bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of treatment outcome after stereotactic radiosurgery for cavernous sinus meningiomas
Authors: Shin Masahiro , Kurita Hiroki , Sasaki Tomio , Kawamoto Shunsuke , Tago Masao , Kawahara Nobutaka , Morita Akio , Ueki Keisuke , Kirino Takaaki
Published: May 2009

Object. The long-term outcome of stereotactic radiosurgery for cavernous sinus (CS) meningiomas is not fully understood. The authors retrospectively reviewed their experience with 40 CS meningiomas treated with gamma knife radiosurgery.

Methods. Follow-up periods for the 40 patients ranged from 12 to 123 months (median 42 months), and the overall tumor control rates were 86.4% at 3 years and 82.3% at 10 years. Factors associated with tumor recurrence in univariate analysis were histological malignancy (p < 0.0001), partial treatment (p < 0.0001), suprasellar tumor extension (p = 0.0201), or extension in more than three directions outside the CS (p = 0.0345). When the tumor was completely covered with a dose to the margin that was higher than 14 Gy (Group A, 22 patients), no patient showed recurrence within the median follow-up period of 37 months. On the other hand, when a part of the tumor was treated with 10 to 12 Gy (Group B, 15 patients) or did not receive radiation therapy (Group C, three patients), the recurrence rates were 20% and 100%, respectively. Neurological deterioration was seen in nine patients, but all symptoms were transient or very mild.

Conclusions. The data indicate that stereotactic radiosurgery can control tumor growth if the whole mass can be irradiated by dosages of more than 14 Gy. When optimal radiosurgical planning is not feasible because of a tumor's large size, irregular shape, or proximity to visual pathways, use of limited surgical resection before radiosurgery is the best option and should provide sufficient long-term tumor control with minimal complications.
Association of increased phosphatidylinositol 3-kinase signaling with increased invasiveness and gelatinase activity in malignant gliomas
Authors: Kubiatowski Tomas , Jang Taichang , Lachyankar Mahesh B. , Salmonsen Rebecca , Nabi Roya R. , Quesenberry Peter J. , Litofsky N. Scott , Ross Alonzo H. , Recht Lawrence D.
Published: May 2009

Object. Glioblastoma multiforme is the most malignant of the primary brain tumors and aggressively infiltrates surrounding brain tissue, resulting in distant foci within the central nervous system, thereby rendering this tumor surgically incurable. The recent findings that both phosphatidylinositol 3-kinase (PI 3-K) and the phosphatase and tensin homolog (PTEN) regulate tumor cell invasiveness have led the authors to surmise that these lipid signaling molecules might play a role in regulating matrix metalloproteinases (MMPs), which are essential for tumor cell invasion.

Methods. Using the C6 glioma cell line, which does not express measurable amounts of PTEN protein and in which in vitro invasiveness is MMP dependent, the authors determined that in vitro glioma cell invasiveness was significantly reduced when cells were preincubated overnight with LY294002 or wortmannin, two specific inhibitors of PI 3-K signaling. Next, using gelatin zymography, it was noted that these compounds significantly inhibited MMP-2 and MMP-9 activities. Moreover, the decrease in MMP activity correlated with the decrease in PI 3-K activity, as assessed by Akt phosphorylation. Finally, using semiquantitative reverse transcriptase—polymerase chain reaction, the authors demonstrated that LY294002 decreased messenger (m)RNA levels for both MMPs. Thus, these in vitro data indicate that PI 3-K signaling modulates gelatinase activity at the level of mRNA.

Using immunostaining of phosphorylated Akt (p-Akt) as a measure of PI 3-K activity, the authors next assessed rat brains implanted with C6 cells. Compared with surrounding brain, there was marked p-Akt staining in C6 glioma cells and in neurons immediately adjacent to the tumor, but not in normal brain. The p-Akt staining in tumors was especially intense in perivascular areas. Using double-labeling techniques, colocalization of p-Akt with MMP-2 and MMP-9 was also noted in perivascular tumor areas.

Conclusions. The increase in p-Akt staining within these PTEN-deficient gliomas is consistent with what would be predicted from unchecked PI 3-K signaling. Furthermore, the immunohistochemically detected colocalization of p-Akt and MMP-2 and MMP-9 supports the authors' in vitro studies and the proposed linkage between PI 3-K signaling and MMP activity in gliomas.
Analysis of brain biocompatibility of drug-releasing biodegradable microspheres by scanning and transmission electron microscopy
Authors: Veziers Joëlle , Lesourd Maurice , Jollivet Christophe , Montero-Menei Claudia , Benoit Jean-Pierre , Menei Philippe
Published: May 2009

Object. Stereotactically guided implantation of biodegradable microspheres is a promising strategy for delivery of neurotrophic factors in a precise and spatially defined brain area. The goal in this study was to show the biocompatibility of poly(D,L,lactide-co-glycolide) microspheres with brain tissue at the ultrastructural level and to analyze the three-dimensional (3D) ultrastructure after intrastriatal implantation of these microparticles.

Methods. Scanning and transmission electron microscopy were used to study the microspheres and their environment after implantation in an inert material (gelatin) and in the rat striatum. Observations were made at different time periods, ranging from 24 hours to 2 months postimplantation.

