bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrocephalus: comparison of clipping and embolization in aneuryson treatment
Authors: Sethi Huma , Moore Anne , Dervin James , Clifton Andrew , MacSweeney J. Emma
Published: May 2009

Object. In this retrospective study conducted at Atkinson Morley's Hospital and Middlesbrough General Hospital, the authors analyzed 100 matched patients who had suffered subarachnoid hemorrhage (SAH) to determine whether the technical procedure by which aneurysms are treated affects the development of chronic hydrocephalus.

Methods. Four hundred seventy-five patients presented with SAH between 1995 and 1998. Exclusion criteria included posterior circulation aneurysms, multiple aneurysms, electively clipped or embolized aneurysms, angiographically undetected SAH, patients who died within 1 month of neurosurgical intervention, and patients with the same aneurysm location but a different Fisher grade.

The authors matched 50 patients who underwent embolization of their aneurysms with another 50 who had similar Fisher grades and aneurysm types and underwent clipping of their aneurysms. The maximum incidence of ruptured aneurysms occurred in patients who were between 41 and 60 years of age, with women preponderant in both study groups. In each group, 27 patients had anterior communicating artery aneurysm, 13 had posterior communicating artery aneurysm, seven had middle cerebral artery aneurysm, and three had internal carotid artery aneurysm. The lesions in three patients in each group were Fisher Grade I, in 23 patients they were Fisher Grade II, in 14 they were Fisher Grade III, and 10 patients had Fisher Grade IV SAH. Nine patients among those with clipped aneurysms and eight of the patients who underwent embolization had hydrocephalus for which they needed intervention. These interventions included lumbar puncture, ventricular drainage, and ventriculoperitoneal (VP) shunt placement; three patients in each group needed VP shunt placement.

Conclusions. The technical procedure used to treat aneurysms, whether clipping or embolization, does not significantly affect the development of chronic hydrocephalus. However, a larger sample of patients is needed for accurate comparisons and stronger conclusions.
Stereotactic radiosurgery of cavernous malformations
Authors: Pollock Bruce E. , Garces Yolanda I. , Stafford Scott L. , Foote Robert L. , Schomberg Paula J. , Link Michael J.
Published: May 2009

Object. The use of stereotactic radiosurgery to treat cerebral cavernous malformations (CMs) is controversial. To evaluate the efficacy and safety of CM radiosurgery, the authors reviewed the experience at the Mayo Clinic during the past 10 years.

Methods. Seventeen patients underwent radiosurgery for high-surgical-risk CMs in the following sites: thalamus/basal ganglia (four patients), brainstem (12 patients), and corpus callosum (one patient). All patients had experienced at least two documented hemorrhages before undergoing radiosurgery. Stereotactic magnetic resonance (MR) imaging was used for target localization in all cases. The median margin radiation dose was 18 Gy and the median maximum dose was 32 Gy. The median length of follow-up review following radiosurgery was 51 months.

The annual hemorrhage rate during the 51 months preceding radiosurgery was 40.1%, compared with 8.8% in the first 2 years following radiosurgery and 2.9% thereafter. In 10 patients (59%) new neurological deficits developed that were associated with regions of increased signal on long—repetition time MR imaging performed a median of 8 months (range 5–16 months) after radiosurgery. Three patients recovered, giving the group a permanent radiation-related morbidity rate of 41%. Compared with 31 patients harboring arteriovenous malformations (AVMs) of sizes and in locations similar to those of the aforementioned CMs, who underwent radiosurgery during the same time period, the patients with CMs were more likely to experience radiation-related complications (any complication, 59% compared with 10%; p < 0.001; permanent complication, 41% compared with 10%; p = 0.02).

Conclusions. It is impossible to conclude that radiosurgery protects patients with CMs against future hemorrhage risk based on the available data, although it appears that some reduction in the bleeding rate occurs after a latency interval of several years. The risk of radiation-related complications after radiosurgery to treat CMs is greater than that found after radiosurgery in AVMs, even when adjusting for lesion size and location and for radiation dose.
A multicenter prospective randomized controlled trial of the efficacy of mild hypothermia for severely head injured patients with low intracranial pressure
Authors: Shiozaki Tadahiko , Hayakata Toshiaki , Taneda Mamoru , Nakajima Yoshikazu , Hashiguchi Naoyuki , Fujimi Satoshi , Nakamori Yasushi , Tanaka Hiroshi , Shimazu Takeshi , Sugimoto Hisashi , _ _
Published: May 2009

Object. The criteria for the use of mild hypothermia (34°C) in severely head injured patients have not been standardized. A prospective randomized controlled trial was conducted to determine whether mild hypothermia is essential in the treatment of severely head injured patients with low intracranial pressure (ICP).

Methods. At 11 medical centers, 91 severely head injured patients with an admission Glasgow Coma Scale score of 8 or less in whom ICP could be maintained below 25 mm Hg by conventional therapies were divided randomly into two groups: the mild hypothermia group (HT group, 45 patients) and the normothermia group (NT group, 46 patients). Patients in the HT group were exposed to mild hypothermia (34°C) for 48 hours, followed by rewarming at 1°C per day for 3 days, whereas patients in the NT group were exposed to normothermia (37°C) for 5 days. The two groups were similar with respect to prognostic factors, and there was no difference in clinical outcome at 3 months postinjury. During treatment, there was a significantly greater use of neuromuscular blocking agents in the HT group (p = 0.011). During the initial 2 weeks postinjury, the incidences of pneumonia, meningitis, leukocytopenia, thrombocytopenia, hypernatremia, hypokalemia, and hyperamylasemia were significantly higher in the HT than in the NT group (p <0.05).

