bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous regression of giant arteriovenous fistulae during the perinatal period
Authors: Hanigan William C. , Brady Terry , Medlock Michael , Smith Edward B.
Published: May 2009

✓ A unique case of spontaneous regression of giant arteriovenous fistulae during infancy is described in this report. A female infant, the product of normal labor and delivery, demonstrated severe ventriculomegaly and an intracranial hemorrhage at birth. Cerebral angiography at 5 days of age revealed several large fistulae fed by the anterior and middle cerebral arteries draining into the deep venous system through a dilated internal cerebral vein and ectatic vein of Galen. Two days following the angiogram, a second intracranial hemorrhage occurred. Active hydrocephalus developed over the next 6 months and was treated with ventriculoperitoneal shunting. When the child was 8 months of age, angiography failed to demonstrate the fistulae. It was postulated that pressure effects from the intracranial hematoma and long-standing intracranial hypertension as well as stenosis in the anomalous venous outflow resulted in vascular stasis, venous thrombosis, and selective arterial occlusion. Hydrocephalus was a result of the compression of the intraventricular foramina by dilated embryonic vessels. This anomaly, predominantly involving the anterior circulation, may be homologous to the vein of Galen aneurysm in the posterior circulation.
Microvascular decompression of cranial nerves: lessons learned after 4400 operations
Authors: McLaughlin Mark R. , Jannetta Peter J. , Clyde Brent L. , Subach Brian R. , Comey Christopher H. , Resnick Daniel K.
Published: May 2009

Object. Microvascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and other cranial nerve rhizopathies. The senior author (P.J.J.) began performing this procedure in 1969 and has performed more than 4400 operations. The purpose of this article is to review some of the nuances of the technical aspects of this procedure.

Methods. A review of 4415 operations shows that numerous modifications to the technique of microvascular decompression have occurred during the last 29 years. Of the 2420 operations performed for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia before 1990, cerebellar injury occurred in 21 cases (0.87%), hearing loss in 48 (1.98%), and cerebrospinal fluid (CSF) leakage in 59 cases (2.44%). Of the 1995 operations performed since 1990, cerebellar injuries declined to nine cases (0.45%), hearing loss to 16 (0.8%), and CSF leakage to 37 (1.85% p < 0.01, test for equality of distributions). The authors describe slight variations made to maximize surgical exposure and minimize potential complications in each of the six principal steps of this operation. These modifications have led to decreasing complication rates in recent years.

Conclusions. Using the techniques described in this report, microvascular decompression is an extremely safe and effective treatment for many cranial nerve rhizopathies.
Elevated jugular venous oxygen saturation after severe head injury
Authors: Cormio Manuela , Valadka Alex B. , Robertson Claudia S.
Published: May 2009

Object. The aim of this study was to investigate the incidence of elevated (≥ 75%) jugular venous oxygen saturation (SjvO2) and its relationship to cerebral hemodynamic and metabolic parameters and to outcome after severe head injury.

Methods. Data from 450 severely head injured patients admitted to the Neurosurgical Intensive Care Unit of Ben Taub General Hospital were analyzed retrospectively. The SjvO2 was measured in blood obtained from indwelling jugular bulb catheters. Patients were classified into the following categories: high (Group I), normal (Group II), or low SjvO2 (Group III) if their mean SjvO2 over the duration of monitoring was 75% or higher, 74 to 56%, or 55% or lower, respectively.

A high SjvO2 occurred in 19.1% of patients. There was no consistent relationship between SjvO2 and simultaneous cerebral blood flow (CBF) or cerebral perfusion pressure measurements. Compared with Groups II and III, the patients in Group I had a significantly higher CBF and lower cerebral metabolic rate of oxygen (CMRO2). In Group I, the outcomes were death or persistent vegetative state in 48.8% of patients and severe disability in 25.6%. These outcomes were significantly worse than for patients in Group II. Within Group I, the patients with a poor neurological outcome were older and more likely to have suffered a focal head injury; they demonstrated a lower CMRO2 and a greater rate of cerebral lactate production than the patients who attained a favorable outcome.

Conclusions. Posttraumatic elevation of SjvO2 is common but cannot be automatically equated with hyperemia. Instead, elevated SjvO2 is a heterogeneous condition that is associated with poor outcome after head injury and may carry important implications for the management of comatose patients.
Cavernous malformations of the brainstem: experience with 100 patients
Authors: Porter Randall W. , Detwiler Paul W. , Spetzler Robert F. , Lawton Michael T. , Baskin Jonathan J. , Derksen Patrick T. , Zabramski Joseph M.
Published: May 2009

Object. In this study the authors review surgical experience with cavernous malformations of the brainstem (CMBs) in an attempt to define more clearly the natural history, indications, and risks of surgical management of these lesions.

