tumors adjacent to or within motor or language cortex underwent resection while awake, with monitoring of neurological function. In these cases, an aggressive resection without increased neurological morbidity was accomplished using the image guidance in conjunction with serial testing. A 1-month postoperative MR image was obtained in all patients. These correlated with the final intraoperative images obtained after the resection was completed. Only one patient had a mild postoperative deficit that remained at the 1-month follow-up examination. As the long-term outcome in patients with low-grade gliomas has been shown to correspond to the degree of resection, surgical resection in which intraoperative MR imaging guidance is used can be an invaluable modality in the treatment of these tumors.
Combined supra/infratentorial-transsinus approach to large pineal region tumors
Authors: Ziyal Ibrahim M. , Sekhar Laligam N. , Salas Eduardo , Olan Wayne J.
Published: January 2008

Object

The authors sought to confirm that the combined supra/infratentorial-transsinus approach offers a safer means of resecting large pineal region tumors than other approaches currently being used. The aforementioned method provides a wider exposure of the pineal region with less brain retraction than the infratentorial-supracerebellar or the occipital-transtentorial approach alone and is applicable to some large and giant tumors of this area. This combined approach was used in six patients to remove large pineal region tumors including four tentorial meningiomas, one pineocytoma, and one epidermoid cyst.

Methods

The transverse sinus and tentorium were sectioned after review of preoperative angiographic studies, after taking intraoperative measurements of the venous pressure in the nondominant transverse sinus before and after clipping and while monitoring the somatosensory evoked potentials. The occipital lobe cortex and cerebellum were retracted slightly along the tentorium. Deep veins of the galenic system, the quadrigeminal area, and the tumor were well exposed. Before it was used for tumor resection the approach was studied in five cadaveric head specimens, and the projection of different approaches was compared radiologically.

The tumors were removed in a gross-total manner in all patients, and none of the major veins of the galenic system was injured. Resuturing of the nondominant transverse sinus was performed postoperatively in one patient. One of the six patients experienced transient visual loss, and another suffered mild right sixth cranial nerve paresis; however, both recovered in 3 weeks. The wide exposure of the combined approach was also confirmed on radiological and anatomical studies.

Conclusions

The combined supra/infratentorial-transsinus approach is preferred for the resection of certain large pineal region tumors.
Neurosurgical considerations in supratentorial low-grade gliomas: experience with 175 patients
Authors: Nikas Dimitrios C. , Bello Lorenzo , Zamani Amir A. , Black Peter McL.
Published: January 2008

The authors reviewed 175 low-grade hemispheric gliomas surgically treated by one surgeon (P.B.) between 1987 and 1996: 74 astrocytomas (42%), 35 oligodendrogliomas (20%), 52 mixed gliomas (30%), 12 gangliogliomas (7%), and two ependymomas (1%). Patient age ranged from 7.5 to 81.9 years (mean 39.2 years); 84 patients (48%) were males and 91 (52%) females. Postsurgical follow-up review ranged from 0.1 to 225.2 months (mean 36.2 months, median 24.9 months). Either T2-weighted or contrast-enhanced T1-weighted magnetic resonance (MR) images were used to evaluate the percentage of resection achieved and volume of residual disease postoperatively. The majority of patients (55%) had seizures as the presenting symptom, and 45% experienced preoperative symptoms for more than 12 months. Tumor enhancement was present in 21% of cases. In 66% of surgical procedures at least one of the following technical adjuncts was used: monitored local anesthesia, real-time MR imaging, stereotactic guidance with computerized tomography, three dimensional reconstruction, cortical mapping with cortical stimulation, somatosensory or visual evoked potential recording, corticography, or intraoperative ultrasound. Intraoperative MR imaging was used for 40 (22.9%) of the craniotomies and nine (5.14%) biopsies. There were no surgery-related deaths. Complications appeared in 6% of the patients. Progression to a higher-grade tumor occurred in 9.2% of patients within the 3-year follow-up period.
Motor-evoked potential monitoring for intramedullary spinal cord tumor surgery: correlation of clinical and neurophysiological data in a series of 100 consecutive procedures
Authors: Kothbauer Karl F. , Deletis Vedran , Epstein Fred J.
Published: January 2008

Resection of intramedullary spinal cord tumors carries a high risk for surgical damage to the motor pathways. This surgery is therefore optimal for testing the performance of intraoperative motor evoked potential (MEP) monitoring. This report attempts to provide evidence for the accurate representation of patients' pre- and postoperative motor status by combined epidural and muscle MEP monitoring during intramedullary surgery.

