bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved survival after aneurysmal subarachnoid hemorrhage: review of management during a 12-year period
Authors: Cesarini Kristina G. , Hårdemark Hans-Göran , Persson Lennart
Published: May 2009

Object. Based on the concept that unfavorable clinical outcome after aneurysmal subarachnoid hemorrhage (SAH), to a large extent, is a consequence of all ischemic insults sustained by the brain during the acute phase of the disease, management of patients with SAH changed at the authors' institution in the mid-1980s. The new management principles affected referral guidelines, diagnostic and monitoring methods, and pharmacological and surgical treatment in a neurointensive care setting. The impact of such changes on the outcome of aneurysmal SAH over a longer period of time has not previously been studied in detail. This was the present undertaking.

Methods. The authors analyzed all patients with SAH admitted to the neurosurgery department between 1981 and 1992. This period was divided in two parts, Period A (1981–1986) and Period B (1987–1992), and different aspects of management and outcome were recorded for each period. In total, 1206 patients with SAH (mean age 52 years, 59% females) were admitted; an aneurysm presumably causing the SAH was found in 874 (72%).

The 30-day mortality rate decreased from 29% during the first 2 years (1981–1982) to 9% during the last 2 years (1991–1992) (Period A 22%; Period B 10%; p < 0.0001) and the 6-month mortality rate decreased from 34 to 15% (Period A 26%; Period B 16%; p < 0.001). At follow-up review conducted 2 to 9 years (mean 5.2 years) after SAH occurred, patients were evaluated according to the Glasgow Outcome Scale. Subarachnoid hemorrhage—related poor outcome (vegetative or dead) was reduced (Period A 30%; Period B 18%; p < 0.001). There was an increase both in patients with favorable outcome (good recovery and moderate disability) (Period A 61%; Period B 66%) and in those with severe disability (Period A 9%; Period B 16%; p < 0.01).

Conclusions. This study provides evidence that the prognosis for patients with aneurysmal SAH has improved during the last decades. The most striking results were a gradual reduction in mortality rates and improved clinical outcomes in patients with Hunt and Hess Grade I or II SAH and in those with intraventricular hemorrhage. The changes in mortality rates and the clinical outcomes of patients with Hunt and Hess Grades III to V SAH were less conspicuous, although reduced incidences of mortality were seen in some subgroups; however, few survivors subsequently appeared to attain a favorable outcome.
Efficacy of induced hypotension in the surgical treatment of large cavernous sinus cavernomas
Authors: Ohata Kenji , El-Naggar Alaa , Takami Toshihiro , Morino Michiharu , El-Adawy Yousry , El-Sheik Kanan , Inoue Yuichi , Hakuba Akira
Published: May 2009

Object. Cavernous sinus cavernomas are rare lesions associated with high rates of intraoperative mortality and morbidity resulting from profuse bleeding. In this paper, the authors report their experience in treating five patients with histologically confirmed cavernous sinus cavernomas and describe the efficacy of induced hypotension in facilitating excision of the lesion.

Methods. All five patients were women ranging in age from 25 to 54 years, with an average age of 42 years. The mass was small in one and large (> 3 cm in diameter) in four. In one patient with a large mass, cardiac arrest occurred after the craniotomy, and remarkable reduction in the size of the cavernoma was evident on postmortem examination. The other three large lesions were successfully removed piecemeal after induction of hypotension (60–80 mm Hg systolic pressure), which remarkably reduced the mass and the bleeding during surgery. In the remaining patient, who had a small lesion, the cavernoma was removed in one piece.

Conclusions. Cavernous sinus cavernoma can be thought of as a cluster of sinusoidal cavities, the size of which varies depending on the systemic blood pressure. During surgery, reduction of the mass and control of bleeding from the cavernoma can be achieved by inducing hypotension, which enables the safe excision of this lesion. This technique should be considered by surgeons resecting a cavernous sinus tumor, especially when cavernoma is suspected.
Theoretical comparison of surgery and radiosurgery in cerebral arteriovenous malformations
Authors: Chang Han Soo , Nihei Hiroshi
Published: May 2009

Object. Management of patients with cerebral arteriovenous malformations (AVMs) is controversial. Excellent surgical results are obtained in patients with low Spetzler—Martin grades, whereas radiosurgery offers a good alternative with its high obliteration rate. In the absence of randomized studies, physicians must choose a treatment plan based on the currently available data. To support this decision-making process, a mathematical model designed to describe patient survival rates after each treatment option was developed.

Methods. The theoretical survival curve in patients undergoing conventional surgery, radiosurgery, or observation was calculated. Theoretical life expectancies in patients with AVMs who presented at various initial ages were calculated for each treatment strategy. A systematic method was also developed to compare the estimated risks of various treatment combinations.

