A novel gas sampling introduction interface for fast analysis of volatile organic compounds using radiofrequency pulsed glow discharge time of flight mass spectrometry.

An improved gas sample introduction interface is developed and characterized for gas chromatography coupling and for direct injection of volatile organic compounds (VOCs), in a pulsed glow discharge (pulsed-GD) ion source coupled to a time of flight mass spectrometer (TOFMS) that is typically used for direct solid analysis. The novel interface allows the introduction of the analytes in the flowing afterglow region of the GD (a few mm away from the negative glow region) to reduce plasma quenching effects. Analyte ion signals are acquired in the temporal afterglow region, where low fragmentation of the molecular species is produced, providing useful qualitative and quantitative molecular information (e.g. molecular ion). Analytical capabilities of the pulsed-GD ion source with the novel gas sampling interface provides improved performance compared to previous designs. In particular, limits of detection for the analysis of VOCs in air were below (better) that legally established limits according to Directive 2008/50/EC of the European Parliament.

Minimally invasive medial supraorbital, combined subfrontal-interhemispheric approach to the anterior communicating artery complex-a cadaveric study.

INTRODUCTION: In selected cases, microsurgical clipping remains a valuable treatment alternative to endovascular occlusion of anterior communicating artery (AComA) aneurysms. Their clipping is challenging and carries a risk of postsurgical cognitive impairment. We evaluate the microsurgical anatomy of a new, minimally invasive combined interhemispheric-subfrontal approach to the AComA complex via a medial supraorbital craniotomy. METHODS: In this descriptive anatomic study, four alcohol-embedded, silicon-injected human cadaver heads were used. In each of the two cadavers, the AComA complex was approached from either the right or left side. An operating microscope and standard microsurgical instruments were used. RESULTS: After a medial eyebrow incision, a medial supraorbital minicraniotomy was performed. The frontal sinus was opened and cranialized. Following the dural opening, a subfrontal arachnoid dissection was performed to identify the optico-carotid complex. By following the A1 segment, a low-lying AComA complex could be visualized. Shifting the corridor towards the midline enabled an interhemispheric dissection. This dissection resulted in a wide superior-inferior corridor. Higher-lying AComA complexes could also be visualized. The achieved exposure of the AComA complex would allow safe dissection and clipping of low- and high-lying AComA aneurysms, with minimal retraction and preservation of the surrounding anatomical structures, in particular the perforators. CONCLUSIONS: We demonstrate the anatomy of a novel approach for surgical clipping of AComA aneurysms. Our study suggests that this approach provides good exposure without concomitant structural and vascular injury and thus might reduce the risk of procedure-related morbidity.

Effect of ADAMTS-13 on cerebrovascular microthrombosis and neuronal injury after experimental subarachnoid hemorrhage.

BACKGROUND: Microthrombosis and reactive inflammation contribute to neuronal injury after subarachnoid hemorrhage (SAH). ADAMTS-13 cleaves von Willebrand factor multimers, and inhibits thrombus formation and, seemingly, inflammatory reactions. OBJECTIVE: To investigate the effect of ADAMTS-13 in experimental SAH. METHODS: A total of 100 male C57/BL6 mice were randomly assigned to four groups: sham (n = 15), SAH (n = 27), vehicle (n = 25), and ADAMTS-13 (n = 23; 100 µL per 10 g of body weight of 100 µg of ADAMTS-13 per 1 mL of 0.9% NaCl; 20 min after SAH). Neurologic performance was assessed on days 1 and 2 after SAH. Animals were killed on day 2. The amounts of subarachnoid blood, microthrombi, apoptosis and degenerative neurons were compared. The degree of neuronal inflammation and vasospasm was also compared. In five mice each (SAH and ADAMTS-13 groups), bleeding time was assessed 2 h after SAH. RESULTS: Systemic administration of ADAMTS-13 achieved significant amelioration of microthrombosis and improvement in neurologic performance. ADAMTS-13 reduced the amount of apoptotic and degenerative neurons. A tendency for decreased neuronal inflammation was observed. ADAMTS-13 did not show any significant effect on vasospasm. The degree of systemic inflammation was not changed by ADAMTS-13 administration. ADAMTS-13 neither increased the amount of subarachnoid blood nor prolonged the bleeding time. CONCLUSIONS: ADAMTS-13 may reduce neuronal injury after SAH by reducing microthrombosis formation and neuronal inflammation, thereby providing a new option for mitigating the severity of neuronal injury after SAH.