The authors used transcranial electrical motor cortex stimulation to elicit MEPs, which were recorded from the spinal cord (with an epidural electrode) and from limb target muscles (thenar, anterior tibial) with needle electrodes. The amplitude of the epidural MEPs and the presence or absence of muscle MEPs were the parameters for MEP interpretation. A retrospective analysis was performed on data from the resection of 100 consecutive intramedullary tumors and MEP data were compared with the pre- and postoperative motor status.

Intraoperative monitoring was feasible in all patients without severe preoperative motor deficits. Preoperatively paraplegic patients had no recordable MEPs. The sensitivity of muscle MEPs to detect postoperative motor deficits was 100% and its specificity was 91%. There was no instance in which a patient with stable MEPs developed a motor deficit postoperatively. Intraoperative MEPs adequately represented the motor status of patients undergoing surgery for intramedullary tumors. Because deterioration of the motor status was transient in all cases, it can be considered that impairment of the functional integrity of the motor pathways was detected before permanent deficits occurred.
The Glioma Outcomes Project: a resource for measuring and improving glioma outcomes
Authors: Anderson Frederick A. , _ _
Published: January 2008

The author describes the Glioma Outcomes (GO) Project which conducts outcomes research and develops educational programs to benefit patients who undergo surgery for glioma. In January 1997 an advisory board of neurosurgeons, neurooncologists, and clinical research scientists was formed to establish the policies governing this project and to control the dissemination of aggregate data on clinical practices and outcomes. This voluntary database is designed to 1) guide the development of educational programs to improve the care of patients and 2) provide a mechanism by which physicians can evaluate the impact of their diagnostic and therapeutic decisions in a manner that is timely, confidential, and objective.
Surgical anatomy of the juxtadural ring area
Authors: Oikawa Susumu , Kyoshima Kazuhiko , Kobayashi Shigeaki
Published: January 2008

Object

The authors report on the surgical anatomy of the juxtadural ring area of the internal carotid artery to add to the information available about this important structure.

Methods

Twenty sides of cadaver specimens were used in this study. The plane of the dural ring was found to incline in the posteromedial direction. Medial inclination was measured at 21.8š on average against the horizontal line in the anteroposterior view on radiographic studies. Posterior inclination was measured at 20.3š against the planum sphenoidale in the lateral projection, and the medial edge of the dural ring was located 0.4 mm above the tuberculum sellae in the same projection. The lateral edge of the tuberculum sellae was located 1.4 mm below the superior border of the anterior clinoid process. The carotid cave was situated at the medial or posteromedial aspect of the dural ring; however, two of the 20 specimens showed no cave formation. The carotid cave contained the subarachnoid space in 13 sides, the arachnoid membrane only in three sides, and the extraarachnoid space in two sides. The authors propose that the marker of the medial side of the dural ring, which is more proximal than the lateral, is the tuberculum sellae in the lateral view on radiographic studies. In the medial aspect of the dural ring the intradural space can be situated below the level of the tuberculum sellae because of the existence of the carotid cave.

Conclusions

The authors found that an aneurysm arising from the medial side of the juxtadural ring area even below the tuberculum sellae is a potential cause of subarachnoid hemorrhage.
Clinical response of O6-methylguanine-DNA methyltransferase levels to 1,3-(2-chloroethyl)-1-nitrosourea chemotherapy in glioma patients
Authors: Chen Zhong-Ping , Yarosh Daniel , Garcia Yesenia , Tampieri Donatella , Mohr Gérard , Langleben Adrian , Panasci Lawrence C.
Published: January 2008

Adjuvant nitrosourea chemotherapy fails to prolong patient survival significantly as many tumors demonstrate resistance to these drugs. It has been documented in cell lines that O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in chloroethylnitrosourea (CENU) drug resistance.