Conclusions. Conventional surgery and radiosurgery definitely produced better survival rates than observation. In the comparison of surgery with radiosurgery, radiosurgery was equivalent to surgery with a combined morbidity and mortality rate of approximately 7% for a 20-year-old patient with an unruptured cerebral AVM. Data for other patient ages and treatment combinations are tabulated for use in determining the best treatment strategy. The authors believe that their analysis will provide logical support for the decision-making process involved in the treatment of patients with cerebral AVMs.
Scanning electron microscopy of the floor of the fourth ventricle in rats subjected to graded impact injury to the sensorimotor cortex
Authors: Sarphie Theodore G. , Carey Michael E. , Davidson June F. , Soblosky Joseph S.
Published: May 2009

Object. Respiratory dysfunction including apnea frequently follows head injury in humans. The purpose of this study was to identify any structural alterations in the region of brainstem respiratory nuclei that might account for immediate postinjury respiratory abnormalities in anesthetized experimental animals.

Methods. Using scanning electron microscopy, the authors examined the floor of the fourth ventricle in injured rats after a piston strike to the sensorimotor cortex that depressed the dura 1, 2, or 4 mm. The rats were killed within minutes of injury. Cortical impact depths measuring either 1 or 2 mm (eight rats) produced no respiratory abnormalities, and the structural integrity of the ependymal lining of the ventricular floor in these animals was not compromised. Thirteen rats were subjected to impact to a 4-mm depth and 10 of these exhibited immediate temporary or permanent apnea. The medullae of nine of these rats were studied using scanning electron microscopy, and the fourth ventricular floors of all nine rats showed tears. Four rats that exhibited immediate, permanent apnea had tears in the caudal fourth ventricle floor near the obex, whereas five rats with no or only transient apnea had tears located more anteriorly, near the aqueduct or laterally. Changes in cerebrospinal fluid flow or pressure dynamics may have caused these tears. Light microscopy, focused near the area postrema, revealed a shearing defect through the ependyma of the fourth ventricular floor into the subjacent neuropil with a disruption of axonal pathways.

Conclusions. Respiratory neuronal network components lying within 2 mm of the area postrema may well have been disrupted by the caudal tears producing permanent apnea. A similar phenomenon could account for the transient or permanent postinjury apnea seen in humans with severe head injury.
Vascular components of cerebrospinal fluid compensation
Authors: Czosnyka Marek , Richards Hugh K. , Czosnyka Zofia , Piechnik Stefan , Pickard John D.
Published: May 2009

Object. The aim of the study was to assess how cerebrospinal fluid (CSF) pressure—volume compensation depends on cerebrovascular tone.

Methods. In 26 New Zealand White rabbits, intracranial pressure (ICP), arterial blood pressure, and basilar artery blood flow velocity were measured continuously. Saline was infused into the cranial subarachnoid space to assess CSF compensatory parameters: the resistance to CSF outflow, the elastance coefficient, and the amplitude of the ICP pulsatile waveform. Infusions were repeated on two different levels of CO2 concentration in the arterial blood (PaCO2), at normotension and hypotension, and after the death of the animal.

An increase in PaCO2 from a mean of 27 to 48 mm Hg was accompanied by an 18% increase in the resistance to CSF outflow (p < 0.005) and a 64% increase (p < 0.05) in the elastance coefficient. A decrease in arterial blood pressure from a mean of 100 to 51 mm Hg caused a 25% decrease in CSF outflow resistance (p < 0.01) but did not affect the elastance coefficient. Postmortem, a 23% decrease in the CSF outflow resistance was associated with a 102% decrease in the elastance coefficient.

Conclusions. Cerebrovascular parameters have a limited but significant impact on CSF infusion studies. The vascular component of ICP may be identified as a significant factor contributing to this phenomenon. During infusion studies, physiological parameters influencing vascular conditions should be maintained as stable as possible.
Cerebral heterotopia of the temporofacial region
Authors: Abdel-Rahman Nabil , Al-Awadi Yousef , Ramadan Abbas Ali , Choudhury Abdur Rashid
Published: May 2009

✓ The authors report a case of cerebral heterotopia in the right temporofacial region of a neonate. The lesion presented as a massive cystic swelling containing cerebrospinal fluid. It produced calvarial and facial bone deformities. After the mass was excised, histological examination revealed glial tissue and choroid plexus.
Lhermitte—Duclos disease as a component of Cowden's syndrome
Authors: Koch Rainer , Scholz Martin , Nelen Marcel R. , Schwechheimer Karl , Epplen Joerg T. , Harders Albrecht G.
Published: May 2009

✓ In recent years, 16 cases involving the association between Lhermitte—Duclos disease (LDD), which is a hamartomatous overgrowth of cerebellar tissue, and Cowden's syndrome (CS), an autosomal-dominant condition characterized by multiple hamartomas and neoplasias, have been reported. LDD may be one of the manifestations of CS. Recently, mutations of the PTEN/MMAC 1 gene, a tumor suppressor gene, have been found in families with CS, including four patients in whom LDD was diagnosed. The authors present a case of LDD in a 53-year-old woman who also had the typical mucocutaneous lesions found in CS, as well as goiter and intestinal polyposis. In this case, CS had never been suspected until the diagnosis of LDD was made. The mutation detected in the PTEN/MMAC 1 gene as well as neuropathological results are described.
Computer-generated surgical simulation of morphological changes in microstructures: concepts of “virtual retractor”
Authors: Koyama Toru , Okudera Hiroshi , Kobayashi Shigeaki
Published: May 2009

✓ The authors' goal was to develop a computer graphics model to simulate the displacement and morphological changes that are caused by the retraction of fine intracranial structures.