Conclusions. Mild hypothermia should not be used for the treatment of severely head injured patients with low ICP because this therapy conveys no advantage over normothermia in such patients.
Cerebrospinal fluid dynamics of the cava septi pellucidi and vergae
Authors: Sencer Altay , Sencer Serra , Turantan İnan , Devecioğlu Ömer
Published: May 2009

✓ This case involved a 26-month-old boy who had recurrent hemorrhagic venous infarction caused by venous sinus occlusion. Distension and enlargement of the cavum septi pellucidi (CSP) and cavum vergae (CV), along with hydrocephalus, was detected during the course of the disease and was observed to regress together with resolution of the venous occlusion. Venous hypertension caused by sinus occlusion was thought to be responsible for the disturbed resorption of cerebrospinal fluid (CSF) in the CSP and CV in this patient. This case is unique because it is the first one to support the hypothesis of resorption of CSF in the cava by a pressure gradient involving the septal capillaries and veins.
Delayed appearance of a traumatic intracranial aneurysm
Authors: Chedid Mokbel K. , Vender John R. , Harrison Steven J. , McDonnell Dennis E.
Published: May 2009

✓ Giant traumatic intracranial aneurysms are rare, and thus their incidence and clinical behavior are poorly understood. In most cases, traumatic aneurysms develop and become symptomatic within months following injury. The authors present the case of a 46-year-old war veteran, in whom a giant internal carotid artery aneurysm developed as a result of a penetrating cranial shrapnel injury sustained 25 years earlier during the Vietnam war. The aneurysm had not been evident on previous imaging studies. At surgery, a piece of shrapnel was found embedded in the dome of the aneurysm. The presentation, diagnosis, management, and treatment options related to this lesion are discussed.
Cerebrospinal fluid hydrodynamics after placement of a shunt with an antisiphon device: a long-term study
Authors: Lundkvist Bo , Eklund Anders , Kristensen Bo , Fagerlund Markku , Koskinen Lars-Owe D. , Malm Jan
Published: May 2009

Object. Few studies have been performed to investigate the cerebrospinal fluid (CSF) hydrodynamic profile in patients with idiopathic adult hydrocephalus syndrome (IAHS) before and after shunt implantation. The authors compared the in vivo CSF hydrodynamic properties, including the degree of gravity-induced CSF flow, of a shunt with an antisiphon device with a standard shunt.

Methods. Twelve patients with IAHS underwent insertion of shunts with Delta valves. Clinical testing, magnetic resonance imaging, and CSF hydrodynamic investigations were conducted with intracranial pressure (ICP), gravity effect, and pressure—flow curve of the shunt estimated at baseline and at 3 and 12 months postoperatively. No shunt was revised.

Despite postoperative clinical improvement in all patients who received Delta valves, the mean ICP was only moderately reduced (mean decrease at 3 months 0.3 kPa [p = 0.02], at 12 months 0.2 kPa [not significant]). Patients with the greatest increase in ICP preoperatively had the most pronounced decrease postoperatively. The hydrostatic effect of the Delta valves was significantly lower than with the Hakim shunts (0.1–0.2 kPa compared with 0.6 kPa). The increased conductance (that is, lowered resistance) was up to 14 times higher with the Delta valves compared with preoperative levels.

Conclusions. The function of a CSF shunt may be more complicated than previously thought; the subcutaneous pressure acting on the antisiphon device can modify the shunt characteristics. A compensatory increase in CSF production may counteract the increased outflow through the shunt. The improved CSF outflow conductance may increase the intracranial compliance and thereby dampen a pathological ICP waveform.
Angiogenic effect of thymidine phosphorylase on macrophages in glioblastoma multiforme
Authors: Hirano Hirofumi , Tanioka Koji , Yokoyama Shunichi , Akiyama Shin-ichi , Kuratsu Jun-ichi
Published: May 2009

Object. Thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF) are known angiogenic factors; however, there are few reports in which the relationship between these two factors is addressed. The authors compared expression patterns of TP and VEGF and investigated their role in the angiogenesis of glioblastoma multiforme (GBM).

Methods. Surgical specimens from 41 cases of GBM were immunohistochemically stained for TP, VEGF, CD68 (a macrophage marker), and CD31 (an endothelial cell marker). Both TP labeling indices and VEGF immunoreactivity displayed significant correlations with vascular density. Although VEGF was diffusely distributed in the tumor, TP was strongly expressed around blood vessels and in vascular proliferation. Double labeling for TP and CD68 in 10 cases indicated that cells that reacted strongly positive for TP were almost always macrophages, and only small numbers of CD68-negative cells weakly expressed TP.

The TP messenger (m)RNA expression was investigated using reverse transcription-polymerase chain reaction in six GBMs. All six specimens expressed TP mRNA. In addition, TP mRNA was detected in two of three groups of cultured GBM cells derived from surgical specimens. Macrophages, the production of which was induced from two volunteers' peripheral blood monocytes by applying macrophage colony-stimulating factor, also expressed TP mRNA. The glioma cell lines U251MG and U87MG, which barely express TP mRNA under normal conditions, expressed TP mRNA in response to interferon-β stimulation or while in an anoxic condition.