The authors evaluated MGMT expression in 22 glioma specimens by using an immunofluorescence assay and compared the results with clinical response of the patients to CENU-based chemotherapy.

The patients were treated with CENU after evidence of progressive disease following surgery and radiotherapy. Eight tumor samples had no detectable MGMT, whereas other samples had from 9989 to 982,401 molecules/nucleus. In one group (12 patients), the tumor decreased in size or was stable (effective group), whereas in the other group (10 patients), the tumor demonstrated continuous growth during chemotherapy (progressive group). The median time to progression (TTP) was 6.7 months with a median survival of 13 months. The Mer− patients (MGMT < 60,000 molecules/nucleus) appeared to have more chance of stable disease or response to CENU therapy than the Mer+ patients (MGMT > 60,000 molecules/nucleus) (chi-square = 4.791, p = 0.0286). In patients with glioblastomas multiforme (GBMs), the TTP of Mer+ patients was shorter than that of Mer− patients (t = 2.04, p = 0.049). As a corollary, the MGMT levels were significantly higher in GBM tumors from the progressive group than those from the effective group (t = -2.26, p = 0.029). The TTP and survival time in the effective GBM group were also longer than those in the progressive GBM group. However, there was no significant correlation between MGMT levels and either the survival time (r = 0.04, p = 0.8595) or TTP (r = 0.107, p = 0.6444).

Results from this study suggested that MGMT positivity is indicative of more aggressive disease that progresses more rapidly when exposed to CENU therapy. However, MGMT-negative tumors are not always sensitive to CENU agents, suggesting that other factors may also be important.
Pathogenesis of intracranial germ cell tumors reconsidered
Authors: Sano Keiji
Published: January 2008

The author studied 153 cases of intracranial germ cell tumors (GCTs) through 1994, 62.7% of which showed monotypic histological patterns and 37.3% of which were shown to be mixed tumors. All of these cases, except for six patients who died soon after admission and underwent autopsy, underwent surgery followed by radio- and/or chemotherapy. All patients with choriocarcinoma died within 2 years. Patients with yolk sac tumor (endodermal sinus tumor) and embryonal carcinoma also had poor outcomes. Patients with mature teratoma had 5- and 10-year survival rates of 92.9% each. Patients with immature teratoma and malignant teratoma had a 5- and 10-year survival rate of 70.7% each. Patients with germinoma had a 5-year survival rate of 95.4% and a 10-year survival rate of 92.7%. These results may bring into question the validity of the germ cell theory, because germinoma, which should be the most undifferentiated according to the theory, was the most benign and choriocarcinoma and yolk sac tumor (endodermal sinus tumor), which should be the most differentiated, were the most malignant according to results obtained during follow-up study.

Therefore, GCTs other than germinoma may not originate from one single type of cell (primordial germ cells). The embryonic cells of various stages of embryogenesis may perhaps be misplaced in the bilaminar embryonic disc at the time of the primitive streak formation, becoming involved in the stream of lateral mesoderm and carried to the future cranial area to become incorrectly enfolded into the brain at the time of the neural tube formation. The authors propound the following law: tumors composed of cells resembling the cells that appear in the earlier stages of embryogenesis (ontogenesis) are more malignant than those composed of cells resembling the cells that appear in the later stages of embryogenesis.
Immunohistochemical analysis of p53 and p21WAF1/Cip1 expression in primary intracranial germ cell tumors
Authors: Nishikawa Ryo , Matsutani Masao
Published: January 2008

Primary intracranial germ cell tumors (GCTs) comprise 3.1% of all brain tumors and 13.6% of those in patients younger than 15 years of age in Japan. They are classified into five basic histological types: germinoma, teratoma, choriocarcinoma, yolk sac tumor, and embryonal carcinoma; or into mixed tumor types when they consist of two or more components. Radiation therapy with or without chemotherapy has proven effective in the treatment of germinoma, whereas there is a poor prognosis for choriocarcinoma, yolk sac tumor, embryonal carcinoma, and mixed tumors having components of the group of malignant intracranial GCTs. The underlying mechanisms for such different responses to radio- and chemotherapies of intracranial GCTs remain unknown.