The authors developed an application program to interpolate the contour of models of an artery and a retractor. The center of the displacement was determined by spatial coordinates, and the shape of the displacement of the arterial model was calculated using a cosine-based formula with representation of a brain retractor. This computer graphics model was applied to the simulation of the displacement and morphological changes that occur when retraction is performed in the optic nerve. An illustrative case is presented, in which the optic nerve was displaced by a retractor to simulate the surgery performed in a carotid cave aneurysm of the internal carotid artery.

The authors have named this methodological tool a “virtual retractor.” This new navigational system for open microneurosurgery would be useful in teaching surgical microanatomy and in presurgical operative planning.
Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery
Authors: Houkin Kiyohiro , Kamiyama Hiroyasu , Kuroda Satoshi , Ishikawa Tatsuya , Takahashi Akihiro , Abe Hiroshi
Published: May 2009

✓ Reconstruction of the carotid artery by using a radial artery graft is a useful option that can produce reliable long-term patency for the surgical treatment of giant and/or large aneurysms of the cavernous and paraclinoid internal carotid artery (ICA).

During the past 10 years, 43 patients with intracavernous and paraclinoid giant aneurysms of the ICA have been treated by reconstruction of the ICA with radial artery grafts after ligation of the cervical ICA. The long-term patency of the grafted radial artery was evaluated over more than a 5-year period (mean 7.2 years) in 20 of these patients by using magnetic resonance angiography or conventional angiography. There was no late occlusion of the graft in any of these cases. Stenotic graft changes were observed in two cases.
Stereotactic radiosurgery in the management of acoustic neuromas associated with neurofibromatosis Type 2
Authors: Subach Brian R. , Kondziolka Douglas , Lunsford L. Dade , Bissonette David J. , Flickinger John C. , Maitz Ann H.
Published: May 2009

Object. Stereotactically guided radiosurgery is one of the primary treatment modalities for patients with acoustic neuromas (vestibular schwannomas). The goal of radiosurgery is to arrest tumor growth while preserving neurological function. Patients with acoustic neuromas associated with neurofibromatosis Type 2 (NF2) represent a special challenge because of the risk of complete deafness. To define better the tumor control rate and long-term functional outcome, the authors reviewed their 10-year experience in treating these lesions.

Methods. Forty patients underwent stereotactic radiosurgery at the University of Pittsburgh, 35 of them for solitary tumors. The other five underwent staged procedures for bilateral lesions (10 tumors, 45 total). Thirteen patients (with 29% of tumors) had undergone a median of two prior resections. The mean tumor volume at radiosurgery was 4.8 ml, and the mean tumor margin dose was 15 Gy (range 12–20 Gy).

The overall tumor control rate was 98%. During the median follow-up period of 36 months, 16 tumors (36%) regressed, 28 (62%) remained unchanged, and one (2%) grew. In the 10 patients for whom more than 5 years of clinical and neuroimaging follow-up results were available (median 92 months), five tumors were smaller and five remained unchanged. Surgical resection was performed in three patients (7%) after radiosurgery; only one showed radiographic evidence of progression. Useful hearing (Gardner—Robertson Class I or II) was preserved in six (43%) of 14 patients, and this rate improved to 67% after modifications made in 1992. Normal facial nerve function (House—Brackmann Grade 1) was preserved in 25 (81%) of 31 patients. Normal trigeminal nerve function was preserved in 34 (94%) of 36 patients.

Conclusions. Stereotactically guided radiosurgery is a safe and effective treatment for patients with acoustic tumors in the setting of NF2. The rate of hearing preservation may be better with radiosurgery than with other available techniques.
Radiotherapy in the treatment of benign meningioma of the skull base
Authors: Nutting Christopher , Brada Michael , Brazil Lucy , Sibtain Ahmen , Saran Frank , Westbury Charlotte , Moore Anne , Thomas David G. T. , Traish Daphne , Ashley Susan
Published: May 2009

Object. This study was undertaken to assess the long-term efficacy and toxicity of conventional fractionated external-beam radiation in the treatment of benign skull base meningioma.

Methods. This is a retrospective study of 82 patients with histologically verified benign skull base meningioma treated by surgery followed by fractionated external-beam radiation at the Royal Marsden Hospital between 1962 and 1992. The 5- and 10-year progression-free survival (PFS) rates were 92% and 83%, respectively, with the site of disease being the only independent prognostic factor for tumor control according to multivariate analysis. The 10-year PFS rate for patients with sphenoid ridge meningiomas was 69% compared with 90% for those with tumors in the parasellar region. The overall 10-year survival rate was 71%, with performance status and patient age found to be significant independent prognostic factors. Six patients had worsening vision, which was due to cataract in five cases and retinopathy in one. There were no recorded cases of cranial nerve neuropathy.

Conclusions. The excellent long-term tumor control and length of survival with minimal toxicity associated with conventional external-beam radiation should serve as a baseline for evaluation of new treatment strategies such as radiosurgery and skull base surgery.
Treatment of basilar artery bifurcation aneurysms by using Guglielmi detachable coils: a 6-year experience
Authors: Bavinzski Gerhard , Killer Monika , Gruber Andreas , Reinprecht Andrea , Gross Cordell E. , Richling Bernd
Published: May 2009

Object. The authors retrospectively analyzed the results of their 6-year experience in the treatment of basilar artery (BA) bifurcation aneurysms by using Guglielmi detachable coils (GDCs).