Conclusions. The progressive degradation of the microspheres, with vacuolization, deformation, and shrinkage, was well visualized. This degradation was identical in microspheres implanted in the inert material and in the rat brain tissue, independent of the presence of macrophages. The studies preformed in the striatum permitted the authors to demonstrate the structural integrity of axons in contact with microspheres, confirming the biocompatibility of the polymer. Furthermore, scanning electron microscopy showed the preservation of the 3D ultrastructure of the striatum around the microparticles. These microparticles, which can be stereotactically implanted in functional areas of the brain and can release neurotrophic factors, could represent, for some indications, an alternative to gene therapy.
Peduncular hallucinosis due to a pineal meningioma
Authors: Miyazawa Takahito , Fukui Shinji , Otani Naoki , Tsuzuki Nobusuke , Katoh Hiroshi , Ishihara Shoichiro , Nawashiro Hiroshi , Wada Kojiro , Shima Katsuji
Published: May 2009

✓ The authors report the case of a 53-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH). The cause of the PH was compression of the quadrigeminal plate and/or the splenium due to a meningioma originating from the falcotentorial junction (pineal meningioma). The nature of the visual hallucinations was depicted in drawings created by the patient herself. This is the first report of PH caused by a tumor located in the pineal region.
Fulminant radiation-induced necrosis after stereotactic radiation therapy to the posterior fossa
Authors: Tandon Nitin , Vollmer Dennis G. , New Pamela Z. , Hevezi James M. , Herman Terence , Kagan-Hallet Kathleen , West G. Alexander
Published: May 2009

✓ The problem of radiation-induced necrosis of normal brain surrounding the target area has been a major catalyst for the development of stereotactically focused radiation therapy. According to current opinion, the effects of stereotactic irradiation are confined to the region targeted. The authors present a case in which the administration of a conventional dose of stereotactically focused irradiation for treatment of a pilocytic astrocytoma produced fulminant necrosis that necessitated a combination of intensive surgical and medical management, after which the patient improved over the course of 1 year. Concomitant with his improvement, the initially remarkable findings on magnetic resonance imaging gradually resolved.

In this presentation the authors emphasize the need to evaluate alternatives carefully before a decision is made to administer therapeutic irradiation. Furthermore, they explore the roles that target, host, and dosage factors play in hypersensitivity to radiation injury, the detection of these factors before treatment, and the administration of radioprotective agents. With the growing use of stereotactically focused irradiation as a primary treatment modality for a variety of neurosurgical conditions, it is important to be cognizant of its uncommon but potentially lethal side effects. A cooperative multicenter database in which the outcomes and morbidity following stereotactic irradiation are recorded is essential to the detection of relatively uncommon but severe complications such as those observed in this case.
Spontaneous retroclival hematoma presenting as a thunderclap headache
Authors: Schievink Wouter I. , Thompson Reid C. , Loh Christopher T. , Maya M. Marcel
Published: May 2009

✓ An excruciating headache of instantaneous onset, or thunderclap headache, may be caused by a variety of serious disorders, including aneurysmal subarachnoid hemorrhage, cerebral venous sinus thrombosis, pituitary apoplexy, and carotid artery or vertebral artery dissection. The authors describe a patient with this type of headache who was found to have a spontaneous retroclival hematoma.

A 49-year-old woman experienced an instantaneous excruciating headache. Results of computerized tomography (CT) scans of the head were normal, but on examination of the cerebrospinal fluid xanthochromia was found. Magnetic resonance (MR) imaging of the cervical spine revealed a retroclival hematoma. Three cerebral angiographic studies did not reveal the source of the hemorrhage and a repeated MR image demonstrated resolution of the hematoma. The patient made an uneventful recovery.

Spontaneous retroclival hematoma is an exceedingly rare type of intracranial hemorrhage and may be associated with normal findings on CT scans. Spontaneous retroclival hematoma should be included in the differential diagnosis of thunderclap headache.
A brachial plexopathy due to myositis ossificans
Authors: Reavey-Cantwell John F. , Garonzik Ira , Viglione Michael P. , McCarthy Edward F. M. , Belzberg Allan J.
Published: May 2009

✓ Myositis ossificans (MO) is a disorder characterized by the intramuscular proliferation of fibroblasts and osteoblasts, with subsequent deposition of bone and cartilage. A typical clinical presentation involves traumatic injury to a young adult, usually localized to the thigh, buttock, or upper arm, with resultant MO and mildly restricted range of motion in adjacent joints. Rarely, MO is associated with peripheral neuropathies involving the radial, median, sciatic, and sural nerves. The authors present an unusual case of MO causing a brachial plexopathy. To their knowledge, this is the first description of such a presentation.
Identification of the carotid artery dural ring by using three-dimensional computerized tomography angiography
Authors: Murayama Yoshihisa , Sakurama Kazuhide , Satoh Koichi , Nagahiro Shinji
Published: May 2009

✓ The carotid artery (CA) dural ring is an important structure in aneurysm surgery of the paraclinoid region. The authors used three-dimensional computerized tomography (3D-CT) angiography to study the CA dural ring.

Three-dimensional computerized tomography angiography was performed in patients with cerebral aneurysms and other cerebrovascular diseases. The paraclinoid segment of the internal carotid artery (ICA) was examined by the shaded surface reconstruction method on targeted 3D-CT angiography. The concavity was recognized in the paraclinoid segment of the ICA. The relationship between the concavity and the dural ring was investigated with anatomical studies and surgical findings.