Aneurysms of the posterior cerebral artery and approach selection in their microsurgical treatment: emphasis on the approaches: SAHEA and SCTTA.

Aneurysms of the posterior cerebral artery (PCA) are infrequent and located in the central depth of the brain. Hence their optimal microsurgical management has not been discussed systematically, as institutions and/or neurosurgeons have only limited experience. The purpose of this communication is to report our considerations on this topic with emphasis on the selection of approaches by reviewing our 20 consecutive cases of PCA aneurysms out of more than 1,000 aneurysm patients seen over the past 15 years. Although the subtemporal approach appears to be prevalent in the literature, in our series we applied the pterional approach with or without selective extradural anterior clinoidectomy (SEAC) for P1, P1-P2 aneurysms, and either a selective amygdalohippocampectomy approach (SAHEA) or supracerebellar transtentorial approach (SCTTA) for P2 and P2-P3 aneurysms. Construction of an extracranial-intracranial EC-IC bypass, when necessary, in conjunction with parent artery occlusion or with trapping of aneurysms was adapted to selected approaches.

Complex bilobular, bisaccular, and broad-neck microsurgical aneurysm formation in the rabbit bifurcation model for the study of upcoming endovascular techniques.

BACKGROUND AND PURPOSE: Despite rapid advances in the development of materials and techniques for endovascular intracranial aneurysm treatment, occlusion of large broad-neck aneurysms remains a challenge. Animal models featuring complex aneurysm architecture are needed to test endovascular innovations and train interventionalists. MATERIALS AND METHODS: Eleven adult female New Zealand rabbits were assigned to 3 experimental groups. Complex bilobular, bisaccular, and broad-neck venous pouch aneurysms were surgically formed at an artificially created bifurcation of both CCAs. Three and 5 weeks postoperatively, the rabbits underwent 2D-DSA and CE-3D-MRA, respectively. RESULTS: Mortality was 0%. We observed no neurologic, respiratory, or gastrointestinal complications. The aneurysm patency rate was 91% (1 aneurysm thrombosis). There was 1 postoperative aneurysm hemorrhage (9% morbidity). The mean aneurysm volumes were 176.9 ± 63.6 mm(3), 298.6 ± 75.2 mm(3), and 183.4 ± 72.4 mm(3) in bilobular, bisaccular, and broad-neck aneurysms, respectively. The mean operation time was 245 minutes (range, 175-290 minutes). An average of 27 ± 4 interrupted sutures (range, 21-32) were needed to create the aneurysms. CONCLUSIONS: This study demonstrates the feasibility of creating complex venous pouch bifurcation aneurysms in the rabbit with low morbidity, mortality, and high short-term aneurysm patency. The necks, domes, and volumes of the bilobular, bisaccular, and broad-neck aneurysms created are larger than those previously described. These new complex aneurysm formations are a promising tool for in vivo animal testing of new endovascular devices.

Monitoring of the inflammatory response after aneurysmal subarachnoid haemorrhage in the clinical setting: review of literature and report of preliminary clinical experience.

BACKGROUND: Clinical and experimental studies showed a marked inflammatory response in aneurysmal subarachnoid haemorrhage (SAH), and it has been proposed to play a key role in the development of cerebral vasospasm (CVS). Inflammatory response and occurrence of CVS may represent a common pathogenic pathway allowing point of care diagnostics of CVS. Therefore, monitoring of the inflammatory response might be useful in the daily clinical setting of an ICU. The aim of the current report is to give a summary about factors contributing to the complex pathophysiology of inflammatory response in SAH and to discuss possible monitoring modalities. METHODS: Review and analysis of the existing literature and definition of own study protocols. RESULTS: In cerebrospinal fluid, interleukin (IL)-6 has been found to be significantly higher in patients with CVS during the peri-vasospasm period. While systemic inflammatory response syndrome, high C-reactive protein levels and leukocyte counts has been linked with the occurrence of CVS, less has been reported about cytokines levels in the jugular bulb of the internal jugular vein and in the peripheral blood. Preliminary evaluation of own data suggests, that IL-6 values in the peripheral blood and the arterio-jugular differences of IL-6 are increased with the inflammatory response after SAH. CONCLUSION: Monitoring of the inflammatory response, in particular IL-6, might be a useful tool for the daily clinical management of patients with SAH and CVS.