Methods. This analysis involved 45 BA tip aneurysms in 16 men and 29 women who ranged in age from 23 to 78 years (mean 50 years). Seventy-five percent of the aneurysms had ruptured and 25% remained unruptured. Of the group whose aneurysms hemorrhaged, 14 patients were Hunt and Hess Grade I or II and 20 were Hunt and Hess Grades III to V; 32 patients were treated within 2 weeks of their subarachnoid hemorrhage (SAH). Initially, treatment with GDCs was limited to poor-grade high-risk patients who refused surgery or patients in whom surgery proved unsuccessful. Later in the study, good-grade patients with narrow-necked aneurysms were also treated using GDCs.

The length of clinical follow up ranged from 1 to 72 months (average 27.4 months) in the 37 surviving patients. In 33 of the 45 aneurysms treated with coil placement, good to excellent results were achieved. There were 12 poor results (27%) including one in a patient from the non-SAH group who suffered a thrombotic complication due to an underlying vasculitis. Eight deaths were recorded in this group of 45 patients. One of these deaths was caused by a complication related to anesthesia, one by unknown causes, and six resulted from complications of the disease. One patient rebled on the 2nd day after the endovascular procedure. The mortality and permanent morbidity rates directly related to the intervention were 2.2% and 4.4%, respectively.

Angiographic studies obtained immediately postintervention demonstrated 99 to 100% occlusion in 30 (67%) of the aneurysms; nine (20%) were more than 90% occluded; and six (13%) were less than 90% occluded by the GDCs. Follow-up angiograms were obtained in 31 patients between 2 and 72 months after coil placement. Nineteen (61%) of the follow-up angiograms revealed stable results (that is, no change from initial treatment). Twelve of the 31 showed coil compaction, but only eight of these lesions could accept additional coils.

In large aneurysms recanalization was seen in 57%, and some of the larger lesions required as many as four embolizations (mean 1.7) to achieve optimal occlusion. When small-necked aneurysms were analyzed as a subset, a stable angiographic result was seen in 92%.

Conclusions. Use of GDCs led to excellent clinical and angiographic results in the majority of patients with BA tip aneurysms included in this limited follow-up study. Rebleeding was encountered in one of the 34 previously ruptured BA aneurysms treated with GDCs, and no hemorrhages have been documented in the 11 unruptured aneurysms treated with GDCs in this series. Long-term follow-up studies are necessary before it is possible to compare adequately the treatment of aneurysms with coil placement to the gold standard of aneurysm clipping.
Prevalence of cerebral aneurysms in patients with persistent primitive trigeminal artery
Authors: Cloft Harry J. , Razack Nasser , Kallmes David F.
Published: May 2009

Object. The aim of this study was to determine the prevalence of cerebral saccular aneurysms in patients with persistent primitive trigeminal artery (PPTA). The prevalence of cerebral saccular aneurysms in patients with PPTA previously has been reported to be 14 to 32%, but this rate range is unreliable because it is based on collections of published case reports rather than a series of patients chosen in an unbiased manner.

Methods. The authors retrospectively evaluated their own series of 34 patients with PPTA to determine the prevalence of cerebral aneurysms in this population. The prevalence of intracranial aneurysms in patients with PPTA was approximately 3% (95% confidence interval 0–9%).

Conclusions. The prevalence of intracranial aneurysms in patients with PPTA is no greater than the prevalence of intracranial aneurysms in the general population.
Effects of clotrimazole on the growth, morphological characteristics, and cisplatin sensitivity of human glioblastoma cells in vitro
Authors: Khalid M. Humayun , Shibata Shobu , Hiura Tsuyoshi
Published: May 2009

Object. Clotrimazole, an antimycotic drug, inhibits proliferation of normal and cancer cells by downregulating the movement of intracellular Ca++ and K+. The authors examined the effect of clotrimazole on the growth and sensitivity to cisplatin of two human glioblastoma cell lines—A172, which has the wild-type p53 gene, and T98G, which has the mutant p53 gene in vitro.

Methods. The A172 and T98G glioblastoma cells were exposed to clotrimazole and cell growth was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium chloride colorimetric assay. Clotrimazole produced a dose-dependent inhibition of cell proliferation and caused changes in cellular structure toward a well-differentiated form. The growth inhibitory effect of clotrimazole was reversible. Western immunoblot analysis revealed a marked increase in cellular glial fibrillary acidic protein and wild-type p53 and a decrease in c-myc and c-fos oncoproteins in both cell lines treated with clotrimazole. Flow cytometric analysis revealed that clotrimazole-treated cells accumulated in the G0/G1 phase with a marked decrease in cells in the S phase; when clotrimazole was washed out from the culture medium, cells again started to proliferate, with a marked decrease in cells in the G0/G1 phase and an increase in cells in the S phase. The growth inhibitory effect of clotrimazole could not be overcome by exogenous stimulation with either epidermal growth factor or c-myc peptide. A combined treatment with clotrimazole and cisplatin significantly enhanced cell cytotoxicity compared with treatment using either drug alone. A DNA fragmentation assay showed that both clotrimazole and cisplatin induced apoptosis, which was increased in cells treated by both drugs.