Conclusions. Although it is feasible that GBM cells can express TP depending on their growing conditions, the majority of TP-expressing cells present in GBMs appear to be infiltrating macrophages. Coexistence of VEGF and TP may indicate a synergistic upregulation for angiogenesis because VEGF exerts a chemotactic activity on macrophages that express TP.
The lateral sellar nerve plexus and its connections in humans
Authors: Bleys Ronald L. A. W. , Janssen Luuk M. , Groen Gerbrand J.
Published: May 2009

Object. The aim of the present study was to elucidate the systematic topography of the lateral sellar (cavernous sinus [CS]) nerve plexus and its connections in humans.

Methods. Seven specimens of human CS and adjacent regions were dissected in steps and stained as whole-mount preparations by using a sensitive acetylcholinesterase method. Another specimen was frozen, cut on a frontal plane, and stained for acetylcholinesterase.

The human CS contains an extensive nerve plexus with small ganglia. The plexus is composed of a main part, the lateral sellar plexus proper, which is located around the abducent nerve and medial to the ophthalmic nerve, and a lateral extension just underneath the outermost layer of the lateral CS wall, which is located lateral to the trochlear and ophthalmic nerves. The lateral sellar plexus is connected to the internal carotid nerve, the pterygopalatine ganglion, and the trigeminal ganglion. From the lateral sellar plexus, nerve branches run along the oculomotor, trochlear, ophthalmic, and abducent nerves into the orbit. In addition, the lateral sellar plexus has multiple connections with nerves located around the internal carotid artery. The presence of connections between the lateral sellar plexus and functionally defined neural structures suggests that the plexus receives sympathetic, parasympathetic, and sensory contributions.

Conclusions. The plexus may distribute nerve subpopulations to several targets, including cerebral arteries and orbital structures. The presence of a mixed nerve plexus that projects to a variety of targets indicates that injury or disease in the CS may result in a variety of symptoms.
Cerebellar mutism associated with a midbrain cavernous malformation
Authors: Wang Marjorie C. , Winston Ken R. , Breeze Robert E.
Published: May 2009

✓ The authors report a case of cerebellar mutism arising from a hemorrhagic midbrain cavernous malformation in a 14-year-old boy. No cerebellar lesion was identified; however, edema of the dorsal midbrain was noted on postoperative magnetic resonance images. Dysarthric speech spontaneously returned and then completely resolved to normal speech. This case provides further evidence for the theory that involvement of the dentatothalamic tracts, and not a cerebellar lesion per se, is the underlying cause of “cerebellar” mutism.
Role of a synthetic pyrimidine compound, MS-818, in reduction of infarct size and amelioration of sensorimotor dysfunction following permanent focal cerebral ischemia in rats
Authors: Mitsuyama Tetsuryu , Kawamata Takakazu , Yamane Fumitaka , Awaya Akira , Hori Tomokatsu
Published: May 2009

Object. A synthetic heterocyclic pyrimidine compound, MS-818 (2-piperadino-6-methyl-5-oxo-5,6-dihydro-(7H) pyrrolo-[3,4-d] pyrimidine maleate) is reported to have a variety of biological activities including neurite outgrowth, astrocyte differentiation, suppression of neuronal apoptosis, regeneration of injured peripheral nerves, fracture repairs, angiogenesis, and superovulation. To be able to explicate the neurotrophic effects of MS-818, the authors evaluated its effect on the reduction of infarct volume and amelioration of sensorimotor dysfunction in a rat model of focal ischemia.

Methods. Forty male Sprague—Dawley rats were subjected to right middle cerebral artery occlusion and assigned to one of four treatment groups (10 animals in each group). The MS-818 (1, 5, or 10 mg/kg) or phosphate-buffered saline (control group) was administered intraperitoneally at onset of ischemia and again 24 hours later. The rats were killed 48 hours after they underwent surgery to induce stroke, and infarct volume was determined using an image-analysis computer software program following staining with 2,3,5-triphenyltetrazolium chloride. Postischemic neurological deficit and body weight were also assessed.

Conclusions. Significant reductions in infarct volume (total and cortical infarction) were found in all the MS-818—treated groups compared with the control group. Furthermore, MS-818 induced significant amelioration of sensorimotor dysfunction, as indicated by the results of forelimb and hindlimb placing tests. The present findings suggest that MS-818, which has a much smaller molecular weight than neurotrophic peptides, represents a new approach to the treatment of focal cerebral ischemia.
Dissecting aneurysms of the vertebral artery: a management strategy
Authors: Iihara Koji , Sakai Nobuyuki , Murao Kenichi , Sakai Hideki , Higashi Toshio , Kogure Shuji , Takahashi Jun C. , Nagata Izumi
Published: May 2009

Object. The authors present a retrospective analysis of their experience in the treatment of vertebral artery (VA) dissecting aneurysms and propose a management strategy for such aneurysms, with special emphasis on the most formidable VA dissecting aneurysms, which involve the origin of the posterior inferior cerebellar artery (PICA).

