bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal injury and neurobehavioral deficits following hyperglycemic cerebral ischemia: effect of theophylline and ZM 241385
Authors: Higashi Hisato , Meno Joseph R. , Marwaha Amitoj S. , Winn H. Richard
Published: May 2009

Object. The effects of the adenosine receptor antagonists theophylline (for A1 and A2) and ZM 241385 (for A2A) on hippocampal injury and Morris water maze (MWM) performance in rats were investigated following normoglycemic and hyperglycemic cerebral ischemia (induced by four vessel occlusion for 10 minutes).

Methods. Theophylline (36 mg/kg), ZM 241385 (1 mg/kg), or an equivalent volume of saline was administered to rats intraperitoneally 30 minutes before ischemia was induced. Moderate hyperglycemia was achieved by intraperitoneal administration of D-glucose (3 g/kg, 15 minutes before induction of ischemia). Morris water maze trials were performed on the 6th, 7th, and 8th days after ischemic insult. After the conclusion of the performance tests, the rat brains were cut into 8-xm sections, stained with cresyl violet and acid fuchsin, and evaluated in a blinded fashion to determine the extent of injury. Theophylline worsened injury in the hippocampus following normoglycemic and hyperglycemic ischemia. Moreover, theophylline significantly (p < 0.05, six animals) worsened latency and learning index (LI) scores during the MWM trials in both normoglycemic and hyperglycemic animals. On the other hand, ZM 241385 had no effect on either ischemic injury or MWM performance in normoglycemic animals. In the animals in the hyperglycemic ischemia group, however, ZM 241385 significantly (p < 0.05, five animals) reduced injury in the CA1 (94.6 ± 1.7% compared with 79.2 ± 10.9%), CA3 (26 ± 12.5% compared with 11.2 ± 4.3%), and hilum (22.4 ± 8.1% compared with 11 ± 5.5%) regions. In addition, ZM 241385 significantly improved latency (52 ± 29.7 seconds compared with 24.8 ± 11.2 seconds, p < 0.05) and LI scores (203.2 ± 33.3 compared with 152.1 ± 31.8, p < 0.05) in the MWM trials. A statistically significant correlation was also found between hippocampal injury (CA1, CA3, and hilum) and MWM performance.

Conclusions. The results of this study provide further evidence for a neuromodulatory role of adenosine during normoglycemic and hyperglycemic ischemia.
Predictors of vestibular schwannoma growth in patients with neurofibromatosis Type 2
Authors: Baser Michael E. , Makariou Erini V. , Parry Dilys M.
Published: May 2009

Object. The results of two longitudinal studies of growth rates of vestibular schwannomas (VSs) in patients with neurofibromatosis Type 2 (NF2) differ as to whether VS growth rates decrease or increase with increasing patient age. The authors undertook this study to assess the relationship between VS growth rates and patient age and type of constitutional NF2 mutation; they also examined variability in VS growth rates among multiple patients in families with NF2.

Methods. Gadolinium-enhanced magnetic resonance images obtained in 18 patients with inherited NF2 from 11 unrelated families were retrospectively analyzed. The patients had been observed for a median of 4 years. Volumes of the VSs were measured using a two-component box model (intrameatal and extrameatal parts measured separately). Single-strand conformation polymorphism analysis and Southern blot analysis were used to identify constitutional NF2 mutations. Growth rates of the VSs were highly variable, but tended to decrease with increasing patient age both at onset of signs or symptoms of NF2 (r2 = 0.35, p = 0.026) and at diagnosis (r2 = 0.33, p = 0.012). The VS growth rates did not vary significantly with the type of constitutional NF2 mutation or the number of non-VS cerebral or spinal tumors. The VS growth rates were highly variable within families and did not correspond to clinical indices of NF2 disease severity, such as patient age at symptom onset and the number of non-VS cerebral and spinal tumors.

Conclusions. The growth rates of VSs in patients with NF2 are highly variable, but tend to decrease with increasing patient age. Clinical treatment of multiple patients in families with NF2 cannot be based on the expectations of similar VS growth rates, even when other clinical aspects of disease severity are similar.
Pterional surgery of suprasellar meningiomas of the tuberculum sellae and planum sphenoidale: surgical results with special consideration of ophthalmological and endocrinological results
Authors: Fahlbusch Rudolf , Schott Werner
Published: May 2009

Object. The authors reviewed 47 cases of suprasellar meningiomas with special attention to ophthalmological and endocrinological outcomes.

Methods. All patients underwent surgery performed via a unilateral pterional approach between January 1983 and January 1998. Ophthalmological and endocrinological examinations were performed before the operation as well as 1 week and 3 months postoperatively. A special scoring system was adopted to quantify the extent of ophthalmological disturbances. Complete tumor resection was possible in all but one patient. There were no fatalities and the rate of visual improvement was 80%. The best prognoses were found in patients younger than 50 years and in patients in whom the duration of symptoms was less than 1 year. Before surgery, tumor-related endocrine disturbances were present in only three women who suffered from secondary hypogonadism; two of these patients recovered after surgery. Postoperatively, no patient needed replacement therapy for pituitary dysfunction. The overall tumor recurrence rate was 2.1% (one of 47 cases). For patients in whom long-term (> 5 years) follow-up data were available, the recurrence rate was 4.2% (one of 24 cases).

