bluuebunny/crossref_metadata_2025 huggingface dataset:
Is the placement of shunts in patients with idiopathic normal pressure hydrocephalus worth the risk? Results of a study based on continuous monitoring of intracranial pressure
Authors: Poca Maria A. , Mataró Maria , Matarín Maria Del Mar , Arikan Fuat , Junqué Carmen , Sahuquillo Juan
Published: May 2009

Object. Data from many studies have demonstrated that shunt insertion in patients with idiopathic normal-pressure hydrocephalus (NPH) is associated with high morbidity and a lack of significant improvement; however, the use of strict diagnostic and treatment protocols can improve the results of surgery in these patients. The primary aim in this prospective study was to analyze the results of shunt placement in 43 patients with idiopathic NPH. A secondary aim was to determine the relationship between several clinical and neuroimaging factors, and patient outcome after surgery.

Methods. Thirty men and 13 women with a mean age of 71.1 ± 6.9 years participated in this study. All patients underwent clinical, neuropsychological, and radiological assessment before and 6 months after surgery. In all patients continuous monitoring of intracranial pressure was performed using a fiberoptic extradural sensor. In 31 patients cerebrospinal fluid dynamics were also determined. Eighty-six percent of patients showed clinical improvement after shunt insertion, 11.6% showed no change, and 2.3% exhibited some worsening. Gait improved in 81.4% of the patients, sphincter control in 69.8%, and cognitive dysfunction in 39.5%. There was no treatment-related death. Early or late postsurgical complications occurred in six patients (14%), although all of these complications were minor or were satisfactorily resolved. The complete clinical triad, cortical sulci size, and periventricular lucencies were related to outcome, whereas patient age, symptom duration, ventricular dilation, and the degree of presurgical dementia were unrelated to outcome.

Conclusions. Given the correct diagnosis, shunt insertion can produce marked improvement in patients with idiopathic NPH syndrome, causing few deaths and few clinically relevant complications.
Magnetocephalography: a noninvasive alternative to the Wada procedure
Authors: Papanicolaou Andrew C. , Simos Panagiotis G. , Castillo Eduardo M. , Breier Joshua I. , Sarkari Shirin , Pataraia Ekaterina , Billingsley Rebecca L. , Buchanan Scott , Wheless James , Maggio Vijayalakshmi , Maggio William W.
Published: May 2009

Object. In this study the authors evaluated the sensitivity and selectivity of a noninvasive language mapping procedure based on magnetoencephalography (MEG), for determining hemispheric dominance for language functions.

Methods. Magnetic activation profiles of the brain were obtained from 100 surgical candidates (age range 8–56 years) with medically intractable seizure disorder by using a whole-head MEG system within the context of a word recognition task. The degree of language-specific activity was indexed according to the number of consecutive sources (modeled as single, moving current dipoles) in perisylvian brain areas. Only activity sources that were observed with a high degree of spatial and temporal overlap in two split-half data sets were used to compute the MEG laterality index. Independently, all patients underwent Wada testing for the determination of hemispheric dominance for language.

Independent clinical judgments based on MEG and Wada data showed a high degree of concordance (87%). Magnetoencephalography laterality judgments had an overall sensitivity of 98%, but a lower selectivity of 83%, which was due to the fact that MEG detected more activity in the nondominant hemisphere than was predicted based on the Wada test. A number of objective criteria were derived based on this large patient series to ensure data quality and bolster the clinical usefulness of MEG for language mapping.

Conclusions. Although the availability of MEG is still limited across epilepsy surgery centers, this study method may be substituted for the Wada procedure in assessing hemispheric dominance for language in select cases.
Role of estrogen receptor—related antigen in initiating the growth of human glioma cells
Authors: Khalid M. Humayun , Shibata Shobu , Furukawa Koichi , Nadel Amal , Ammerman Matthew D. , Caputy Anthony J.
Published: May 2009

Object. The expression of estrogen receptor—related antigen (ER-D5) has been demonstrated in many tumors, including those of the brain, but the actual role of ER-D5 in cell growth is unknown. The authors evaluated the role of ER-D5 in the growth of gliomas in vitro.

Methods. Human glioblastoma multiforme (GBM) cell lines A172, T98G, U87MG, and U118MG; rat C6 glioma and 9L gliosarcoma; AS human astrocytoma; GBM in primary culture and tumor tissues; and normal brain tissues were examined for ER-D5 by using immunohistochemical, Western immunoblot, flow cytometry, and enzyme-linked immunosorbent assays. The ER-D5 was detected in all tumor cell types of human origin, but not in rat cell lines and normal brain; the expression of ER-D5 was not related to cell cycle phase. Kinetic analysis of ER-D5 expression in cultured cell lines revealed that an enhanced and sharp accumulation of ER-D5 occurred during the first 24 hours of culture, followed by a sharp fall in the next 24 hours. Gradual decreases of ER-D5 during the subsequent days were demonstrated in all human cell lines, and in primary cultures of GBM. This accumulation pattern of ER-D5 was confirmed on Western blot analysis. The ER-D5 was also detected in cells cultured in serum-free medium. Culture cells were treated with D5 antibody against ER-D5 for 48 hours and the effects were evaluated using a monotetrazolium colorimetric assay; the result revealed that growth of cultured cells was inhibited in a dose-dependent manner, and that addition of a single median inhibitory concentration dose resulted in complete growth inhibition and arrest of cell growth at the G0/G1 phase at 96 hours posttreatment.