In anatomical studies, the concavity in the paraclinoid segment of the ICA on 3D-CT angiography coincided with the level of attachment of the dural ring. Using 3D-CT angiography, it is possible to identify the location of the dural ring in patients being considered for aneurysm surgery.
Adult respiratory distress syndrome: a complication of induced hypertension after severe head injury
Authors: Contant Charles F. , Valadka Alex B. , Gopinath Shankar P. , Hannay H. Julia , Robertson Claudia S.
Published: May 2009

Object. The factors involved in the development of adult respiratory distress syndrome (ARDS) after severe head injury were studied. The presence of ARDS complicates the treatment of patients with severe head injury, both because hypoxia causes additional injury to the brain and because therapies that are used to protect the lungs and improve oxygenation in patients with ARDS can reduce cerebral blood flow (CBF) and increase intracranial pressure (ICP). In a recent randomized trial of two head-injury management strategies (ICP-targeted and CBF-targeted), a fivefold increase in the incidence of ARDS was observed in the CBF-targeted group.

Methods. Injury severity, physiological data, and treatment data in 18 patients in whom ARDS had developed were compared with the remaining 171 patients in the randomized trial in whom it had not developed. Logistic regression analysis was used to study the interaction of the factors that were related to the development of ARDS.

In the final exact logistic regression model, several factors were found to be significantly associated with an increased risk of ARDS: administration of epinephrine (5.7-fold increased risk), administration of dopamine in a larger than median dose (10.8-fold increased risk), and a history of drug abuse (3.1-fold increased risk).

Conclusions. Although this clinical trial was not designed to study the association of management strategy and the occurrence of ARDS, the data strongly indicated that induced hypertension in this high-risk group of patients is associated with the development of symptomatic ARDS.
Hyperacute measurement of intracranial pressure, cerebral perfusion pressure, jugular venous oxygen saturation, and laser Doppler flowmetry, before and during removal of traumatic acute subdural hematoma
Authors: Verweij Bon H. , Muizelaar J. Paul , Vinas Federico C.
Published: May 2009

Object. The poor prognosis for traumatic acute subdural hematoma (ASDH) might be due to underlying primary brain damage, ischemia, or both. Ischemia in ASDH is likely caused by increased intracranial pressure (ICP) leading to decreased cerebral perfusion pressure (CPP), but the degree to which these phenomena occur is unknown. The authors report data obtained before and during removal of ASDH in five cases.

Methods. Five patients who underwent emergency evacuation of ASDH were monitored. In all patients, without delaying treatment, a separate surgical team (including the senior author) placed an ICP monitor and a jugular bulb catheter, and in two patients a laser Doppler probe was placed.

The ICP prior to removing the bone flap in the five patients was 85, 85, 50, 59, and greater than 40 mm Hg, resulting in CPPs of 25, 3, 25, 56, and less than 50 mm Hg, respectively. Removing the bone flap as well as opening the dura and removing the blood clot produced a significant decrease in ICP and an increase in CPP. Jugular venous oxygen saturation (SjvO2) increased in four patients and decreased in the other during removal of the hematoma. Laser Doppler flow also increased, to 217% and 211% compared with preevacuation flow.

Conclusions. Intracranial pressure is higher than previously suspected and CPP is very low in patients with ASDH. Removal of the bone flap yielded a significant reduction in ICP, which was further decreased by opening the dura and evacuating the hematoma. The SjvO2 as well as laser Doppler flow increased in all patients but one immediately after removal of the hematoma.
Risk factors affecting survival after brain metastases from non—small cell lung carcinoma: a follow-up study of 70 patients
Authors: Abrahams John M. , Torchia Maria , Putt Mary , Kaiser Larry R. , Judy Kevin D.
Published: May 2009

Object. The authors present their experience with the treatment of brain metastases from non—small cell lung carcinoma (NSCLC).

Methods. A retrospective review was conducted in which records from 74 patients treated at the authors' institution between 1994 and 1999 were assessed. Survival and functional outcome were reviewed relative to individual patient variables. The median survival time was 12.9 months, with 1-, 2-, and 5-year survival milestones reached by 52.2%, 30.7%, and 18.1% of patients, respectively. Patients were stratified into groups composed of those with synchronous brain metastases (tumors diagnosed within 3 months of NSCLC) and metachronous brain metastases (tumors diagnosed 3 months after NSCLC). The median survival time and 5-year survival rate were 18 months and 28.9% for metachronous, compared with 9.9 months and 0% for synchronous brain metastases. In univariate analyses, the stage of brain metastases, an initial Karnofsky Performance Scale (KPS) score of 90 or less, and conservative therapy for NSCLC were associated with worse outcomes (p < 0.05). In analyses in which tumors were stratified by synchronous compared with metachronous brain metastases, a preoperative KPS score of 90 or less and radiation therapy (RT) alone for brain metastases were associated with worse outcomes in patients with metachronous brain metastases but not with synchronous tumors (p < 0.05). When stratified by preoperative KPS score, the synchronous brain metastases stage or treatment of brain metastases with RT alone were associated with worse outcome in patients with KPS scores of 100, but had no discernible effect on patients with KPS scores of 90 or less (p < 0.05).