Conclusions. In this series, complete resection of suprasellar meningiomas was possible through a unilateral pterional craniotomy and was associated with a low morbidity rate and no deaths.
Intraoperative complications in aneurysm surgery: a prospective national study
Authors: Fridriksson Steen , Säveland Hans , Jakobsson Karl-Erik , Edner Göran , Zygmunt Stefan , Brandt Lennart , Hillman Jan
Published: May 2009

Object. With increasing use of endovascular procedures, the number of aneurysms treated surgically will decline. In this study the authors review complications related to the surgical treatment of aneurysms and address the issue of maintaining quality standards on a national level.

Methods. A prospective, nonselected amalgamation of every aneurysm case treated in five of six neurosurgical centers in Sweden during 1 calendar year was undertaken (422 patients; 7.4 persons/100,000 population/year). The treatment protocols at these institutions were very similar. Outcome was assessed using clinical end points. In this series, 84.1% of the patients underwent surgery, and intraoperative complications occurred in 30% of these procedures. Poor outcome from technical complications was seen in 7.9% of the surgically treated patients. Intraoperative aneurysm rupture accounted for 60% and branch sacrifice for 12% of all technical difficulties. Although these complications were significantly related to aneurysm base geometry and the competence of the surgeon, problems still occurred apparently at random and also in the best of hands (17%). The temporary mean occlusion time in the patients who suffered intraoperative aneurysm rupture was twice as long as the temporary arrest of blood flow performed to aid dissection.

Conclusions. The results obtained in this series closely reflect the overall management results of this disease and support the conclusion that surgical complications causing a poor outcome can be estimated on a large population-based scale. Intraoperative aneurysm rupture was the most common and most devastating technical complication that occurred. Support was found for a more liberal use of temporary clips early during dissection, regardless of the experience of the surgeon. Temporary regional interruption of arterial blood flow should be a routine method for aneurysm surgery on an everyday basis. A random occurrence of difficult intraoperative problems was clearly shown, and this factor of unpredictability, which is present in any preoperative assessment of risk, strengthens the case for recommending neuroprotection as a routine adjunct to virtually every aneurysm operation, regardless of the surgeon's experience.
Simultaneous intrastriatal and intranigral fetal dopaminergic grafts in patients with Parkinson disease: a pilot study
Authors: Mendez Ivar , Dagher Alain , Hong Murray , Gaudet Paula , Weerasinghe Swarna , McAlister Vivian , King David , Desrosiers Jacques , Darvesh Sultan , Acorn Tanya , Robertson Harold
Published: May 2009

✓ The main neural transplantation strategy in Parkinson disease (PD) has been focused on reinnervating the striatum. The clinical results reported in patients who receive transplants have been limited and do not justify the use of neural transplantation as a routine therapeutic procedure for PD. Identifying the optimal target for transplantation may be one of the critical factors for optimizing clinical outcomes. Evidence from preclinical studies indicates that simultaneous intrastriatal and intranigral grafts (double grafts) may produce a more complete functional recovery. The authors report the clinical and positron emission tomography (PET) scanning results in three patients enrolled in a safety and feasibility pilot study who received double grafts and who have been followed for up to 13 months posttransplantation.

Patients included in the study had idiopathic PD. All patients underwent detailed assessments before and after surgery, in accordance with the Core Assessment Program for Intracerebral Transplantation. The patients received implants of fetal mesencephalic cell suspensions in the putamen and substantia nigra (SN) bilaterally. There were no intraoperative or perioperative complications. Follow-up PET scans demonstrated an increase in the mean fluorodopa uptake constant values in the putamen and SN 12 months postsurgery. Improvements were also noted in the total Unified Parkinson′s Disease Rating Scale, Hoehn and Yahr, Schwab and England, and pronation/supination scores after transplantation. The authors demonstrate the feasibility of reinnervating the SN and striatum by using a double transplant strategy in humans.
Detection of hyperacute subarachnoid hemorrhage of the brain by using magnetic resonance imaging
Authors: Wiesmann Martin , Mayer Thomas E. , Yousry Indra , Medele Ralph , Hamann Gerhard F. , Brückmann Hartmut
Published: May 2009

Object. The purpose of this study was to determine the diagnostic accuracy of high-field (1.5-tesla) magnetic resonance (MR) imaging in the assessment of hyperacute (< 12 hours after onset of symptoms) subarachnoid hemorrhage (SAH).

Methods. This investigation included 13 patients who were examined 2 to 12 hours posthemorrhage by using an MR imaging protocol consisting of T2-weighted and proton-density (PD)-weighted images, T1-weighted images, fast echoplanar—diffusion-weighted (EP-DW) images, and fluid-attenuated inversion-recovery (FLAIR) images. Subarachnoid hemorrhage had been diagnosed using computerized tomography (CT) scanning in all cases.

In all 13 cases, SAH was reliably detected on both PD-weighted and FLAIR images. In contrast with FLAIR studies, the PD-weighted images were free of cerebrospinal fluid flow artifacts. The SAH was detected on T1-weighted images in only two cases and could not be detected on any T2-weighted or EP-DW images.