Conclusions. The present study indicates that clotrimazole inhibits cell proliferation accompanied by morphological changes toward differentiation of glioblastoma cells and that this drug synergistically enhances the antitumor effect of cisplatin by inducing wild-type p53—mediated apoptosis.
Reversal of experimental parkinsonism by using selective chemical ablation of the medial globus pallidus
Authors: Lieberman Daniel M. , Corthesy Marc-Etienne , Cummins Alex , Oldfield Edward H.
Published: May 2009

Object. Symptoms from Parkinson's disease improve after surgical ablation of the medial globus pallidus (GPm). Although, in theory, selective chemical ablation of neurons in the GPm could preserve vital structures jeopardized by surgery, the potential of this approach is limited when using traditional techniques of drug delivery. The authors examined the feasibility of convection-enhanced distribution of a neurotoxin by high-flow microinfusion to ablate the neurons of the GPm selectively and reverse experimental Parkinson's disease (akinesia, tremor, and rigidity).

Methods. Initially, to test the feasibility of this approach, the GPms of two naive rhesus macaques were infused with kainic acid or ibotenic acid through two cannulas that had been placed using the magnetic resonance imaging—guided stereotactic technique. Two weeks later the animals were killed and their brains were examined histologically to determine the presence of neurons in the GPm and the integrity of the optic tract and the internal capsule. To examine the therapeutic potential of this paradigm, unilateral experimental Parkinson's disease was induced in six macaques by intracarotid infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and their behavior was studied for 12 weeks after chemopallidotomy was performed using kainic acid (three animals) or control infusion (three animals).

Conclusions. Chemopallidotomy using kainic acid permanently reversed the stigmata of MPTP-induced parkinsonism. By contrast, the control animals exhibited a transient recovery following intrapallidal infusion and then relapsed back to their baseline state. The use of high-flow microinfusion of selectively active toxins has the potential for treatment of Parkinson's disease and, by expanding the range of approachable targets to include large nuclei, for broad applications in clinical and experimental neuroscience.
Intracerebral hemorrhage caused by the rupture of a nontraumatic middle meningeal artery aneurysm
Authors: Sandin John A. , Salamat M. Shahriar , Baskaya Mustafa , Dempsey Robert J.
Published: May 2009

✓ The authors report on the case of a 46-year-old man who presented with an intraparenchymal hemorrhage after the rupture of a nontraumatic aneurysm arising from the middle meningeal artery (MMA). A review of the literature revealed no published cases of intraparenchymal hemorrhage resulting from the rupture of an MMA aneurysm.
Percutaneous transfemoral embolization of an indirect carotid—cavernous fistula with cortical venous access to the cavernous sinus
Authors: Bellon Richard J. , Liu Amon Y. , Adler John R. , Norbash Alexander M.
Published: May 2009

✓ The authors present the case of a 61-year-old man with an indirect carotid—cavernous fistula (CCF). Many now advocate a primary transvenous approach to deal with such lesions, with packing and thrombosis of the cavernous sinus leading to fistula obliteration. Transvenous access to the cavernous sinus via the inferior petrosal sinus is the usual route of access; both surgical and transfemoral superior ophthalmic vein approaches are also well described. In the case presented, the anatomy of the CCF was unfavorable for these approaches and its dominant venous egress was via a single enlarged arterialized cortical vein. The cavernous sinus was accessed with a transfemoral retrograde approach to the cortical draining vein. Successful CCF embolization was documented radiographically and clinically. To the authors' knowledge, this procedure has not been previously described in the English literature.
Diffuse calvarial meningioma
Authors: Anegawa Shigetaka , Hayashi Takashi , Torigoe Ryuichiro , Furukawa Yoshihiko
Published: May 2009

✓ An extremely unusual calvarial meningioma in a 77-year-old woman is reported. The meningioma spread widely and symmetrically within the calvaria and grew extracranially within the scalp as well as intracranially. Reactive dural hyperplasia induced narrowing of the intracranial space and occlusion of the superior sagittal sinus, resulting in intracranial hypertension. After external decompression, the patient's symptoms markedly resolved. The authors review the literature on calvarial meningioma, discuss its pathogenesis, and propose mechanisms responsible for the patient's intracranial hypertension.
Neural network analysis of preoperative variables and outcome in epilepsy surgery
Authors: Arle Jeffrey E. , Perrine Kenneth , Devinsky Orrin , Doyle Werner K.
Published: May 2009

Object. Because appropriate patient selection is essential for achieving successful outcomes after epilepsy surgery, the need for more robust methods of predicting postoperative seizure control has been created. Standard multivariate techniques have been only 75 to 80% accurate in this regard. Recent use of artificial intelligence techniques, including neural networks, for analyzing multivariate clinical data has been successful in predicting medical outcome.

Methods. The authors applied neural network techniques to 80 consecutive patients undergoing epilepsy surgery in whom data on demographic, seizure, operative, and clinical variables to predict postoperative seizures were collected.