Conclusions. The tumor stage and preoperative KPS score were significantly associated with survival. Craniotomy plus RT significantly improved the prognosis in patients with metachronous brain metastases or those with a preoperative KPS score of 100.
Monitoring of intraoperative motor evoked potentials to increase the safety of surgery in and around the motor cortex
Authors: Kombos Theodoros , Suess Olaf , Ciklatekerlio Öczan , Brock Mario
Published: May 2009

Object. The repetitive application of high-frequency anodal monopolar stimulation during surgery in or near the motor cortex allows a qualitative and quantitative evaluation of motor evoked potentials (MEPs). Using this method, motor pathways and motor function can be continuously monitored during surgery.

Methods. In this prospective study, 70 patients underwent MEP monitoring during surgery performed in the central region. All procedures were performed after general anesthesia had been induced without the aid of muscle relaxants. The motor pathways were monitored during the entire surgical procedure by repetitive high-frequency anodal monopolar stimulation (frequency 400–500 Hz; train 7–10 pulses; impulse duration 0.2–0.7 msec; and stimulation intensity 16.9 ± 7.76 mA). The MEPs were continuously evaluated to assess their latency, potential duration, and amplitude. Recorded alterations in these parameters were subsequently correlated with surgical maneuvers and with postoperative neurological deterioration.

The monitoring parameters (latency, potential duration, and amplitude) had a broad interindividual range of variation. A correlation between individual intraoperative changes in the potentials and surgical maneuvers or postoperative neurological deterioration was observed in eight cases. A spontaneous shift in latency greater than 15% or a sudden reduction in the amplitude of the potential greater than 80% was considered a warning criterion. In all cases in which there was an irreversible change in latency or a complete loss of potentials were observed, there was postoperative neurological deterioration.

Conclusions. Improved surgical safety can be achieved using intraoperative neurophysiological monitoring procedures. Repetitive stimulation of the motor cortex proved to be a reliable method for monitoring subcortical motor pathways. Changes in MEP latency and MEP amplitude served as warning criteria during surgery and possessed prognostic value.
Strategies for reoperation after comprehensive epilepsy surgery
Authors: Schwartz Theodore H. , Spencer Dennis D.
Published: May 2009

Object. Prior reports of seizure control following reoperation for failed epilepsy surgery have shown good results. These studies included patients who presented during the era preceding magnetic resonance (MR) imaging, and the patients were often not monitored intracranially or underwent subtotal hippocampal resections. In this study, the authors hypothesized that reoperation for recurrent seizures following a more comprehensive initial workup and surgery would not yield such good results.

Methods. The authors examined a consecutive series of patients who underwent two operations at Yale—New Haven Hospital for medically intractable epilepsy and in whom there was a minimum of 1-year follow up after the second surgery. All patients were evaluated and treated according to a standard protocol, including preoperative MR imaging, a low threshold for invasive monitoring, and a radical amygdalohippocampectomy when indicated.

Twenty-seven patients were identified (five with mesial temporal sclerosis, 20 with neocortical disease, and two with multifocal sites of seizure onset) of whom six (22%) underwent intentionally palliative second surgery (corpus callostomy or placement of a vagus nerve stimulator [VNS]). Of the remaining 21 patients, only four (19%) became seizure free after a second resective operation. The most common causes of treatment failure were dual pathology, recurrent tumor, limited resection to preserve function, widespread developmental abnormalities, and electrographic sampling error. Successful outcomes resulted from removal of recurrent tumors, completion of a functional hemispherectomy, or repeated invasive monitoring to correct a sampling error. Five (83%) of the six intentionally palliative second operations resulted in more than a 50% decrease in seizure frequency.

Conclusions. If an aggressive preoperative evaluation and surgical resection are performed, reoperation for recurrent seizures has a much lower likelihood of cure than previously reported. Intentionally palliative surgery such as placement of a VNS unit may be considered for patients in whom the initial operation fails to decrease seizure frequency.
Endovascular treatment with Guglielmi detachable coils for basilar artery trunk aneurysms: clinical experience with 41 aneurysms in 39 patients
Authors: Uda Ken , Murayama Yuichi , Gobin Y. Pierre , Duckwiler Gary R. , Viñuela Fernando
Published: May 2009

Object. The authors present a retrospective analysis of their clinical experience in the endovascular treatment of basilar artery (BA) trunk aneurysms with Guglielmi detachable coils (GDCs).

Methods. Between April 1990 and June 1999, 41 BA trunk aneurysms were treated in 39 patients by inserting GDCs. Twenty-seven patients presented with subarachnoid hemorrhage, six had intracranial mass effect, and in six patients the aneurysms were found incidentally. Eighteen lesions were BA trunk aneurysms, 13 were BA—superior cerebellar artery aneurysms, four were BA—anterior inferior cerebellar artery aneurysms, and six were vertebrobasilar junction aneurysms. Thirty-five patients (89.7%) had excellent or good clinical outcomes; procedural morbidity and mortality rates were 2.6% each. Thirty-six aneurysms were selectively occluded while preserving the parent artery, and in five cases the parent artery was occluded along with the aneurysm. Immediate angiographic studies revealed complete or nearly complete occlusion in 35 aneurysms (85.4%). Follow-up angiograms were obtained in 29 patients with 31 aneurysms; the mean follow-up period was 17 months. No recanalization was observed in the eight completely occluded aneurysms. In 19 lesions with small neck remnants, seven (36.8%) had further thrombosis, three (15.8%) remained anatomically unchanged, and nine (47.3%) had recanalization caused by coil compaction. In one patient (2.6%) the aneurysm rebled 8 years after the initial embolization.

