bluuebunny/crossref_metadata_2025 huggingface dataset:
Endoscopic resection of solid intraventricular brain tumors
Authors: Souweidane Mark M. , Luther Neal
Published: January 2008

Object

Endoscopic removal of intraventricular brain tumors is well established for cystic tumors such as colloid cysts. Aspiration followed by removal or ablation of the membranous wall is possible given the constituent features of these tumors. It is generally expected that endoscopic removal of solid brain tumors from the intraventricular compartment would impose additional technical demands. In this paper, the feasibility and safety of endoscopic removal of solid intraventricular brain tumors is evaluated.

Methods

Eighty-one patients who underwent endoscopic management of an intraventricular brain tumor were identified from a prospective database. Of these patients, seven underwent attempted endoscopic surgical removal of a solid primary brain tumor. Patient selection, surgical technique, procedure-related morbidity, and extent of removal were reviewed.

Five patients underwent complete resection of a solid intraventricular brain tumor, a treatment option that was based on intraoperative assessment and confirmed by postoperative imaging. No patient experienced any procedure-related morbidity. Of the individuals in whom a total endoscopic resection was successful, there has been no symptomatic or radiological evidence of recurrence (mean follow up 20 months). Maximum tumor diameter ranged from 0.5 to 1.8 cm for patients who underwent complete resection, whereas maximum tumor diameter measured 2.4 and 2.5 cm in the two patients in whom a subtotal excision was performed.

Conclusions

In select patients, complete endoscopic removal of solid intraventricular brain tumors is possible and safe. Factors that influence the ability of a surgeon to perform a complete endoscopic resection include tumor size, composition, and vascularity. The procedure requires careful patient selection, the use of refined endoscopic instrumentation, and a disciplined surgical technique.
Involvement of phospholipase C in endothelin 1–induced stimulation of Ca++ channels and basilar artery contraction in rabbits
Authors: Kawanabe Yoshifumi , Masaki Tomoh , Hashimoto Nobuo
Published: January 2008

Object

Endothelin 1 (ET-1) is a major cause of cerebral vasospasm after subarachnoid hemorrhage (SAH), and extracellular Ca++ influx plays an essential role in ET-1–induced vasospasm. The authors recently demonstrated that ET-1 activates two types of Ca++-permeable nonselective cation channels (designated NSCC-1 and NSCC-2) and a store-operated Ca++ channel (SOCC) in vascular smooth-muscle cells located in the basilar arteries (BAs) of rabbits. In the present study, they investigate the effects of phospholipase C (PLC) on ET-1–induced activation of these Ca++ channels and BA contraction by using the PLC inhibitor U73122.

Methods

To determine which Ca++ channels are activated via a PLC-dependent pathway, these investigators monitored the intracellular free Ca++ concentration ([Ca++]i). The role of PLC in ET-1–induced vascular contraction was examined by performing a tension study of rabbit BA rings.

The U73122 inhibited the ET-1–induced transient increase in [Ca++]i, which resulted from mobilization of Ca++; from the intracellular store. Phospholipase C also inhibited ET-1–induced extracellular Ca++ influx through the SOCC and NSCC-2, but not through the NSCC-1. The U73122 inhibited the ET-1–induced contraction of the rabbit BA rings, which depended on extracellular Ca++ influx through the SOCC and NSCC-2.

Conclusions

These results indicate the following. 1) The SOCC and NSCC-2 are stimulated by ET-1 via a PLC-dependent cascade whereas NSCC-1 is stimulated via a PLC-independent cascade. 2) The PLC is involved in the ET-1–induced contraction of rabbit BA rings, which depends on extracellular Ca++ influx through the SOCC and NSCC-2.
Optic radiations: a microsurgical anatomical study
Authors: Peltier Johann , Travers Nadine , Destrieux Christophe , Velut Stéphane
Published: January 2008

Object

In this study, the authors used a fiber-dissection technique to describe the optic radiation. They focused on the morphological characteristics (length and breadth) of this structure, its course, and its relationships with neighboring fasciculi and the lateral ventricle.

Methods

The authors dissected 10 previously frozen, formalin-fixed human brains with the aid of an operating microscope by following the fiber dissection technique described by Klingler in 1960. Lateral, inferior, and medial approaches were made. The optic radiation, also known as the Gratiolet radiation, extended from the lateral geniculate body to the calcarine fissure. The average distance from the tip of the anterior Meyer loop to the calcarine sulcus was 105 mm (range 95–114 mm). The breadth of the optic radiations, one on each side of the brain, averaged 17 mm at the level of the inferior horn (range 15–18 mm). This tract could be divided into three main segments: the anterior or Meyer loop, the body, and the end of the optic radiation. Adjacent anatomical structures included: laterally, the inferior longitudinal fasciculi; medially, the tapetum of the corpus callosum; and the ependyma of the inferior horn of the lateral ventricle.