In this study, the authors analyzed the expression of p53 and p21WAF1/Cip1 proteins by immunohistochemical analysis in 35 intracranial GCTs. Expression of p53 protein was observed in 33 (94%) of 35 intracranial GCTs. Expression of p21WAF1/Cip1 was detected in seven (20%) of 35 intracranial GCTs. None of the 15 germinomas was immunoreactive for p21WAF1/Cip1 protein, whereas in a group of malignant intracranial GCTs, four (80%) of five cases showed immunoreactivity for p21WAF1/Cip1 protein. Analysis of the data suggests that overexpression of p21WAF1/Cip1 in intracranial GCTs may correlate with decreased sensitivity to radio- and chemotherapy and suggest a poor prognosis.
Expression of CD44 adhesion molecules in intracranial germinomas
Authors: Huang Tzuu-Yuan , Kuratsu Jun-ichi , Takeshima Hideo , Nishi Toru , Ushio Yukitaka
Published: January 2008

Adhesion molecules play a role in tumor growth, invasiveness, and the metastatic process. The expression of CD44 adhesion molecules in 11 intracranial germinoma specimens was investigated using anti-CD44 monoclonal antibody and immunohistochemical methods. In six of 11 specimens studied, CD44 antibodies were bound to the membrane of tumor cells; in five of six specimens, CD44 antigen was also present in the cytoplasm of tumor cells. The only three patients who showed CD44-positive expression in tumor cells, lymphocytes, and extracellular matrix (ECM) exhibited either cerebrospinal fluid dissemination or multiple tumors at different locations. In all 11 specimens, no expression of CD44 in normal glial cells or capillary endothelium was detected. According to the authors' findings, the expression of CD44 in intracranial germinomas is similar to that of gonadal seminomas. Analysis of the results further suggests the possibility that the expression of CD44 in intracranial germinoma tumor cells, lymphocytes, and ECM may contribute to tumor cell migration, adhesion to cerebrospinal fluid dissemination, and/or multiple tumor locations.
Blood to cerebrospinal fluid human chorionic gonadotropin-beta ratios in intracranial germ cell tumors
Authors: Rogers Paul B. , Sims Eliot C. , Plowman Nicholas
Published: January 2008

Levels of human chorionic gonadotropin-beta (HCG-beta) are elevated in up to 43% of patients with intracranial germ cell tumors (GCTs) and are useful in the diagnosis of these tumors and the follow up of such patients. The ratio of blood HCG-beta to lumbar cerebrospinal fluid (CSF) HCG-beta in these patients at presentation has not been defined. Twenty-two patients with intracranial GCTs have been treated at St. Bartholomew's Hospital over the past 15 years. Two (17%) of 12 germinomas and seven (70%) of 10 nongerminomatous GCTs had elevated blood HCG-beta at presentation. Four cases of pineal region GCTs (one of 12 germinomas and three of 10 nongerminomatous GCTs) had paired, elevated, blood and lumbar CSF HCG-beta levels. The mean blood to CSF ratio was 1:10 (range 1.7-18.4), which is substantially lower than the ratio of 286:1 reported in systemic GCTs. The authors confirm the finding of a previous single report showing that ventricular CSF HCG-beta sampling via an accessible ventriculoperitoneal shunt reservoir may give a spuriously negative result, and they discuss the pathophysiology of the blood-brain barrier in the pineal region and the implications of the intrathecal administration of chemotherapy.
Occult neurohypophyseal germinomas in patients presenting with central diabetes insipidus
Authors: Kato Tsutomu , Sawamura Yutaka , Tada Mitsuhiro , Murata Jun-ichi , Abe Hiroshi , Shirato Hiroki , Fujieda Kenji
Published: January 2008

Although neurohypophyseal germinoma is known be a common initial symptom in cases of diabetes insipidus (DI), its radiological detection may take months or years even by a high-resolution magnetic resonance (MR) imaging. The term “occult neurohypophyseal germinoma” denotes such cases, but its clinical picture remains obscure.