Conclusions. Even hyperacute SAH can be diagnosed reliably from high-field MR images obtained using PD-weighted or FLAIR sequences. Use of these sequences in an emergency MR protocol may preclude the need for additional CT studies to rule out SAH.
Magnetic resonance neurography of peripheral nerve following experimental crush injury, and correlation with functional deficit
Authors: Cudlip Simon A. , Howe Franklyn A. , Griffiths John R. , Bell B. Anthony
Published: May 2009

Object. In a number of clinical studies magnetic resonance (MR) neurography has been used to examine patients with peripheral nerve damage, but little is understood about the sequence of imaging changes following nerve injuries, and how they correlate with functional deficit. The goal of this study was to further understanding of these changes and their implications.

Methods. Using the rat sciatic nerve crush model, the sciatic nerve was imaged at intervals over 70 days in 12 rats. Sham-operated contralateral nerves served as controls. A 4.7-tesla MR imager with a custom-made surface coil was used. The T2 maps were calculated from images obtained at four echo times and from regions of interest designated on the nerve at three sites. Walking-track analysis was performed at the same intervals as imaging. Magnetic resonance neurography revealed a mean T2 of normal sciatic nerve of 36 msec (standard deviation [SD] 1.2 msec). Crushed nerves demonstrated a sequence of changes in signal intensity that were maximal at 14 days, with a mean T2 of 64 msec (SD 5.2 msec), then falling to a T2 of 53 msec (SD 3.7 msec). Sham-operated nerves had a short and nonsustained rise in signal at 7 days. Walking-track analysis revealed maximum deficit immediately postinjury, with an improvement in function approaching that of control nerves at 30 days.

Conclusions. In this study the authors demonstrate that quantitative assessment of nerve signals with MR neurography allows the sequence of events following nerve crush injury to be followed in vivo, and that a return toward a normal signal correlates with functional improvement. Assessment of peripheral nerve injury in patients by using MR neurography has the potential to confirm acute nerve injury as well as to monitor the recovery process.
Polyester meshes and adhesive materials in the brain: comparative research in rats to optimize surgical strategy
Authors: Quester Ralf , Klosterhalfen Bernd , Stützer Hartmut , Schröder Roland , Klug Norfrid
Published: May 2009

Object. The goal of this study was to determine the biocompatibility of polyester mesh electrode carriers for auditory brainstem implants with and without adhesives in a rat model.

Methods. Physical properties of the meshes were evaluated within the fourth ventricle region, both without (Group A) and with adhesives (muscle, Group B; oxidized regenerated cellulose [ORC], Group C; and fibrin glue, Group D). The stability of the mesh position, the healing process, and host defense reaction after 2 to 60 days were examined in series of tissue sections in which meshes were preserved in situ. The cellular reaction was further evaluated using electron microscopy.

Although otherwise pliable, polyester meshes were too rigid when used with adhesives, especially fibrin glue or muscle. Also, the sharp edges of the meshes presented a risk of brainstem and cerebellar lesions. Regardless of the material, meshes induced persistent inflammatory tissue reactions characterized by numerous macrophages and foreign-body giant cells. After 14 days, the cellular response had resulted in sufficient fibroblast and collagen fiber encapsulation of the meshes and remained essentially unchanged thereafter. No influence of adhesives on the healing process was observed, and, unexpectedly, these substances did not reduce the risk of dislocation prior to adequate cellular encasement. In some rats in Groups A and C, purulent inflammation, in part with Gram-positive bacteria, occurred after 2 to 14 days. The ORC exhibited persistent swelling, introducing the risk of occlusive hydrocephalus and/or brainstem compression.

Conclusions. Polyester meshes and various adhesives exhibited acceptable biocompatibility in terms of local tissue reaction. Adhesives reduced pliability of the meshes, however, and were ineffective in reducing the risk of dislocation. Handling characteristics could be improved by better mesh designs, and risk of infection could be reduced by both improved designs and surface treatment of the meshes with antibacterial agents.
Clinical and molecular analysis of disseminated hemangioblastomatosis of the central nervous system in patients without von Hippel—Lindau disease
Authors: Weil Robert J. , Vortmeyer Alexander O. , Zhuang Zhengping , Pack Svetlana D. , Theodore Nicholas , Erickson Robert K. , Oldfield Edward H.
Published: May 2009

✓ Hemangioblastomas of the central nervous system (CNS) may occur sporadically or in association with von Hippel—Lindau (VHL) syndrome. The authors present four patients with no family history or clinical evidence of VHL syndrome in whom extensive, progressive, en plaque coating of the brainstem and spinal cord with hemangioblastomas developed 1 to 8 years after complete resection of a solitary cerebellar hemangioblastoma.

Analysis included detailed physical, biochemical, radiological, and pathological examinations in all four patients, combined with family pedigree analysis. In addition, a detailed investigation of the VHL gene was undertaken. Allelic loss, comparative genomic hybridization (CGH), single-stranded conformational polymorphism screening, CpG island methylation status, and X chromosome inactivation clonality analyses were performed. Although there was no evidence of germline alterations in the VHL gene on clinical and radiological examination or in the family history (all four patients) or analysis of peripheral blood (three patients), somatic deletion of one copy of the VHL gene occurred in these tumors. These findings indicate that the multiple, separate deposits of tumors were likely derived from a single clone. Results of CGH indicate that one or several additional genes are probably involved in the malignant behavior of the hemangioblastomas in these patients. Furthermore, the malignant biological and clinical behavior of these tumors, in which multiple sites of subarachnoid dissemination developed 1 to 8 years after initial complete resection, followed by progressive tumor growth and death of the patients, occurred despite a histological appearance typical of benign hemangioblastomas.