Conclusions

Various practical surgical approaches are discussed. The knowledge gained by studying this particular anatomy will help prevent injury to the optic radiations during neurosurgery.
Spontaneous bacterial peritonitis causing Serratia marcescens and Proteus mirabilis ventriculoperitoneal shunt infection
Authors: Tumialán Luis M. , Lin Franklin , Gupta Sanjay K.
Published: January 2008

✓The authors report their experience treating a polymicrobial ventriculoperitoneal (VP) shunt infection in a developmentally delayed 21-year-old woman. Cerebrospinal fluid (CSF) cultures grew Serratia marcescens and Proteus mirabilis. On admission and throughout her hospitalization, results of physical examination of her abdomen were normal, and radiographic studies showed no evidence of bowel perforation or pseudocyst formation. Contrast-enhanced computed tomography of the abdomen revealed a small fluid collection. After a course of intravenous gentamicin and imipenem with cilastatin in conjunction with intrathecal gentamicin, the infection was resolved and the VP shunt was reimplanted.

Although VP shunt infections are not uncommon, S. marcescens as a causative agent is exceedingly rare and potentially devastating. Only two previous cases of S. marcescens shunt infection have been reported in the literature. Authors reporting on S. marcescens infections in the central nervous system (CNS) have observed significant morbidity and death. Although more common, the presence of P. mirabilis in the CSF is still rare and highly suggestive of bowel perforation, which was absent in this patient. Spontaneous bacterial peritonitis was the likely source from which these bacteria gained entrance into the VP shunt system, eventually causing ventriculitis in this patient.

The authors conclude that in light of the high morbidity associated with S. marcescens infection of the CNS, intrathecal administration of gentamicin should be strongly considered as part of first-line therapy for S. marcescens infections in VP shunts.
Skull base abnormalities in osteogenesis imperfecta: a cephalometric evaluation of 54 patients and 108 control volunteers
Authors: Kovero Outi , Pynnönen Seppo , Kuurila-Svahn Kaija , Kaitila Ilkka , Waltimo-Sirén Janna
Published: January 2008

Object

Osteogenesis imperfecta (OI), which usually results from mutations in type I collagen genes, causes bone fragility and deformities. The head is often abnormally shaped, and changes in skull base anatomy in the form of basilar impression and basilar invagination have been reported. The authors analyzed the skull base anatomy on standardized lateral cephalograms from 54 patients with OI (Types I, III, and IV) and 108 control volunteers. They were surprised to find that the previously used diagnostic measures for basilar abnormality in patients with OI were exceeded in 6.5 to 7.4% of the controls, and hence needed to be reevaluated.

Methods

The authors calculated the distance from the odontoid process to four reference lines, including a novel one, in the controls. The normal mean distances were exceeded by more than two standard deviations (SDs) in 28.3 to 35.2%, and by more than three SDs in 13.2 to 16.6% of the patients with OI. The latter figures reliably reflect the prevalence of basilar impression. As a sign of basilar invagination the odontoid process protruded into the foramen magnum or reached the foramen magnum level in 22.2% of the patients with OI, whereas none of the controls showed this feature. Platybasia (an anterior cranial base angle > 146°) was present in 11.1% of the patients but in none of the controls.

Conclusions

Platybasia, basilar impression, and basilar invagination were often coexpressed, but each was also present as an isolated abnormality. These three abnormalities and wormian bones were predominantly found in OI Types III and IV as well as in patients exhibiting dentinal abnormality.
Balloon-assisted coil embolization of intracranial aneurysms: incidence, complications, and angiography results
Authors: Sluzewski Menno , Van Rooij Willem Jan , Beute Guus N. , Nijssen Peter C.
Published: January 2008

Object

The aim of this study was to assess the incidence, indications, complications, and angiography results associated with balloon-assisted coil embolization (BACE) of intracranial aneurysms and to compare these factors with those for conventional coil embolization (CE).

Methods

Between 1995 and 2005, 827 intracranial aneurysms in 757 consecutive patients were packed with coils. Balloon-assisted coil embolization was used in 8.6% (71 of 827) of the coil insertion procedures and was more frequently used in large aneurysms, unruptured lesions, and those located on the vertebrobasilar system and carotid artery. Procedure-related complications leading to death or dependency were significantly higher in BACEs (14.1%) compared with those in CEs (3%). Packing densities and the results of 6-month follow-up angiography studies did not differ significantly between the two types of treatments. There was a strong trend for a higher retreatment rate in the aneurysms treated with BACE.

Conclusions

Balloon-assisted coil embolization of intracranial aneurysms is associated with a high complication rate and should only be used if conventional CE of these lesions is impossible or has failed and if anticipated surgical risks are too high. The BACE procedure does not improve the occlusion rates of the aneurysms on follow-up evaluation.
Blood blister–like aneurysms at nonbranching sites of the internal carotid artery
Authors: Sim Sook Young , Shin Yong Sam , Cho Kyung Gi , Kim Sun Yong , Kim Se Hyuk , Ahn Young Hwan , Yoon Soo Han , Cho Ki Hong
Published: January 2008

Object

The clinical features of blood blister–like aneurysms (BBAs) that arise at nonbranching sites of the internal carotid artery (ICA) differ from those of saccular aneurysms. In this study, the authors attempt to describe optimal treatments for BBAs, which have yet to be clearly established.