Methods. The authors retrospectively reviewed the cases of 100 patients (38 males and 62 females; mean age 37 years) harboring 103 lesions at treated a single institution between 1984 and 1997. Clinical histories, radiographs, pathology records, and operative reports were evaluated. The brainstem lesions were distributed as follows: pons in 39 patients, medulla in 16, midbrain in 16, pontomesencephalic junction in 15, pontomedullary junction in 10, midbrain—hypothalamus/thalamus region in two patients, and more than two brainstem levels in five. The retrospective annual hemorrhage rate was most conservatively estimated at 5% per lesion per year. Standard skull base approaches were used to resect lesions in 86 of the 100 patients. Intraoperatively, all 86 patients were found to have a venous anomaly in association with the CMB. Follow up was available in 98% (84 of 86) of the surgical patients. Of these, 73 (87%) were the same or better after surgical intervention, eight (10%) were worse, and three (4%) died. Two surgical patients were lost to follow-up review. Incidences of permanent or severe morbidity occurred in 10 (12%) of the surgically treated patients. The average postoperative Glasgow Outcome Scale score for surgically treated patients was 4.5, with a mean follow-up period of 35 months.

Conclusions. The natural history of CMBs is worse than that of cavernous malformations in other locations. These CMBs can be resected using skull base approaches, which should be considered in patients with symptomatic hemorrhage who harbor lesions that approach the pial surface. Venous anomalies are always associated with CMBs and must be preserved.
Endovascular thrombolysis for symptomatic cerebral venous thrombosis
Authors: Philips Matthew F. , Bagley Linda J. , Sinson Grant P. , Raps Eric C. , Galetta Steven L. , Zager Eric L. , Hurst Robert W.
Published: May 2009

Object. The authors sought to treat potentially catastrophic intracranial dural and deep cerebral venous thrombosis by using a multimodality endovascular approach.

Methods. Six patients aged 14 to 75 years presented with progressive symptoms of thrombotic intracranial venous occlusion. Five presented with neurological deficits, and one patient had a progressive and intractable headache. All six had known risk factors for venous thrombosis: inflammatory bowel disease (two patients), nephrotic syndrome (one), cancer (one), use of oral contraceptive pills (one), and puerperium (one). Four had combined dural and deep venous thrombosis, whereas clot formation was limited to the dural venous sinuses in two patients. All patients underwent diagnostic cerebral arteriograms followed by transvenous catheterization and selective sinus and deep venous microcatheterization. Urokinase was delivered at the proximal aspect of the thrombus in dosages of 200,000 to 1,000,000 IU. In two patients with thrombus refractory to pharmacological thrombolytic treatment, mechanical wire microsnare maceration of the thrombus resulted in sinus patency. Radiological studies obtained 24 hours after thrombolysis reconfirmed sinus/vein patency in all patients. All patients' symptoms and neurological deficits improved, and no procedural complications ensued. Follow-up periods ranged from 12 to 35 months, and all six patients remain free of any symptomatic venous reocclusion. Factors including patients' age, preexisting medical conditions, and duration of symptoms had no statistical bearing on the outcome.

Conclusions. Patients with both dural and deep cerebral venous thrombosis often have a variable clinical course and an unpredictable neurological outcome. With recent improvements in interventional techniques, endovascular therapy is warranted in symptomatic patients early in the disease course, prior to morbid and potentially fatal neurological deterioration.
Treatment of patients with primary glioblastoma multiforme with standard postoperative radiotherapy and radiosurgical boost: prognostic factors and long-term outcome
Authors: Shrieve Dennis C. , Alexander Eben , Black Peter McL. , Wen Patrick Y. , Fine Howard A. , Kooy Hanne M. , Loeffler Jay S.
Published: May 2009

Object. To assess the value of stereotactic radiosurgery (SRS) as adjunct therapy in patients suffering from glioblastoma multiforme (GBM), the authors analyzed their experience with 78 patients.

Methods. Between June 1988 and January 1995, 78 patients underwent SRS as part of their initial treatment for GBM. All patients had undergone initial surgery or biopsy confirming the diagnosis of GBM and received conventional external beam radiotherapy. Stereotactic radiosurgery was performed using a dedicated 6-MV stereotactic linear accelerator. Thirteen patients were alive at the time of analysis with a median follow-up period of 40.8 months. The median length of actuarial survival for all patients was 19.9 months. Twelve- and 24-month survival rates were 88.5% and 35.9%, respectively. Patient age and Radiation Therapy Oncology Group (RTOG) class were significant prognostic indicators according to univariate analysis (p < 0.05). Twenty-three patients aged younger than 40 years had a median survival time of 48.6 months compared with 55 older patients who had 18.2 months (p < 0.001). Patients in this series fell into RTOG Classes III (27 patients), IV (29 patients), or V (22 patients). Class III patients had a median survival time of 29.5 months following diagnosis; this was significantly longer than median survival times for Classes IV and V, which were 19.2 and 18.2 months, respectively (p = 0.001). Only patient age (< 40 years) was a significant prognostic factor according to multivariate analysis. Acute complications were unusual and limited to exacerbation of existing symptoms. There were no new neuropathies secondary to SRS. Thirty-nine patients (50%) underwent reoperation for symptomatic necrosis or recurrent tumor. The rate of reoperation at 24 months following SRS was 54.8%.

Conclusions. The addition of a radiosurgery boost appears to confer a survival advantage to selected patients.
Preliminary observations for a new treatment in children with primary intracranial yolk sac tumor or embryonal carcinoma
Authors: Ushio Yukitaka , Kochi Masato , Kuratsu Jun-ichi , Itoyama Youichi , Marubayashi Toru
Published: May 2009

✓ The authors evaluated the effect of adjuvant therapy (preoperative chemotherapy combined with radiotherapy) followed by radical tumor removal in the treatment of children with primary intracranial yolk sac tumor, embryonal carcinoma, or mixed germ cell tumors containing yolk sac tumor components.