Improved microsurgical creation of venous pouch arterial bifurcation aneurysms in rabbits.

BACKGROUND AND PURPOSE: The choice of the experimental aneurysm model is essential for valid embolization-device evaluations. So far, the use of the rabbit venous pouch arterial bifurcation aneurysm model has been limited by demanding microsurgery, low aneurysm patency rates, and high mortality. This study aimed to facilitate microsurgery and to reduce mortality by optimized peri-/postoperative management. MATERIALS AND METHODS: Aneurysms were created in 16 New Zealand white rabbits under general intravenous anesthesia. Using modified microsurgical techniques, we sutured a jugular vein pouch into a bifurcation created between both CCAs. Aggressive anticoagulation (intraoperative intravenous: 1000-IU heparin, 10-mg acetylsalicylic acid/kg; postoperative subcutaneous: 14 days, 250-IU/kg /day heparin) and prolonged postoperative anesthesia (fentanyl patches: 12.5 µg/h for 72 hours) were applied. Angiographic characteristics of created experimental aneurysms were assessed. RESULTS: The reduced number of interrupted sutures and aggressive anticoagulation caused no intra-/postoperative bleeding, resulting in 0% mortality. Four weeks postoperation, angiography showed patency in 14 of 16 aneurysms (87.5%) and Ohshima type B bifurcation geometry. Mean values of parent-artery diameters (2.3 mm), aneurysm lengths (7.9 mm), and neck widths (4.1 mm) resulted in a mean 1.9 aspect ratio. CONCLUSIONS: Compared with historical controls, the use of modified microsurgical techniques, aggressive anticoagulation, and anesthesia resulted in higher aneurysm patency rates and lower mortality rates in the venous pouch arterial bifurcation aneurysm model. Gross morphologic features of these aneurysms were similar to those of most human intracranial aneurysms.

Prognostic and developmental factors in patients receiving liver transplant due to hepatocellular carcinoma: one center's experience in the north of Spain.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most frequent types of tumor. The aim of this study was to determine the survival of patients who had received liver transplants as a result of the disease. METHODS: This observational follow-up study included 150 patients who received liver transplantations from June 1994 to December 2007. The study considered epidemiological and staging variables, tumor descriptions, and follow-up variables. We employed Kaplan-Meier methodology together with a Cox multivariate regression analysis. RESULTS: The incidence of tumor relapse was 13.3%, with survival rates at 1, 3, and 5 years of 89.3%, 73.1%, and 61.4%, respectively. Variables that showed an independent effect to predict mortality were the degree of histological differentiation and of macrovascular invasion. Patients with poorly differentiated HCC had a 4.03 fold (95% confidence interval [CI]: 1.61-10.06) greater possibility of dying. Macrovascular involvement increased the risk of death (relative risk = 2.23), an effect that was at the limit of significance (95% CI 0.99-5.04). CONCLUSIONS: The survival rate was consistent with the literature. Poor tumor differentiation and macrovascular involvement were independent predictors of mortality.

Lhermitte-Duclos disease with atypical vascularization--case report and review of the literature.

OBJECTIVE: A case of Lhermitte-Duclos disease (LDD, dysplastic gangliocytoma) with atypical vascularization is reported. LDD is a rare cerebellar mass lesion which may be associated with Cowden's syndrome and the PTEN germline mutation. CASE MATERIAL: A 61-year-old male presented 15 years before with a transient episode of unspecific gait disturbance. Initial magnetic resonance (MR) imaging revealed a right-sided, diffuse, nonenhancing cerebellar mass lesion. No definitive diagnosis was made at that time, and the symptoms resolved spontaneously. 15 years later, the patient presented with acute onset of vomiting associated with headache and ataxic gait. MR imaging showed a progression of the lesion with occlusive hydrocephalus. The lesion depicted a striated pattern characteristic for LDD with T1-hypointense and T2-hyperintense bands, nonenhancing with contrast. After resection of the mass lesion, the cerebellar and hydrocephalic symptoms improved rapidly. The pathological examination confirmed the diagnosis of dysplastic gangliocytoma (WHO Grade I) with enlarged granular and molecular cell layers, reactive gliosis and dysplastic blood vessels. No other clinical features associated with Cowden's syndrome were present. CONCLUSIONS: This case illustrates that LDD with atypical vascularization is a slow-growing posterior fossa mass lesion which may remain asymptomatic for many years. Timing of surgical treatment and extent of resection in patients with LDD is controversial. The typical features on standard T1-/T2-weighted MR imaging allow a diagnosis without surgery in most cases. The authors believe that the decision to treat in these cases should be based on clinical deterioration.