Methods

Ten of 483 patients with aneurysmal subarachnoid hemorrhage who had been seen at the authors’ institution between March 2001 and June 2005 had intraoperatively confirmed BBAs at nonbranching sites of the ICA. All ten patients were women between the ages of 37 and 64 years (mean age 49.3 years); five had a history of hypertension. The BBAs were localized to the right side of the ICA in seven cases. All patients were successfully treated; clipping was undertaken in six, clipping combined with wrapping in three, and trapping in one. These methods were used in conjunction with various other surgical techniques such as brain relaxation by draining cerebrospinal fluid, anterior clinoidectomy, exposing the cervical ICA, gentle subpial dissection (for aneurysms that adhered to the frontal lobe), complete trapping of the ICA before clipping, and protecting the brain. Clip slippage occurred at the end of dural closing in two cases; the aneurysm was completely obliterated using multiple clips combined with ICA stenosis in one of these cases and ICA trapping with good collateral flow in the other. An excellent clinical outcome was achieved in eight patients, whereas two patients were disabled from massive vasospasm. The authors retrospectively reviewed radiological and surgical data in all cases to determine which treatment methods produced a favorable outcome.

Conclusions

Blood blister–like aneurysms located at nonbranching sites of the ICA are difficult to treat. Preoperative awareness and careful consideration of these lesions during surgery can prevent poor clinical outcomes.
Three-dimensional rotational angiography guidance for aneurysm surgery
Authors: Raabe Andreas , Beck Jürgen , Rohde Stefan , Berkefeld Joachim , Seifert Volker
Published: January 2008

Object

The aim of this study was to investigate the feasibility of integrating three-dimensional rotational angiography (3D-RA) data into a surgical navigation system and to assess its accuracy and potential clinical benefit.

Methods

The study cohort consisted of 16 patients with 16 intracranial aneurysms who had been scheduled for routine or emergency surgery. Rotational angiography data were exported using a virtual reality modeling language file format and imported into the BrainLAB VectorVision2 image-guided surgery equipment. During 3D-RA the position of the head was measured using a special headframe. The authors also determined the accuracy of 3D-RA image guidance and the clinical benefit as judged by the surgeon, including, for example, early identification of branching vessels and the aneurysm.

There was good correspondence between the 3D-RA–based navigation data and the intraoperative vascular anatomy in all cases, with a maximum error of 9° of angulation and 9° of rotation. In eight cases, the surgeon determined that the 3D-RA image guidance facilitated the surgical procedure by predicting the location of the aneurysm or the origin of a branching artery that had been covered by brain tissue and blood clots.

Conclusions

The integration of 3D-RA into surgical navigation systems is feasible, but it currently requires a new perspective-registration technique. The intraoperative 3D view provides useful information about the vascular anatomy and may improve the quality of aneurysm surgery in selected cases.
Influence of intraventricular hemorrhage and occlusive hydrocephalus on the long-term outcome of treated patients with basal ganglia hemorrhage: a case–control study
Authors: Huttner Hagen B. , Köhrmann Martin , Berger Christian , Georgiadis Dimitrios , Schwab Stefan
Published: January 2008

Object

Only limited data exist addressing the long-term outcome of patients with ganglionic hemorrhage complicated by intraventricular hemorrhage (IVH) and hydrocephalus that requires an external ventricular drain (EVD). The aim of this study was to compare the long-term outcome of patients with pure ganglionic hemorrhage and those requiring an EVD due to additional IVH and hydrocephalus.

Methods

For this study, 116 patients with supratentorial ganglionic hemorrhage and occlusive hydrocephalus were screened. To avoid any bias the authors excluded all patients with nonprimary intracerebral hemorrhage as well as those who received no treatment. Forty patients with IVH and subsequent hydrocephalus were examined, and 40 more patients with pure ganglionic hematomas were matched with regard to age, sex, Glasgow Coma Scale score, need for mechanical ventilation, and, in particular, hematoma volume. Outcome analysis was performed using the Barthel Index and the modified Rankin Scale (mRS).

The mean hematoma volume was 25.3 ± 15.2 ml. The overall long-term outcome was unfavorable (mRS Score 4–6) in 59% of all patients. Good outcome (mRS score < 4) was observed in 25 (62.5%) of 40 patients with hematoma volumes less than 25 ml, compared with eight (20%) of 40 who had hematoma volumes greater than 25 ml (p < 0.05, chi-square test). The need for an EVD was not associated with a worse long-term outcome in patients with comparable hematoma volumes. In contrast, the duration of treatment in the intensive care unit was longer for patients with EVDs than for those who had pure ganglionic hematomas (16 [range 5–29] days compared with 8 [range 2–19] days; p < 0.05, Mann–Whitney U-test), regardless of hematoma volume.

Conclusions

The long-term outcome of treated patients with supratentorial ganglionic hemorrhage with ventricular involvement and occlusive hydrocephalus is comparable to that of patients with similar hematoma volumes but no IVH.
Prolongation of survival following depletion of CD4+CD25+ regulatory T cells in mice with experimental brain tumors
Authors: Andaloussi Abdeljabar El , Han Yu , Lesniak Maciej S.
Published: January 2008

Object

Regulatory CD4+CD25+ T cells have been shown to play an important role in the regulation of the immune response. Whereas the presence of these cells has been associated with immune suppression, the lack of regulatory T (Treg) cells has been shown to induce autoimmunity. The purpose of this study was to define the role of Treg cells in tumors of the central nervous system (CNS).