Between 1988 and 1995, five consecutive patients were treated with adjuvant therapy followed by total tumor removal. The diagnosis was based on markedly elevated concentrations of serum α-fetoprotein (AFP) and/or β-human chorionic gonadotropin (β-HCG) in four children and the results of biopsy sampling in one child. The chemotherapy regimen consisted of cisplatin (20 mg/m2) and etoposide (60 mg/m2) daily for 5 days (one course) given three times at 4-weeks intervals. Radiotherapy consisted of 30 to 40 Gy to the whole brain or an area including all ventricles and a 15- to 20-Gy boost to the tumor site. Spinal radiation of 25 Gy was added in one patient. In all patients the serum level of AFP and β-HCG gradually decreased during the adjuvant therapy and disappeared completely on its completion. In two of the five patients the tumor disappeared as well. In the other three patients the tumor size was moderately or markedly reduced and the remaining tumor was totally removed; there were no neurological deficits. Chemotherapy was maintained after the initial treatment and was repeated every 2 to 4 months for less than 2 years. All children are alive and well without recurrence at 33 to 118 months (average 88 months) after the start of adjuvant therapy.

Our preliminary results indicate that adjuvant therapy consisting of combination chemotherapy with cisplatin and etoposide and concomitant radiotherapy, followed by removal of the tumor, is highly effective in the treatment of pediatric patients with primary intracranial yolk sac tumor, embryonal carcinoma, or mixed germ cell tumors containing yolk sac tumor components.
Aseptic meningitis caused by Teflon implantation for microvascular decompression
Authors: Bobek Miroslav P. , Sagher Oren
Published: May 2009

✓ The authors present the case of a 47-year-old man who, after undergoing microvascular decompression for trigeminal neuralgia, experienced symptomatic pain relief but developed prolonged aseptic meningitis. This case is unusual in that the patient remained dependent on steroid medications for nearly 5 months following the initial surgery and the aseptic meningitis did not resolve until after surgical removal of the Teflon used to pad the trigeminal nerve. The pathophysiological characteristics of the body's reaction to implanted Teflon are discussed along with the rationale for removing this substance in cases of prolonged intractable aseptic meningitis.
Use of microvascular Doppler probe to avoid basilar artery injury during endoscopic third ventriculostomy
Authors: Schmidt Richard H.
Published: May 2009

✓ Basilar artery (BA) injury has been reported in a number of cases as a major complication of third ventriculostomy for hydrocephalus. This report describes the deployment of a pulsed-wave microvascular Doppler probe through the endoscope to locate the BA complex and subsequently to select a safe zone for perforation of the third ventricular floor. This procedure is quick and easily learned, and it is hoped that it can decrease the risk of vascular injury during third ventriculostomy.
Accuracy of true frameless stereotaxy: in vivo measurement and laboratory phantom studies
Authors: Dorward Neil L. , Alberti Olaf , Palmer James D. , Kitchen Neil D. , Thomas David G. T.
Published: May 2009

✓ The authors present the results of accuracy measurements, obtained in both laboratory phantom studies and an in vivo assessment, for a technique of frameless stereotaxy. An instrument holder was developed to facilitate stereotactic guidance and enable introduction of frameless methods to traditional frame-based procedures. The accuracy of frameless stereotaxy was assessed for images acquired using 0.5-tesla or 1.5-tesla magnetic resonance (MR) imaging or 2-mm axial, 3-mm axial, or 3-mm helical computerized tomography (CT) scanning. A clinical series is reported in which biopsy samples were obtained using a frameless stereotactic procedure, and the accuracy of these procedures was assessed using postoperative MR images and image fusion.

The overall mean error of phantom frameless stereotaxy was found to be 1.3 mm (standard deviation [SD] 0.6 mm). The mean error for CT-directed frameless stereotaxy was 1.1 mm (SD 0.5 mm) and that for MR image—directed procedures was 1.4 mm (SD 0.7 mm). The CT-guided frameless stereotaxy was significantly more accurate than MR image—directed stereotaxy (p = 0.0001). In addition, 2-mm axial CT-guided stereotaxy was significantly more accurate than 3-mm axial CT-guided stereotaxy (p = 0.025). In the clinical series of 21 frameless stereotactically obtained biopsies, all specimens yielded the appropriate diagnosis and no complications ensued. Early postoperative MR images were obtained in 16 of these cases and displacement of the biopsy site from the intraoperative target was determined by fusion of pre- and postoperative image data sets. The mean in vivo linear error of frameless stereotactic biopsy sampling was 2.3 mm (SD 1.9 mm). The mean in vivo Euclidean error was 4.8 mm (SD 2 mm). The implications of these accuracy measurements and of error in stereotaxy are discussed.
Surgical decompression for traumatic brain swelling: indications and results
Authors: Guerra Waltraud Kleist-Welch , Gaab Michael R. , Dietz Hermann , Mueller Jan-Uwe , Piek Jürgen , Fritsch Michael J.
Published: May 2009

Object. Decompressive craniectomy has been performed since 1977 in patients with traumatic brain injury. The authors assess the efficacy of this treatment and the indications for its use.