Decompressive craniectomy in severe cerebral venous and dural sinus thrombosis.

OBJECTIVE: To evaluate the outcome of patients with most severe cerebral venous and dural sinus thrombosis (CVT) after decompressive craniectomy. Indications and techniques for decompressive craniectomy and intensive care regimen are discussed. METHODS: Between 2000 and 2004 15 patients with CVT and intracerebral hemorrhage were treated at the Department of Neurosurgery, University Hospital Zurich. Among them, four patients with the most severe illness course were treated with decompressive craniectomy. Indications for decompressive craniectomy were deterioration of level of consciousness with CT signs of space occupying brain edema, venous infarction and congestional bleeding with mass effect, midline shift and obliteration of the basal cisterns. RESULTS: Among 15 patients with CVT and intraparenchymatous hemorrhage four patients were treated with decompressive craniectomy. Glasgow Coma Scale (GCS) immediately before the operation was in mean 10.2 (range 6 to 13). No patient showed signs of unilateral or bilateral third nerve palsy before surgery. No surgical complications were observed. All four patients who underwent decompressive craniectomy recovered with favourable functional outcome (Glasgow Outcome Scale; GOS 4 and 5). Anticoagulation therapy with heparin was reconvened 12 hours postoperatively with half dosage and 12 hours later with full dosage. No enlargement of existing intraparenchymatous hematoma or other intracranial bleeding complications occurred. CONCLUSIONS: Favorable functional outcome in selected patients with most severe courses of CVT can be achieved after decompressive craniectomy. Postoperative anticoagulation therapy with full dose heparin 24 hours after craniotomy seems to be safe. Precise indications and techniques for combined surgical decompression and thrombectomy deserve to be evaluated in future studies.

[Quadrigeminal cistern and calcarine fissure lipoma: case report and review of the literature]. / Lipoma de la cisterna cuadrigémina y cisura calcarina: caso clínico y revisión de la literatura.

We report the case of a multiple intracranial lipoma in a 47 year-old patient presenting with headache dizziness and quadrantanopsia. MR imaging revealed the presence of 2 lipomas, one located within the quadrigeminal cistern and the other in the calcarine fissure. To our knowledge, this combination of this rare lesion has not been yet described. We review the current literature.

[Ischemic stroke, secondary to fibromuscular dysplasia: a case report]. / Accidente vascular cerebral isquémico secundario a displasia fibromuscular: a propósito de un caso.

INTRODUCTION: Fibromuscular dysplasia is an infrequent angiopathy that occurs more often in young women. It consists in a series of heterogeneous histological changes that finally lead to the narrowing of arteries. Clinical manifestations depend on the vessel involved, but high blood pressure (renal artery involvement) and stroke (carotid artery involvement) are the most common. Little has been published about this process in recent years. CASE REPORT: A 30-year-old female with extensive infarction of the right middle cerebral artery caused by obstruction of the internal carotid artery. Arteriographical examination revealed the dissection of the four supra-aortic trunks together with alterations to the renal artery. The patient's age and the involvement of the four cerebral arteries with irregular stenoses led us to consider a fibromuscular dysplasia (FMD) as the first diagnostic option. A conservative attitude was adopted towards the vascular lesions and therapy was carried out with a view to rehabilitating the neurological deficits. DISCUSSION: Brain FMD can be asymptomatic and is often diagnosed by chance. The usual clinical presentation is a stenosis-related ischemic stroke, arterial obstruction or arterio-arterial thromboembolism. Arteriography or magnetic resonance angiography are useful for diagnosis; the involvement of different supra-aortic vessels is characteristic. Despite the good results shown by percutaneous transluminal angioplasty, there is still a need for prospective studies that determine the optimal treatment for this pathology.

[Intracranial lipomas]. / Lipomas intracraneales.

