bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective effect of nimodipine on behavior and white matter of rats with hydrocephalus
Authors: Del Bigio Marc R. , Massicotte Eric M.
Published: May 2009

Object. Hydrocephalus, a pathological dilation of the ventricles of the brain, causes damage to periventricular white matter, at least in part, through chronic ischemia. The authors tested the hypothesis that treatment with nimodipine, an L-type calcium channel-blocking agent with demonstrated efficacy in a range of cerebral ischemic disorders, would ameliorate the adverse effects of experimental hydrocephalus.

Methods. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. The rats were treated by continuous administration of nimodipine or control vehicle for 2 weeks, beginning 2 weeks after induction of hydrocephalus. During the treatment period, the animals underwent repeated tests of motor and cognitive behavior. At the end of the treatment period, the rat brains were analyzed by histopathological and biochemical means.

Nimodipine treatment prevented the declines in motor and cognitive behavior that were observed in untreated control rats. During the treatment period, ventricular enlargement, determined by magnetic resonance imaging, was equal in the two groups, although the corpus callosum was thicker in the treated rats. Myelin content in white matter and synaptophysin content in gray matter, an indicator of synapses, did not differ.

Conclusions. The protective effect of nimodipine is most likely based on improved blood flow, although prevention of calcium influx—mediated proteolytic processes in axons cannot be excluded. Adjunctive pharmacological therapy may be beneficial to patients with hydrocephalus.
Neurotization as an alternative for restoring finger and wrist extension
Authors: Üstün Mehmet Erkan , Öğün Tunç Cevat , Büyükmumcu Mustafa
Published: May 2009

Object. In cases of irreparable injuries to the radial nerve or in cases in which nerves are repaired with little anticipation of restoration of function, tendon transfers are widely used. In this study, the authors searched for a more natural alternative for selectively restoring function, with the aid of a motor nerve transfer.

Methods. Ten arms from five cadavers were used in the study. The posterior interosseous nerve and the median nerve together with their motor branches were exposed in the proximal forearm. The possibility of posterior interosseous nerve neurotization via the median nerve through its motor branches leading to the pronator teres, flexor pollicis longus, flexor digitorum profundus, and pronator quadratus muscles was investigated. The lengths of the nerves from points of divergence and their widths were measured using calipers, and the means with standard deviations of all nerves were calculated.

Motor branches to the pronator teres, flexor pollicis longus, and pronator quadratus muscles were found to be suitable for neurotization of the posterior interosseous nerve at different levels and in various combinations. The motor nerve extending to the flexor digitorum profundus muscle was too short to use for transfer.

Conclusions. These results offer a suitable alternative to tendon transfer for restoring finger and wrist extension in cases of irreversible radial palsy. The second step would be clinical verification in appropriate cases.
Analysis of loss of heterozygosity on chromosomes 10q, 11, and 16 in medulloblastomas
Authors: Yin Xiao-lu , Pang Jesse C. , Liu Yan-hui , Chong Edith Y. , Cheng Yue , Poon Wai-sang , Ng Ho-keung
Published: May 2009

Object. The loss of genetic material from specific chromosome loci is a common feature in the oncogenesis of tumors and is often indicative of the presence of important tumor suppressor genes at these loci. Recent molecular genetic analyses have demonstrated frequent loss of chromosomes 10q, 11, and 16 in medulloblastomas. The aim of this study was to localize the targeted deletion regions on the three aforementioned chromosomes in medulloblastomas.

Methods. Loss of heterozygosity (LOH) was examined on chromosomes 10q, 11, and 16 in a series of 22 primary and two recurrent medulloblastomas by using polymerase chain reaction—based microsatellite analysis. The DNA extracted from the tumors and corresponding normal blood samples were amplified independently in the presence of radioactively labeled microsatellite primers, resolved by denaturing gel electrophoresis and processed for autoradiography. The DNA obtained from control blood samples that displayed allelic heterozygosity at a given microsatellite locus were considered informative. Loss of heterozygosity was inferred when the allelic signal intensity of the tumor sample was reduced by at least 40%, relative to that of the constitutional control. The LOH analysis demonstrated that deletions of chromosomes 10q, 11p, and 16q are recurrent genetic events in the development of medulloblastomas. Three subchromosomal regions of loss have been identified and are localized to the deleted in malignant brain tumors 1 [DMBT1] gene site on chromosomes 10q25, 11p13–11p15.1, and 16q24.1–24.3.

Conclusions. These results indicate that DMBT1 is closely associated with the oncogenesis of medulloblastomas and highlight regions of loss on chromosomes 11p and 16q for further fine mapping and cloning of candidate tumor suppressor genes that are important for the genesis of medulloblastoma.
Intraneural perineurioma of the common peroneal nerve
Authors: Heilbrun Marta E. , Tsuruda Jay S. , Townsend Jeannette J. , Heilbrun M. Peter
Published: May 2009

✓ Intraneural perineurioma, or localized hypertrophic mononeuropathy (LHM), is a focal lesion that produces a slowly progressive mononeuropathy in a peripheral nerve. The authors describe the clinical presentation, magnetic resonance (MR) neurography characteristics, and pathological characteristics of a perineurioma involving the peroneal nerve. Although there has been much debate surrounding the cause of this lesion, a literature review supports the argument that this is a neoplastic lesion, best referred to as intraneural perineurioma. Surgical management includes excision to prevent progression of palsy and placement of a nerve graft if clinically indicated.