Conclusions. These findings indicated that synthesis and accumulation of ER-D5 is an essential event in the very early phase of in vitro growth of human gliomas.
Bilateral diploic arteriovenous fistula causing scalp hematoma
Authors: Benndorf Goetz , Lehmann Thomas Nicolas
Published: May 2009

✓ The authors report an unusual case of an extensive spontaneous subgaleal hematoma caused by a bilateral arteriovenous shunting lesion involving the diploic veins. The enlarged diploic canals and the existence of bilateral diploic arteriovenous shunts with no history of fracture or trauma indicate that these fistulas developed spontaneously over a long period of time. Angiographic findings in these unusual arteriovenous shunting lesions and their endovascular management are briefly illustrated. A case of a bilateral diploic fistula has not been reported before and it may contribute to the understanding of the diversity of dural arteriovenous shunting lesions.
Sciatic nerve sarcoidosis: utility of magnetic resonance peripheral nerve imaging and treatment with radiation therapy
Authors: Dailey Andrew T. , Rondina Matthew T. , Townsend Jeannette J. , Shrieve Dennis C. , Baringer J. Richard , Moore Kevin R.
Published: May 2009

✓ Sarcoidosis may involve both the central and peripheral nervous system, although peripheral nerve manifestations are usually seen late in the disease. In this report, the authors describe a case of sarcoidosis in a 22-year-old woman who presented with a foot drop. Although results of conventional lumbar magnetic resonance (MR) imaging were normal, MR peripheral nerve imaging of the thigh showed a mass in the sciatic nerve indicating tumor. An intraoperative biopsy sample revealed noncaseating granulomas consistent with sarcoid. The patient was treated with steroid drugs to control the manifestations of her disease but exhibited early signs of femoral bone necrosis, which required discontinuation of the steroids. She was then treated with local radiation therapy. At her 2-year follow-up visit the patient demonstrated relief of her symptoms and improvement on MR peripheral nerve imaging. This case demonstrates that sarcoidosis may present with peripheral nerve manifestations. The appearance of a diffusely swollen nerve on MR imaging should prompt clinicians to include sarcoidosis in the differential diagnosis and plan surgery accordingly. Patients who are not responsive to or who are unable to tolerate medical therapy may be treated with radiation therapy.
Correlation between decreased ventricular size and positive clinical outcome following shunt placement in patients with normal-pressure hydrocephalus
Authors: Meier Ullrich , Mutze Sven
Published: May 2009

Object. It is well known that in patients with communicating hydrocephalus or normal-pressure hydrocephalus (NPH), ventricular size decreases following implantation of shunts with differential pressure valves. The aim of this study was to determine whether ventricular size correlates with a positive clinical outcome following shunt placement.

Methods. Hydrostatic valves (dual-switch valves) were implanted in 80 patients with NPH at Unfallkrankenhaus, Berlin, between September 1997 and January 2002. One year postoperatively, these patients underwent computerized tomography scanning, and their ventricular size was ascertained using the Evans Index.

Among 80% of the patients who showed no postoperative change in ventricular volume, 59% nonetheless had good to excellent clinical improvements, 17% satisfactory improvement, and 24% no improvement. Furthermore, a moderate reduction in ventricular size was observed in 14% of patients in this cohort. Among these, 36% experienced good to excellent clinical improvements, 28% satisfactory improvement, and 36% unsatisfactory improvement. A marked reduction in ventricular size was observed in 6% of the patients. Of this latter group, 60% demonstrated good to excellent outcomes, whereas 40% had unsatisfactory outcomes.

Conclusions. Favorable outcomes following the implantation of a hydrostatic shunt in patients with NPH did not correlate with decreased ventricular volume 1 year after surgery. In fact, better clinical outcomes were observed in patients with little or no alteration in ventricular size, compared with those in patients with a marked decrease in ventricular size. A postoperative change in ventricular volume should be assessed differently in patients with NPH compared with those suffering from hypertensive hydrocephalus.
Intraaneurysmal flow visualization by using phase-contrast magnetic resonance imaging: feasibility study based on a geometrically realistic in vitro aneurysm model
Authors: Tateshima Satoshi , Grinstead John , Sinha Shantanu , Nien Yih-Lin , Murayama Yuichi , Villablanca J. Pablo , Tanishita Kazuo , Viñuela Fernando
Published: May 2009

Object. The aim of this study was to evaluate the feasibility of complex intraaneurysmal flow visualization with the currently available phase-contrast magnetic resonance (MR) imaging modality.

Methods. A geometrically realistic in vitro aneurysm model, in which detailed flow velocity analysis had already been conducted using laser Doppler velocimetry was used for this in vitro hemodynamic simulation, so that the results of phase-contrast velocity measurements could be compared with the previous reliable results. On a 1.5-tesla unit, three orthogonal components of velocity were obtained using a standard two-dimensional fast low—angle shot flow quantification sequence. Three-dimensional (3D) intraaneurysmal flow structures recorded during one cardiac cycle were depicted in one midsagittal and three axial cross-sectional planes with the aid of gray scale phase-contrast velocity maps. Isovelocity contour maps and secondary flow vectors were also created based on the phase-contrast velocity maps by using MATLAB software. The isovelocity contours in those three axial sections could demonstrate the shapes of inward and outward flow areas and their alternation over one cardiac cycle. The secondary flow vectors demonstrated twin vortices within the outward flow area adjacent to the boundary layer of inward and outward flow in all axial planes.