Methods

The authors implanted syngeneic GL261 tumor cells in the brains or flanks of C57BL/6 mice. The resulting tumors were later removed at specific time points, and the presence of tumor-infiltrating lymphocytes was analyzed by performing flow cytometry for the presence of Treg cells. In a separate experiment, mice with GL261 tumors were treated with injections of anti-CD25 monoclonal antibody (mAb) to determine whether depletion of Treg cells may have an impact on the length of survival in mice with brain tumors.

Tumor-infiltrating lymphocytes isolated from mice with GL261 tumors were found to have a significant increase in the presence of Treg cells compared with control lymphocytes (p < 0.05). Moreover, Treg cells isolated in murine brain tumors expressed FoxP3, CTLA-4, and CD62L. Mice treated with anti-CD25 mAb lived significantly longer than tumor-bearing control animals (p < 0.05). An analysis of brains in surviving animals showed a depletion of CD4+CD25+ T cells.

Conclusions

The results of this study indicate that CD4+CD25+ Treg cells play an important role in suppressing the immune response to CNS tumors. These Treg cells may therefore represent a potentially novel target for immunotherapy of malignant gliomas.
Oligodendroglioma of the pineal region
Authors: Das Sunit , Chandler James P. , Pollack Ania , Biggio Eileen H. , Diaz Leslie , Raizer Jeffrey J. , Batjer H. Hunt
Published: January 2008

✓ The authors describe an oligodendroglioma of the pineal region in a 59-year-old woman. The patient presented with intermittent confusion, memory disturbance, and headache associated with a cystic pineal region mass demonstrated on magnetic resonance imaging. Gross-total resection was performed via a suboccipital supratentorial approach. Pathological and genetic evaluation showed the tumor to be an anaplastic oligodendroglioma. Although the spectrum of tumors arising within the region of the pineal gland is broad, to the authors’ knowledge this is the first report of an oligodendroglioma occurring in this area.
Tako-tsubo cardiomyopathy: reversible heart failure with favorable outcome in patients with intracerebral hemorrhage
Authors: Deininger Martin H. , Radicke Dirk , Buttler Jürgen , Scheufler Kai-Michael , Freiman Thomas , Zentner Josef F.
Published: January 2008

✓ In patients with intracerebal hemorrhage, cardiac dysfunction is a common phenomenon. Tako-tsubo cardiomyopathy is characterized by complete reversibility and therefore may constitute an entity with a favorable outcome. In this case report the authors describe a previously healthy 23-year-old man with no history of cardiac disease who suffered a severe fourth ventricular hemorrhage due to an angioma of the vermis cerebelli. After emergency surgery, progressive tachycardia, fibrillation, and electromechanical decoupling developed in the patient. An echocardiogram revealed left ventricular apical akinesia and basal hyperkinesis characteristic of tako-tsubo cardiomyopathy. One week after admission, cardiac function was normal. Tako-tsubo cardiomyopathy differs from common cardiac dysfunction in its reversible nature. This characteristic must be taken into consideration when treating patients with intracerebral hemorrhage to avoid misclassification of the disease.
Angiographically occult, progressively expanding, giant vertebral artery aneurysm
Authors: Komotar Ricardo J. , Mocco J , Lavine Sean D. , Solomon Robert A.
Published: January 2008

✓Hunterian ligation is a well-known treatment for complex aneurysms not amenable to direct microsurgical clip application. After proximal parent vessel occlusion, cerebral angiography is typically used to confirm aneurysm thrombosis. The authors report on a vertebral artery (VA) aneurysm that had progressively expanded and caused brainstem compression after hunterian ligation, despite nondiagnostic findings on both conventional and computed tomography (CT) angiography at multiple time points.

This 64-year-old woman underwent hunterian ligation of a 1.8-cm VA aneurysm at the origin of the right posterior inferior cerebellar artery. An immediately postoperative conventional angiogram and follow-up CT angiograms obtained 5 and 6 years postligation confirmed complete obliteration of the lesion. Nine years after the initial surgery, however, the patient experienced neurological deterioration. Although CTs showed substantial aneurysm enlargement together with pontine compression, angiograms once again demonstrated complete right VA occlusion with no retrograde filling of the aneurysm. On reexploration, the aneurysm was effectively debulked, clipped, and obliterated. Arterial bleeding was found in the lesion neck, as was evidence of microrecanalization.