Methods. The clinical status of the 57 patients, their computerized tomography (CT) scans, and intracranial pressure (ICP) levels were documented prospectively in a standard protocol. At the beginning of the study, all patients older than 30 years were excluded. As of 1989 patients older than 40 years were excluded until 1991; since that time patients older than 50 years have been excluded. Primary brain or brainstem injury with fully developed bulbar brain syndrome, loss of auditory evoked potentials (AEPs), and/or oscillation flow in a transcranial Doppler ultrasound examination were contraindications to decompressive craniectomy. A positive indication for decompression was given in the case of progressive therapy-resistant intracranial hypertension in correlation with clinical (Glasgow Coma Scale [GCS] score, decerebrate posturing, dilating of pupils) and electrophysiological (electroencephalography, somatosensory evoked potentials, and AEPs) parameters and with findings on CT scans. Unilateral decompressive craniectomy was performed in 31 patients and bilateral craniectomy in 26 patients. In all cases, a wide frontotemporoparietal craniectomy was followed by a dura enlargement covered with temporal muscle fascia.

The outcomes of the treatment were surprisingly good. Only 11 patients (19%) died, three of whom died of acute respiratory disease syndrome. Five patients (9%) survived, but remained in a persistent vegetative state; six patients (11%) survived with a severe permanent neurological deficit, and 33 patients (58%) attained social rehabilitation. Two patients (3.5%) did not have a follow-up examination. The GCS score on the 1st day posttrauma and the mean ICP turned out to be the best predictors for a good prognosis. The results demonstrate the importance of decompressive craniectomy in the treatment of traumatic brain swelling.

Conclusions. Surgical decompression should be routinely performed when indicated before irreversible ischemic brain damage occurs.
Embolization of incidental cerebral aneurysms by using the Guglielmi detachable coil system
Authors: Murayama Yuichi , Viñuela Fernando , Duckwiler Gary R. , Gobin Y. Pierre , Guglielmi Guido
Published: May 2009

Object. Guglielmi detachable coil (GDC) technology is a valuable therapeutic alternative to the surgical treatment of ruptured or incidental intracranial aneurysms. The authors describe their technical and clinical experience in the use of the GDC technique in patients who underwent endovascular occlusion for the treatment of incidentally found intracranial aneurysms.

Methods. One hundred fifteen patients with 120 incidentally found intracranial aneurysms underwent embolization by means of the GDC endovascular technique. Ninety-one patients were females and 24 were males. Patient age ranged from 13 to 80 years. In 64 patients the incidental aneurysms were discovered when unrelated nonneurological conditions signaled the need for angiography or magnetic resonance angiography (Group 1). Twenty patients who presented with incidental aneurysms that were discovered during treatment for an acutely ruptured aneurysm underwent treatment of both types of aneurysm during the acute phase of subarachnoid hemorrhage (SAH) (Group 2). Sixteen patients with incidental aneurysms were treated during the chronic phase of SAH (Group 3). Group 4 included 15 patients who had incidental aneurysms associated with brain tumors or arteriovenous malformations.

Angiographic results revealed complete or near-complete occlusion in 109 aneurysms (91%) and incomplete occlusion in five aneurysms (4%). Guglielmi detachable coil embolization was attempted unsuccessfully in six aneurysms (5%). One hundred nine patients (94.8%) remained neurologically intact or unchanged from their initial clinical status. Five patients (4.3%) deteriorated as a result of immediate procedural complications. All these complications occurred in the first 50 patients treated in the series. No clinical complications were observed in the last 65 patients. In one patient, a partially embolized aneurysm ruptured 3 years postprocedure. In Groups 1 and 3, the average length of hospitalization was 3.3 days.

Conclusions. The evolution of GDC technology has proved to provide safe treatment of incidental aneurysms (a morbidity rate of 0% was achieved in the last 65 patients). The topography of the aneurysm and the clinical condition of the patient did not influence final anatomical or clinical outcomes. The GDC technology also confers a positive economic impact by decreasing hospital length of stay and by eliminating the need for postembolization intensive care.
Pathogenesis of intracranial germ cell tumors reconsidered
Authors: Sano Keiji
Published: May 2009

Object. To determine the pathogenesis of intracranial germ cell tumors (GCTs), the author studied 153 cases of these tumors encountered through 1994, 62.7% of which showed monotypic histological patterns and 37.3% of which were shown to be mixed tumors.

Methods. Six patients died soon after admission and underwent autopsy; the other patients underwent surgery followed by radio- and/or chemotherapy. One hundred thirty-four cases were followed through the end of 1997. All patients with a choriocarcinoma died within 1 year. Patients with a yolk sac tumor (endodermal sinus tumor) or an embryonal carcinoma also had poor outcomes. Patients with a mature teratoma had 5- and 10-year survival rates of 93% each. Patients with an immature teratoma had 5- and 10-year survival rates of 86% each, whereas patients who had a teratoma with malignant transformation had a 3-year survival rate of 50%. Patients with a germinoma had a 5-year survival rate of 96% and a 10-year survival rate of 93%. These results may bring into question the validity of the germ cell theory because germinoma, which should be the most undifferentiated tumor according to the theory, was the most benign and choriocarcinoma and yolk sac tumor (endodermal sinus tumor), which should be the most differentiated tumors, were the most malignant according to results obtained during the follow-up study.