Methods. Since 1998, 18 patients with VA dissecting aneurysms, 11 of whom presented with subarachnoid hemorrhage (SAH), have been treated by endovascular surgery at the authors' institution. Obliteration of the entire segment of the dissected site with coils (internal trapping) was performed for aneurysms without involvement of the origin of the PICA (12 cases; among these the treatment-related morbidity rate was 16.7%). The treatment strategy applied to PICA-involved VA dissecting aneurysms presenting with SAH (three cases) included proximal occlusion of the parent artery followed by internal trapping of the aneurysm (one case), proximal occlusion of the parent artery followed by occipital artery (OA)—PICA bypass (one case), and two-staged internal trapping of the aneurysm involving double PICAs (one case). For PICA-involved VA dissecting aneurysms that were not associated with SAH at presentation (three cases), OA—PICA bypass was performed and followed by internal trapping of the aneurysm (two cases). In the remaining case in which a fetal-type posterior communicating artery was present, internal trapping was performed following successful balloon test occlusion (BTO). Overall, there was no sign of infarction in the PICA territory, despite complete occlusion of aneurysms involving the PICA. There was no recurrent bleeding or ischemic symptoms during the follow-up periods. The overall treatment-related morbidity rate for the VA dissecting aneurysms involving the PICA was 16.7%.

Conclusions. Dissecting VA aneurysms that do not involve the PICA can be safely treated by internal trapping. For those lesions that do involve the PICA, a decision-making algorithm is advocated to maximize the efficacy of the treatment as well as to minimize the risks of treatment-related morbidity based on BTO.
Separation of craniopagus joined at the occiput
Authors: Campbell Scott , Theile Richard , Stuart Gordon , Cheng Eddie , Sinnott Stephen , Pritchard Gary , Isles Alan
Published: May 2009

✓ Siamese or conjoined twins have intrigued both the physician and layperson for centuries. The craniopagus type (joined at the head) is exceedingly rare, with an incidence of one in 2.5 million births. Most clinicians never see a case of craniopagus, and those who do rarely see more than one. The authors present a case of the craniopagus type of conjoined twins born and recently separated in Brisbane, Australia. The prenatal diagnosis, subsequent investigations, separation, and outcome are presented.
Radiosurgery for non—small cell lung carcinoma metastatic to the brain: long-term outcomes and prognostic factors influencing patient survival time and local tumor control
Authors: Sheehan Jason P. , Sun Ming-Hsi , Kondziolka Douglas , Flickinger John , Lunsford L. Dade
Published: May 2009

Object. Lung carcinoma is the leading cause of death from cancer. More than 25% of those patients with lung cancer develop a brain metastasis at some time during the course of their disease. Corticosteroid therapy, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, the median survival for patients with lung carcinoma metastasis is approximately 3 to 6 months. The authors examine the efficacy of gamma knife radiosurgery (GKS) for treating non—small cell lung carcinoma (NSCLC) metastases to the brain and evaluate factors affecting long-term patient survival.

Methods. A retrospective review of 273 patients who had undergone GKS to treat a total of 627 NSCLC metastases was performed. Clinical and neuroimaging data encompassing a 14-year treatment interval were collected. Univariate and multivariate analyses were performed to determine significant prognostic factors influencing patient survival.

The overall median patient survival time was 15 months (range 1–116 months) from the diagnosis of brain metastases. The median survival was 10 months from GKS treatment in those patients with adenocarcinoma and 7 months for those with other histological tumor types. In patients with no active extracranial disease at the time of GKS, the median survival time was 16 months. In multivariate analyses, factors significantly affecting survival included: 1) female sex (p = 0.014); 2) preoperative Karnofsky Performance Scale score (p < 0.0001); 3) adenocarcinoma histological subtype (p = 0.0028); 4) active systemic disease (p = 0.0001); and 5) time from lung cancer diagnosis to the development of brain metastasis (p = 0.0074). Prior tumor resection or whole-brain radiation therapy did not correlate with extended patient survival time.

Postradiosurgical imaging of brain metastases revealed that 60% decreased, 24% remained stable, and 16% eventually increased in size. Factors affecting local tumor control included tumor volume (p = 0.042) and treatment isodose (p = 0.015). Fourteen patients (5.1%) later underwent craniotomy and tumor resection for tumor refractory to GKS or a new symptomatic metastasis.

Conclusions. Gamma knife surgery for NSCLC metastases affords effective local tumor control in approximately 84% of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including GKS can afford patients an extended survival time.
Rapid development of an intranidal aneurysm with perifocal brain edema in an unruptured cerebral arteriovenous malformation
Authors: Akabane Atsuya , Jokura Hidefumi , Ogasawara Kuniaki , Takahashi Kou , Sugai Kazuyuki , Ogawa Akira , Yoshimoto Takashi
Published: May 2009

✓ The authors present the case of a 22-year-old man with an unruptured arteriovenous malformation (AVM) in which an intranidal aneurysm had grown in the course of 3 months and was complicated by perifocal brain edema. A left parietal AVM was incidentally diagnosed on magnetic resonance (MR) imaging. No aneurysms were noted on cerebral angiograms obtained simultaneously. Three months later, T2-weighted MR imaging revealed perifocal brain edema (increased signal intensity in the brain parenchyma adjacent to the nidus). An aneurysm-like signal void was demonstrated in the center of the high-signal area, but no previous hemorrhages could be detected. Angiographic studies revealed an intranidal aneurysm 4 mm in diameter projecting anterolaterally from the nidus. Surgical removal was performed without incident, and no neurological deficits or postoperative complications were observed. An MR image obtained 2 weeks postsurgery revealed complete resolution of the perifocal brain edema. To the authors' knowledge, this is the first reported case of an unruptured AVM in which an intranidal aneurysm with perifocal brain edema developed rapidly (within a few months).
Radiosurgery in patients with renal cell carcinoma metastasis to the brain: long-term outcomes and prognostic factors influencing survival and local tumor control
Authors: Sheehan Jason P. , Sun Ming-Hsi , Kondziolka Douglas , Flickinger John , Lunsford L. Dade
Published: May 2009

Object. Renal cell carcinoma is a leading cause of death from cancer and its incidence is increasing. In many patients with renal cell cancer, metastasis to the brain develops at some time during the course of the disease. Corticosteroid therapy, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, the median survival in patients with renal cell carcinoma metastasis is approximately 3 to 6 months. In this study the authors examined the efficacy of gamma knife surgery in treating renal cell carcinoma metastases to the brain and evaluated factors affecting long-term survival.