Conclusions. In this clinical series the authors show that the GDC placement procedure is valuable in the therapeutic management of BA trunk aneurysms. The endovascular catheterization of these lesions tends to be relatively simple, in contrast with more complex neurosurgical approaches. Endosaccular obliteration of these aneurysms also decreases the possibility of unwanted occlusion of perforating arteries to the brainstem.
Cerebellar liponeurocytoma
Authors: Jackson Thad R. , Regine William F. , Wilson Dianne , Davis Daron G.
Published: May 2009

✓ Cerebellar liponeurocytoma is a rare tumor of the posterior fossa that has many morphological similarities to medulloblastoma and neurocytoma. Recently the World Health Organization working group for classification of central nervous system neoplasms adopted the term “cerebellar liponeurocytoma” to provide a unified nomenclature for a tumor variously labeled in the literature as lipomatous medulloblastoma, lipidized medulloblastoma, medullocytoma, neurolipocytoma, lipomatous glioneurocytoma, and lipidized mature neuroectodermal tumor of the cerebellum. The rarity of this tumor and paucity of pertinent information regarding its biological potential and natural history have resulted in the application of various treatment modalities. It is suggested in the available literature that these lesions have a much more favorable prognosis than typical medulloblastomas, and that adjuvant therapy for liponeurocytoma need not be as extensive as that administered for medulloblastomas.
Compressive optic neuropathy caused by renal osteodystrophy
Authors: Schmidt Richard H. , Rietz Lisa A. , Patel Bhupendra C. K. , Osborne Anne G. , Pratt David , Digre Kathleen B.
Published: May 2009

✓ Compressive optic neuropathy with acute or chronic vision loss has been associated with various skull base tumors, aneurysms, Graves disease, trauma, and, less commonly, fibrous dysplasia and osteopetrosis. The authors present a case of acute visual deterioration in a 25-year-old woman who had massive calvarial hypertrophy with optic canal stenosis secondary to renal osteodystrophy (uremic leontiasis ossea [ULO]: bighead disease). Significant visual field restoration was achieved with high-dose corticosteroids followed by optic nerve decompression. This is the first case report of cranial neuropathy associated with ULO.
Radiosurgery-induced brain tumor
Authors: Kaido Takanobu , Hoshida Tohru , Uranishi Ryunosuke , Akita Nobuhisa , Kotani Akihira , Nishi Noriyuki , Sakaki Toshisuke
Published: May 2009

✓ The authors describe a case of glioblastoma multiforme (GBM) associated with previous gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A 14-year-old boy had undergone radiosurgery for an AVM, which was performed using a 201-source 60Co gamma knife system at another institution. The maximum and margin radiation doses used in the procedure were 40 and 20 Gy, respectively. One year after radiosurgery, the patient noticed onset of mild left hemiparesis due to radiation necrosis.

Six and one-half years after radiosurgery, at the age of 20 years, the patient experienced an attack of generalized tonic—clonic seizure. Magnetic resonance (MR) imaging revealed the existence of a brain tumor in the right parietal lobe. The patient underwent an operation and the histological diagnosis of the lesion was GBM. Ten months following the operation, that is, 99 months postradiosurgery, this patient died.

To the best of the authors' knowledge, this is the first reported case of a neoplasm induced by radiosurgery for an AVM and the second case in which it occurred following radiosurgery for intracranial disease.
Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation
Authors: Dare Amos O. , Landi Michael K. , Lopes Demetrius K. , Grand Walter
Published: May 2009

✓ A modification of the supraorbital keyhole approach, the eyebrow incision—minisupraorbital craniotomy with orbital osteotomy, is described. Unique to this approach is a one-piece supraorbital craniotomy, measuring 2.5 × 3.5 cm, that incorporates the orbital rim and roof and the frontal process of the zygomatic bone through an eyebrow incision. The orbital osteotomy facilitates view of the anterior and middle cranial fossa through the operating microscope, as well as the maneuverability of instruments through a small craniotomy. A pericranial flap is elevated with its base at the orbit and used for closure of the frontal sinus, if necessary. The approach was used successfully in elective surgery of 10 aneurysms of the anterior circulation. The mean aneurysm size was 5.9 mm, with a range of 4 to 10 mm. Advantages of this approach include minimal disruption and exposure of normal brain tissue, reduced frontal lobe retraction, and an excellent postoperative cosmetic result. The approach is performed quickly by virtue of a limited skin incision with minimal temporalis muscle dissection and a small bone flap. The neuroendoscope, although helpful at times, is not essential and no special instruments or intraoperative image guidance is required. Relative contraindications include the presence of a large frontal sinus, severe brain edema, and recent subarachnoid hemorrhage. In addition, this approach has not been used for the treatment of giant intracranial aneurysms.
Cerebral autoregulation following head injury
Authors: Czosnyka Marek , Smielewski Piotr , Piechnik Stefan , Steiner Luzius A. , Pickard John D.
Published: May 2009

Object. The goal of this study was to examine the relationship between cerebral autoregulation, intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP) after head injury by using transcranial Doppler (TCD) ultrasonography.