Conclusions. The phase-contrast MR imaging method was able to depict the complex 3D intraaneurysmal flow structures in the in vitro aneurysm model. Detailed 3D intraaneurysmal flow information will be obtainable in vivo after improvements are made in spatial resolution, which is expected in the near future. The capability to visualize intraaneurysmal flow structures directly with the use of noninvasive MR imaging technology will have a positive impact on future clinical practice.
Cooperative function of Chk1 and p38 pathways in activating G2 arrest following exposure to temozolomide
Authors: Hirose Yuichi , Katayama Makoto , Berger Mitchel S. , Pieper Russell O.
Published: May 2009

Object. The Chk1 and p38 mitogen-activated protein kinase (MAPK) pathways play key roles in the G2 arrest caused by exposing glioma cells to temozolomide (TMZ). Although inhibition of either pathway sensitizes glioma cells to TMZ-induced cytotoxicity, the relative contributions of these pathways to TMZ-induced G2 arrest and to TMZ resistance conferred by G2 arrest have not been defined.

Methods. The authors pharmacologically inhibited the Chk1 and/or p38 pathways in U87MG human glioma cells prior to and/or after exposure to TMZ; thereafter, effects on the TMZ-induced G2 arrest pathway and toxicity were monitored. The p38 inhibitor SB203580 or the Chk1 inhibitor UCN-01 or their combination blocked TMZ-mediated inactivation of cdc25C and cdc2, suggesting that p38 and Chk1 pathways work cooperatively and are both necessary to inactivate cdc25C and cdc2. Consistent with this idea, the inhibition of both Chk1 and p38 pathways did not lead to greater bypass of TMZ-induced G2 arrest or greater cytotoxicity than inhibition of either pathway alone. Inhibition of p38 did not alter TMZ-induced Chk1 activation/phosphorylation and vice versa, suggesting that p38 and Chk1 do not cooperatively bring about G2 arrest by reciprocal activation/phosphorylation. The two pathways, however, are not functionally identical; the Chk1 pathway was required for both the initiation and maintenance of TMZ-induced G2 arrest, whereas the p38 pathway played a role only in the initiation.

Conclusions. The Chk1 and p38 pathways cooperate to bring about TMZ-induced G2 arrest, and the inhibition of either pathway alone is sufficient to sensitize U87MG glioma cells to TMZ-induced cytotoxicity.
Deep brain stimulation of the nucleus ventralis intermedius for Holmes (rubral) tremor and associated dystonia caused by upper brainstem lesions
Authors: Nikkhah Guido , Prokop Thomas , Hellwig Bernhard , Lücking Carl Hermann , Ostertag Christoph B.
Published: May 2009

✓ Holmes tremor is caused by structural lesions in the perirubral area of the midbrain. Patients often present with associated symptoms such as dystonia and paresis, which are usually refractory to medical therapy. Here, the authors describe two patients in whom both tremor and associated dystonia improved markedly following unilateral stimulation of the thalamic nucleus ventralis intermedius.
Extradural neurenteric cyst of the cerebellopontine angle
Authors: Inoue Tomohiro , Kawahara Nobutaka , Shibahara Junji , Masumoto Tomohiko , Usami Kenichi , Kirino Takaaki
Published: May 2009

✓ Neurenteric cyst is a developmental malformation found mainly in the spinal canal. The authors report on a 47-year-old man with a neurenteric cyst of the cerebellopontine angle (CPA) who presented with progressive hearing disturbance and facial palsy. The tumor was located extradurally with marked destruction of the petrous bone around the internal auditory canal and demonstrated irregular and heterogeneous high-intensity signals on T1- and T2-weighted on MR images, which is atypical for neurenteric cysts. The pathological findings in samples obtained after resection disclosed a single epithelial layer (a feature of neurenteric cyst), which was accompanied by marked xanthogranulomatous changes. Although several neurenteric cysts have been reported in the CPA, extradural lesions with unusual imaging features and marked bone destruction have not been reported previously. This benign developmental lesion should be considered, although it is extremely rare, in patients harboring an extradural temporal bone tumor around the CPA.
Treatment of spontaneous intracranial hypotension with percutaneous placement of a fibrin sealant
Authors: Schievink Wouter I. , Maya M. Marcel , Moser Franklin M.
Published: May 2009

✓ Spontaneous intracranial hypotension due to a cerebrospinal fluid (CSF) leak in the spine is an important cause of new, daily persistent headaches. Most patients respond well to conservative treatments including epidural blood patching. Limited options for effective treatment are available for patients in whom these treatments fail. The authors treated four patients (mean age 38 years; range 26–43 years) with percutaneous placement of a fibrin sealant. All these patients presented with intractable positional headaches. The CSF leak was located in the lower cervical spine in three patients and in the lower thoracic spine in one patient. Four to 20 milliliters of fibrin sealant was injected at the site of the CSF leak. Two of the four patients became asymptomatic within days of the procedure and thus avoided surgery. There were no complications of this procedure. Percutaneous placement of a fibrin sealant is a safe, minimally invasive treatment for spontaneous spinal CSF leaks and should be considered in patients in whom conservative treatment has failed.
Gradual recovery from dyslexia and related serial magnetoencephalographic changes in the lexicosemantic centers after resection of a mesial temporal astrocytoma
Authors: Kamada Kyousuke , Sawamura Yutaka , Takeuchi Fumiya , Houkin Kiyohiro , Kawaguchi Hideaki , Iwasaki Yoshinobu , Kuriki Shinya
Published: May 2009