Hunterian ligation for complex aneurysms carries the risk of microrecanalization and lesion expansion despite non-diagnostic angiography. Although this ligation procedure remains a viable treatment option in carefully selected patients, an extended follow-up evaluation period may be required even when imaging suggests aneurysm obliteration.
Very low pressure hydrocephalus
Authors: Clarke Michelle J. , Maher Cormac O. , Nothdurft Georgia , Meyer Fredric
Published: January 2008

✓ Low-pressure hydrocephalus is an extremely rare condition. Authors of the few previous reports on this subject have suggested that symptoms are gradual in onset and successfully treated. In this report the authors presented two unique cases of very low pressure hydrocephalus in which the patients experienced rapid deterioration requiring negative-pressure cerebrospinal fluid drainage to achieve the best possible neurological function; outcomes in both patients ultimately were poor. The constellation of findings suggests that this may be a distinct clinical entity.
Retrograde suction decompression of giant paraclinoid aneurysms using a No. 7 French balloon–containing guide catheter
Authors: Parkinson Richard J. , Bendok Bernard R. , Getch Christopher C. , Yashar Parham , Shaibani Ali , Ankenbrandt William , Awad Issam A. , Batjer H. Hunt
Published: January 2008

✓ The treatment of large and giant paraclinoid carotid artery (CA) aneurysms often requires the use of suction decompression for safe and effective occlusion. Both open and endovascular suction decompression techniques have been described previously. In this article the authors describe a revised endovascular suction decompression technique that provides several advantages in the treatment of large and giant paraclinoid and CA aneurysms.

A 51-year-old woman presented with a relatively brief history of progressive visual loss in the right eye, nonspecific headache, and an afferent pupillary defect. After angiography studies had been obtained, it was determined that she had a giant right paraclinoid internal CA aneurysm with a dome size of approximately 26 mm on the right and a neck diameter of 10 mm.

A modified technique was performed in which suction decompression was used. With the aid of a No. 7 French Concentric balloon guide catheter (Concentric Medical, Inc., Mountain View, CA) and application of a temporary clip distal to the aneurysm, the aneurysm was trapped and decompressed using retrograde suction through the guide catheter when the balloon was inflated. After satisfactory placement of three permanent clips, an intraoperative angiogram obtained through the same guide catheter confirmed CA patency. The aneurysm was then punctured and aspirated, ensuring complete occlusion of the aneurysm sac and reconstruction of the parent vessel. The patient made an excellent recovery and did not suffer any complications. She did not experience worsening in her vision.

This technical modification to endovascular suction decompression allows several potential advantages, including higher volume decompression and the ability to deliver endovascular devices to distal arterial locations.
Personal recollections of Walter E. Dandy and his Brain Team
Authors: Sherman Irving J. , Kretzer Ryan M. , Tamargo Rafael J.
Published: January 2008

✓ Walter Edward Dandy (1886–1946) began his surgical training at the Johns Hopkins Hospital in 1910 and joined the faculty in 1918. During the next 28 years at Johns Hopkins, Dandy established a neurosurgery residency training program that was initially part of the revolutionary surgical training system established by William S. Halsted but eventually became a separate entity. Dandy’s residents were part of his “Brain Team,” a highly efficient organization that allowed Dandy to perform over 1000 operations per year, not counting ventriculograms. This team also provided rigorous training in the Halsted mold for the neurosurgical residents. Although exacting and demanding, Dandy was universally admired by his residents and staff. This article describes Dandy’s neurosurgical residency program at Johns Hopkins, and provides personal recollections of training under Walter Dandy.
Bo Sung Sim (1924–2001): a pioneer of neurosurgery in Korea
Authors: Kim Dong Gyu , Park Chul-Kee , Paek Sun Ha
Published: January 2008

✓ Bo Sung Sim (1924–2001) stands as a prominent figure in the history of Korean neurosurgery. His devoted contributions have led to the fruitful development of modern neurosurgery in Korea. Sim practiced advanced neurosurgical techniques, undertook basic research, was passionate about education in the early years of neurosurgery in Korea, and played an essential role in founding the Korean Neurosurgical Society. Sim was a true neurosurgeon—a teacher, a scientist, and a superb pioneer in Korean neurosurgery.
Improved preservation of hearing and facial nerve function in vestibular schwannoma surgery via the retrosigmoid approach in a series of 200 patients
Authors: Samii Madjid , Gerganov Venelin , Samii Amir
Published: January 2008

Object

The aim of this study was to evaluate and present the results of current surgical treatment of vestibular schwannomas (VSs) and to report the refinements in the operative technique.

Methods

The authors performed a retrospective study of 200 consecutive patients who had undergone VS surgery over a 3-year period. Patient records, operative reports, follow-up data, and neuroradiological findings were analyzed. The main outcome measures were magnetic resonance imaging, neurological status, patient complaints, and surgical complications.

Complete tumor removal was achieved in 98% of patients. Anatomical preservation of the facial nerve was possible in 98.5% of patients. In patients treated for tumors with extension Classes T1, T2, and T3, the rate of facial nerve preservation was 100%. By the last follow-up examination, excellent or good facial nerve function had been achieved in 81% of the cases. By at least 1 year postsurgery, no patients had total facial palsy. In the patients with preserved hearing, the rate of anatomical preservation of the cochlear nerve was 84%. The overall rate of functional hearing preservation was 51%. There was no surgery-related permanent morbidity in this series of patients. Cerebrospinal fluid leakage was diagnosed in 2% of the patients. The mortality rate was 0%.

Conclusions

The goal of VS treatment should be total removal in one stage and preservation of neurological function, as they determine a patient’s quality of life. This goal can be safely and successfully achieved using the retrosigmoid approach.
Indications for surgery in patients with asymptomatic meningiomas based on an extensive experience
Authors: Yano Shigetoshi , Kuratsu Jun-ichi , _ _
Published: January 2008

Object

To determine the indications for surgery in patients harboring asymptomatic meningiomas, the authors retrospectively analyzed the natural course and surgical outcome of asymptomatic meningiomas and then compared these to the natural course and surgical outcome of symptomatic meningiomas.