INTRODUCTION: This paper reviews current literature about intracranial lipomas with emphasis on histogenesis, diagnosis and therapy. DEVELOPMENT: Intracranial lipoma is a congenital malformation. Epilepsy, mental dysfunctions and headache are the most common clinical manifestations, being a third of the asymptomatic cases; certain localizations cause specific symptomatology of the involved area. Associate anomalies are given in half of the lipomas, being the most frequent the agenesia of the corpus callosus. The diagnosis is not possible based on the clinical data, so it is necessary the practice of complementary exams in every suspected cases. The neuroimaging studies (TC or MRI) usually permit the diagnosis of this entity in an objective way and practically of certainty. It has been adduced a numberless histogenic theory on the lipomas, being accepted the lipoma like congenital malformation at the present time. The surgery is contraindicated, however still play a role in the management of some cases of hydrocephalus and bony affectation. The medical control of the epilepsy is forced. CONCLUSIONS: The development of the neuroimaging techniques and the biggest compression in the histogenesis have increased the knowledge that one had of the intracranial lipomas, modifying their presage and giving up the aggressive surgery of last times.

Simplified quantitative determination of cerebral perfusion reserve with H2(15)O PET and acetazolamide.

The measurement of regional cerebral blood flow (rCBF) and perfusion reserve (PR) with H2(15)O positron emission tomography (PET) and acetazolamide challenge is of importance in evaluating patients with cerebrovascular disease and is thought to be useful in selecting patients for possible vascular surgery. Full quantitative assessment of rCBF with PET requires arterial blood sampling, which is inconvenient in a clinical setting. In this work, we present a simple non-invasive method with which to quantitatively evaluate PR in one PET session lasting no more than 30 min. In ten patients with cerebrovascular disease, rCBF was measured with H2(15)O PET under the baseline condition and after administration of 1 g acetazolamide using a standard technique involving arterial blood sampling. The activity accumulated over 60 s was normalized to injected activity per kilogram body weight (nAA) and compared with rCBF in eight different brain regions. A high linear correlation was found for PR based on nAA (PRnAA) and rCBF (PRrCBF) (PRnAA=0.843 PRrCBF + 0.092, r=-0.83, Pearson's correlation coefficient). Bland-Altman analyses further confirmed that PRnAA reflects PR in a quantitative manner. These results demonstrate that the method based on normalized counts allows the quantitative assessment of PR without blood sampling.

Corpus callosotomy in Colombia and some reflections on care and research among the poor in developing countries.

The authors present the results of a series of corpus callosotomies (CCS) in 97 patients performed from 1989 to 1997 at the Hospital Neurologico of the Liga Colombiana Contra La Epilepsia, Cartagena, Colombia. This study demonstrates the feasibility of performing these procedures in the developing world and analyzes the outcome and cost of treatment. Patients with medically intractable secondarily generalized epilepsy, bilateral nonfocal epileptic electroencephalogram (EEG), and absence of progressive encephalopathy were accepted as candidates (patients aged 0-30 years; 62 children, 19 girls and 43 boys, with mean age at surgery of 7.9 years; 35 adults, 19 women and 16 men, with mean age at surgery of 25.8 years). Preoperatively, the mean seizure frequency was 12.1 per day, or 364 per month (range, 0.06-200 per day, 1.8-6000 per month). Before surgery, 40% of patients were classified with generalized tonic-clonic seizures of different etiologies, or cryptogenic seizures; 36% had mixed seizures; 19% had Lennox-Gastaut Syndrome; and 5% had West Syndrome. Usually, routine EEG, computed tomography, and clinical findings sufficed for the surgical decision. The standard microsurgical technique performed was an anterior two-thirds CCS by the same surgeon under general anesthesia. In five cases, an additional frontal lobe excision after electrocorticography and subdural electrode monitoring was carried out in the same session. The results were evaluated after a mean follow-up of 35 months (range, 12-28). Two thirds of patients became seizure-free or were left with none or some disabling seizures. AED medication was eased slightly after surgery. The complication rate was low. The patients underwent postoperative psychosocial studies and neuropsychological rehabilitation and showed tendencies toward improvement. The direct cost of CCS in U.S. dollars (US$) ranged between 3,137 and 3,995 depending on the preoperative studies. Thus, CCS is well suited for selected patients in developing countries. Thus far, implantation of a vagus nerve stimulator has exceeded our economic possibilities in treating similar patients. Some reflections on care and research among epilepsy patients in developing countries are discussed.