✓ Letter-perception centers are not held in as high regard as motor- and language-related cortices during planning of neurosurgical procedures, and there have been no reports suggesting cortical reorganization of reading ability. The authors describe a patient with a left mesial temporal glioma in whom two letter-perception centers (the anterior portion of the left superior temporal gyrus and the left fusiform gyrus) were successfully localized before surgery by performing magnetoencephalography (MEG) during reading tasks. Control MEG examinations of 15 healthy volunteers were also performed to assist in a careful interpretation of patient results. Although a radical resection of the mesial temporal glioma, which involved the left fusiform gyrus, caused severe dyslexia, the patient's impaired reading skills improved gradually during a 1-year postoperative period. In the meantime, the spared left superior temporal gyrus displayed an overshot recovery of MEG responses. During the postoperative period there was no obvious recovery in MEG signals and no compensatory activity in the contralateral fusiform gyrus. This case demonstrates that lexicosemantic centers involved in the reading process can be noninvasively localized using MEG and that the results obtained are highly reliable for surgical planning. The results of the repeated MEG reflected sequentially the patient's recovery from dyslexia. This is the first report in which MEG studies have been shown to predict preoperatively the risk of dyslexia and demonstrate its serial physiological recovery.
Necrobiotic xanthogranuloma with cutaneous and cerebral manifestations
Authors: Shah Kiritkumar Chhanalal , Poonnoose Santosh Isaac , George Renu , Jacob Mary , Rajshekhar Vedantam
Published: May 2009

✓ Necrobiotic xanthogranuloma (NXG) is a rare inflammatory histiocytic disease of the skin. Xanthogranuloma of the central nervous system is rare and few cases have been reported. To the authors' knowledge, there has been no previously reported case of NXG in which an intracranial lesion was found.

This 52-year-old man, in whom NXG with all its cutaneous manifestations had been diagnosed, presented with three episodes of generalized tonic—clonic seizures. A contrast-enhanced computerized tomography scan of his brain revealed a bifrontal, dura-based mass lesion. The lesion was excised and reported to be an NXG that was similar, but not identical to the skin lesions. The patient was placed on a regimen of antiepileptic drug and chlorambucil after surgery.
Erdheim—Chester disease mimicking a primary brain tumor
Authors: Rushing Elisabeth J. , Bouffard John Paul , Neal Chris J. , Koeller Kelly , Martin Jonathan , Ozdemirli Metin , Mena Hernando , Ecklund James M.
Published: May 2009

✓ Erdheim—Chester disease (ECD) is a rare systemic histiocytic disease. The authors present a case report detailing the presentation and treatment of a 26-year-old man diagnosed with seizures and a well-circumscribed temporoparietal mass that had been demonstrated on imaging studies. Both preoperative and intraoperative diagnoses were consistent with a low-grade astrocytic neoplasm. Subsequent pathological examination indicated a histiocytic proliferation positive for CD68 and factor VIII, and negative for CD1a and S100, with Touton giant cells characteristic of ECD. This case represents the first isolated occurrence of intracranial ECD and its potential to mimic glial neoplasms.
Minimally invasive implantation of epidural spinal cord neurostimulator electrodes by using a tubular retractor system
Authors: Johnson Matthew R. , Tomes Daniel J. , Treves John S. , Leibrock Lyal G.
Published: May 2009

✓ The authors describe a novel technique for the implantation of multipolar epidural spinal cord neurostimulator electrodes with the aid of a tubular retractor system. Spinal cord neurostimulation is used as a neuroaugmentive tool for treating chronic intractable pain syndromes. Minimally invasive placement of the multipolar neurostimulator electrodes may allow for shorter hospital stays and less postoperative pain associated with the incision.
Blood transfusion and increased risk for vasospasm and poor outcome after subarachnoid hemorrhage
Authors: Smith Michelle J. , Le Roux Peter D. , Elliott J. Paul , Winn H. Richard
Published: May 2009

Object. Nitric oxide (NO) metabolism may influence vasospasm after subarachnoid hemorrhage (SAH). It has been demonstrated in recent studies that erythrocytes carry NO for release in vessels, whereas transfused erythrocytes may lack stored NO. Several converging lines of evidence also indicate that blood transfusion may exacerbate poor outcomes in some critically ill patients. In this study the authors hypothesized that patients with SAH who received red blood cell (RBC) transfusions were at greater risk for vasospasm and poor outcome.

Methods. The authors retrospectively reviewed a prospective observational database, including hospital records, computerized tomography (CT) scans, and pre- and postoperative four-vessel angiograms, in which the management methods used in 441 patients undergoing surgery for ruptured cerebral aneurysms were described. Two hundred seventy patients (61.2%) received an RBC transfusion during their hospital stay. After adjustment for Hunt and Hess grade, SAH grade on CT scans, delay between rupture and surgery, smoking status, and intraoperative aneurysm rupture, a worse outcome was more likely in patients who received intraoperative blood (odds ratio [OR] 2.44, confidence interval [CI] 1.32–4.52; 120 patients). Intraoperative RBC transfusion did not influence subsequent angiographically confirmed vasospasm (OR 0.92, CI 0.6–1.4). Worse outcome was observed in patients who received blood postoperatively (OR 1.81, CI 1.21–2.7), but not after adjustments were made for confounding variables (OR 1.48, CI 0.83–2.63). Angiographic vasospasm was observed in 217 patients and, after adjusting for confounding variables, was more frequent among patients who received postoperative RBC transfusion (OR 1.68, CI 1.02–2.75). Among patients in whom angiographically confirmed vasospasm developed there was a tendency to have received more blood than in those with no vasospasm; however, a clear dose-dependent response was not observed.