Malignant hemangioblastomatosis developed 1 to 8 years after resection of an isolated cerebellar hemangioblastoma. Alterations of the VHL gene may be permissive in this setting, but other genes are likely to be the source of the novel biological and clinical presentation of the disseminated hemangioblastomas in these patients. This appears to represent a novel condition in which the product of one or more mutations in several genes permits malignant tumor behavior despite retention of a benign histological picture, a circumstance previously not recognized in CNS tumors.
Postprocedure ischemic events after treatment of intracranial aneurysms with Guglielmi detachable coils
Authors: Derdeyn Colin P. , Cross DeWitte T. , Moran Christopher J. , Brown George W. , Pilgram Thomas K. , Diringer Michael N. , Grubb Robert L. , Rich Keith M. , Chicoine Michael R. , Dacey Ralph G.
Published: May 2009

Object. Ischemic stroke or transient ischemic attack (TIA) may occur after the treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs). The purpose of the present study is to investigate possible risk factors for thromboembolic events and to determine their frequency and time course.

Methods. The records of 178 consecutive patients with 193 treated intracranial saccular aneurysms were reviewed. A total of 159 GDC procedures were performed to treat 143 aneurysms in 133 of those patients who were in good neurological condition, allowing clinical detection of postprocedure ischemic events (TIA or stroke). The association of clinical, anatomical, and pharmacological factors with intraprocedure intraarterial thrombus and with postprocedure ischemic events was investigated by using uni- and multivariate analyses.

Thrombus protruding into the parent artery was noted during six of 159 GDC procedures, resulting in a clinical deficit in one patient. No factor was associated with intraprocedure intraarterial thrombus. Ten postprocedure ischemic events occurred in nine patients. Seven events occurred within 24 hours, and three events occurred between 24 hours and 58 days. Aneurysm diameter and protruding coils were significant independent predictors of postprocedure ischemic events in multivariate analysis (both p = 0.02). The actuarial risk of stroke was 3.8%.

Conclusions. Larger aneurysm diameter and protruding loops of coils are associated with postprocedure ischemic events after GDC placement. It is unlikely that GDC-treated aneurysms retain thromboembolic potential beyond 2 months.
Correlation between auditory function and internal auditory canal pressure in patients with vestibular schwannomas
Authors: Lapsiwala Samir B. , Pyle G. Mark , Kaemmerle Ann W. , Sasse Frank J. , Badie Behnam
Published: May 2009

Object. Hearing loss is the most common presenting symptom in patients who harbor a vestibular schwannoma (VS). Although mechanical injury to the cochlear nerve and vascular compromise of the auditory apparatus have been proposed, the exact mechanism of this hearing loss remains unclear. To test whether pressure on the cochlear nerve from tumor growth in the internal auditory canal (IAC) is responsible for this clinical finding, the authors prospectively evaluated intracanalicular pressure (ICaP) in patients with VS and correlated this with preoperative brainstem response.

Methods. In 40 consecutive patients undergoing a retrosigmoid—transmeatal approach for tumor excision, ICaP was measured by inserting a pressure microsensor into the IAC before any tumor manipulation. Pressure recordings were correlated with tumor size and preoperative auditory evoked potential (AEP) recordings.

The ICaP, which varied widely among patients (range 0–45 mm Hg), was significantly elevated in most patients (median 16 mm Hg). Although these pressure measurements directly correlated to the extension of tumor into the IAC (p = 0.001), they did not correlate to total tumor size (p = 0.2). In 20 patients in whom baseline AEP recordings were available, the ICaP directly correlated to wave V latency (p = 0.0001), suggesting that pressure from tumor growth in the IAC may be responsible for hearing loss in these patients.

Conclusions. Tumor growth into the IAC results in elevation of ICaP and may play a role in hearing loss in patients with VS. The relevance of these findings to the surgical treatment of these tumors is discussed.
Experimental validation of deuterium oxide—mediated antitumoral activity as it relates to apoptosis in murine malignant astrocytoma cells
Authors: Uemura Takeshi , Moritake Kouzo , Akiyama Yasuhiko , Kimura Yoriyoshi , Shingu Takashi , Yamasaki Toshiki
Published: May 2009

Object. Deuterium oxide (D2O), or heavy water, affects a variety of biological activities different from those of water. The authors examined the antitumoral effect of D2O on brain neoplasms and demonstrated D2O-mediated cytotoxicity by using a Rous sarcoma virus—induced murine malignant astrocytoma cell line, RSVM. The mechanism of the observed cytotoxicity may involve D2O-induced apoptosis and cell-cycle modulation.