A 28-year-old woman presented with a 2-year history of progressive painless right peroneal nerve palsy. Magnetic resonance neurography revealed a right common peroneal nerve mass. At surgery, the mass was easily excised, leaving significant nerve fascicles intact. Intraoperative biopsy was not performed nor was a nerve graft placed. Pathological investigation demonstrated onion bulb—shaped whorls consistent with the appearance of intraneural perineurioma; immunochemical analysis confirmed the diagnosis.

A review of the literature supports the argument that perineurioma, or LHM, is a neoplastic process, making “intraneural perineurioma” the most appropriate name. The authors also demonstrate the utility of MR neurography in the identification isolated nerve tumors and review the surgical management of this lesion.
Meningeal melanocytoma of the planum sphenoidale
Authors: Chow Michael , Clarke David B. , Maloney William J. , Sangalang Virgilio
Published: May 2009

✓ Meningeal melanocytoma is a rare benign primary melanotic tumor of the meninges, most commonly found in the spinal canal and the posterior fossa. The authors report the 19th published case of a supratentorial meningeal melanocytoma and the first reported case in which the tumor arose from the planum sphenoidale. The patient's presenting symptoms were characteristic of a large bifrontal lesion and included headaches, personality change, lethargy, and urinary and fecal incontinence. Computerized tomography and magnetic resonance imaging studies revealed an extraaxial lesion arising from the planum sphenoidale. The patient underwent successful gross total removal of the tumor without neurological sequelae. Based on the findings shown in this case report, meningeal melanocytoma should be included in the differential diagnosis of extraaxial lesions arising from the area of the planum sphenoidale.
Long-term survival in a patient with brain metastases preceding the diagnosis of endometrial cancer
Authors: Petru Edgar , Lax Sigurd , Kurschel Senta , Gücer Fatih , Sutter Bernhard
Published: May 2009

✓ Only five patients found to have brain metastasis preceding the diagnosis of endometrial cancer have been reported in the literature, and none of these survived beyond 38 months. The authors report on two patients with primary endometrial cancer who initially presented with cerebral metastasis. One of these patients died of disease 15 months after diagnosis. The other patient is still alive, with no evidence of disease, 171 months after she underwent radiosurgery for a solitary brain metastasis, aggressive cytoreductive abdominal and pelvic surgery, and doxorubicin-based chemotherapy. To the best of their knowledge, the authors believe that no similar observation has been made for any primary gynecological neoplasm, including endometrial, ovarian, or cervical cancer.

This is the first report documenting that survival beyond one decade may be achieved after intensive multimodal therapy in selected patients in whom a solitary brain metastasis has been found before diagnosis of endometrial cancer. Aggressive therapy appears to be warranted in these patients.
Treatment of hydrocephalus in adults by placement of an open ventricular shunt
Authors: Sotelo Julio , Izurieta Mario , Arriada Nicasio
Published: May 2009

Object. Ventricular shunt placement is the neurosurgical procedure most frequently associated with complications. Over the years, it has been a growing concern that the performance of most shunting devices does not conform to physiological parameters. An open ventriculoperitoneal (VP) bypass with a peritoneal catheter for which the cross-sectional internal diameter was 0.51 mm as a distinctive element for flow resistance was evaluated for use in the treatment of adult patients with hydrocephalus.

Methods. During a 2-year period, open shunts were surgically implanted in 54 adults with hydrocephalus; conventional shunts were implanted in 80 matched controls. Periodic evaluations were performed using neuroimaging studies and measures of clinical status. All patients were followed from 12 to 36 months, 18.5 ± 4 months for patients with the open shunt and 19.1 ± 8.1 months for controls (mean ± standard deviation). The device continued to function in 50 patients with the open shunt (93%) and in 49 controls (61%; p < 0.001). The Evans index in patients with the open shunt was 0.33 ± 0.09 throughout the follow up. No cases of infection, overdrainage, or slit ventricles were observed; the index in controls was 0.28 ± 0.08; 60% of them developed slit ventricles. During the follow-up period occlusion occurred in four patients with the open shunt (7%) and in 31 controls (39%; p < 0.001).

Conclusions. The daily cerebrospinal fluid (CSF) drainage through the open VP shunt is close to 500 ml of uninterrupted flow propelled by the hydrokinetic force generated by the combination of ventricular pressure and siphoning effect. It complies with hydrokinetic parameters imposed by a bypass connection between the ventricular and peritoneal cavities as well as with the physiological archetype of continuous flow and drainage according to CSF production. The open shunt is simple, inexpensive, and an effective treatment for hydrocephalus in adults.
Evaluation of iatrogenic lesions in 722 surgically treated cases of peripheral nerve trauma
Authors: Kretschmer Thomas , Antoniadis Gregor , Braun Veit , Rath Stefan A. , Richter Hans-Peter
Published: May 2009

Object. The purpose of this study was to discover the number and types of iatrogenic nerve injuries that were surgically treated during a 9-year period at a relatively busy nerve center. The specific nerves involved, their sites of injury, and the mechanisms of injury were also documented.