Methods. Using ICP monitoring and TCD ultrasonography, the authors previously investigated whether the response of flow velocity (FV) in the middle cerebral artery to spontaneous variations in ABP or CPP provides reliable information about cerebral autoregulatory reserve. In the present study, this method was validated in 187 head-injured patients who were sedated and receiving mechanical ventilation. Waveforms of ICP, ABP, and FV were recorded over intervals lasting 20 to 120 minutes. Time-averaged mean FV and CPP were determined. The correlation coefficient index between FV and CPP (the mean index of autoregulation [Mx]) was calculated over 4-minute epochs and averaged for each investigation.

The distribution of averaged mean FV values converged with the shape of the autoregulatory curve, indicating lower (CPP < 55 mm Hg) and upper (CPP > 105 mm Hg) thresholds of autoregulation. The relationship between the Mx and either the CPP or ABP was depicted as a U-shaped curve. Autoregulation was disturbed in the presence of intracranial hypertension (ICP ≥ 25 mm Hg) and when mean ABP was too low (ABP < 75 mm Hg) or too high (ABP > 125 mm Hg). Disturbed autoregulation (p < 0.005) and higher ICP (p < 0.005) occurred more often in patients with unfavorable outcomes than in those with favorable outcomes.

Conclusions. Autoregulation not only is impaired when associated with a high ICP or low ABP, but it can also be disturbed by too high a CPP. The Mx can be used to guide intensive care therapy when CPP-oriented protocols are used.
Chiari I malformation: a rare cause of noncommunicating hydrocephalus treated by third ventriculostomy
Authors: Decq Philippe , Guérinel Caroline Le , Sol Jean-Christophe , Brugières Pierre , Djindjian Michel , Nguyen Jean-Paul
Published: May 2009

Object. Hydrocephalus associated with Chiari I malformation is a rare entity related to an obstruction in the flow of cerebrospinal fluid (CSF) in the foramen of Magendie. Like all forms of noncommunicating hydrocephalus, it can be treated by endoscopic third ventriculostomy (ETV). The object of this study is to report a series of five cases of hydrocephalus associated with Chiari I malformation and to evaluate the use of ETV in the treatment of this anomaly.

Methods. Five patients (four women and one man with a mean age of 29.6 years) underwent ETV for hydrocephalus associated with Chiari I malformation between April 1991 and February 1997. All patients had presented with paroxysmal headaches, which in two cases were associated with visual disorders. All patients had also presented with hydrocephalus (mean transverse diameter of the third ventricle 12.79 mm; mean sagittal diameter of the fourth ventricle 18.27 mm) with a mean herniation of the cerebellar tonsils at 13.75 mm below the basion—opisthion line. Surgery was performed in all patients by using a rigid endoscope. No complications occurred either during or after the procedure, except in one patient who experienced a wound infection that was treated by antibiotic medications.

The mean duration of follow up in this study was 50.39 months. Four patients became completely asymptomatic and remained stable throughout the follow-up period. One patient required an additional third ventriculostomy after 1 year, due to secondary closure, and has remained stable since that time. Postoperative magnetic resonance images demonstrated a significant reduction in the extent of hydrocephalus in all patients (mean transverse diameter of the third ventricle 6.9 mm [p = 0.0035]; mean sagittal diameter of the fourth ventricle 10.32 mm [p = 0.007]), with a mean ascent of the cerebellar tonsils from 13.75 mm below the basion—opisthion line to 7.76 mm below it (p = 0.01). In addition, CSF flow was identified on either side of the orifice of the third ventriculostomy in all patients postoperatively.

Conclusions. Results in this series confirm the efficacy of ETV in the treatment of hydrocephalus associated with Chiari I malformation. It is a reliable, minimally invasive technique that also provides a better understanding of the pathophysiology of this malformation.
Functional and diffusion-weighted magnetic resonance images of space-occupying lesions affecting the motor system: imaging the motor cortex and pyramidal tracts
Authors: Krings Timo , Reinges Marcus H. T. , Thiex Ruth , Gilsbach Joachim M. , Thron Armin
Published: May 2009

Object. During neurosurgical interventions, preservation of subcortical axons is as important as preservation of cortical neurons. The goal of this study was to assess the combined use of functional (f) and diffusion-weighted (DW) magnetic resonance (MR) imaging to assist in the preservation of the structure and function of the motor system.

Methods. The authors evaluated the combination of fMR imaging and DW MR imaging to detect cortical motor areas with their corresponding pyramidal tracts in 12 healthy volunteers and in 10 consecutive patients with various space-occupying lesions affecting the central motor system.

Activation within the primary motor cortex (M1) and white matter bundles originating from this cortical region was demonstrated in 21 of the 22 individuals examined. Additional activation was exhibited along the course of white matter tracts at the level of the pons and, in the contralateral hemisphere, in the M1. Fiber tract displacement was visualized in all patients in white matter that had appeared normal on routine T1- and T2-weighted MR images.