Methods. The authors conducted a retrospective review of 69 patients undergoing stereotactic radiosurgery for a total of 146 renal cell cancer metastases. Clinical and radiographic data encompassing a 14-year treatment interval were collected. Multivariate analyses were used to determine significant prognostic factors influencing survival.

The overall median length of survival was 15 months (range 1–65 months) from the diagnosis of brain metastasis. After radiosurgery, the median survival was 13 months in patients without and 5 months in those with active extracranial disease. In a multivariate analysis, factors significantly affecting the rate of survival included the following: 1) younger patient age (p = 0.0076); 2) preoperative Karnofsky Performance Scale score (p = 0.0012); 3) time from initial cancer diagnosis to brain metastasis diagnosis (p = 0.0017); 4) treatment dose to the tumor margin (p = 0.0252); 5) maximal treatment dose (p = 0.0127); and 6) treatment isodose (p = 0.0354). Prior tumor resection, chemotherapy, immunotherapy, or whole-brain radiation therapy did not correlate with extended survival.

Postradiosurgical imaging of the brain demonstrated that 63% of the metastases had decreased, 33% remained stable, and 4% eventually increased in size. Two patients (2.9%) later underwent a craniotomy and resection for a tumor refractory to radiosurgery or a new symptomatic metastasis. Eighty-three percent of patients died of progression of extracranial disease.

Conclusions. Stereotactic radiosurgery for treatment of renal cell carcinoma metastases to the brain provides effective local tumor control in approximately 96% of patients and a median length of survival of 15 months. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can offer patients an extended survival.
Hemangiopericytoma in the central nervous system: treatment, pathological features, and long-term follow up in 38 patients
Authors: Ecker Robert D. , Marsh W. Richard , Pollock Bruce E. , Kurtkaya-Yapicier Özlem , McClelland Robyn , Scheithauer Bernd W. , Buckner Jan C.
Published: May 2009

Object. The authors reviewed the Mayo Clinic experience with the treatment of hemangiopericytoma in the primary central nervous system (CNS).

Methods. A retrospective study of all patients at the Mayo Clinic revealed 38 who had been treated for hemangiopericytoma in the CNS. Twenty of these patients were diagnosed in the decade between 1990 and 2000; 18 were initially diagnosed and underwent surgery before 1990.

In the patients treated since 1990, the 5-year Kaplan—Meier survival rate was 93%. The 5-year disease-free survival rate was 89%. Sixty percent of patients treated with the aid of stereotactic radiosurgery for recurrent disease were alive 4.4 years after their initial treatment. Salvage chemotherapy was not effective. No survival benefit was detected in patients who had received initial adjuvant external-beam radiation therapy. High-grade tumors recurred 6.7 years earlier than did low-grade lesions (p = 0.004).

Conclusions. The 5-year survival rate in patients with hemangiopericytoma of the CNS has improved at the authors' institution during the last 10 years. Although the reason for this is not entirely clear, the authors suspect that the improved treatment of patients with cancer, a 0% intraoperative mortality rate, and the use of radiosurgery in the treatment of recurrent disease all likely contribute. High-grade tumors recurred statistically significantly earlier than low-grade lesions. Current chemotherapies are ineffective in the treatment of hemangiopericytoma of the CNS.
Combined transvenous and transarterial embolization of a tentorial—incisural dural arteriovenous malformation followed by primary stent placement in the associated stenotic straight sinus
Authors: Troffkin Neil A. , Graham Cole Blease , Berkmen Turgut , Wakhloo Ajay K.
Published: May 2009

✓ Dural arteriovenous malformations (AVMs) involving the tentoria—incisura are associated with an aggressive clinical course characterized by subarachnoid and intracranial hemorrhage (ICH). In these lesions, venous outflow obstruction precipitates leptomeningeal venous drainage, resulting in the arterialization of pial veins and the formation of venous aneurysms, both of which are prone to hemorrhage. Stenotic lesions of the dural sinuses also contribute to the development of retrograde leptomeningeal drainage, which is responsible for the aggressive clinical course of the dural AVM. Endovascular approaches are successful in the treatment of these lesions and of any potential venous outflow obstruction caused by stenosis of a dural sinus. The authors report on a patient with a tentorial—incisural dural AVM and an accompanying stenotic venous sinus. A combined transvenous and transarterial embolization procedure was performed, resulting in complete obliteration of the dural AVM, followed by primary stent placement across a stenotic segment of the straight sinus and normalization of venous outflow. The authors conclude that dural AVMs can be treated safely by using a combined transarterial and transvenous approach and that an extensive search for venous outflow obstruction often reveals stenosis of a draining sinus. Consideration should be given to primary stent placement in the stenotic sinus to protect against ICH.
Evolving metabolic changes during the first postoperative year after subthalamotomy
Authors: Trošt Maja , Su Philip C. , Barnes Anna , Su Sherwin L. , Yen Ruoh-Fang , Tseng Ham-min , Ma Yilong , Eidelberg David
Published: May 2009

Object. Short-term benefit from unilateral subthalamotomy for advanced Parkinson disease (PD) is associated with metabolic alterations in key targets of subthalamic nucleus (STN) and globus pallidus (GP) output. In this study positron emission tomography (PET) scanning was used to assess these changes and their relation to long-term benefits of subthalamotomy.