Conclusions. Germ cell tumors other than germinomas 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 neural plate area to become incorrectly enfolded into the brain at the time of neural tube formation. The author propounds the following hypothesis: 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.
Benign cerebellar astrocytomas in children
Authors: Pencalet Philippe , Maixner Wirginia , Sainte-Rose Christian , Lellouch-Tubiana Arielle , Cinalli Giuseppe , Zerah Michel , Pierre-Kahn Alain , Hoppe-Hirsch Elisabeth , Bourgeois Marie , Renier Dominique
Published: May 2009

Object. Cerebellar astrocytomas are benign tumors of childhood known to be associated with excellent long-term survival in patients in whom complete surgical resection is possible. However, the roles of other factors—clinical, radiological, histological, and therapeutic—in the survival of the patient, tumor recurrence, and long-term patient outcome remain imprecise. The goal of this study was to examine these factors and their relationships.

Methods. To clarify these issues a retrospective review was conducted of 168 children who were surgically treated for a cerebellar astrocytoma at Hôpital Necker—Enfants Malades between 1955 and 1995. These patients' clinical files were examined, the histological characteristics of their tumors were reviewed, and their outcomes were assessed according to Bloom's scale and the Wechsler intelligence quotient test.

Of the 168 patients in the study, 91 were male and 77 were female with a mean age of 6.9 years and a mean follow up lasting 7.7 years. Tumors were identified as being strictly located in the cerebellum in 76.2% of the patients and as involving the brainstem (referred to as the “transitional form”) in 23.8% of the patients. Complete surgical excision was possible in 88.7% of cases. There was a total mortality rate of 4.2% and a tumor recurrence rate of 9.5%. Fifty-eight percent of the patients had no neurological sequelae at follow-up evaluation.

Pejorative factors that were discovered by multivariate analysis to be important included: a long preoperative duration of symptoms and the transitional form of tumor with respect to survival; incomplete tumor excision with respect to an increased risk of recurrence; and a long preoperative duration of symptoms, an early epoch during which surgery was performed (1955–1974), severe ventricular dilation, and the transitional form of tumor with respect to a poorer long-term patient outcome.

Conclusions. The presence of brainstem involvement (tumor in the transitional form) emerged as a significant negative prognostic factor and should be treated as a distinct nosological entity. The extent of surgical excision has a significant bearing on the risk of tumor recurrence.
Bilateral decrease in interictal hippocampal blood flow in unilateral mesiotemporal epilepsy
Authors: Rougier Alain , Lurton Dominique , El Bahh Bouchaib , Lespinet Véronique , Bidabé Anne-Marie , Guillot Martine , Caillé Jean-Marie
Published: May 2009

Object. The goal of this study was to determine whether regional cerebral blood flow (rCBF) changes that were found contralaterally to a verified unilateral epileptic focus were associated with the spatiotemporal organization of epileptic abnormalities.

Methods. The CBF in both hippocampi was assessed using stable Xe-enhanced computerized tomography in a series of 19 patients with unilateral mesiotemporal epilepsy. Results were compared according to the distribution of interictal spiking and the spatiotemporal organization of the ictal discharges as determined by stereoelectroencephalography. Two groups were defined: in Group 1 (nine patients), the discharge remained unilateral; in Group 2 (10 patients), the discharge spread to contralateral mesiotemporal structures. For Group 1, the rates of ipsi- and contralateral hippocampal blood flow (HBF) were 32.88 ± 15.53 and 45.88 ± 17.19 ml/100 g/minute, respectively, whereas in Group 2 they were 36.7 ± 11.54 and 36.4 ± 11.27 ml/100 g/minute (mean ± standard deviation). A two-way analysis of variance combining type of seizure (Group 1 compared with Group 2) and HBF (ipsi-compared with contralateral absolute values) demonstrated a main effect for HBF (F[1,17] = 5.051; p = 0.0382), a significant interaction between the two factors (F[1,17] = 6.188; p = 0.0235), and no main effect for type of seizure (F[1,17] = 0.258; p = 0.6178).

Conclusions. In unilateral mesiotemporal epilepsy, asymmetrical interictal hippocampal perfusion was correlated with restricted unilateral ictal discharges, whereas bilateral hippocampal hypoperfusion was correlated with ictal discharges spreading to the contralateral mesiotemporal structures. The lack of correlation between the degree of hypoperfusion and the percentage of neuron cell loss indicated that the decrease in rCBF has both functional and lesional origins.
Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors
Authors: Østergaard Leif , Hochberg Fred H. , Rabinov James D. , Sorensen A. Gregory , Lev Michael , Kim Lyndon , Weisskoff Robert M. , Gonzalez R. Gilberto , Gyldensted Carsten , Rosen Bruce R.
Published: May 2009

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.

Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.

Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.
Multiple genetic aberrations including evidence of chromosome 11q13 rearrangement detected in pituitary adenomas by comparative genomic hybridization
Authors: Metzger Andrew K. , Mohapatra Gayatry , Minn Yuriko A. , Bollen Andrew W. , Lamborn Kathleen , Waldman Frederic M. , Wilson Charles B. , Feuerstein Burt G.
Published: May 2009

Object. This study was conducted to determine whether comparative genomic hybridization (CGH) is a more sensitive method for detecting genetic aberrations than other tests currently in use.