Methods

Between 1989 and 2003, 1434 patients harboring meningiomas, who were treated in Kumamoto Prefecture, Japan, were enrolled in this study. Six hundred three patients had asymptomatic lesions and 831 had symptomatic ones. The authors analyzed the sizes of the lesions at detection, their growth over time, and any appearances of symptoms associated with previously asymptomatic meningiomas. The authors then compared the surgery-related morbidity rates associated with asymptomatic and symptomatic meningiomas arising at different locations.

Of the 603 asymptomatic meningiomas, 351 (58.2%) were treated conservatively. Tumor growth was observed in 25 (37.3%) of 67 patients who participated in follow up for longer than 5 years, and symptoms developed in 11 (16.4%) of the 67 patients over a mean follow-up period of 3.9 years. Among the 213 patients with surgically treated asymptomatic meningiomas, the morbidity rate was 4.4% in patients younger than 70 years of age and 9.4% in those 70 years of age or older. Although the total morbidity rate was lower in patients with asymptomatic lesions than in those with symptomatic ones, it exceeded 6% in patients whose asymptomatic tumors were located at the convexity or falx.

Conclusions

Approximately 63% of asymptomatic meningiomas did not exhibit tumor growth, and only 6% of all patients with these lesions experienced symptoms during the observation period. To avoid surgery-related incidences of morbidity in patients with asymptomatic meningiomas, conservative treatment with close follow-up review may be the best therapeutic strategy.
In vivo accuracy of image guidance performed using optical tracking and optimized registration
Authors: Mascott Christopher R.
Published: January 2008

Object

Image guidance systems involving the use of frameless referencing of surgical space to compile volumetric imaging data sets recently have come into widespread use. Few studies have addressed the true intraoperative surgical accuracy (that is, the application accuracy) of these systems except in a subjective manner. Calculated accuracies given by the systems do not necessarily reflect true intraoperative accuracy.

Methods

To objectively assess the stereotactic accuracy of a frameless image guidance system using optical spatial referencing, the author analyzed postoperative magnetic resonance (MR) images after placement of depth electrodes for the investigation of epilepsy. Preoperative planning for the treatment of seven patients included implanting skull fiducial screws and obtaining computed tomography/MR fusion images by using ImMerge image fusion software on the StealthStation (Medtronic, Inc.). A total of 42 electrodes were placed. Postoperative volumetric MR images were fused with preoperative study images. The difference between the planned electrode trajectories and targets and the visualized electrodes was measured in stereotactic space.

Conclusions

The mean distance between the distal electrode contact and the distal end of the planned trajectory for the 42 targets was 3 ± 1.5 mm. The most common error was in depth. The author’s technique did not involve rigid skull fixation of electrodes because they were subsequently tunneled subcutaneously and later removed at the bedside of the patient. Errors in depth were known to be due to traction at the time of tunneling and not due to stereotactic factors. Correcting for depth along the electrode trajectory, the mean accuracy was found to be 2.4 ± 1 mm.
Conventional neurocritical care and cerebral oxygenation after traumatic brain injury
Authors: Stiefel Michael F. , Udoetuk Joshua D. , Spiotta Alejandro M. , Gracias Vicente H. , Goldberg Aaron , Maloney-Wilensky Eileen , Bloom Stephanie , Le Roux Peter D.
Published: January 2008

Object

Control of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) is the foundation of traumatic brain injury (TBI) management. In this study, the authors examined whether conventional ICP- and CPP-guided neurocritical care ensures adequate brain tissue O2 in the first 6 hours after resuscitation.

Methods

Resuscitated patients with severe TBI (Glasgow Coma Scale score ≤ 8 and Injury Severity Scale score ≥ 16) who were admitted to a Level I trauma center and who underwent brain tissue O2 monitoring within 6 hours of injury were evaluated as part of a prospective observational database. Therapy was directed to maintain an ICP of 25 mm Hg or less and a CPP of 60 mm Hg or higher.

Data from a group of 25 patients that included 19 men and six women (mean age 39 ± 20 years) were examined. After resuscitation, ICP was 25 mm Hg or less in 84% and CPP was 60 mm Hg or greater in 88% of the patients. Brain O2 probes were allowed to stabilize; the initial brain tissue O2 level was 25 mm Hg or less in 68% of the patients, 20 mm Hg or less in 56%, and 10 mm Hg or less in 36%. Nearly one third (29%) of patients with ICP readings of 25 mm Hg or less and 27% with CPP levels of 60 mm Hg or greater had severe cerebral hypoxia (brain tissue O2 ≤10 mm Hg). Nineteen patients had both optimal ICP (≤25 mm Hg) and CPP (> 60 mm Hg); brain tissue O2 was 20 mm Hg or less in 47% and 10 mm Hg or less in 21% of these patients. The mortality rate was higher in patients with reduced brain tissue O2.