Methods. The authors retrospectively evaluated the surgically treated iatrogenic lesions by reviewing case histories, operative reports, and follow-up notes in 722 cases of trauma. These cases were treated between January 1990 and December 1998 because of pain, dysesthesias, and sensory and/or motor deficits.

Iatrogenic injury was a much larger category of trauma than predicted. One hundred twenty-six (17.4%) of the 722 surgically treated cases were iatrogenic in origin. Most of these injuries occurred during a previous operation. To a major extent, nerves of the extremities were affected, and a relatively large number of injuries occurred in the neck and groin. Incidence was highest in the spinal accessory nerve (14 cases), the common peroneal nerve (11 cases), the superficial radial nerve (10 cases), the genitofemoral nerve branches (10 cases), and the median nerve (nine cases). At least two thirds of the patients did not undergo surgery for the iatrogenic injury within an optimal time interval due to delayed referral. Follow-up data were available in 97 of the 126 patients. Surgical outcomes demonstrated improvement in 70% of patients. Operative results were especially favorable in patients suffering from iatrogenic injuries to the accessory and superficial sensory radial nerves.

Conclusions. Iatrogenic injuries should be corrected in a timely fashion just like any other traumatic injury to nerve.
Safety of perioperative minidose heparin in patients undergoing brain tumor surgery: a prospective, randomized, double-blind study
Authors: Constantini Shlomi , Kanner Andy , Friedman Adi , Shoshan Ygal , Israel Zvi , Ashkenazi Eli , Gertel Moshe , Even Amiran , Shevach Yoshi , Shalit Mordechay , Umansky Felix , Rappaport Zvi H.
Published: May 2009

Object. Thromboembolic phenomena (TEPs) continue to be a significant source of morbidity and mortality in patients undergoing neurosurgery. Although the efficacy of low-dose heparin in preventing TEPs in neurosurgical patients is well established, neurosurgeons are reluctant to use it perioperatively because of concern for increased bleeding complications. To clarify this issue, the authors used a prospective, randomized, double-blind design to evaluate the safety of minidose heparin treatment in patients undergoing surgery for supratentorial brain tumors.

Methods. One hundred three patients, all 40 years of age or older, were treated with either 5000 U of heparin (55 patients) or placebo (48 patients) starting 2 hours before surgery and continuing until full mobilization or for 7 days. Both groups were well matched for sex, weight, duration of surgery, and tumor diagnosis.

Subjective and objective parameters were used to estimate and calculate the perioperative bleeding tendency in all patients. Red blood cell mass loss was calculated by assessing the preoperative and postoperative hematocrit and the patient's weight. Intraoperative blood loss was determined by measuring the quantity of blood in the suction containers and subtracting the amount of irrigation fluids. Postoperative bleeding was measured by determining the amount of fluid in the subgaleal drain, and blood cell replacement was monitored during and after the procedure. Intracranial bleeding was graded according to findings on the postoperative computerized tomography scan obtained 48 to 72 hours after surgery. In addition, the senior surgeon in each case was asked to assess each patient's bleeding tendency during the operation. The results showed that perioperative administration of heparin did not significantly alter bleeding tendency by any measured parameter. The surgeon was blinded to which group individual patients had been allocated.

Conclusions. Perioperative minidose heparin is safe for use in patients undergoing craniotomy for supratentorial tumors. This relatively simple and inexpensive measure is recommended as a routine regimen for the prevention of TEPs in patients undergoing neurosurgery.
Determinants of tumor size and growth in vestibular schwannomas
Authors: Nutik Stephen L. , Babb Michael J.
Published: May 2009

Object. This study was undertaken to analyze factors associated with the size of unilateral vestibular schwannomas (VSs).

Methods. A retrospective analysis of an unselected and sequential series of 433 patients with unilateral VSs was conducted. Tumor size was defined by the largest dimension of the tumor in the cerebellopontine angle, and the size was tested for a relationship with patient age and sex. In a subgroup of 231 patients in whom data were available, tumor size was also tested for a relationship with tumor cysts or the absence of an internal auditory canal (IAC) component. Some patients underwent a period of surveillance with serial imaging studies to monitor for tumor growth. Data from these patients, excluding those with cystic tumors, were analyzed to see if tumor growth was related to patient age, sex, or tumor size.

Conclusions. Larger tumors were found in younger patients, in females, in the subgroup of cystic tumors, and in patients in whom there was no tumor component in the IAC. The probable explanations for these larger tumors are a faster growth rate and/or a delay in symptom onset. When untreated tumors are managed with observation, measurable growth is more often seen in larger tumors, although smaller tumors have a faster relative growth rate than larger ones.
Three-dimensional anisotropy contrast magnetic resonance axonography to predict the prognosis for motor function in patients suffering from stroke
Authors: Watanabe Toru , Honda Yoshiho , Fujii Yukihiko , Koyama Miyako , Matsuzawa Hitoshi , Tanaka Ryuichi
Published: May 2009

Object. The purpose of this study was to assess how early wallerian degeneration in the corticospinal tracts of patients who had suffered from stroke was detected using three-dimensional anisotropy contrast (3D-AC) magnetic resonance (MR) axonography and to explore the possibility of predicting the prognosis for motor function in these patients.