Methods. The authors used CGH to examine 40 primary and 13 recurrent adenomas obtained from 52 patients for loss and gain of genetic material. Copy number aberrations (CNAs) were detected in 25 (48%) of the 52 patients studied. The chromosomes affected were, in order of decreasing frequency, 11, 7, X, 1, 8, 13, 5, 14, 2, 6, 9, 10, 12, 3, 18, 21, 4, 16, 15, 19, 22, and Y. Endocrinologically active adenomas were more likely to contain (p = 0.009) and had a greater number (p = 0.003) of CNAs. Of 26 adenomas with CNAs, 18 showed multiple aberrations involving entire chromosomes or chromosome arms. The most frequent CNA involving a chromosome subregion, which was present in four (8%) of 53 adenomas, was the loss of all chromosome 11 material except for a preserved common segment containing 11q13. Immunoperoxidase staining did not detect cyclin D1 expression in those four cases, making cyclin D1 an unlikely target of this rearrangement.

Conclusions. These findings indicate that genetic abnormalities are present in pituitary adenomas at a higher rate than previously reported, are associated with endocrinological activity, and often involve several chromosomes. Rearrangement at 11q13 may inactivate a tumor suppressor gene or activate an oncogene that is important in the initiation or progression of sporadic pituitary adenomas.
A comparative study of the effects of two nitric oxide synthase inhibitors and two nitric oxide donors on temporary focal cerebral ischemia in the Wistar rat
Authors: Coert Bert A. , Anderson Robert E. , Meyer Fredric B.
Published: May 2009

Object. A critical review of the literature indicates that the effects of nitric oxide synthase (NOS) inhibitors on focal cerebral ischemia are contradictory. In this experiment the authors methodically examined the dose-dependent effects of two NOS inhibitors and two NO donors on cortical infarction volume in an animal model of temporary focal cerebral ischemia simulating potential ischemia during neurovascular interventions.

Methods. Ninety-two Wistar rats underwent 3 hours of combined left middle cerebral artery and bilateral common carotid artery occlusion after having been anesthetized with 1% halothane. A nonselective NOS inhibitor, NG-nitro-l-arginine-methyl-ester (l-NAME), and two NO donors, 3-morpholinosydnonimine hydrochloride and NOC-18, DETA/NO, (Z)-1-[2(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate, were administered intravenously 30 minutes before ischemia was induced. A selective neuronal NOS inhibitor, 7-nitroindazole (7-NI), was administered intraperitoneally in dimethyl sulfoxide (DMSO) 60 minutes before ischemia was induced. Two ischemic control groups, to which either saline or DMSO was administered, were also included in this study. Seventy-two hours after flow restoration, the animals were perfused with tetrazolium chloride for histological evaluation.

Cortical infarction volume was significantly reduced by 71% in the group treated with 1 mg/kg l-NAME when compared with the saline-treated ischemic control group (27.1 ± 37 mm3 compared with 92.5 ± 26 mm3, p < 0.05). The NOS inhibitor 7-NI significantly reduced cortical infarction volume by 70% and by 92% at doses of 10 and 100 mg/kg: 35.2 ± 32 mm3 (p < 0.05) and 9 ± 13 mm3 (p < 0.005), respectively, when compared with the DMSO-treated ischemic control group (119 ± 43 mm3). There was no significant difference between the saline-treated and DMSO-treated ischemic control groups. Treatment with NO donors did not significantly alter cortical infarction volume.

Conclusions. These results support an important role for NO in ischemic neurotoxicity and indicate that neuronal NOS inhibition may be valuable in reducing cortical injury in patients suffering temporary focal cerebral ischemia during neurovascular procedures.
Hypothermia: depression of tricarboxylic acid cycle flux and evidence for pentose phosphate shunt upregulation
Authors: Kaibara Taro , Sutherland Garnette R. , Colbourne Fred , Tyson Randy L.
Published: May 2009

Object. Hypothermia is used in neurosurgery and other surgical disciplines to reduce tissue injury, but the mechanism of such protection remains elusive. The authors have endeavored to delineate the mechanism of neural protection afforded by hypothermia through a study of glucose metabolism.

Methods. Nuclear magnetic resonance spectroscopy was used to follow the carbon-13 label from [1-13C]glucose as it was metabolized through the glycolytic and tricarboxylic acid pathways. Male Sprague—Dawley rats were maintained at either 37.5°C or 31°C and infused with labeled glucose for 10, 30, 60, 100, or 200 minutes (five rats were used for each time point and for each temperature). At the end of the infusion period, the rats' brains were subjected to rapid freeze-funnel fixation. Water-soluble metabolites were extracted from samples of the neocortex and hippocampus by using perchloric acid extraction. The fractional enrichment of these metabolites was used to calculate the reaction rate constant of formation and steady-state enrichment for a number of metabolites.

Hypothermia resulted in a 30 to 40% depression of metabolism (p < 0.0001) in both the neocortex and hippocampus. Steady-state fractional enrichment of metabolites was also decreased by 20 to 25% with hypothermia (p < 0.0001), implying a loss of label during metabolism.