Conclusions. Development of angiographically confirmed vasospasm after SAH is associated with postoperative RBC transfusion and worse outcome is associated with intraoperative RBC transfusion. Before blood is transfused, patients with SAH should be carefully assessed to determine if they are symptomatic because of anemia.
Management and outcomes in 353 surgically treated sciatic nerve lesions
Authors: Kim Daniel H. , Murovic Judith A. , Tiel Robert , Kline David G.
Published: May 2009

Object.This is a retrospective analysis of 353 surgically treated sciatic nerve lesions in which injury mechanisms, location, time to surgical repair, surgical techniques, and functional outcomes are reported. Results are presented to provide guidelines for management of these injuries.

Methods.One hundred seventy-five patients with buttock-level and 178 with thigh-level sciatic nerve injury were surgically treated at the Louisiana State University Health Sciences Center between 1968 and 1999. Buttock-level injury mechanisms included injection in 64 patients, hip fracture/dislocation in 26, contusion in 22, compression in 19, gunshot wound (GSW) in 17, hip arthroplasty in 15, and laceration in 12; at the thigh level, GSW was the cause in 62 patients, femoral fracture in 34, laceration in 32, contusion in 28, compression in 12, and iatrogenic injury in 10. Patients with sciatic nerve divisions in which positive intraoperative nerve action potentials (NAPs) were found underwent neurolysis and attained at least Grade 3 functional outcomes in 108 (87%) of 124 and in 91 (96%) of 95 buttock- and thigh-level tibial divisions, respectively, compared with 84 (71%) of 119 and 75 (79%) of 95, respectively, in the peroneal divisions. For suture repair, recovery to at least Grade 3 occurred in eight (73%) of 11 buttock-level and in 27 (93%) of 29 thigh-level tibial division injuries, and in three (30%) of 10 buttock-level and 20 (69%) of 29 thigh-level peroneal division lesions. For graft repair, good recovery occurred in 21 (62%) of 34 and in 43 (80%) of 54 buttock- and thigh-level tibial divisions, respectively, even in proximal repairs requiring long grafts, and in only nine (24%) of 37 and 22 (45%) of 49 buttock- and thigh-level peroneal division lesions, respectively.

Conclusions.Surgical exploration and neurolysis after positive NAP readings, or repair with sutures or grafts after negative NAP results are worthwhile in selected cases.
Analysis of nidus obliteration rates after gamma knife surgery for arteriovenous malformations based on long-term follow-up data: the University of Tokyo experience
Authors: Shin Masahiro , Maruyama Keisuke , Kurita Hiroki , Kawamoto Shunsuke , Tago Masao , Terahara Atsuro , Morita Akio , Ueki Keisuke , Takakura Kintomo , Kirino Takaaki
Published: May 2009

Object. A large number of clinical studies have been made on treatment outcomes of radiosurgery for arteriovenous malformations (AVMs), but the reported obliteration rates following this treatment vary significantly, perhaps reflecting the different methods and timings of the imaging studies used.

Methods. The authors retrospectively analyzed their experience with gamma knife surgery in 400 patients with AVMs (follow-up period 1–135 months, median 65 months), with special reference to the imaging modality used in each case. The calculated obliteration rates varied from 68.2 to 92%, depending on imaging modality and timing of evaluation. When only unquestionable imaging data such as demonstrations of a residual nidus on computerized tomography (CT) or magnetic resonance (MR) images or findings on angiograms were used in the calculation, the obliteration rates were 72% at 3 years and 87.3% at 5 years. Factors leading to a better obliteration rate were previous hemorrhage (p = 0.0084), smaller nidus (p = 0.0023), and higher radiation dose to the lesion's margin (p = 0.0495), as determined in a multivariate analysis. Factors leading to an earlier obliteration of the nidus were male sex (p = 0.0001), previous hemorrhage (p = 0.0039), smaller nidus diameter (p = 0.0006), and dose planning using angiography alone (p = 0.0201).

Conclusions. After the introduction of CT and MR images into dose planning, the conformity and selectivity of dosimetry improved remarkably, although the latency intervals until obliteration were prolonged. Imaging outcomes for AVMs should be evaluated using data provided by longer follow-up periods. The timing of additional treatments for residual AVMs should be decided cautiously, considering the size of the AVM, the patient age and sex, and the history of hemorrhage before radiosurgery.
Intracranial vertebral artery dissection with subarachnoid hemorrhage: clinical characteristics and outcomes in conservatively treated patients
Authors: Yamada Masaru , Kitahara Takao , Kurata Akira , Fujii Kiyotaka , Miyasaka Yoshio
Published: May 2009

Object. Intracranial vertebral artery (VA) dissection with subarachnoid hemorrhage is notorious for frequent rebleeding and a poor prognosis. Nevertheless, some patients survive with a good final outcome. The factors associated with the prognosis of this disease are not fully understood and appropriate treatment strategies continue to be debated. The authors retrospectively evaluated the clinical features of conservatively treated patients to elucidate the relationship between the clinical and angiographic characteristics of the disease and final outcomes.

Methods. This study includes 24 patients who were treated by conservative methods between 1990 and 2000. Conservative treatment was chosen because of delayed diagnosis, poor clinical condition, or anatomical features such as bilateral lesions and contralateral VA hypoplasia.