Of seven patients with neurohypophyseal germinoma presenting with DI during the last 5 years, three patients showed no evidence of tumor at the onset of DI and were treated as “idiopathic” DI. Neurohypophyseal germinoma was eventually diagnosed in these three patients as the tumor became evident on sequential MR imaging studies and the patients were successfully treated with chemotherapy and radiation therapy. To delineate the clinical features of the occult neurohypophyseal germinoma, the authors analyzed endocrinological aspects and MR images in these patients and compared them with those in two patients with true idiopathic DI and four patients with overt neurohypophyseal germinoma and DI. Nine previously reported cases in the literature were reviewed. During the stage at which the germinoma gave no notable change on MR images, patients often displayed anterior pituitary dysfunction, particularly growth hormone (GH) deficiency, or an elevation of serum or cerebrospinal fluid human chorionic gonadotropin-beta. Preceding the appearance of an obvious tumor mass, a slight swelling of the pituitary stalk with loss of normal hyperintensity of the posterior pituitary lobe was a common finding on MR imaging.

Central DI associated either with an enlarged stalk, decreased GH secretion, or an elevated serum human chorionic gonadotropin-beta should prompt the diagnosis of an occult germinoma.
Factors affecting excitatory amino acid release following severe human head injury
Authors: Bullock Ross , Zauner Alois , Woodward John J. , Myseros John , Choi Sung C. , Ward John D. , Marmarou Anthony , Young Harold F.
Published: January 2008

Recent animal studies demonstrate that excitatory amino acids (EAAs) play a major role in neuronal damage after brain trauma and ischemia. However, the role of EAAs in patients who have suffered severe head injury is not understood. Excess quantities of glutamate in the extracellular space may lead to uncontrolled shifts of sodium, potassium, and calcium, disrupting ionic homeostasis, which may lead to severe cell swelling and cell death. The authors evaluated the role of EEAs in human traumatic brain injury.

In 80 consecutive severely head injured patients, a microdialysis probe was placed into the gray matter along with a ventriculostomy catheter or an intracranial pressure (ICP) monitor for 4 days. Levels of EAAs and structural amino acids were analyzed using high-performance liquid chromatography. Multifactorial analysis of the amino acid pattern was performed and its correlations with clinical parameters and outcome were tested. The levels of EAAs were increased up to 50 times normal in 30% of the patients and were significantly correlated to levels of structural amino acids both in each patient and across the whole group (p < 0.01). Secondary ischemic brain injury and focal contusions were most strongly associated with high EAA levels (27 ± 22 μmol/L). Sustained high ICP and poor outcome were significantly correlated to high levels of EAAs (glutamate > 20 μmol/L; p < 0.01).

The release of EAAs is closely linked to the release of structural amino acids and may thus reflect nonspecific development of membrane micropores, rather than presynaptic neuronal vesicular exocytosis. The magnitude of EAA release in patients with focal contusions and ischemic events may be sufficient to exacerbate neuronal damage, and these patients may be the best candidates for treatment with glutamate antagonists in the future.
Neurosurgical credentials: a history and critique
Authors: Tolchin Sidney
Published: January 2008

The author presents a review of the process of peer evaluation in this century, as well as how certification and techniques of evaluation in the practice of medicine and neurosurgery have evolved. The effect of licensure on the workforce, the influence of trade laws on quality of education and training, and the new paradigm of competition and managed medical practices have made a remarkable impact on the nature of the care of patients in the United States. The author also discusses the effect of risk management and litigation on the quality of medical care, the nature of outcomes evaluation and economic credentials in the absence of appropriate instruments for such evaluation, and alternatives for the future of the credentials process.