Conclusions. The results of this study suggest that an increased fraction of glucose metabolism was shunted through the pentose phosphate pathway in the presence of hypothermia.
Central neurocytoma: morphological, flow cytometric, polymerase chain reaction, fluorescence in situ hybridization, and karyotypic analyses
Authors: Jay Venita , Edwards Vern , Hoving Eelco , Rutka James , Becker Laurence , Zielenska Maria , Teshima Ikuko
Published: May 2009

✓ The results of cytogenetic and molecular genetic analysis of a central neurocytoma are presented. Central neurocytomas are intriguing neoplasms that exhibit primarily neuronal, but also glial characteristics, which indicate an origin from a pluripotential neuroglial precursor. The authors describe an intraventricular neurocytoma in an 11-year-old boy that showed anaplastic features with widespread necrosis and mitoses, as well as extensive calcification and foci that exhibited marked neuronal differentiation with clusters of ganglion cells. Immunohistochemical examination showed prominent synaptophysin and neurofilament positivity and focal glial fibrillary acidic protein positivity. Electron microscopy revealed abundant neuritic processes with microtubules and dense core granules as well as mature ganglion cells. Flow cytometry studies revealed increased S (7.8%) and G2M (9.7%) phase components. Molecular and cytogenetic studies were undertaken to assess whether there were similarities to two other tumor types that exhibit neuronal differentiation, the neuroblastoma and medulloblastoma. Polymerase chain reaction and fluorescence in situ hybridization (FISH) analysis revealed no evidence of amplification of the MYCN oncogene or chromosome 1p deletion, which are common in neuroblastomas. Chromosomal analysis by G banding revealed a complex karyotype, with counts in the near-diploidy range (45–48). Two chromosomes 1 appeared normal on G banding and FISH analysis, with p58 signals present on the distal p arm of both chromosomes 1; however, three additional copies of distal 1q were present in rearrangements with 4 and 7. Although the histological findings indicate a kinship to the neuroblastoma and medulloblastoma, the central neurocytoma appears to have a different karyotypic profile, although more cases need to be assessed using molecular genetic analysis.
The peer-review process of the Journal of Neurosurgery
Authors: Firlik Katrina S. , Firlik Andrew D.
Published: May 2009

✓ Peer review is the process by which scientific articles are evaluated and selected for publication. To clarify this procedure for readers and writers, the authors present a detailed description of peer review at the Journal of Neurosurgery (JNS) in the context of other journals. They discuss the unique characteristics of JNS's peer-review process and how it contributes to the quality of the JNS.
Changes in hemodynamics of the carotid and middle cerebral arteries before and after endoscopic sympathectomy in patients with palmar hyperhidrosis: preliminary results
Authors: Jeng Jiann-Shing , Yip Ping-Keung , Huang Sheng-Jean , Kao Ming-Chien
Published: May 2009

Object. The purpose of this study was to analyze the change in carotid and middle cerebral artery (MCA) hemodynamics before and after endoscopic upper thoracic sympathectomy in patients with palmar hyperhidrosis (PH).

Methods. Sixty-eight patients with PH (35 males and 33 females) for whom the average age was 24.5 ± 10.7 years (± standard deviation) were recruited into this study. These patients all underwent routine upper T-2 sympathectomy to treat their PH. Ultrasonography studies of the carotid arteries (CAs) and MCA were obtained in each patient before and after T-2 sympathectomy. The blood flow volume, flow velocity, and resistivity index (RI) in the bilateral common CAs (CCAs), internal CAs (ICAs), and external CAs (ECAs) were evaluated using duplex ultrasonography. The systolic peak velocity, mean velocity, diastolic peak velocity, pulsatility index, and RI of the bilateral MCAs were evaluated using transcranial Doppler ultrasonography. Blood pressure and heart rate were also recorded during this study. The Student paired t-test was used to analyze the differences between studies before and after bilateral T-2 sympathectomy. There was a significant reduction in diastolic pressure after T-2 sympathectomy (p = 0.003), but not in systolic pressure or heart rate. The vessel diameter was increased after sympathectomy in the left CAs and right CCA. The T-2 sympathectomy led to significant elevation of blood flow volume and RI in the left CCA, ICA, and ECA (p < 0.05). The authors found significant increases in maximum flow velocity and RI in the left MCA (p < 0.05).

Conclusions. Patients who underwent T-2 sympathectomy demonstrated a significant increase in blood flow volume and flow velocities of the CAs and MCA, especially on the left side. Asymmetry of sympathetic influence on the hemodynamics of the CAs and MCA was noted. The usefulness of sympathectomy for the treatment of ischemic cardiovascular and cerebrovascular disease deserves further investigation.
Ultra-early clot aspiration after lysis with tissue plasminogen activator in a porcine model of intracerebral hemorrhage: edema reduction and blood-brain barrier protection
Authors: Wagner Kenneth R. , Xi Guohua , Hua Ya , Zuccarello Mario , de Courten-Myers Gabrielle M. , Broderick Joseph P. , Brott Thomas G.
Published: May 2009

Object. Ultra-early hematoma evacuation (< 4 hours) after intracerebral hemorrhage (ICH) may reduce mass effect and edema development and improve outcome. To test this hypothesis, the authors induced lobar hematomas in pigs.

Methods. The authors infused 2.5 ml of blood into the frontal cerebral white matter in pigs weighing 8 to 10 kg. In the treatment group, clots were lysed with tissue plasminogen activator ([tPA], 0.3 mg) and aspirated at 3.5 hours after hematoma induction. Brains were frozen in situ at 24 hours post-ICH and hematomal and perihematomal edema volumes were determined on coronal sections by using computer-assisted morphometry.