Neural networks could be used to predict postoperative seizures in up to 98% of cases. Student's t-tests or chi-square analysis performed on individual variables revealed that only the preoperative medication index was significantly different (p = 0.02) between the two outcome groups. Six different combinations of input variables were used to train the networks. Neural network accuracies differed in their ability to predict seizures: using all data (96%); all data minus electroencephalography concordance and operative side (93%); all data except intra- or postoperative variables such as tissue pathological category (98%); all data excluding pathological category, intelligence quotient (IQ) data, and Wada results (84%); only demographics and tissue pathological category (65%); and only IQ data (63%).

Conclusions. Analysis of the results reveals that several networks that are trained with the usual accepted variables characterizing the typical evaluation of epilepsy patients can predict postoperative seizures with greater than 95% accuracy.
Double-blind, randomized, vehicle-controlled study of high-dose tirilazad mesylate in women with aneurysmal subarachnoid hemorrhage. Part II. A cooperative study in North America
Authors: Lanzino Giuseppe , Kassell Neal F. , _ _
Published: May 2009

Object. To test the safety and efficacy of high-dose (15 mg/kg/day) tirilazad mesylate in women suffering from aneurysmal subarachnoid hemorrhage (SAH), a prospective randomized, double-blind, vehicle-controlled trial (parallel to the one conducted in Europe, Australia, New Zealand, and South Africa) was performed at 65 North American neurosurgical centers.

Methods. Of the 832 patients who were randomized, 823 received at least one dose of tirilazad (410 patients) or placebo vehicle containing citrate (413 patients). The two groups were similar with respect to their prognostic factors for overall outcome and delayed cerebral ischemia. There were no differences in medical and surgical interventions including hyperdynamic therapy (intentional hypervolemia, induced hypertension, and/or hemodilution) between the two treatment groups.

In contrast to the accompanying study, the protocol for the North American study was formally amended, in that a sequential analysis of the primary efficacy end point, mortality rate at 91 days postdosing, was performed. This analysis revealed a statistically significant difference in mortality rates, favoring the study drug, among patients who were neurological Grade IV or V at admission (24.6% compared with 43.4% in the placebo-treated group, p = 0.016). No significant differences, however, were found when the entire patient population was considered (15.6% in the placebo-treated group and 13% in the tirilazad-treated group). Other major and secondary end points, which included rate of favorable outcome (74% in the placebo-treated group and 71% in the tirilazad-treated group); symptomatic vasospasm (38% in the placebo-treated group and 35% in the tirilazad-treated group); and vasospasm severity (severe symptomatic vasospasm in 14% of patients in both groups), were also not significantly different between the two groups. In patients with neurological Grades I through III, rates of favorable outcome advantageous to the vehicle-treated group were observed (83.3% compared with 76.7%, p = 0.04).

Conclusions. High-dose tirilazad mesylate is well tolerated in women with aneurysmal SAH. Sequential analysis revealed a significant reduction in mortality rates among patients with neurological Grades IV and V, favoring the study drug and confirming the same effect observed in male patients in previous large studies. No beneficial effect was observed in patients who were in a good neurological grade at admission.
Endovascular coil placement compared with surgical clipping for the treatment of unruptured middle cerebral artery aneurysms: a consecutive series
Authors: Regli Luca , Uske Antoine , de Tribolet Nicolas
Published: May 2009

Object. The goal of this study was to delineate the angioanatomical features that determine whether a patient with an unruptured middle cerebral artery (MCA) aneurysm is treated using endovascular coil placement or surgical clipping.

Methods. Thirty consecutive patients harboring 34 unruptured MCA aneurysms were evaluated. Patients with unruptured aneurysms are managed prospectively according to the following protocol: the primary treatment recommendation is endovascular packing with Guglielmi detachable coils (GDCs). Surgical clipping is recommended after failed attempts at coil placement or in the presence of angioanatomical features that contraindicate that type of endovascular therapy.

Of 34 unruptured MCA aneurysms, two (6%) were successfully embolized and 32 (94%) were clipped. Of these 32 surgically treated aneurysms, in 11 (34%) an attempt at GDC embolization had failed, whereas in 21 (66%) primary clipping was performed because of unfavorable angioanatomy. Of the 13 aneurysms treated endovascularly, two (15%) were successfully excluded, whereas GDC treatment failed in 11 (85%). An unfavorable dome/neck ratio (< 2) and an arterial branch originating at the aneurysm base were the reasons for embolization failure.

Conclusions. Careful evaluation of the angioanatomy of unruptured aneurysms allows selection of the most appropriate treatment. However, for unruptured MCA aneurysms, surgical clipping appears to be the most efficient treatment option. Series of unruptured aneurysms are ideal for comparing treatment results.
Carotid artery angioplasty and use of stents in high-risk patients with contralateral occlusions
Authors: Mericle Robert A. , Kim Stanley H. , Lanzino Giuseppe , Lopes Demetrius K. , Wakhloo Ajay K. , Guterman Lee R. , Hopkins L. Nelson
Published: May 2009

Object. The risks associated with carotid endarterectomy (CEA) are increased in the presence of contralateral carotid artery (CA) occlusion. The 30-day stroke and death rate for patients in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) who had contralateral CA occlusion was 14.3%. The authors analyze their experience with angioplasty and/or stent placement in patients with contralateral CA occlusion to determine the safety and efficacy of endoluminal revascularization in this subgroup.