Methods. The authors performed an assay with methylthiazol tetrazolium bromide and a trypan blue dye exclusion test to confirm in vitro D2O-mediated cytotoxicity for RSVM cells. At D2O concentrations of 10 to 50%, the cytotoxic effect was dose and time dependent. Flow cytometry analysis revealed programmed cell death (apoptosis) and the accumulation of RSVM cells during the G2/M phase. By applying the terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling method, fluorescein isothiocyanate—annexin V and propidium iodide double staining, and caspase-family protease activity analysis, the authors demonstrated both DNA fragmentation and enhancement of caspase activity after a 48-hour treatment with D2O, thus indicating that D2O induces apoptosis in RSVM cells. Apoptotic DNA fragmentation was completely abolished by the caspase inhibitor Z-VAD-FMK (benzyloxycarbonil-Val-Ala-Aps-fluoromethylketone). The findings indicate that the caspase activation pathway may be involved in D2O-induced apoptosis.

Conclusions. The authors found that D2O is cytotoxic to malignant astrocytoma cells. The mechanism of D2O-mediated cytotoxicity involved the induction of apoptosis and cell accumulation during the G2/M phase. This D2O-induced apoptosis is modulated through the caspase activation pathway.
Axonal regeneration after cold preservation of nerve allografts and immunosuppression with tacrolimus in mice
Authors: Grand Aaron G. , Myckatyn Terence M. , Mackinnon Susan E. , Hunter Daniel A.
Published: May 2009

Object. The purpose of this study was to combine the immunosuppressive and neuroregenerative effects of tacrolimus (FK506) with cold preservation of peripheral nerve allografts to maximize axonal regeneration across short peripheral nerve gaps.

Methods. Ninety-six male C3H mice were randomized to six groups, which were composed of animals with isografts (Group 1, positive control), allografts (Group 2, negative control), allografts treated with subtherapeutic doses of FK506 without and with cold preservation (Groups 3 and 4), and allografts treated with therapeutic doses of FK506 without and with cold preservation (Groups 5 and 6). Results were determined using walking-track data and histomorphometric measurements.

Three weeks postoperatively, animals treated with therapeutic doses of FK506 after receiving cold-preserved allografts demonstrated accelerated functional recovery relative to all other groups. In addition, histomorphometric parameters in these animals (1257 ± 847 total axons, 6.7 ± 3.3% nerve tissue, 11.8 ± 6.5% neural debris, 8844 ± 4325 fibers/mm2 nerve density, and 2.53 ± 0.25 µm fiber width) were the same as or better than in all other groups. The parameters of percent nerve tissue (p < 0.016), nerve density (p < 0.038), and percent neural debris (p < 0.01) were statistically significantly better than those in all other groups, including Group 1 (isograft, positive control).

Conclusions. The combination of FK506 treatment with cold preservation of nerve allografts resulted in functional and histomorphometric recovery superior to that with either modality alone.
Intraoperative angiography during aneurysm surgery: a prospective evaluation of efficacy
Authors: Tang Gordon , Cawley C. Michael , Dion Jacques E. , Barrow Daniel L.
Published: May 2009

Object. Indications for intraoperative angiography during aneurysm surgery remain unclear. To define its use, the authors report the results of a prospective study in which this modality was used in all patients undergoing surgery for intracranial aneurysms.

Methods. Intraoperative angiography was performed prospectively in the surgical treatment of 517 consecutive aneurysms regardless of the lesion's location, size, or complexity. In 64 (12.4%) of 517 aneurysms intraoperative angiography findings prompted a change in surgical treatment. Residual aneurysm (47%) was the most frequent finding leading to clip revision. In 44% of cases, intraoperative angiography revealed vessel compromise. Surgery for aneurysms of the proximal internal carotid artery (ICA) was the most frequently altered, with lesions located at the superior hypophyseal artery (SHA) and clinoidal region having the highest revision rates, eight (40%) of 20 and eight (44%) of 18, respectively. Aneurysm size predicted the need for revision; giant aneurysms (> 24 mm) underwent revision in nine (29%) of 31 cases, whereas large aneurysms (15–24 mm) were revised in 12 (22%) of 54 cases. In a multivariate logistic regression model, factors related to increased revision rates included the SHA and clinoidal locations, as well as giant and large size. Ninety-five patients underwent both intraoperative and postoperative angiography. Five discrepancies were noted (95% accuracy); four were flow-related and one involved a previously unrecognized residual aneurysm. Complications attributable to intraoperative angiography occurred in 0.4% of cases.

Conclusions. Proximal ICA location and large aneurysm size significantly predicted revision of surgery following intraoperative angiography. Unexpected findings, even in less complex locations, are frequently identified on intraoperative angiography. Low complication rates, high accuracy, and the unexpected need for clip readjustments favor a more widespread use of intraoperative angiography.
Investigations using magnetic resonance imaging: is neurovascular compression present in patients with essential hypertension?
Authors: Säglitz Sylvia A. , Gaab Michael R.
Published: May 2009

Object. A possible relationship between neurovascular compression of the rostral ventrolateral medulla oblongata (RVLM) and essential hypertension is investigated using a specifically designed magnetic resonance (MR) imaging method.

In conjunction with the ninth and 10th cranial nerves, baroreceptor afferents enter the RVLM, which represents a crucial relay for regulation of autonomic blood pressure. In 1985 Jannetta and coworkers proposed a causal relationship between essential hypertension and intraoperatively observed neurovascular compression of the left RVLM.