Of nine patients with an admission Hunt and Kosnik Grade I or II, eight had good outcomes (mean follow-up period 8 years and 4 months). All 15 patients with Grade III, IV, or V died and in 10 of these the cause of death was rebleeding. Among the 24 patients, 14 suffered a total of 35 rebleeding episodes; in 10 (71.4%) of these 14 patients rebleeding occurred within 6 hours and in 13 (93%) within 24 hours. Compared with the survivors, there was a female preponderance (0.022) among patients who died. These patients also had significantly shorter intervals between onset and hospital admission (p = 0.0067), a higher admission Hunt and Kosnik grade (p = 0.0001), a higher incidence of prehospitalization (p = 0.0296) and postadmission (p = 0.0029) rebleeding episodes, and a higher incidence of angiographically confirmed pearl-and-string structure of the lesion (p = 0.0049).

Conclusions. In our series of preselected patients, poor admission neurological grade, rebleeding episode(s), and lesions with a pearl-and-string structure were predictive of poor outcomes. Our findings indicate that patients with these characteristics may be candidates for aggressive attempts to prevent rebleeding during the acute stage. Patients without these characteristics may be good candidates for conservative treatment, especially those who survive the acute phase without rebleeding.
Tremor cells in the human thalamus: differences among neurological disorders
Authors: Brodkey Jason A. , Tasker Ronald R. , Hamani Clement , McAndrews Mary Pat , Dostrovsky Jonathan O. , Lozano Andres M.
Published: May 2009

Object. Thalamic neurons firing at frequencies synchronous with tremor are thought to play a critical role in the generation and maintenance of tremor. The authors studied the incidence and locations of neurons with tremor-related activity (TRA) in the thalamus of patients with varied pathological conditions—including Parkinson disease (PD), essential tremor (ET), multiple sclerosis (MS), and cerebellar disorders—to determine whether known differences in the effectiveness of thalamic stereotactic procedures for these tremors could be correlated to differences in the incidence or locations of TRA cells.

Methods. Seventy-five operations were performed in 61 patients during which 686 TRA cells were recorded from 440 microelectrode trajectories in the thalamus. The locations of the TRA cells in relation to electrophysiologically defined thalamic nuclei and the commissural coordinates were compared among patient groups.

The authors found that TRA cells are present in patients with each of these disorders and that these cells populate several nuclei in the ventral lateral tier of the thalamus. There were no large differences in the locations of TRA cells among the different diagnostic classes, although there was a difference in the incidence of TRA cells in patients with PD, who had greater than 3.8 times more cells per thalamic trajectory than patients with ET and approximately five times more cells than patients with MS or cerebellar disorders.

Conclusions. There was an increased incidence of TRA in the thalamus of patients with PD. The location of thalamic TRA cells in patients with basal ganglia and other tremor disorders was similar.
Stimulation of the subthalamic region for essential tremor
Authors: Plaha Puneet , Patel Nikunj K. , Gill Steven S.
Published: May 2009

Object. The goal of this study was to determine the safety and efficacy of bilateral subthalamic region stimulation in the treatment of essential tremor (ET).

Methods. Following induction of general anesthesia, four patients with disabling tremor that had proved to be refractory to pharmacotherapy underwent magnetic resonance imaging—guided deep brain stimulation (DBS) of the bilateral subthalamic region. Tremor was assessed by applying the Fahn-Tolosa-Marín Tremor Rating Scale at baseline and again at the 12-month follow-up examination.

Following surgery the total tremor score improved by 80.1% (from a baseline mean score of 63 ± 15.1 to a score of 11.8 ± 3.9 at 12 months postoperatively). There was a significant improvement (p < 0.0001) in the mean tremor score of the upper limb (postural and action component) from a baseline score of 3 ± 0.9 to a score of 0.5 ± 0.5 at 12 months postoperatively. In two patients with Score 4 head tremor complete arrest of the tremor was observed at 12 months. Motor function scores of the upper limb for drawing spirals, pouring water, and drawing lines improved significantly (p < 0.05) by 66.7, 76.9, and 58.3%, respectively. Handwriting improved by 68%, but this gain was not significant. The mean activities of daily living score at baseline was 20 ± 3.2; there was an 88.8% improvement in this score to 2.3 ± 1.5 at the 12-month evaluation. The voltage required for effective tremor control was low (mean 1.8 ± 0.2 V) and, along with the other parameters of DBS (frequency and pulse width), did not change significantly over the 12-month period. Tolerance to the action component of tremor was not seen. There was no procedural or stimulation-related complication.

Conclusions. Bilateral subthalamic region stimulation is effective in arresting tremor and head titubation, as well as functional disability in ET. Complications like dysarthria and disequilibrium were not seen. These patients required low voltages of stimulation and did not develop a tolerance to the treatment.
Inhibition of cerebral vasospasm by intracranial delivery of ibuprofen from a controlled-release polymer in a rabbit model of subarachnoid hemorrhage
Authors: Frazier James L. , Pradilla Gustavo , Wang Paul P. , Tamargo Rafael J.
Published: May 2009

Object.Leukocyte—endothelial cell interactions may play a role in the development of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) because the extravasation of circulating leukocytes into the periadventitial space within 24 hours after the hemorrhage appears to be a critical event in this process. Ibuprofen is an antiinflammatory agent that inhibits the expression of specific cell adhesion molecules and, consequently, disrupts leukocyte—endothelial cell interactions. The authors investigated the efficacy of ibuprofen delivered locally from controlled-release polymers in the rabbit basilar artery (BA) model of cerebral vasospasm.