Methods. Ten healthy volunteers and 16 stroke patients with hemiparesis were studied using MR images including 3D-AC MR axonography images obtained using a 1.5-tesla MR imaging system. The axonography was performed using an echoplanar imaging method. All patients underwent MR studies 2, 3, and 10 weeks after stroke onset. To detect wallerian degeneration, the diffusion anisotropy in the corticospinal tracts at the level of the upper pons was evaluated on axial images. These MR findings were compared with the patients' motor functions, which were classified according to the Brunnstrom criteria 12 weeks after the onset of stroke.

In all patients with poor recovery (Brunnstrom Stages I–IV), wallerian degeneration, which was demonstrated as a reduction in diffusion anisotropy on axonography images, could be observed in the corticospinal tracts; this degeneration was not found in patients with good recovery (Stages V and VI). Axonography could be used to detect degeneration between 2 and 3 weeks after stroke onset. On conventional T2-weighted MR images, hyperintense areas indicating wallerian degeneration were not detected until 10 weeks after stroke onset.

Conclusions. With the aid of 3D-AC MR axonography, wallerian degeneration can be detected in the corticospinal tracts during the early stage of stroke (2–3 weeks after onset), much earlier than it can be detected using T2-weighted MR imaging. The procedure of 3D-AC MR axonography may be useful in predicting motor function prognosis in stroke patients.
Intraoperative ultrasound arteriography with the “Coded Harmonic Angio” technique
Authors: Otsuki Hideo , Nakatani Susumu , Yamasaki Mami , Kinoshita Akira , Iwamoto Fuminori , Kagawa Naoki
Published: May 2009

✓ The result of combining the ultrasound Coded Excitation method and an ultrasound contrast agent (UCA), the Coded Harmonic Angio (CHA) technique provides arterial images with exceptional spatial, temporal, and contrast resolution that are comparable to those produced by conventional digital subtraction angiography. The authors report on their experience with intraoperative ultrasound arteriography performed using the transdural CHA technique in three patients: one harboring a meningioma, another with a middle cerebral artery aneurysm, and a third with an arteriovenous malformation. The present study demonstrates how intraoperative cerebral ultrasound arteriography can be applied to assess the adequacy of neurovascular procedures without the presence of an experienced operator.
External carotid artery reconstruction performed using an autologous internal carotid artery patch
Authors: Pritz Michael B.
Published: May 2009

✓ The reconstruction of the external carotid artery (ECA) and obliteration of an occluded stump or atretic internal carotid artery (ICA) are described. In this method the occluded ICA is used as an autologous patch graft. Satisfactory ICA obliteration and expanded, smooth common carotid artery—ECA contour were obtained in three patients. Advantages of this procedure include ICA obliteration and precise patch placement by using an ideal, autologous, arterial graft.
Extended transsphenoidal approach with submucosal posterior ethmoidectomy for parasellar tumors
Authors: Kitano Masahiko , Taneda Mamoru
Published: May 2009

✓ The authors have developed an extended transsphenoidal approach with submucosal posterior ethmoidectomy for resection of tumors located in the cavernous sinus or the suprasellar region that are difficult to remove via the conventional transsphenoidal approach. Surgery was performed using this approach in 14 patients with large pituitary adenomas, three patients with craniopharyngiomas, and one patient with a meningioma of the tuberculum sellae. The submucosal dissection of the nasal septum used in the conventional transsphenoidal approach was extended to the superior lateral wall of the nasal cavity to expose the bony surface of the superior turbinate lying under the nasal mucosa. Submucosal posterior ethmoidectomy widened the area visualized through the conventional transsphenoidal approach both superiorly and laterally. This provided a safer and less invasive access to lesions in the cavernous sinus or the suprasellar region through the sphenoid sinus. Using this approach the authors encountered no postoperative complications, such as olfactory disturbance, cranial nerve palsy, or arterial injury. In this article the authors present the surgical methods used in this approach.
Revision of deep brain stimulator for tremor
Authors: Schwalb Jason M. , Riina Howard A. , Skolnick Brett , Jaggi Jurg L. , Simuni Tanya , Baltuch Gordon H.
Published: May 2009

✓ The treatment of essential tremor with thalamic deep brain stimulation (DBS) is considered to be more effective and to cause less morbidity than treatment with thalamotomy. Nonetheless, implantation of an indwelling electrode, connectors, and a generator is associated with specific types of morbidity. The authors describe three patients who required revision of their DBS systems due to lead breakage. The connector between the DBS electrode and the extension wire, which connects to the subclavicular pulse generator, was originally placed subcutaneously in the cervical region to decrease the risk of erosion through the scalp and to improve cosmesis. Three patients presented with fractured DBS electrodes that were located in the cervical region near the connector, necessitating reoperation with stereotactic retargeting and placement of a new intracranial electrode. At reoperation, the connectors were placed subgaleally over the parietal region.