Methods. Twenty-six procedures were evaluated in 23 patients with high-grade CA stenosis and contralateral CA occlusion. The first 15 procedures were evaluated retrospectively, and the next 11 prospectively. All patients had severe medical comorbidities and were considered too high risk for CEA, even without considering the contralateral occlusion. Clinical follow-up review was performed an average of 18 months later (median 15 months).

Conclusions. The average ipsilateral CA stenosis according to NASCET criteria was 78% preprocedure and 5% postprocedure. There were no changes in neurological or functional outcome immediately postoperatively in any patient. The 30-day postoperative stroke and death rates were zero. However, there was one symptomatic femoral hematoma that resolved without surgery. At follow up, there were three patients who had suffered stroke or death. One patient died secondary to respiratory arrest at 2 months; one died secondary to prostate carcinoma at 12 months; and one patient experienced a minor stroke contralateral to the treated artery at 41 months. Despite the substantial preoperative risk factors in patients in this series, the 30-day stroke and death rate for angioplasty and/or stent placement appears to be lower than that of CEA in patients with contralateral occlusions.
An ultrarapid prognostic index in microprolactinoma surgery
Authors: Guieu Régis , Dufour Henri , Grisoli François , Jaquet Philippe , Guieu Yves , Rosso Jean Pierre , Munier Muriel , Dicostanzo Véronique , Brue Thierry , Enjalbert Alain , Begoud Dominique , Rochat Hervé
Published: May 2009

Object. Prolactinomas account for approximately 40% of pituitary tumors. If the tumor does not exceed 10 mm at its largest diameter (microprolactinoma), the chances of definitive cure as a result of surgery alone vary from 62 to 89% depending on the series. Until now, however, there was no mechanism to predict whether total excision of a tumor had been accomplished. To improve the chances of total excision, we compared the peri- and postoperative kinetics of circulating prolactin (PRL) in patients judged to be cured and those not cured.

Methods. The pre-, peri-, and postoperative variations in blood PRL concentrations were determined using assays conducted at 10-minute intervals. Of the 36 patients included in the study, 27 were considered cured (resumption of a normal menstrual cycle within 6 months, PRL concentration at 9 days [mean ± standard deviation 2.5 ± 2.1 ng/ml] and 12 months [4.5± 2.2 ng/ml] after the operation < 10 ng/ml and normally stimulated by metoclopramide and thyrotropin-releasing hormone [TRH]). Nine patients were not cured (PRL 20 ± 15.7 ng/ml at 9 days after surgery, with no response to metoclopramide and TRH). The kinetics of PRL decrease in definitively cured patients were characterized by the following: 1) the initial slope of the curve decreased by at least 11% within the first 10 minutes after resection, and 2) immediate postoperative PRL concentrations were 20 ng/ml or less.

Conclusions. The measurement of the kinetics of PRL decrease during surgery allows the chance of gross-total resection to be successfully predicted less than 25 minutes after excision of the adenoma. Provided an ultrarapid assay is available (the test used in the present study took < 15 minutes), this prognostic index would be useful to make a decision to continue the surgical procedure when the initial PRL slope is judged to be insufficient. Its use may also be extended to other pituitary tumors such as somatotropic adenoma and basophilic adenoma (Cushing's disease).
Anterior interosseous nerve compression after supracondylar fracture of the humerus: a metaanalysis
Authors: Joist Alexander , Joosten Uwe , Wetterkamp Dirk , Neuber Michael , Probst Axel , Rieger Horst
Published: May 2009

Object. The authors conducted a metaanalysis of reports of anterior interosseous nerve syndrome, a rare nerve compression neuropathy that affects only the motor branch of the median nerve. This syndrome is characterized by paralysis of the flexor pollicis longus, the flexor digitorum profundus to the index finger, and the pronator quadratus, with weakness on flexion of the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger without sensory loss.

Methods. The authors reviewed reports of 34 cases of anterior interosseous nerve syndrome combined with supracondylar fractures of the humerus in children. They have added a new case identified in a 7-year-old boy in whom a diagnosis was made from the clinical findings and whose treatment and outcome are analyzed. The ages of patients reported in the literature ranged from 4 to 10 years. Ten patients (29%) were treated with closed reduction and application of a cast, whereas 25 patients (71%) were treated with open reduction and fixation of the fracture.

Conclusions. All patients regained full flexion and strength after 4 to 17 weeks. The fractures that were surgically treated showed no entrapment of the anterior interosseous nerve.
Contribution of polyamine oxidase to brain injury after trauma
Authors: Doğan Aclan , Rao a. Muralikrishna , Baskaya Muştafa K. , Hatcher James , Temiz Cuneyt , Rao V. L. Raghavendra , Dempsey Robert J.
Published: May 2009

Object. The possible role of the polyamine interconversion pathway on edema formation, traumatic injury volume, and tissue polyamine levels after traumatic brain injury (TBI) was studied using an inhibitor of the interconversion pathway enzyme, polyamine oxidase.