Conclusions. The combination of DW MR and fMR imaging allows visualization of the origin, direction, and functionality of large white matter tracts. This will prove helpful for imaging structural connectivity within the brain during functional imaging. Moreover, local relationships of cerebral tumors that encroach upon M1 and subcortical fiber tracts can be defined. This promises to decrease patient morbidity and to broaden the clinical applications of functional imaging.
Surgical management of brainstem cavernomas
Authors: Samii Madjid , Eghbal Rama , Carvalho Gustavo Adolpho , Matthies Cordula
Published: May 2009

Object. A careful retrospective analysis of 36 cases was performed to evaluate the pre- and postoperative rates of morbidity that occur in patients with brainstem cavernous angiomas.

Methods. The authors evaluated immediate postoperative and follow-up outcomes with regard to clinical findings, the incidence of preoperative hemorrhage(s), location and size of the lesions, and the timing of the surgical procedure after the last hemorrhagic event. Specifically, the following parameters were analyzed: 1) number of hemorrhages; 2) the precise brainstem location (pontomesencephalic, pons, and medulla oblongata); 3) pre- and postoperative cranial nerve status; 4) pre- and postoperative motor and sensory deficits; 5) size (volume) of the lesions; and 6) pre- and postoperative Karnofsky Performance Scale (KPS) scores. Multiple hemorrhages were observed in 16 patients, particularly in those with pontomesencephalic cavernous angiomas (75%). The mean preoperative KPS score was 70.3 ± 16.3 (± standard deviation). Twenty-six patients (72.2%) presented with cranial nerve impairment, 13 (36.1%) with motor deficits, and 17 (47.2%) with sensory disturbance. Volume of the lesions ranged from 0.18 to 18.18 cm3 (mean 4.75 cm3). Postoperative complications included new cranial nerve deficits in 17 patients, motor deficits in three, and new sensory disturbances in 12 patients. In a mean follow-up period of 21.5 months, KPS scores were 80 to 100 in 22 patients. Timing of surgery (posthemorrhage) and multiple hemorrhages did not influence the long-term results. Higher preoperative KPS scores and smaller-volume lesions, however, were factors associated with a better final outcome (p < 0.05). Major morbidity was related mainly to preoperative status and less to surgical treatment. The incidence of new postoperative cranial nerve deficits was clearly lower than that demonstrated preoperatively because of the brainstem hemorrhages.

Conclusions. Based on these findings, resection of brainstem cavernomas is the treatment of choice in the majority of these cases because of the high incidence of morbidity related to one or often several brainstem hemorrhages.
Duplicated abducent nerve and its course: microanatomical study and surgery-related considerations
Authors: Iaconetta Giorgio , Tessitore Enrico , Samii Madjid
Published: May 2009

Object. The anatomy of the abducent nerve is well known; its duplication (ranging from 5 to 28.6%), however, has rarely been reported in the literature. The authors performed a microanatomical study in 100 cadaveric specimens (50 heads) to evaluate the prevalence of this phenomenon and to provide a clear anatomical description of the course and relationships of the nerve. The surgery-related implications of this rare anatomical variant will be highlighted.

Methods. The 50 human cadaveric heads (100 specimens) were embalmed in a 10% formalin solution for 3 weeks. Fifteen of them were injected with colored neoprene latex. A duplicated abducent nerve was found in eight specimens (8%). In two (25%) of these eight specimens the nerve originated at the pontomedullary sulcus as two independent trunks: in one case the superior trunk was thicker than the inferior and in the other it was thinner. In the other six cases (75%) the nerve originated as a single trunk, splitting in two trunks into the cisternal segment: in two of them the trunks ran below the Gruber ligament, whereas in four specimens one trunk ran below and one above it. In all the specimens, the duplicated nerves fused again into the cavernous sinus, just after the posterior genu of the internal carotid artery.

Conclusions. Although the presence of a duplicated abducent nerve is a rare finding, preoperative magnetic resonance imaging should be performed to rule out this possibility, thus tailoring the operation to avoid postoperative deficits.
Mild head injury increasing the brain's vulnerability to a second concussive impact
Authors: Laurer Helmut L. , Bareyre Florence M. , Lee Virginia M. Y. C. , Trojanowski John Q. , Longhi Luca , Hoover Rachel , Saatman Kathryn E. , Raghupathi Ramesh , Hoshino Shigeru , Grady M. Sean , McIntosh Tracy K.
Published: May 2009

Object. Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model to investigate the behavioral and pathological changes associated with RHI.

Methods. Adult male C57BL/6 mice were subjected to a single injury (43 mice), repetitive injury (two injuries 24 hours apart; 49 mice), or no impact (36 mice). Cognitive function was assessed using the Morris water maze test, and neurological motor function was evaluated using a battery of neuroscore, rotarod, and rotating pole tests. The animals were also evaluated for cardiovascular changes, blood—brain barrier (BBB) breakdown, traumatic axonal injury, and neurodegenerative and histopathological changes between 1 day and 56 days after brain trauma. No cognitive dysfunction was detected in any group. The single-impact group showed mild impairment according to the neuroscore test at only 3 days postinjury, whereas RHI caused pronounced deficits at 3 days and 7 days following the second injury. Moreover, RHI led to functional impairment during the rotarod and rotating pole tests that was not observed in any animal after a single impact. Small areas of cortical BBB breakdown and axonal injury, observed after a single brain injury, were profoundly exacerbated after RHI. Immunohistochemical staining for microtubule-associated protein—2 revealed marked regional loss of immunoreactivity only in animals subjected to RHI. No deposits of β-amyloid or tau were observed in any brain-injured animal.