Methods. Currently, MR imaging is the method of choice for the assessment of neurovascular relationships at the brainstem. By obtaining axial images of a thin-slice turbo inversion-recovery sequence and three-dimensional time-of-flight MR angiograms (fast imaging with steady-state precision), the authors documented the occurrence of neurovascular contacts with the RVLM at the level of the root entry zones (REZs) of the ninth and 10th cranial nerves in 25 patients with essential hypertension, 30 normotensive volunteers, and 10 patients with renal hypertension.

Neurovascular contacts with the REZ at the left RVLM were found in 32% of patients with essential hypertension, 37% of normotensive volunteers, and 20% of patients with renal hypertension. In total, neurovascular contacts on either side of the RVLM were documented in 68% of patients with essential hypertension, 53% of normotensive volunteers, and 50% of patients with renal hypertension.

Conclusions. The results do not support the theory of neurovascular compression in cases of essential hypertension. Findings of neurovascular contacts on MR images are not indications for decompression surgery. For further clarification, however, prospective MR imaging studies should be considered in young patients with essential hypertension in whom the history of high blood pressure is short.
Temporary ventricular drainage and emergency radiotherapy in the management of hydrocephalus associated with germinoma
Authors: Buatti John M. , Friedman William A.
Published: May 2009

Object. The authors used an alternative strategy to avoid shunt placement for hydrocephalus associated with germinoma, and the ensuing complications.

Methods. Between 1998 and 2000, five patients presenting with germinomas of the pineal area and symptomatic obstructive hydrocephalus were treated with a novel strategy. On arrival, they underwent ventriculostomy placement and one of several surgical procedures to obtain tissue for diagnosis. Within several days of the initial diagnosis, stereotactically guided fractionated radiotherapy was started. All patients experienced rapid tumor shrinkage and resolution of hydrocephalus, allowing discontinuation of external ventricular drainage without the need for permanent shunting of cerebrospinal fluid. To date, follow up reveals 100% radiographically and clinically confirmed tumor control.

Conclusions. Prompt resolution of hydrocephalus and absence of complications make this a potentially valuable therapy for control of germinomas and their symptoms.
A metaanalysis comparing the results of pallidotomy performed using microelectrode recording or macroelectrode stimulation
Authors: Palur Ravikant S. , Berk Caglar , Schulzer Michael , Honey Christopher R.
Published: May 2009

Object. There is an active debate regarding whether pallidotomy should be performed using macroelectrode stimulation or the more sophisticated and expensive method of microelectrode recording. No prospective, randomized trial results have answered this question, although personnel at many centers claim one method is superior. In their metaanalysis the authors reviewed published reports of both methods to determine if there is a significant difference in clinical outcomes or complication rates associated with these methods.

Methods. A metaanalysis was performed with data from reports on the use of unilateral pallidotomy in patients with Parkinson disease (PD) that were published between 1992 and 2000. A Medline search was conducted for the key word “pallidotomy” and additional studies were added following a review of the references. Only those studies dealing with unilateral procedures performed in patients with PD were included. Papers were excluded if they described a cohort smaller than 10 patients or a follow-up period shorter than 3 months or included cases that previously had been reported. The primary end points for outcome were the percentages of improvement in dyskinesias and in motor scores determined by the Unified PD Rating Scale (UPDRS). Complications were categorized as mortality, intracranial hemorrhage, visual deficit, speech deficit, cognitive decline, weakness, and other.

There were no significant differences between the two methods with respect to improvements in dyskinesias (p = 0.66) or UPDRS motor scores (p = 0.62). Microelectrode recording was associated with a significantly higher (p = 0.012) intracranial hemorrhage rate (1.3 ± 0.4%), compared with macroelectrode stimulation (0.25 ± 0.2%).

Conclusions. In reports of patients with PD who underwent unilateral pallidotomy, operations that included microelectrode recording were associated with a small, but significantly higher rate of symptomatic intracranial hemorrhage; however, there was no difference in postoperative reduction of dyskinesia or bradykinesia compared with operations that included macroelectrode stimulation.
Tissue resonance analysis: a novel method for noninvasive monitoring of intracranial pressure
Authors: Michaeli David , Rappaport Z. Harry
Published: May 2009

✓ A number of noninvasive methods used to measure intracranial pressure (ICP) have been proposed in the literature. For a variety of reasons, however, none of these have displayed significant practical applicability. The authors describe their development of a new, computerized, portable device based on tissue resonance analysis (TRA) technology for the noninvasive monitoring and measurement of ICP.

In response to the heart beat, the soft tissue and fluid compartments of the brain each exhibit characteristic vibration and mechanical resonant responses that radiate through the organs and tissues of the body. Patterns of vibration and mechanical resonance of various body organs and tissues are different and provide the possibility of extracting new and specific information in a noninvasive fashion. According to the TRA approach, ICP is dependent on the value of the dominant secondary (mechanical) resonance level of brain tissue. By digitally processing a reflected ultrasound signal (by using a concave ultrasonography probe with a carrier frequency of 1 MHz) from the third ventricle, the authors obtained a digital high-resolution echopulsogram, which visually is equivalent to ICP waves that are obtained invasively. The fast Fourier relationship of electrocardiogram and echopulsogram waves allowed the derivation of the secondary mechanical resonance levels. The authors developed a formula for a quantitative, noninvasive measurement of ICP, which uses information regarding multiple components of the intracranial space—both mechanical (secondary resonance) and physiological (time required for transfer of arterial blood to venous blood through brain tissue)—and the relationship between these components. A comparison of invasive and noninvasive ICP measurements was made during blinded trials in 40 patients with various diseases of the central nervous system, and ranges of ICP were measured from 1 to 66 mm Hg.