Methods. Experimental TBI was induced in Sprague—Dawley rats by using a controlled cortical impact device at a velocity of 3 m/second, resulting in a 2-mm deformation. Immediately after TBI was induced, 100 mg/kg of N1,N4-bis(2,3-butadienyl)-1,4-butanediamine 2HCl (MDL 72527) or saline was injected intraperitoneally. Brain water content and tissue polyamine levels were measured at 24 hours after TBI. Traumatic injury volume was evaluated using 2% cresyl violet solution 7 days after TBI occurred. The MDL 72527 treatment significantly reduced brain edema (80.4 ± 0.8% compared with 81.2 ± 1.2%, p < 0.05) and injury volume (30.1 ± 6.6 mm3 compared with 42.7 ± 13.3 mm3, p < 0.05) compared with the saline treatment. The TBI caused a significant increase in tissue putrescine levels at the traumatized site (65.5 ± 26.5 pmol/g in the cortex and 70.9 ± 22.4 pmol/g in the hippocampus) compared with the nontraumatized site (7 ± 2.4 pmol/g in the cortex and 11.4 ± 6.4 pmol/g in the hippocampus). The increase in putrescine levels in both the traumatized and nontraumatized cortex and hippocampus was reduced by a mean of 60% with MDL 72527 treatment.

Conclusions. These results demonstrate, for the first time, that the polyamine interconversion pathway has an important role in the increase of putrescine levels after TBI and that the polyamine oxidase inhibitors, blockers of the interconversion pathway, can be neuroprotective against edema formation and necrotic cavitation after TBI.
Inducible nitric oxide synthase: a possible key factor in the pathogenesis of chronic vasospasm after experimental subarachnoid hemorrhage
Authors: Widenka Darius C. , Medele Ralph J. , Stummer Walter , Bise Karl , Steiger Hans J.
Published: May 2009

Object. The role of nitric oxide (NO) in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH) is not well understood. Nitric oxide is a well-established vasodilatory substance; however, in SAH, NO may become a major source for the production of injurious free-radical species, leading to chronic cerebral vasospasm. Reactive overproduction of NO to counteract vascular narrowing might potentiate the detrimental effects of NO. The focus of the present study is to determine the extent of reactive induction of inducible nitric oxide synthase (iNOS) after experimental SAH.

Methods. Chronic vasospasm was induced in male Wistar rats by an injection of autologous blood (100 µl) into the cisterna magna followed by a second injection 24 hours later. A control group of 10 animals was treated with injections of 0.9% sodium chloride solution. Vasospasm was verified by pressure-controlled angiography after retrograde cannulation of the external carotid artery 7 days later. In 11 of 15 animals radiographic evidence of cerebral vasospasm was seen. The animals were perfusion fixed and their brains were removed for immunohistochemical assessment. With the aid of a microscope, staining for iNOS was quantified in 40-µm floating coronal sections.

Immunohistochemical staining for iNOS was markedly more intense in animals with significant angiographic evidence of vasospasm. Virtually no staining was observed in control animals. Seven days after the second experimental SAH, labeling of iNOS was found in endothelial cells, in vascular smooth-muscle cells, and, above all, in adventitial cells. Some immunohistochemical staining of iNOS was observed in rod cells (activated microglia), in glial networks, and in neurons.

Conclusions. The present study demonstrates induction of iNOS after experimental SAH.
Increased inspired oxygen concentration as a factor in improved brain tissue oxygenation and tissue lactate levels after severe human head injury
Authors: Menzel Matthias , Doppenberg Egon M. R. , Zauner Alois , Soukup Jens , Reinert Michael M. , Bullock Ross
Published: May 2009

Object. Early impairment of cerebral blood flow in patients with severe head injury correlates with poor brain tissue O2 delivery and may be an important cause of ischemic brain damage. The purpose of this study was to measure cerebral tissue PO2, lactate, and glucose in patients after severe head injury to determine the effect of increased tissue O2 achieved by increasing the fraction of inspired oxygen (FiO2).

Methods. In addition to standard monitoring of intracranial pressure and cerebral perfusion pressure, the authors continuously measured brain tissue PO2, PCO2, pH, and temperature in 22 patients with severe head injury. Microdialysis was performed to analyze lactate and glucose levels. In one cohort of 12 patients, the PaO2 was increased to 441 ± 88 mm Hg over a period of 6 hours by raising the FiO2 from 35 ± 5% to 100% in two stages. The results were analyzed and compared with the findings in a control cohort of 12 patients who received standard respiratory therapy (mean PaO2 136.4 ± 22.1 mm Hg).

The mean brain PO2 levels increased in the O2-treated patients up to 359 ± 39% of the baseline level during the 6-hour FiO2 enhancement period, whereas the mean dialysate lactate levels decreased by 40% (p < 0.05). During this O2 enhancement period, glucose levels in brain tissue demonstrated a heterogeneous course. None of the monitored parameters in the control cohort showed significant variations during the entire observation period.

Conclusions. Markedly elevated lactate levels in brain tissue are common after severe head injury. Increasing PaO2 to higher levels than necessary to saturate hemoglobin, as performed in the O2-treated cohort, appears to improve the O2 supply in brain tissue. During the early period after severe head injury, increased lactate levels in brain tissue were reduced by increasing FiO2. This may imply a shift to aerobic metabolism.