Conclusions

Brain resuscitation based on current neurocritical care standards (that is, control of ICP and CPP) does not prevent cerebral hypoxia in some patients. This finding may help explain why secondary neuronal injury occurs in some patients with adequate CPP and suggests that the definition of adequate brain resuscitation after TBI may need to be reconsidered.
Cavernous angiomas within the internal auditory canal
Authors: Samii Madjid , Nakamura Makoto , Mirzai Shahram , Vorkapic Peter , Cervio Andres
Published: January 2008

Object

The aim of this study was to describe the symptomatology, radiological features, and surgical treatment of patients with cavernous angiomas within the internal auditory canal (IAC).

Methods

The authors reviewed the cases of seven patients with cavernous angiomas in the IAC that had been surgically treated in the 22-year period between 1983 and 2005. All the patients had presented with sensorineural hearing loss, and four suffered from tinnitus. Four patients also reported facial symptoms such as hemispasm or progressive palsy; one of these patients had presented with sudden facial paresis due to intrameatal tumor hemorrhage. According to computed tomography (CT) results, the lesions caused enlargement of the IAC. Interestingly, these same angiomas showed variable features on magnetic resonance (MR) imaging, making their differentiation from intrameatal vestibular schwannomas (VSs) sometimes impossible. In all patients the lesions were totally removed via the suboccipital retrosigmoid approach. They could be dissected away from the facial nerve in five cases, whereas in two cases, because of the location of the lesion, the seventh cranial nerve had to be sectioned and repaired with a sural nerve graft. Transient worsening of seventh cranial nerve symptoms occurred in two patients, with postoperative improvement in each of them. The cochlear nerve could not be functionally preserved because of its extreme adherence to the tumor, although its continuity was preserved in four patients. Complete deafness was the only postoperative complication.

Conclusions

Cavernous angiomas of the IAC are very uncommon lesions that can imitate the symptoms of VSs. Although it is the most sensitive study available, MR imaging does not show sufficiently specific findings to differentiate the two lesion types. Thus, the preoperative diagnosis must be based on patient symptoms plus the CT and MR imaging features.
Motor field sensitivity for preoperative localization of motor cortex
Authors: Lin Peter T. , Berger Mitchel S. , Nagarajan Srikantan S.
Published: January 2008

Object

In this study the role of magnetic source imaging for preoperative motor mapping was evaluated by using a single-dipole localization method to analyze motor field data in 41 patients.

Methods

Data from affected and unaffected hemispheres were collected in patients performing voluntary finger flexion movements. Somatosensory evoked field (SSEF) data were also obtained using tactile stimulation. Dipole localization using motor field (MF) data was successful in only 49% of patients, whereas localization with movement-evoked field (MEF) data was successful in 66% of patients. When the spatial distribution of MF and MEF dipoles in relation to SSEF dipoles was analyzed, the motor dipoles were not spatially distinct from somatosensory dipoles.

Conclusions

The findings in this study suggest that single-dipole localization for the analysis of motor data is not sufficiently sensitive and is nonspecific, and thus not clinically useful.
Peripheral nerve regeneration through allografts compared with autografts in FK506-treated monkeys
Authors: Aubá Cristina , Hontanilla Bernardo , Arcocha Juan , Gorría Óscar
Published: January 2008

Object

The clinical use of nerve allografts combined with immunosuppressant therapy has become a genuine possibility that could supersede the classic use of autografts. However, contradictory data have been reported on whether immunosuppressant therapy should be temporarily administered. The purpose of this study was to compare the nerve regeneration obtained using ulnar nerve allografts in nonhuman primates temporarily treated with FK506 (tacrolimus) with that obtained using nerve autografts.

Methods

Four-centimeter nerve autografts or allografts were placed in the distal ulnar motor nerve of eight monkeys. The FK506 was temporarily administered to the animals of the allograft group for 2 months. At periods of 3, 5, and 8 months postsurgery, quantitative electrophysiological recordings were obtained to estimate muscle response. A quantitative analysis of ulnar motor neurons in the spinal cord was performed and axons were counted stereologically.

No statistically significant differences were found in the neuronal and axonal counts between autograft and allograft groups at 8 months. The electrophysiological studies showed no differences relative to the amplitude, but the autograft group presented with a greater nerve conduction velocity (NCV). However, no statistically significant differences were found between the number of neurons and distal axonal counts in the two groups.

Conclusions

Nerve regeneration through cold-preserved allografts in a primate model temporarily treated with FK506 was similar to that obtained using nerve autografts, in terms of neuronal and axonal counts. Nevertheless, temporary immunosuppression produced lower NCV when allografts were used, with less maturation of the myelinated fibers, which indicated that a partial rejection had taken place.
Use of a static magnetic field to promote recovery after peripheral nerve injury
Authors: Kelleher Michael O. , Al-Abri Rashid K. , Lenihan David V. , Glasby Michael A.
Published: January 2008

Object

While pulsed electromagnetic stimulation has been shown to enhance peripheral nerve regeneration, the effect of a static magnetic field on nerve repair is less clear. The aim of this study was to establish what effect an imposed exogenous static magnetic field has on peripheral nerve regeneration after transection and repair.