Methods. To determine whether the early postoperative changes persisted at longer-term follow up, the authors assessed six patients with advanced PD by using [18F]fluorodeoxyglucose—PET at 3 and 12 months postsurgery. The authors compared each of the postoperative images with baseline studies, and assessed interval changes between the short- and long-term follow-up scans.

Clinical improvement at 3 and 12 months was associated with sustained metabolic decreases in the midbrain GP internus (GPi), thalamus, and pons of the lesioned side (p < 0.01). The activity of a PD-related multiregional brain network, which correlated with bradykinesia and rigidity, was reduced at both postoperative time points (p < 0.05). Comparisons of 3- and 12-month images revealed a relative metabolic increase in the GP externus (GPe) (p < 0.001), which was associated with worsening gait, postural stability, and tremor at long-term follow up.

Conclusions. These findings indicate that subthalamotomy may have differential effects on each of the functional pathways that mediate parkinsonian symptomatology. Sustained relief of akinesia and rigidity is associated with suppression of a pathological network involving the GPi and its output. In contrast, the recurrence of tremor may relate to changes in the function of an STN—GPe oscillatory network.
Cerebral metabolic correlates as potential predictors of response to anterior cingulotomy for treatment of major depression
Authors: Dougherty Darin D. , Weiss Anthony P. , Cosgrove G. Rees , Alpert Nathaniel M. , Cassem Edwin H. , Nierenberg Andrew A. , Price Bruce H. , Mayberg Helen S. , Fischman Alan J. , Rauch Scott L.
Published: May 2009

Object. Neurosurgical procedures are a viable intervention for severe, treatment-refractory major depression, although they have been associated with only modest rates of efficacy. The purpose of this study was to identify possible neuroimaging predictors of treatment response to anterior cingulotomy in patients with major depression.

Methods. Thirteen patients underwent stereotactic anterior cingulotomy for treatment-refractory major depression. Symptom severity was measured using the Beck Depression Inventory (BDI) both before and approximately 12 months after surgery. The authors performed [18F]fluorodeoxyglucose—positron emission tomography (PET) studies in all patients preoperatively. Statistical parametric mapping methods were used to test for loci of significant correlation between preoperative regional cerebral metabolism and postoperative reduction in BDI scores.

The mean (± standard deviation) change in the BDI score from the preoperative period (43.7 ± 7.8) to the postoperative period (30.5 ± 21.3) was 33.1 ± 45.4%. Two loci—the left subgenual prefrontal cortex and left thalamus—were identified as sites at which preoperative metabolism was significantly correlated with subsequent improvement in depressive symptom severity following cingulotomy. Specifically, higher preoperative rates of metabolism at these loci were associated with better postoperative results.

Conclusions. Possible PET scanning predictors of treatment response were identified in patients with major depression who had undergone anterior cingulotomy. Further research will be necessary to determine the reproducibility of this finding. If confirmed, the availability of an index for noninvasively predicting a patient's response to cingulotomy for the treatment of major depression would be of great clinical value.
Subthalamic nucleus deep brain stimulation in a patient with levodopa-responsive multiple system atrophy
Authors: Chou Kelvin L. , Forman Mark S. , Trojanowski John Q. , Hurtig Howard I. , Baltuch Gordon H.
Published: May 2009

✓ The authors report the clinicopathological findings in a patient in whom levodopa-responsive parkinsonism developed at 45 years of age. The patient experienced asymmetrical onset of symptoms, sustained benefit from levodopa, and motor fluctuations and dyskinesias, but there were no prominent autonomic, cerebellar, or pyramidal signs. He was diagnosed clinically with Parkinson disease (PD) and underwent bilateral subthalamic nucleus deep brain stimulation (DBS) surgery 9 years after symptom onset. He did not respond to stimulation or medication postoperatively, however, and died 12 weeks after surgery of repeated aspiration pneumonias. Postmortem examination revealed neuron loss in the substantia nigra and basal ganglia, and numerous α-synuclein—positive glial cytoplasmic inclusions in the subcortical nuclei, cerebellum, and brainstem, findings that established a neuropathological diagnosis of multiple system atrophy (MSA). Furthermore, there was an atypical and robust inflammatory reaction, as well as numerous glial cytoplasmic inclusions surrounding both DBS electrode termination sites. The authors speculate that the presence of α-synuclein in the striatum, combined with the inflammation surrounding the electrodes, contributed to the ineffectiveness of stimulation and dopaminergic medications postoperatively. This case demonstrates the ineffectiveness of DBS in MSA, even when the patient is responsive to levodopa, and emphasizes the need for diagnostic modalities that can be used to distinguish PD from MSA and other parkinsonian syndromes in which the levodopa response pattern is typical of PD.
Intractable hiccups as a presenting symptom of cerebellar hemangioblastoma
Authors: Nagayama Tetsuya , Kaji Masatomo , Hirano Hirofumi , Niiro Masaki , Kuratsu Jun-ichi
Published: May 2009