The ICP values obtained using the two methods were highly correlated (r = 0.99), without a statistically significant difference between simultaneously obtained readings (p = 1).

By using an integrative approach that reflects all components of the intracranial compartment, TRA allows for accurate noninvasive recordings of ICP. This method has significant advantages over other noninvasive technologies reported to date.
R. Glen Spurling: surgeon, author, and neurosurgical visionary
Authors: Shields Christopher B. , Shields Lisa B. E.
Published: May 2009

✓ Doctor Roy Glenwood Spurling (1894–1968) stands as a prominent figure in the field of neurosurgery. His innovative contributions have left an indelible mark, particularly in the treatment of lumbar and cervical intervertebral disc diseases and peripheral nerve injuries. He was instrumental in founding the Harvey Cushing Society (later renamed the American Association of Neurological Surgeons) and the American Board of Neurological Surgery. Spurling was a major participant in the military during World War II; he was stationed at Walter Reed Hospital and in the European Theater, and later became well known for his care of General George S. Patton. Glen Spurling is a role model to a younger generation of neurosurgeons for his tireless effort toward the advancement of neurosurgery.
Primary meningiomas of the jugular fossa
Authors: Arnautović Kenan I. , Al-Mefty Ossama
Published: May 2009

Object. Primary jugular fossa meningomas (JFMs) are one of the rarest subgroups of meningioma, with fewer than 40 cases reported in the literature. The authors retrospectively analyzed the results of surgical treatment in their series of patients, including clinical, pathological, and complication features. The surgical approach was mandated by the pathological anatomy of the tumor as well as by the anatomy of the individual patient.

Methods. During a 6.5-year period, the authors performed nine surgeries in eight patients (seven women [88%] and one man [12%]) with JFMs. Six lesions occurred on the right side and two on the left. The most common presenting symptoms were altered hearing in five patients (62%), swallowing difficulties in four patients (50%), and a deficit of the 11th cranial nerve in three patients (38%); a combination of two or more signs or symptoms was common. The surgical approach was tailored to the local anatomy (tumor—neurovascular relationships) found in each patient; three different routes were used. Radical tumor removal was achieved in all patients; one tumor recurrence occurred after 20 months in a patient in whom the tumor had displayed atypical histological features. This woman underwent a second operation. The mean length of hospital stay was 1 week. The mean and the median follow-up period were 45 and 40 months, respectively. The most common complications were transient lower cranial nerve deficits, which resolved or were compensated for in all patients within 1 month.

Conclusions. With a careful, extensive preoperative evaluation and appropriate tailoring of the operative approach, JFMs can be radically resected with the expectation of good outcome.
Multiple subpial transections: outcome and complications in 20 patients who did not undergo resection
Authors: Schramm Johannes , Aliashkevich Ales F. , Grunwald Thomas
Published: May 2009

Object. The authors describe patient characteristics, surgical methods, complications, and outcome over time in a cohort of patients who underwent multiple subpial transection (MST) without concomitant cortical resection.

Methods. Twenty consecutive patients in whom drug-resistant epilepsy had been diagnosed a mean of 16 ± 9 years earlier (mean ± standard deviation [SD]) were treated with MST without cortical resection. The mean follow-up period was 49.3 ± 18.3 months (mean ± SD, median 58 months). At 12 months of follow up, two of the 20 patients were Engel Class I, one was Class II, six were Class III, and 11 were Class IV. At latest follow up, one patient was Engel Class I, one was Class II, seven were Class III, and 11 were Class IV.

According to an alternative five-tiered classification system, two outcomes were excellent, seven were good, one was fair, nine were poor, and one was worse. Outcome was found to be better in patients with no lesions observed on magnetic resonance (MR) imaging, and worse in those with large MST areas. Outcome had a tendency to change (this occurred in 13 of 20 cases). Five patients (25%) improved and seven (35%) deteriorated in Engel outcome class, and in one (5%) both developments occurred over time. Most outcome class changes occurred before the end of the 2nd year (nine), and four were observed in the 5th year. There where seven transient neurological deficits and four surgical complications. There was no permanent significant morbidity, and there were no deaths.

Conclusions. Forty-five percent of patients achieved a worthwhile improvement after pure MST, if Engel outcome Class III is deemed a worthwhile improvement. The alternative five-tiered classification resulted in 50% with worthwhile improvement (excellent, good, or fair outcome), 45% with poor, and 5% with worse outcome. Lesions that are detectable on MR imaging, and large MST areas are predictive of worse results. Significant intraoperative problems may arise, but this happens infrequently. There is a notable rate of transient morbidity but the rate of permanent morbidity is not significant.
Stereotactic radiosurgery for pilocytic astrocytomas when multimodality therapy is necessary
Authors: Hadjipanayis Constantinos G. , Kondziolka Douglas , Gardner Paul , Niranjan Ajay , Dagam Shekhar , Flickinger John C. , Lunsford L. Dade
Published: May 2009

Object. The goal of this study was to examine the role of stereotactic radiosurgery in the treatment of patients with recurrent or unresectable pilocytic astrocytomas.