Management of these cases has led to modifications in the operative procedure designed to improve the durability of DBS systems. The authors recommend that surgeons avoid placing the connection between the DBS electrode and the extension wire in the cervical region because patient movement can cause microfractures in the electrode. Such microfractures require intracranial revision, which may be associated with a higher risk of morbidity than the initial operation. The authors also recommend considering prophylactic relocation of the connectors from the cervical area to the subgaleal parietal region to decrease the risk of future DBS electrode fracture, which would necessitate a more lengthy procedure to revise the intracranial electrode.
Is stagnating flow in former feeding arteries an indication of cerebral hypoperfusion after resection of arteriovenous malformations?
Authors: Meyer Bernhard , Urbach Horst , Schaller Carlo , Schramm Johannes
Published: May 2009

Object. The authors' goal in this study was to challenge the proposed mechanism of the occlusive hyperemia theory, in which it is asserted that stagnating flow in the former feeding arteries of cerebral arteriovenous malformations (AVMs) leads to parenchymal hypoperfusion or ischemia, from which postoperative edema and hemorrhage originate.

Methods. Cortical oxygen saturation (SaO2) was measured in 52 patients by using microspectrophotometry in areas adjacent to AVMs before and after resection. The appearance of the former feeding arteries was categorized as normal (Group A); moderately stagnating (Group B); and excessively stagnating (Group C) on postoperative angiographic fast-film series. Patients and SaO2 values were pooled accordingly and compared using analysis of variance and Duncan tests (p < 0.05). Angiographic stagnation times in former feeding arteries were correlated in a linear regression/correlation analysis with SaO2 data (p < 0.05). All values are given as the mean ± standard deviation.

The average median postoperative SaO2 in Group C (15 patients) was significantly higher than in Groups B (17 patients) and A (20 patients) (Group C, 75.2 ± 8.5; Group B, 67.5 ± 10.8; Group A, 67.1 ± 12 %SaO2), as was the average postoperative increase in SaO2 (Group C, 25.9 ± 14.9; Group B, 14.6 ± 14; Group A, 11.1 ± 14 %SaO2). Angiographically confirmed stagnation times were also significantly longer in Group C than in Group B (Group C, 5.6 ± 2.5; Group B, 1.3 ± 0.6 seconds). A significant correlation/regression analysis showed a clear trend toward higher postoperative SaO2 levels with increasing stagnation time.

Conclusions. Stagnating flow in former feeding arteries does not cause cortical ischemia, but its presence on angiographic studies is usually indicative of hyperperfusion in the surrounding brain tissue after AVM resection. In the context of the pathophysiology of AVMs extrapolations made from angiographically visible shunt flow to blood flow in the surrounding brain tissue must be regarded with caution.
Outcomes in a consecutive series of 111 surgically treated plexal tumors: a review of the experience at the Louisiana State University Health Sciences Center
Authors: Ganju Aruna , Roosen Norbert , Kline David G. , Tiel Robert L.
Published: May 2009

Object. The authors conducted a retrospective study of 107 consecutive patients with 111 brachial plexus tumors surgically treated at the Louisiana State University Health Sciences Center (LSUHSC).

Methods. During a 12-year period, from 1986 to 1998, 371 patients with lesions of the brachial plexus underwent surgery at LSUHSC. Among this group, 107 patients harbored 111 tumors of the brachial plexus. Neural sheath tumors were the most commonly found and included 33 neurofibromas (20 of which were associated with von Recklinghausen disease), 36 schwannomas, and 12 malignant neural sheath tumors. Of the non—neural sheath tumors, 13 were benign and 17 were malignant. Presenting symptoms included pain (59%), palpable mass (52%), paresthesias (30%), and paresis (29%).

Anterior supraclavicular (82%) or posterior subscapular (18%) approaches were used to achieve gross-total (79%) or subtotal (21%) resection of tumor. The average follow-up period was 38.3 months or 3.2 years.

Seventy percent of patients with benign neural sheath tumors became free from pain postoperatively or reported improvement in their preoperative pain status. Function remained intact or improved in 50% and remained stable postoperatively in another 20% of cases.

Preservation of function was more likely in patients who presented intact and in those who had not undergone a previous attempted biopsy procedure or resection than in those in whom such manipulation had occurred.

Conclusions. Resection of most plexal tumors is technically feasible and associated with acceptable morbidity and mortality rates.
Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features
Authors: Leonard Jeffrey R. , Cai Dan X. , Rivet Dennis J. , Kaufman Bruce A. , Park T. S. , Levy Beth K. , Perry Arie
Published: May 2009

Object. Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution.

Methods. Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered.

Conclusions. A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.
Detection of simian virus 40 DNA sequence in human primary glioblastomas multiforme
Authors: Kouhata Tomohiko , Fukuyama Kouzou , Hagihara Naoshi , Tabuchi Kazuo
Published: May 2009

Object. Deoxyribonucleic acid oncoviruses can induce neoplastic transformation of cells because their viral proteins interfere with antiproliferative cellular proteins. Simian virus 40 (SV40) is a DNA virus that induces the emergence of ependymomas, choroid plexus tumors, mesotheliomas, osteosarcomas, sarcomas, and various tumors when injected into newborn hamsters. Recently, approximately 60% of human ependymomas, choroid plexus tumors, and mesotheliomas were reported to contain and express SV40 DNA sequences. In this study the presence of SV40 DNA sequences was investigated in human brain tumors.