Methods

Three groups of six adult sheep were used. The first group acted as normal controls. In the second group, the median nerve was divided and immediately repaired by entubulation within a “controlled-release” biodegradable glass tube. In the third group, small magnets were applied to the sides of the biodegradable glass tubes before the median nerve was repaired using these magnetic tubes. The sheep were allowed to recover and were reexamined 10 months later. The animals underwent comprehensive morphometric (cross-sectional morphometry and measurement of internodal lengths), electrophysiological (determinations of stimulated jitter, maximum conduction velocity, refractory period, and F waves), and isometric tension (isometric twitch and tetanic tension) assessments.

Conclusions

Exogenously applied static electromagnetic fields do not enhance peripheral nerve regeneration.
Ependymoma of the pituitary fossa
Authors: Mukhida Karim , Asa Sylvia , Gentili Fred , Shannon Patrick
Published: January 2008

✓The authors describe a case of pituitary fossa ependymoma and discuss its immunohistochemical and ultrastructural characteristics. A 43-year-old man presented with decreased libido and panhypopituitarism. Magnetic resonance imaging demonstrated a well-demarcated enhancing lesion of the pituitary fossa that was completely resected via a trans-sphenoidal approach. Ependymomas rarely occur in the pituitary fossa, and have been reported in this location only three times in humans and once in a horse. This is the first study in which investigators examined the appearance of a pituitary ependymoma by using electron microscopy. Theories of the origin and treatment of these rare tumors are discussed as they relate to other articles on intracranial ependymomas.
Contribution of endovascular therapy to the management of poor-grade aneurysmal subarachnoid hemorrhage: clinical and angiographic outcomes
Authors: Suzuki Shuichi , Jahan Reza , Duckwiler Gary R. , Frazee John , Martin Neil , Viñuela Fernando
Published: January 2008

Object

Treatment of patients presenting with poor-grade (Hunt and Hess Grade IV or V) subarachnoid hemorrhage (SAH) is controversial. Endovascular coil embolization has been considered a valuable therapeutic alternative to surgical clip placement for this kind of patient. The aim of the present study was to evaluate immediate and long-term angiographic and clinical outcomes in patients with poor-grade SAH treated by endovascular embolization.

Methods

One hundred eleven patients with Hunt and Hess Grade IV or V SAH were treated with endovascular embolization at the University of California at Los Angeles Medical Center between October 1990 and December 2004. Eighty patients harbored Grade IV hemorrhages and 31 patients had Grade V ones. Immediate and long-term anatomical and clinical outcomes were evaluated in all patients. Long-term clinical outcome assessments were based on follow-up data obtained over an average of 32 months posttherapy.

Technical complications occurred in 15 patients (13.5%). Immediate complete aneurysm occlusion was observed in 51.4% of aneurysms. Angiographic, long-term follow-up review revealed aneurysm recanalization in 16.2% of cases. Thirty-nine patients (35.1%) demonstrated a favorable long-term clinical outcome. The overall mortality rate in this patient series was 32.4%. The mortality rate associated with vasospasm was significantly higher in patients with Grade IV SAHs than in those with Grade V hemorrhages.

Conclusions

The results of this study demonstrate a valuable contribution of endovascular therapy of ruptured intracranial aneurysms in patients with Hunt and Hess Grade IV or V SAH. This technique was successful in decreasing repeated aneurysm rupture and in enabling aggressive medical management during the acute phase of SAH. This is particularly important in patients with Grade IV SAH because of their potential for obtaining higher physical and functional recoveries.
Monitoring of muscle motor evoked potentials during cerebral aneurysm surgery: intraoperative changes and postoperative outcome
Authors: Szelényi Andrea , Langer David , Kothbauer Karl , de Camargo Adauri Bueno , Flamm Eugene S. , Deletis Vedran
Published: January 2008

Object

The authors in this study evaluated muscle motor evoked potentials (MMEPs) elicited by transcranial electrical stimulation (TES) and direct cortical stimulation as a means of monitoring during cerebral aneurysm surgery. The analysis focused on the value and frequencies of any intraoperative changes and their correlation to the postoperative motor status.

Methods

One hundred nineteen patients undergoing surgery for 148 cerebral aneurysms were included in the study. Muscle motor evoked potentials were elicited by a train of five constant-current anodal stimuli with an individual pulse duration of 0.5 msec and a stimulation rate of 2 Hz. Stimulation intensity was up to 240 mA for TES and up to 33 mA for direct cortical stimulation. The MMEPs were continuously recorded from the abductor pollicis brevis and tibialis anterior muscles bilaterally and from the biceps brachii and extensor digitorum communis muscles contralateral to the surgical side. The motor status was evaluated immediately after surgery and 7 days later.

In 97% of the patients MMEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 14 patients significant intraoperative MMEP changes occurred, resulting in a transient motor deficit in one patient and a permanent motor deficit in six. The permanent loss of MMEPs in three patients was followed by a permanent severe motor deficit in one patient and severe clinical deterioration in the other two.

Conclusions

Data in this study demonstrated that MMEPs are a useful means of intraoperative neurophysiological monitoring of motor pathway integrity and predicting postoperative motor status. The intraoperative loss of MMEPs reliably predicts both severe and permanent postoperative motor deficits.