✓ The authors report on a 52-year-old woman with a cerebellar hemangioblastoma who presented with a 2-year history of intractable hiccups. Computerized tomography scans and magnetic resonance images revealed a cerebellar hemangioblastoma with compression of the brainstem at the level of the medulla oblongata. The patient has been free of hiccups and has been neurologically intact since the day after total removal of the tumor. A review of the literature on medullary lesions presenting with intractable hiccups is provided.
Cerebral oxygenation following decompressive hemicraniectomy for the treatment of refractory intracranial hypertension
Authors: Stiefel Michael F. , Heuer Gregory G. , Smith Michelle J. , Bloom Stephanie , Maloney-Wilensky Eileen , Gracias Vincente H. , Grady M. Sean , Leroux Peter D.
Published: May 2009

Object.Medically intractable intracranial hypertension is a major cause of morbidity and mortality after severe brain injury. One potential treatment for intracranial hypertension is decompressive hemicraniectomy (DCH). Whether and when to use DCH, however, remain unclear. The authors therefore studied the effects of DCH on cerebral O2to develop a better understanding of the effects of this treatment on the recovery from injury and disease.

Methods.The study focused on seven patients (mean age 30.6 ± 9.7 years) admitted to the hospital after traumatic brain injury (five patients) or subarachnoid hemorrhage (two patients) as part of a prospective observational database at a Level I trauma center. At admission the Glasgow Coma Scale (GCS) score was 6 or less in all patients. Patients received continuous monitoring of intracranial pressure (ICP), cerebral perfusion pressure (CPP), blood pressure, and arterial O2saturation. Cerebral oxygenation was measured using the commercially available Licox Brain Tissue Oxygen Monitoring System manufactured by Integra NeuroSciences. A DCH was performed when the patient's ICP remained elevated despite maximal medical management.

Conclusions.All patients tolerated DCH without complications. Before the operation, the mean ICP was elevated in all patients (26 ± 4 mm Hg), despite maximal medical management. After surgery, there was an immediate and sustained decrease in ICP (19 ± 11 mm Hg) and an increase in CPP (81 ± 17 mm Hg). Following DCH, cerebral oxygenation improved from a mean of 21.2 ± 13.8 mm Hg to 45.5 ± 25.4 mm Hg, a 114.8% increase. The change in brain tissue O2and the change in ICP after DCH demonstrated only a modest relationship (r2= 0.3). These results indicate that the use of DCH in the treatment of severe brain injury is associated with a significant improvement in brain O2.
Reduction of neural adhesions by biodegradable autocrosslinked hyaluronic acid gel after injury of peripheral nerves: an experimental study
Authors: Smit Xander , van Neck Johan W. , Afoke Andrew , Hovius Steven E. R.
Published: May 2009

Object. Adhesion formation is a serious problem in peripheral nerve surgery, frequently causing dysfunction and pain. The authors aimed to develop an objective biomechanical method of quantifying nerve adhesions and to use this technique for the evaluation of the efficacy of an autocrosslinked hyaluronic acid (HA) gel as an antiadhesion therapy.

Methods. Thirty-three female Wistar rats underwent dissection, crush injury, or transection plus repair of the sciatic nerve. The nerves were or were not treated with the HA gel. Six weeks after surgery, the adhesions formed were assessed by measuring the peak force required to break the adhesions over a standardized area. Results of biomechanical measurements demonstrated that the peak force significantly increased as the severity of the injury increased. After using the HA gel to treat the nerve, the peak force was significantly reduced in rats with any of the three types of injuries; peak force decreased by 26% in the animals in the dissection group, 29% in the crush injury group, and 38% in the transection and repair group, compared with the untreated animals.

Conclusions. The biomechanical method described is an objective, quantitative technique for the assessment of nerve adherence to surrounding tissue. It will be a valuable tool in future studies on antiadhesion therapies. Furthermore, HA gel significantly reduces nerve adhesions after different types of nerve injuries.
Isolation of immortalized, INK4a/ARF-deficient cells from the subventricular zone after in utero N-ethyl-N-nitrosourea exposure
Authors: Savarese Todd M. , Jang Taichang , Pang Low Hoi , Salmonsen Rebecca , Litofsky N. Scott , Matijasevic Zdenka , Ross Alonzo H. , Recht Lawrence D.
Published: May 2009

Object. Brain tumors, including gliomas, develop several months after rats are exposed in utero to N-ethyl-N-nitrosourea (ENU). Although pathological changes cannot be detected until these animals are several weeks old, the process that eventually leads to glioma formation must begin soon after exposure given the rapid clearance of the carcinogen and the observation that transformation of brain cells isolated soon after exposure occasionally occurs. This model can therefore potentially provide useful insights about the early events that precede overt glioma formation. The authors hypothesized that future glioma cells arise from stem/progenitor cells residing in or near the subventricular zone (SVZ) of the brain.