Methods.Ibuprofen was incorporated into controlled-release ethylene—vinyl acetate copolymer (EVAc) constituting 45% of the resulting polymer by weight. Fifty-four New Zealand White rabbits were randomized to 10 groups: sham operation (seven animals); SAH only (seven animals); and SAH plus either empty EVAc or ibuprofen—EVAc polymer at 30 minutes or 6, 12, or 24 hours (five animals per group; 40 total). The rabbits were killed 72 hours after induction of SAH, at the time of maximal vasospasm. The efficacy of ibuprofen in preventing vasospasm was assessed by measuring lumen patency of the rabbit's BAs. The intracranial controlled release of ibuprofen resulted in a significant inhibition of vasospasm when treatment was initiated at 30 minutes (patency 92.3 ± 5.1% compared with 52.1 ± 5.1% in animals given empty EVAc; p < 0.001) and 6 hours (patency 69.5 ± 3.5% compared with 47.2 ± 1.5% in animals given empty EVAc; p < 0.03) after blood deposition compared with treatment with empty EVAc. No effect was observed when treatment was begun at either 12 or 24 hours.

Conclusions.Local intracranial delivery of ibuprofen accomplished using controlled-release polymers prevents vasospasm in the rabbit BA model of vasospasm when administered within 6 hours after blood exposure.
Improvement in neurological outcome after administration of atorvastatin following experimental intracerebral hemorrhage in rats
Authors: Seyfried Donald , Han Yuxia , LU Dunyue , Chen Jieli , Bydon Ali , Chopp Michael
Published: May 2009

Object. Atorvastatin, a β-hydroxy-β-methylglutaryl coenzyme A reductase inhibitor, improves neurological functional outcome, reduces cerebral cell loss, and promotes regional cellular plasticity when administered after intracerebral hemorrhage (ICH) in rats.

Methods. Autologous blood was stereotactically injected into the right striatum in rats, and atorvastatin was administered orally beginning 24 hours after ICH and continued daily for 1 week. At a dose of 2 mg/kg, atorvastatin significantly reduced the severity of neurological deficit from 2 to 4 weeks after ICH. The area of cell loss in the ipsilateral striatum was also significantly reduced in these animals. Consistent with previous study data, higher doses of atorvastatin (8 mg/kg) did not improve functional outcome or reduce the extent of injury. Histochemical stains for markers of synaptogenesis, immature neurons, and neuronal migration revealed increased labeling in the region of hemorrhage in the atorvastatin-treated rats.

Conclusions. Analysis of the data in this study indicates that atorvastatin improves neurological recovery after experimental ICH and may do so in part by increasing neuronal plasticity.
Retinotopy with coordinates of lateral occipital cortex in humans
Authors: Kaido Takanobu , Hoshida Tohru , Taoka Toshiaki , Sakaki Toshisuke
Published: May 2009

Object. The lateral occipital cortex in humans is known as the “extrastriate visual cortex.” It is, however, an unexplored field of research, and the anatomical nomenclature for its surface has still not been standardized. This study was designed to investigate whether the lateral occipital cortex in humans has retinotopic representation.

Methods. Four right-handed patients with a diagnosis of intractable epilepsy from space-occupying lesions in the occipital lobe or epilepsy originating in the occipital lobe received permanently implanted subdural electrodes. Electrical cortical stimulation was applied directly applied to the brain through metal electrodes by using a biphasic stimulator. The location of each electrode was measured on a lateral skull x-ray study. Each patient considered a whiteboard with vertical and horizontal median lines. The patient was asked to look at the midpoint on the whiteboard. If a visual hallucination or illusion occurred, the patient recorded its outline, shape, color, location, and motion on white paper one tenth the size of, and with vertical and horizontal median lines similar to those on, the whiteboard. Polar angles and eccentricities of the midpoints of the phosphenes from the coordinate origin were measured on the paper. On stimulation of the lateral occipital lobe, 44 phosphenes occurred. All phosphenes were circular or dotted, with a diameter of approximately 1 cm, except one that was like a curtain in the peripheral end of the upper and lower visual fields on stimulation of the parietooccipital region. All phosphenes appeared in the visual field contralateral to the cerebral hemisphere stimulated. On stimulation of the lateral occipital lobe, 22 phosphenes moved centrifugally or toward a horizontal line. From three-dimensional scatterplots and contour maps of the polar angles and eccentricities in relation to the x-ray coordinates of the electrodes, one can infer that the lateral occipital cortex in humans has retinotopic representation.

Conclusions. The authors found that phosphenes induced by electrical cortical stimulation of the lateral occipital cortex represent retinotopy. From these results one can assert that visual field representation with retinotopic relation exists in the extrastriate visual cortex.
Life span extension and reduced neuronal death after weekly intraventricular cyclosporin injections in the G93A transgenic mouse model of amyotrophic lateral sclerosis
Authors: Karlsson Jenny , Fong Keith S. K. , Hansson Magnus J. , Elmàr Eskil , Csiszar Katalin , Keep Marcus F.
Published: May 2009

Object. The authors investigated whether cyclosporin A (CsA), a cyclophilin ligand with mitochondrial permeability transition pore-blocking and calcineurin-inhibiting properties, affects motor function, neuronal death, and life span in the G93A transgenic mouse model of familial amyotrophic lateral sclerosis (FALS).