Hematoma evacuation rapidly reduced elevated cerebral tissue pressure from 12.2 ± 1.3 to 2.8 ± 0.8 mm Hg. At 24 hours, prior clot removal markedly reduced hematoma volumes (0.40 ± 0.10 compared with 1.26 ± 0.13 cm3, p < 0.005) and perihematomal edema volumes (0.28 ± 0.05 compared with 1.46 ± 0.24 cm3, p < 0.005), compared with unevacuated control lesions. Furthermore, no Evans blue dye staining of perihematomal edematous white matter was present in brains in which the hematomas had been evacuated, compared with untreated controls.

Conclusions. Hematomas were quickly and easily aspirated after treatment with tPA, resulting in significant reductions in mass effect. Hematoma aspiration after fibrinolysis with tPA enabled removal of the bulk of the hematoma (> 70%), markedly reduced perihematomal edema, and prevented the development of vasogenic edema. These findings in a large-animal model of ICH provide support for clinical trials that include the use of fibrinolytic agents and ultra-early stereotactically guided clot aspiration for treating ICH.
Improved motor outcome in response to magnesium therapy received up to 24 hours after traumatic diffuse axonal brain injury in rats
Authors: Heath Deanne L. , Vink Robert
Published: May 2009

Object. The goal of this study was to establish the therapeutic window during which delayed therapy with MgSO4 improves neurological motor outcome in rats that have suffered severe traumatic axonal brain injury.

Methods. Severe brain injury was induced in male Sprague—Dawley rats by using the impact—acceleration model of severe traumatic diffuse axonal brain injury. Injured animals were subsequently treated with MgSO4 (750 µmol/kg) infused intramuscularly at 30 minutes or at 8, 12, or 24 hours after trauma and were tested for neurological motor outcome during the following week by using the rotarod test. Injured untreated (control) animals demonstrated highly significant (p < 0.001) neurological motor deficits that were sustained over the 1-week assessment period. Animals treated with MgSO4 at 30 minutes or at 8 or 12 hours postinjury demonstrated significantly improved motor outcomes compared with untreated control animals at all time points (0.001 < p < 0.05). Animals treated with MgSO4 at 24 hours had motor scores that were similar to those of untreated control animals early in the week, but demonstrated a significantly more rapid recovery in function and, by the end of the assessment period, they demonstrated significantly improved motor scores (p < 0.01). Repeated administration of MgSO4 over the 1-week observation period did not further improve outcome.

Conclusions. The present results demonstrate that Mg++ plays a neuroprotective role following severe diffuse traumatic axonal brain injury. Moreover, Mg++ therapy significantly improved motor outcome when administered up to 24 hours after injury, with early treatments providing the most significant benefit. Repeated administration beyond 24 hours postinjury did not provide additional neuroprotection.
Influence of early posttraumatic hypothermia therapy on cerebral blood flow and glucose metabolism after fluid-percussion brain injury
Authors: Zhao Weizhao , Alonso Ofelia F. , Loor Judith Y. , Busto Raul , Ginsberg Myron D.
Published: May 2009

Object. Using autoradiographic image averaging, the authors recently described prominent foci of marked glucose metabolism-greater-than-blood-flow uncoupling in the acutely traumatized rat brain. Because hypothermia is known to ameliorate injury in this and other injury models, the authors designed the present study to assess the effects of posttraumatic therapeutic hypothermia on the local cerebral metabolic rate of glucose (LCMRglu) and local cerebral blood flow (LCBF) following moderate parasagittal fluid-percussion head injury (FPI) in rats.

Methods. Either cranial hypothermia (30°C) or normothermia (37°C) was induced for 3 hours in matched groups of rats immediately after FPI; LCMRglu and LCBF were assessed 3 hours after concluding these temperature manipulations.

In rats subjected to FPI, regardless of whether normothermia or hypothermia ensued, LCBF was reduced relative to the sham-injury groups. In addition, when FPI was followed by hypothermia (FPI—30°C group), the subsequent LCBF was significantly lower (35–38% on average) than in FPI—37°C rats. Statistical mapping of LCBF difference imaging data revealed confluent cortical and subcortical zones of significantly reduced LCBF (largely ipsilateral to the prior injury) in FPI—30°C rats relative to the FPI—37°C group. Local glucose utilization was reduced in both hemispheres of FPI—37°C rats relative to the sham-injury group and was lower in the right (traumatized) hemisphere than in the left. However, LCMRglu values were largely unaffected by temperature manipulation in either the FPI or sham-injury groups. The LCMRglu/LCBF ratio was nearly doubled in FPI—30°C rats relative to the FPI—37°C group, in a diffuse and bihemispheric fashion. Linear regression analysis comparing LCMRglu and LCBF revealed that the FPI—37°C and FPI—30°C data sets were completely nonoverlapping, whereas the two sham-injury data sets were intermixed.

Conclusions. Despite its proven neuroprotective efficacy, early posttraumatic hypothermia (30°C for 3 hours) nonetheless induces a moderate decline in cerebral perfusion without the (anticipated) improvement in cerebral glucose utilization, so that a state of mild metabolism-greater-than-blood-flow dissociation is perpetuated.