Methods. Cells obtained from the SVZ or corpus striatum in ENU-exposed and control rats were cultured in an epidermal growth factor (EGF)-containing, chemically defined medium. Usually, rat SVZ cells cultured in this manner (neurospheres) are nestin-positive, undifferentiated, and EGF-dependent and undergo cell senescence. Consistent with these prior observations, control SVZ cells undergo senescence by the 12th to 15th doubling (20 of 20 cultures). In contrast, three of 15 cultures of cells derived from the SVZs of individual ENU-treated rats continue to proliferate for more than 60 cell passages. Each of these nestin-expressing immortalized cell lines harbored a common homozygous deletion spanning the INK4a/ARF locus and was unable to differentiate into neural lineages after exposure to specific in vitro stimuli. Nevertheless, unlike the rat C6 glioma cell line, these immortalized cell lines demonstrate EGF dependence and low clonogenicity in soft agar and did not form tumors after intracranial transplantation.

Conclusions. Data in this study indicated that immortalized cells may represent glioma precursors that reside in the area of the SVZ after ENU exposure that may serve as a reservoir for further genetic and epigenetic hits that could eventually result in a full glioma phenotype.
Limited efficacy of gene transfer in herpes simplex virus-thymidine kinase/ganciclovir gene therapy for brain tumors
Authors: Hadaczek Piotr , Mirek Hanna , Berger Mitchel S. , Bankiewicz Krystof
Published: May 2009

Object. Low efficacy of gene transfer, transient gene expression, and toxicity of viral vectors are the major hurdles in successful anticancer gene therapy. The authors conducted in vitro (U87MG cell line) and in vivo (xenograft, tumor-bearing rodent model) studies to address the stability of transduction by using the adenoassociated virus serotype-2 (AAV2)—thymidine kinase (TK) vector over time.

Methods. Standard methods for cell growth and a ganciclovir (GCV) cytotoxicity assay were applied. The AAV2-TK was infused into implanted tumors in athymic rats via convection-enhanced delivery (CED). Thymidine kinase expression was evaluated through immunohistochemical analysis, and the distribution volumes of the transduced tumors were calculated. Twenty-four hours following the viral infusions, animals were treated with GCV (50 mg/kg intraperitoneally every day for 10 days; six rats) or phosphate-buffered saline (six rats).

A rapid decrease in TK expression over time was observed both in vitro and in vivo. A large volume of the tumor (up to 39%) was transduced with AAV2-TK following CED. Administration of GCV resulted in limited therapeutic effects (survival of 25.8 compared with 21.3 days).

Conclusions. Rapid elimination of TK expression from dividing tumor cells and focal transduction of the brain tumor were most likely responsible for the limited bystander effect in this approach. Immediate administration of GCV is crucial to assure maximal efficacy in the elimination of cancer cells. In addition, the complete or diffused transduction of a brain tumor with TK may be required for its total eradication.
Trigeminal nerve schwannoma with ancient change
Authors: Ugokwe Kene , Nathoo Narendra , Prayson Richard , Barnett Gene H.
Published: May 2009

✓ Ancient change in a schwannoma is a histological variant typically found in longstanding tumors. Histologically, the tumor has biphasic features typical of a schwannoma with evidence of degenerative changes that may complicate diagnosis. The authors report on a 23-year-old man with no features of neurofibromatosis who presented with headaches, blurred vision, and ataxic gait. Magnetic resonance imaging demonstrated a rim-enhancing lesion in the cerebellopontine angle with displacement of brainstem structures and no supratentorial hydrocephalus. Using a lateral suboccipital approach together with image guidance and intraoperative neurophysiological monitoring, a gross-total macroscopic excision was performed. At surgery, the tumor was found to arise from the inferior division of the trigeminal nerve. The final histological diagnosis was schwannoma with ancient change. Note that ancient change in schwannomas is a histological variant thought to result from degenerative changes in longstanding tumors. To the authors' knowledge, this is the first independent report of this histological variant in an intracranial schwannoma.
Does new magnetic resonance imaging technology provide better geometrical accuracy during stereotactic imaging?
Authors: Novotny Josef , Vymazal Josef , Novotny Josef , Tlachacova Daniela , Schmitt Michal , Chuda Pavel , Urgosik Dusan , Liscak Roman
Published: May 2009

Object.The authors sought to compare the accuracy of stereotactic target imaging using the Siemens 1T EXPERT and 1.5T SYMPHONY magnetic resonance (MR) units.

Methods.A water-filled cylindrical Perspex phantom with axial and coronal inserts containing grids of glass rods was fixed in the Leksell stereotactic frame and subjected to MR imaging in Siemens 1T EXPERT and Siemens 1.5T SYMPHONY units. Identical sequences were used for each unit. The images were transferred to the GammaPlan treatment planning system. Deviations between stereotactic coordinates based on MR images and estimated real geometrical positions given by the construction of the phantom insert were evaluated for each study. The deviations were further investigated as a function of the MR unit used, MR sequence, the image orientation, and the spatial position of measured points in the investigated volume.

Conclusions.Larger distortions were observed when using the SYMPHONY 1.5T unit than those with the EXPERT 1T unit. Typical average distortion in EXPERT 1T was not more than 0.6 mm and 0.9 mm for axial and coronal images, respectively. Typical mean distortion for SYMPHONY 1.5T was not more than 1 mm and 1.3 mm for axial and coronal images, respectively. The image sequence affected the distortions in both units. Coronal T2-weighted spin-echo images performed in subthalamic imaging produced the largest distortions of 2.6 mm and 3 mm in the EXPERT 1T and SYMPHONY 1.5T, respectively. Larger distortions were observed in coronal slices than in axial slices in both units, and this effect was more pronounced in SYMPHONY 1.5T. Noncentrally located slice positions in the investigated volume of the phantom were associated with larger distortions.