Methods. Three of 32 glioblastomas mutiforme (GBMs), but none of two ependymomas and five medulloblastomas, were found to possess SV40 DNA sequences when examined using polymerase chain reaction (PCR). The DNA sequence analysis of PCR-amplified fragments disclosed that the samples were identical to the regulatory region of SV40. All three GBMs, which arose in elderly patients with wild-type p53, were considered to be primary (de novo) tumors. Although each of the three tumors was immunohistochemically negative for SV40 T antigen, in situ hybridization successfully demonstrated the messenger RNA for SV40 T antigen.

Conclusions. The results of this study indicate that latent infection of SV40 in elderly people may be implicated in the tumorigenesis of certain primary GBMs.
Migratory neurocysticercosis mimicking a third ventricular colloid cyst
Authors: Wray Steven D. , Ellis Thomas L. , Bianco Sabatino
Published: May 2009

✓ The authors report on a case of solitary neurocysticercosis located in the anterior third ventricle of a 21-year-old Hispanic man who presented with progressive headache, nausea, and mental decline. The appearance of the lesion on computerized tomography and magnetic resonance studies was typical of that of a colloid cyst, which was the presumptive preoperative diagnosis. A transcortical-transventricular microsurgical approach was used, and inspection of the anterior third ventricle via the ipsilateral foramen of Monro revealed no lesion. Inspection of the floor of the ipsilateral lateral ventricle revealed the intact cyst, which had migrated since the preoperative studies had been obtained. The lesion was removed intact, and histopathological examination confirmed the diagnosis of neurocysticercosis. The authors review the radiographic findings in this case and further illustrate the potential for neurocysticercosis to masquerade as other intracranial lesions.
Occult rupture of a giant vertebral artery aneurysm following proximal occlusion and intrasaccular thrombosis
Authors: Piepgras David G. , Khurana Vini G. , Nichols Douglas A.
Published: May 2009

✓ The authors describe a unique clinicopathological phenomenon in a patient who presented with an unruptured giant vertebral artery aneurysm and who underwent endovascular proximal occlusion of the parent artery followed, several days later, by surgical trapping of the aneurysm after delayed subarachnoid hemorrhage (SAH). The intraoperative finding of a thrombus extruding from the wall of the aneurysm at a site remote from the origin of the SAH underscores the possibility that occult rupture of an aneurysmal sac can occur in patients with thrombosed giant aneurysms.
Development of the Spitz—Holter valve in Philadelphia
Authors: Boockvar John A. , Loudon William , Sutton Leslie N.
Published: May 2009

✓ The history of the treatment for hydrocephalus dates back to the Fertile Crescent thousands of years ago. Despite three millennia of management, significant advances in the surgical treatment of the disease have been infrequent. During the 1950s, a milestone occurred at the Children's Hospital of Philadelphia, with the successful development of the first working shunt valve for the treatment of hydrocephalus. In this historical vignette, based on recent interviews with John Holter, D.Sc. (Hon) and Eugene Spitz, M.D., and on a review of the available literature, the authors narrate the exciting story of the development of the Spitz-Holter valve, which took place in Philadelphia during the early 1950s.
“The art is long and the life short”: the letters of Wilder Penfield and Harvey Cushing
Authors: Preul Mark C. , Feindel William
Published: May 2009

✓ Wilder Penfield and Harvey Cushing created legacies to neurosurgery, both in terms of those they trained and in their philosophical approach to the field. Their biographies provide only brief comments on their relationship without any thorough examination of their personal correspondence. In this article the Penfield—Cushing relationship is examined through an analysis of their unpublished personal letters. The Penfield—Cushing correspondence is a treasure for neurosurgery; it provides remarkable insight into the embryonic period of the discipline and into the relationship of two of the most influential figures in modern neurosurgery.
Surgical anatomy of the cerebral arteries in patients with subarachnoid hemorrhage: comparison of computerized tomography angiography and digital subtraction angiography
Authors: Velthuis Birgitta K. , van Leeuwen Maarten S. , Witkamp Theodoor D. , Ramos Lino M. P. , van der Sprenkel Jan Willem Berkelbach , Rinkel Gabriël J. E.
Published: May 2009

Object. The purpose of this study was to compare computerized tomography (CT) angiography and digital subtraction (DS) angiography studies in patients with subarachnoid hemorrhage (SAH) to assess their vascular anatomy relevant to cerebral aneurysm surgery.

Methods. From a prospective series of 100 patients with SAH, the authors selected 73 patients whose CT angiography studies were of adequate quality and in whom DS angiography of both carotid arteries had been performed. Eleven patients with no DS angiographic studies of the vertebrobasilar artery were only evaluated for the anterior half of the circle of Willis. Anterior communicating arteries (ACoAs), both precommunicating anterior cerebral arteries (A1 segments), both posterior communicating arteries (PCoAs), and both precommunicating posterior cerebral arteries (P1 segments) were assessed on CT angiography and DS angiography by two independent observers.