Methods. During a 13-year interval, 37 patients (median age 14 years) required multimodal treatment of recurrent or unresectable pilocytic astrocytomas. Tumors involved the brainstem in 18 patients, cerebellum in three, thalamus in five, temporal lobe in four, and parietal lobe in two, as well as the hypothalamus, optic tract, corpus callosum, insular cortex, and third ventricle in one patient each. Diagnosis was confirmed with the aid of stereotactic biopsy in 12 patients, open biopsy in five, partial resection in eight, and near-total resection in 12. Multimodal treatment included fractionated radiation therapy in 10 patients, stereotactic intracavitary irradiation of tumor in four, chemotherapy in two, cyst drainage in six, ventriculoperitoneal shunt placement in three, and additional cytoreductive surgery in four. Tumor volumes varied from 0.42 to 25 cm3. The median radiosurgical dose to the tumor margin was 15 Gy (range 9.6–22.5 Gy).

After radiosurgery, serial imaging demonstrated complete tumor resolution in 10 patients, reduced tumor volume in eight, stable tumor volume in seven, and delayed tumor progression in 12. No procedure-related death was encountered. Thirty-three (89%) of 37 patients are alive at a median follow-up period of 28 months after radiosurgery and 59 months after diagnosis. Eight patients participated in follow-up review for more than 60 months. Three patients died of local tumor progression.

Conclusions. Stereotactic radiosurgery is a valuable adjunctive strategy in the management of recurrent or unresectable pilocytic astrocytomas. Despite the favorable histological characteristics and prognosis usually associated with this neoplasm, an adverse location, recurrence, or progression of this disease requires alternative therapeutic approaches such as radiosurgery.
Ischemic depolarization monitoring: evaluation of protein synthesis in the hippocampal CA1 after brief unilateral ischemia in a gerbil model
Authors: Sorimachi Takatoshi , Abe Hiroshi , Takeuchi Shigekazu , Tanaka Ryuichi
Published: May 2009

Object. The authors investigate whether depolarization monitoring is an accurate index of ischemic damage in a gerbil model of unilateral ischemia and assess the effects of brief cerebral ischemia on protein synthesis in this model.

Methods. The authors evaluate the relationship between the duration of ischemic depolarization caused by unilateral carotid artery occlusion and ischemia-induced neuronal damage in the CA1 subregion 7 days after ischemia. When the depolarization period exceeded 210 seconds, some neuronal damage was detected, and almost complete neuronal damage was observed when the period exceeded 400 seconds. Uptake of [14C]valine was evaluated in ischemic and nonischemic CA1 subregions. Disturbances in protein synthesis were seen in all animals subjected to sublethal ischemia (≤ 210-second depolarization) after a 10-minute recirculation, and after 2 and 6 hours of recirculation in animals with 90 seconds or more of depolarization. Inhibition of protein synthesis was proportional to the length of the depolarization period. After 1 and 3 days of recirculation, protein synthesis returned to near normal, and some animals with depolarizations greater than 180 to 210 seconds showed an increase in protein synthesis. Protein synthesis in all animals returned to normal levels after 7 days of recirculation.

Conclusions. In this study the authors demonstrate that monitoring of ischemic depolarization is a useful method to predict neuronal damage in the hippocampal CA1 in this model, and they identify subtle changes in protein synthesis after brief ischemia. Sublethal ischemia was divided into three categories by its depolarization period (< 90 seconds, 90–180 seconds, and > 180–210 seconds) with regard to changes in protein synthesis.
Acetazolamide therapy for symptomatic plateau waves in patients with brain tumors
Authors: Watling Christopher J. , Cairncross J. Gregory
Published: May 2009

✓ In this report, the authors describe three patients with malignant gliomas who experienced paroxysmal neurological symptoms triggered by standing. The symptoms were attributed to acute elevations of intracranial pressure, an uncommon phenomenon called “plateau waves.” In each instance, the attacks occurred despite the fact that the patient was receiving dexamethasone therapy and stopped promptly with the addition of acetazolamide. Acetazolamide, an orally administered carbonic anhydrase inhibitor, appears to be a specific and effective therapy for this uncommon neurological disorder.
Surgical complications associated with the endoscopic endonasal transsphenoidal approach for pituitary adenomas
Authors: Cappabianca Paolo , Cavallo Luigi Maria , Colao AnnaMaria , de Divitiis Enrico
Published: May 2009

Object. To assess postoperative complications related to the surgical procedure, a retrospective analysis was conducted in a series of 146 consecutively treated patients who underwent an endoscopic endonasal transsphenoidal approach to the sellar region for resection of pituitary adenomas between January 1997 and July 2001.

Methods. Complications were divided into groups (nasofacial, sphenoid sinus, sella turcica, supra or parasellar, and endocrine complications) according to the anatomical structures and the systems involved. Overall, a decreased incidence of complications has been observed, compared with large historical series of the traditional microsurgical transsphenoidal approach, likely because of the overview inside the anatomy facilitated by the endoscope, and the decreased surgical trauma.

Conclusions. Transsphenoidal surgery, either microscopic or endoscopic, is a safe procedure in experienced hands, but serious complications still occur and must be reduced as much as possible. Additional improvement can be expected with greater experience and new technical developments. A coordinated team effort with other dedicated colleagues from different specialties is advised.