Conclusions. On the basis of their results, the authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.
Intractable epilepsy following radiosurgery for arteriovenous malformation
Authors: Husain Aatif M. , Mendez Melissa , Friedman Allan H.
Published: May 2009

✓ Radiosurgery is often used to treat arteriovenous malformations (AVMs) located in deep brain locations. Most of these procedures are successful not only in obliterating the AVM but also in decreasing the frequency and severity of associated seizures. Although radiosurgery is occasionally associated with the development of easy-to-control seizures immediately postoperatively, there have been no reports of intractable epilepsy developing after radiosurgery. In this report, however, a case is presented in which a patient underwent gamma knife surgery (GKS) for an AVM, after which intractable epilepsy and mesial temporal sclerosis (MTS) gradually developed.

A 37-year-old right-handed woman underwent GKS for a right mesial parietotemporooccipital AVM. One year later, the AVM had reduced in size, but the patient began to experience complex partial seizures (CPSs). These CPSs initially occurred at a frequency of one per month, but 6 months later they were occurring every other week. She also started having secondarily generalized tonic—clonic seizures (GTCSs) once per month. Over the next year the frequency of her seizures gradually increased to several CPSs per day and two to three GTCSs per week, despite treatment with various combinations of antiepileptic drugs. By this time her AVM had decreased to one half of its original size. Video-electroencephalography monitoring demonstrated that both the CPSs and GTCSs were arising from the right posterior quadrant. Magnetic resonance imaging revealed not only the presence of the right-sided AVM, but also right-sided MTS. The patient underwent surgical resection of the AVM and right temporal lobectomy. She has been free from seizure for longer than 1 year.

Radiosurgery may be associated with intractable epilepsy and MTS.
Extraosseous endolymphatic sac low-grade adenocarcinoma mimicking posterior fossa meningioma
Authors: Al-Anazi Abdul Rahman , Holliday William , Sheikh Bassem , Gentili Fred
Published: May 2009

✓ Low-grade adenocarcinoma arising from the endolymphatic sac is an uncommon tumor that is characterized clinically by hearing loss and radiologically by temporal bone destruction. The authors report a case of low-grade adenocarcinoma of endolymphatic sac origin that mimicked a posterior fossa meningioma in both clinical and neuroimaging examinations. In this case, the most unusual and interesting feature was the lack of auditory symptoms and temporal bone destruction. The lesion occurred in a 21-year-old man who presented with headaches that had been increasing in frequency for 6 months and was associated with blurring of vision, diplopia, occasional nausea and vomiting, and gait disturbance. On examination, this patient exhibited bilateral papilledema, left sixth cranial nerve palsy, and gait ataxia. Neuroimaging studies revealed a large right posterior fossa tumor. At surgery, a hemorrhagic papillary adenocarcinoma of endolymphatic sac origin was found.
Syringomyelia in spontaneous intracranial hypotension
Authors: Sharma Pranshu , Sharma Aseem , Chacko Ari G.
Published: May 2009

✓ The authors describe the presence of a syrinx in a patient with spontaneous intracranial hypotension. The likely pathophysiological basis of this hitherto unreported association is also presented. It is believed that chronic obstruction at the foramen magnum may be the most important factor for the development of syringes.
Changes in functional outcome and quality of life in patients and caregivers after aneurysmal subarachnoid hemorrhage
Authors: Hop Jeannette W. , Rinkel Gabriel J. E. , Algra Ale , van Gijn Jan
Published: May 2009

Object. Although the case-fatality rate after subarachnoid hemorrhage (SAH) does not change considerably after the first 4 weeks, functional outcome and the quality of life (QOL) may. To assess the extent of changes in functional outcome and QOL after SAH, the authors conducted a follow-up study at 18 months in patients and caregivers who had participated in a previous study of QOL 4 months after SAH.

Methods. In a consecutive series of 98 patients admitted with SAH, 68 had survived until 4 months postbleed, at which time an initial outcome assessment had been performed in 64 of them. This series of 64 patients was contacted again at a median of 18 months after SAH. In all patients, functional outcome was assessed by means of the modified Rankin Scale (mRS). In 48 patients and 35 caregivers QOL was assessed using the SF-36, the Sickness Impact Profile (SIP), and a visual analog scale. The results were compared with the scores that had been obtained at 4 months after SAH.

Thirty-two patients (50%) had improved at least one point on the mRS, in 23 patients functional outcome had remained unchanged, six patients had deteriorated one point on the mRS, and three had died. No major changes in the QOL of patients and caregivers could be found on the SIP, but on the SF-36 an improved QOL was detected in patients with better Rankin grades. On both instruments, the QOL at 18 months was still reduced compared with the reference population in all patients.

Conclusions. Functional outcome improves significantly between 4 months and 18 months post-SAH; studies on functional outcome after SAH can be compared only if outcome is assessed at the same time interval. The improved functional outcome seems to be accompanied by an improved QOL.