Conclusions. Computerized tomography angiography compares well with DS angiography for visualizing normal-sized arteries, and is superior for visualizing ACoAs and hypoplastic A1 and P1 segments. Important preoperative aspects such as dominant A1 segments and PCoAs are equally well seen using either modality. Neither method enabled the authors to visualize more than 50% of PCoAs. Use of CT angiography can provide the required preoperative anatomical information for aneurysm surgery in most patients with SAH.
Carbon dioxide reactivity, pressure autoregulation, and metabolic suppression reactivity after head injury: a transcranial Doppler study
Authors: Lee Jae Hong , Kelly Daniel F. , Oertel Matthias , McArthur David L. , Glenn Thomas C. , Vespa Paul , Boscardin W. John , Martin Neil A.
Published: May 2009

Object. Contemporary management of head-injured patients is based on assumptions about CO2 reactivity, pressure autoregulation (PA), and vascular reactivity to pharmacological metabolic suppression. In this study, serial assessments of vasoreactivity of the middle cerebral artery (MCA) were performed using bilateral transcranial Doppler (TCD) ultrasonography.

Methods. Twenty-eight patients (mean age 33 ± 13 years, median Glasgow Coma Scale score of 7) underwent a total of 61 testing sessions during postinjury Days 0 to 13. The CO2 reactivity (58 studies in 28 patients), PA (51 studies in 23 patients), and metabolic suppression reactivity (35 studies in 16 patients) were quantified for each cerebral hemisphere by measuring changes in MCA velocity in response to transient hyperventilation, arterial blood pressure elevation, or propofol-induced burst suppression, respectively. One or both hemispheres registered below normal vasoreactivity scores in 40%, 69%, and 97% of study sessions for CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.0001), respectively. Intracranial hypertension, classified as intracranial pressure (ICP) greater than 20 mm Hg at the time of testing, was associated with global impairment of CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.05). A low baseline cerebral perfusion pressure (CPP) was also predictive of impaired CO2 reactivity and PA (p < 0.01). Early postinjury hypotension or hypoxia was also associated with impaired CO2 reactivity (p < 0.05), and hemorrhagic brain lesions in or overlying the MCA territory were predictive of impaired metabolic suppression reactivity (p < 0.01). The 6-month Glasgow Outcome Scale score correlated with the overall degree of impaired vasoreactivity (p < 0.05).

Conclusions. During the first 2 weeks after moderate or severe head injury, CO2 reactivity remains relatively intact, PA is variably impaired, and metabolic suppression reactivity remains severely impaired. Elevated ICP appears to affect all three components of vasoreactivity that were tested, whereas other clinical factors such as CPP, hypotensive and hypoxic insults, and hemorrhagic brain lesions have distinctly different impacts on the state of vasoreactivity. Incorporation of TCD ultrasonography—derived vasoreactivity data may facilitate more injury- and time-specific therapies for head-injured patients.
Diagnosis and management of pituitary abscess: a review of twenty-four cases
Authors: Vates G. Edward , Berger Mitchel S. , Wilson Charles B.
Published: May 2009

Object. Pituitary abscess is a rare but serious intrasellar infection. To better determine the salient signs and symptoms that help in making the diagnosis, and to determine the most appropriate treatment, the authors reviewed their experience in a series of 24 patients treated at the University of California at San Francisco.

Methods. Nine of the patients were female and 15 were male, and their mean age was 41.2 years (range 12–71 years). Surprisingly, most patients in our series presented with complaints and physical findings consistent with a pituitary mass, but rarely with evidence of a serious infection. Headache, endocrine abnormalities, and visual changes were the most common clinical indicators; fever, peripheral leukocytosis, and meningismus were present in 33% or fewer of the patients. Imaging tests demonstrated a pituitary mass in all patients, but the features evident on computerized tomography and magnetic resonance studies did not distinguish pituitary abscesses from other, more common intrasellar lesions. Because of the ambiguous clinical features and imaging findings, most abscesses were not diagnosed before treatment; rather, the diagnosis was made during surgical exploration of the sella turcica, when the surgeon encountered a cystic mass containing pus. There were only two deaths in this series (8.3%). Patients presenting with headache and visual changes noted improvement in almost all cases; patients with endocrine dysfunction generally did not recover normal pituitary function, but were easily treated with hormone replacement therapy.

Conclusions. Antibiotic therapy is suggested for patients who have symptoms of sepsis, or for patients in whom specific organisms are identified from cultures obtained during surgery. The transsphenoidal approach is recommended over open craniotomy for surgical drainage.
Surgery on a saccular vertebral artery—posterior inferior cerebellar artery aneurysm via the transcondylar fossa (supracondylar transjugular tubercle) approach or the transcondylar approach: surgical results and indications for using two different lateral skull base approaches
Authors: Matsushima Toshio , Matsukado Koichiro , Natori Yoshihiro , Inamura Takanori , Hitotsumatsu Tsutomu , Fukui Masashi
Published: May 2009

Object. The authors report on the surgical results they achieved in caring for patients with vertebral artery—posterior inferior cerebellar artery (VA—PICA) saccular aneurysms that were treated via either the transcondylar fossa (supracondylar transjugular tubercle) approach or the transcondylar approach. In this report they clarify the characteristics of and differences between these two lateral skull base approaches. They also present the techniques they used in performing the transcondylar fossa approach, especially the maneuver used to remove the jugular tubercle extradurally without injuring the atlantooccipital joint.