Methods. The G93A mice received weekly intracerebroventricular injections of CsA (20 µg/mouse/week) starting at the age of 65 days, and physical performance on an exercise wheel was monitored beginning at 84 days of age. Mice were allowed to survive for clinical observation of body weight, hindlimb weakness, and life span or until a defined end stage or were killed at 110 days of age for histological analysis.

Conclusions. Treatment with CsA significantly delayed the onset of hindlimb weakness and also extended the time from its onset to paralysis. The overall life span of CsA-treated G93A mice was significantly extended, by 12% compared with vehicle-treated transgenic littermates. The CsA also prolonged physical performance on the exercise wheel and delayed weight loss. Histologically, there was significant preservation of both cervical and lumbar spine motor neurons and also tyrosine hydroxylase—positive dopaminergic substantia nigra neurons in 110-day-old CsA-treated mice compared with their transgenic littermates. The local administration of CsA directly into the brain ventricles is an effective means of central nervous system drug delivery (because CsA does not readily cross the blood—brain barrier), which in this study ameliorated clinical and neuropathological features of FALS in G93A mice. The remarkably low intrathecal CsA dose required for neuroprotection reduces potential adverse effects of systemic immunosuppression or nephrotoxicity seen with chronic systemic delivery of the drug.
Intentional partial coil occlusion followed by delayed clip application to wide-necked middle cerebral artery aneurysms in patients presenting with severe vasospasm
Authors: Brisman Jonathan L. , Roonprapunt Chan , Song Joon K. , Niimi Yasunari , Setton Avi , Berenstein Alejandro , Flamm Eugene S.
Published: May 2009

✓ The treatment of ruptured cerebral aneurysms in patients presenting with vasospasm remains a particular challenge. The authors treated two patients harboring Hunt and Hess Grade 1 subarachnoid hemorrhages from middle cerebral artery (MCA) aneurysms associated with severe local angiographically demonstrated yet asymptomatic vasospasm on presentation. Because both aneurysms had wide necks and were located at the MCA bifurcation, they were believed to be anatomically suitable for microsurgical clip application. Severe M1 vasospasm was believed to be a relative contraindication to open surgery, however.

An intentionally staged endovascular and microsurgical treatment strategy was planned in each patient. Partial coil occlusion of the aneurysmal dome was performed to prevent the lesion from rebleeding and was followed by balloon angioplasty of the spastic vessel. Early treatment of the severe spasm appeared to prevent significant delayed neurological ischemic deficit. Following resolution of the vasospasm, definitive clipping of the aneurysms was performed on Day 13 post embolization. One patient had a good clinical recovery and was discharged without neurological deficit. The other patient's hospital course was complicated by the occurrence of a postoperative posterior temporal infarct requiring partial temporal lobectomy, although she eventually had a good recovery with only a small visual field deficit. Based on data obtained in these two patients, one can infer that ruptured wide-necked MCA aneurysms associated with severe local vasospasm may best be treated using a staged combined treatment plan. Delayed clip application might be performed more safely 4 to 6 weeks postocclusion, or later, than at 2 weeks.
Stimulation of the subthalamic nucleus compared with the globus pallidus internus in patients with Parkinson disease
Authors: Peppe Antonella , Pierantozzi Mariangela , Bassi Andrea , Altibrandi Maria Grazia , Brusa Livia , Stefani Alessandro , Stanzione Paolo , Mazzone Paolo
Published: May 2009

Object. The authors compared the effects of deep brain stimulation (DBS) in the globus pallidus internus (GPi) with those in the subthalamic nucleus (STN) in patients with Parkinson disease (PD) in whom electrodes had been bilaterally implanted in both targets.

Methods. Eight of 14 patients with advanced PD in whom electrodes had been implanted bilaterally in both the GPi and STN for DBS were selected on the basis of optimal DBS effects and were studied 2 months postsurgery in offand on-stimulus conditions and after at least 1 month of pharmacological withdrawal. Subcutaneous administration of an apomorphine test dose (0.04 mg/kg) was also performed in both conditions. Compared with the off status, the results showed less reduction in the Unified PD Rating Scale Section III scores during DBS in the GPi (43.1%) than during DBS of the STN (54.5%) or DBS of both the STN and GPi (57.1%). The difference between the effects of DBS in the GPi compared with that in the STN or simultaneous DBS was statistically significant (p < 0.01). In contrast, no statistical difference was found between DBS in the STN and simultaneous DBS in the STN and GPi (p < 0.9). The improvement induced by adding apomorphine administration to DBS was similar in all three stimulus modalities. The abnormal involuntary movements (AIMs) induced by apomorphine were almost abolished by DBS of the GPi, but were not affected by stimulation of the STN. The simultaneous stimulation of STN and GPi produced both antiparkinsonian and anti-AIM effects.

Conclusions. The improvement of parkinsonian symptoms during stimulation of the GPi, STN, and both nuclei simultaneously may indicate a similar DBS mechanism for both nuclei in inducing antiparkinsonian effects, although STN is more effective. The antidyskinetic effects produced only by DBS of the GPi, with or without STN, may indicate different mechanisms for the antidyskinetic and antiparkinsonian activity related to DBS of the GPi or an additional mechanism in the GPi. These findings indicate that implantation of double electrodes for DBS should not be proposed as a routine procedure, but could be considered as a possible subsequent choice if electrode implantation for DBS of the STN does not control AIMs.