Methods. Eight patients underwent surgery for VA—PICA saccular aneurysms (six ruptured and two unruptured ones) during which one of the two approaches was performed. Clinical data including neurological and radiological findings and reports of the operative procedures were analyzed. The Glasgow Outcome Scale was used to estimate the activities of daily living experienced by the patients.

In all cases the aneurysm was successfully clipped and no permanent neurological deficits remained, except for one case of severe vasospasm. In seven of the eight patients, the transcondylar fossa approach provided a sufficient operative field for clipping the aneurysm without difficulty. In the remaining patient, in whom the aneurysm was located at the midline on the clivus at the level of the hypoglossal canal, the aneurysm could not be found by using the transcondylar fossa approach; thus, the route was changed to the transcondylar approach, and clipping was performed below the hypoglossal nerve rootlets.

Conclusions. Both approaches offer excellent visualization and a wide working field, with ready access to the lesion. This remarkably reduces the risk of development of postoperative deficits. These approaches should be used properly: the transcondylar fossa approach is indicated for aneurysms located above the hypoglossal canal and the transcondylar approach is indicated for those located below it.
Enhancement of the response to levodopa therapy after intrastriatal transplantation of autologous sympathetic neurons in patients with Parkinson disease
Authors: Nakao Naoyuki , Kakishita Koji , Uematsu Yuji , Yoshimasu Tatsuya , Bessho Toshiya , Nakai Kunio , Naito Yasuaki , Itakura Toru
Published: May 2009

Object. There is growing evidence to indicate that tissue transplantation can potentially be a restorative neurosurgical treatment for patients with Parkinson disease (PD). In this study the authors investigated the clinical effect of unilateral intrastriatal grafting of autologous sympathetic neurons in patients with PD.

Methods. Four patients with PD who had been observed for 1 year after graft placement of autologous sympathetic neurons were selected for an analysis of the effect of that procedure. Sympathetic ganglion tissue was endoscopically excised from the thoracic sympathetic trunk and grafted into the unilateral caudate head and putamen of the PD patients. No changes were made in the patients' preoperative regimens of antiparkinsonian medications, and clinical evaluations were made principally according to those established by the Core Assessment Program for Intracerebral Transplantation Committee.

Whereas the sympathetic neuron grafts failed to affect clinical scores reflecting the patients' motor performance, which was evaluated during either the “on” or “off” phases, the grafts significantly increased the duration of the levodopa-induced on period with consequent reduction in the percentage of time spent in the off phase. This beneficial effect may be explained by the results of the present in vitro experiment, which show that human sympathetic neurons have the ability to convert exogenous levodopa to dopamine and to store this synthesized dopamine.

Conclusions. Sympathetic neuron autografts were found to improve performance status in patients with PD by reducing the time spent in the off phase. This clearly indicates that sympathetic ganglion tissue, the use of which involves few ethical issues, can be an efficacious donor source in cell transplantation therapy for PD. Further studies are needed to determine whether the grafts may provide long-lasting clinical benefits.
Diagnostic value of 201Tl—single-photon emission computerized tomography studies in cases of posterior fossa hemangioblastomas
Authors: Kondo Takeo , Kumabe Toshihiro , Maruoka Shin , Yoshimoto Takashi
Published: May 2009

Object. The 201Tl uptake index was evaluated for its usefulness in formulating a diagnosis of hemangioblastoma. Thallium-201—single-photon emission computerized tomography (SPECT) studies were performed in nine patients harboring hemangioblastomas in the posterior fossa and in five patients (six lesions) with gliomas in the posterior fossa.

Methods. The 201Tl uptake index was defined as the ratio of mean counts of isotope per pixel in the tumor to mean counts of isotope per pixel in the homologous region of the healthy brain. The 201Tl uptake indices of the early image (TlE) and that of the delayed image (TlD) were calculated. The isotope retention index (RI) was calculated as (TlE − TlD)/TlE. The TlE was 2.7 ± 0.7 in hemangioblastomas and 2.9 ± 1.7 in gliomas (mean ± standard deviation). The TlD was 1.5 ± 0.4 in hemangioblastomas and 2.4 ± 1.6 in gliomas. There were no significant differences between hemangioblastomas and gliomas when TlEs and TlDs were compared. The isotope RI was 0.43 ± 0.07 in hemangioblastomas and 0.15 ± 0.1 in gliomas, showing a significantly higher RI in hemangioblastomas compared with gliomas (p < 0.01).

Conclusions. Thallium-201 washout is significantly faster in hemangioblastomas. Hemangioblastoma is biologically benign, but contains a rich capillary network that forms a hypervascular tumor bed. Variations in its appearance on magnetic resonance images may cause difficulties in the differential diagnosis of hemangioblastoma. Thallium-201 SPECT studies can be used to distinguish hemangioblastomas from gliomas in the posterior fossa.