Intraoperative validation of functional magnetic resonance imaging and cortical reorganization patterns in patients with brain tumors involving the primary motor cortex.

OBJECT: The purpose of the present study was to compare the results of functional magnetic resonance (fMR) imaging with those of intraoperative cortical stimulation in patients who harbored tumors close to or involving the primary motor area and to assess the usefulness of fMR imaging in the objective evaluation of motor function as part of the surgical strategy in the treatment of these patients. METHODS: A total of 11 consecutive patients, whose tumors were close to or involving the central region, underwent presurgical blood oxygen level-dependent fMR imaging while performing a motor paradigm that required them to clench and spread their hands contra- and ipsilateral to the tumor. Statistical cross-correlation functional maps covering the primary and secondary motor cortical areas were generated and overlaid onto high-resolution anatomical MR images. Intraoperative electrical cortical stimulation was performed to validate the presurgical fMR imaging findings. In nine (82%) of 11 patients, the anatomical fMR imaging localization of motor areas could be verified by intraoperative electrical cortical stimulation. In seven patients two or more activation sites were demonstrated on fMR imaging, which were considered a consequence of reorganization phenomena of the motor cortex: contralateral primary motor area (nine patients), contralateral premotor area (four patients), ipsilateral primary motor area (two patients), and ipsilateral premotor area (four patients). CONCLUSIONS: Functional MR imaging can be used to perform objective evaluation of motor function and surgical planning in patients who harbor lesions near or involving the primary motor cortex. Correlation between fMR imaging findings and the results of direct electrical brain stimulation is high, although not 100%. Based on their study, the authors believe that cortical reorganization patterns of motor areas might explain the differences in motor function and the diversity of postoperative motor function among patients with central tumors.

Extradural vertebral artery dissecting aneurysm causing subarachnoid haemorrhage.

The authors report the case of a 37-year-old man who presented with subarachnoid haemorrhage (SAH) after rupture of an extradural vertebral artery dissecting aneurysm. The patient underwent a left lateral suboccipital craniotomy with removal of the medial part of the occipital condyle and the fusiform dilatation was coated. The angiograms 3 months after surgery showed aneurysm resolution and normal vessel calibre. To the authors' knowledge, it is the second reported case of extracranial vertebral aneurysm of its kind presenting as SAH. The result after surgery in this case indicates that coating of a dissecting aneurysm of the extracranial portion of the vertebral artery (VA) is a valid alternative surgical technique for the prevention of rebleeding.

[Giant intraventricular arachnoid cyst: report of 2 cases]. / Quiste aracnoideo intraventricular gigante: a propóposito de dos casos.

INTRODUCTION: It is very unusual to find cysts situated intraventricularly. Only 24 cases have been described to date in the literature. CLINICAL CASES: In this paper we present two new cases considering that because of their exceptional size they deserve to be called 'giant'. The two patients had been diagnosed as having epilepsy during childhood or youth. No neuroradiological studies had ever been done. The cause of hospital admission in the first case was headache and vomiting and in the second case a convulsive crisis. We did cerebral CT scans in both cases and a MR control scan in the second case. This formed the basis for our diagnosis. Unlike previous cases they were not operated on. Their clinical course may be considered satisfactory to date, since there have been no further convulsive crisis nor other neurological alterations. We have therefore been conservative with regard to the indication for surgery in these patients. CONCLUSIONS: Review of the literature does not completely clarify the origin of these lesions but we are inclined to believe that there is an intimate relationship between the formation of an intraventricular arachnoid cyst and the choroid plexus. Many new cases will have to be diagnosed before we can fully understand the true physiopathology of these cysts.

Aneurysm surgery in the acute stage: results of structured treatment.

To evaluate the results of a structured treatment approach to aneurysm surgery in the acute stage, 150 consecutive patients with aneurysmal subarachnoid hemorrhage were studied, including 46 males and 104 females; World Federation of Neurological Surgeons grade I: 21 cases, II: 65, III: 41, IV: 23; day of operation < or = day 3: 103 cases, < or = day 7: 131. Patients underwent angiography on the day of admission or the next followed by surgery. The lamina terminalis and the membrane of Liliequest were routinely opened at surgery. The aneurysm neck was radically clipped after temporary clipping or trapping of the parent arteries. Intraoperative hemodynamic monitoring was used, and the craniotomies were closed without cisternal, epidural, or subgaleal drains. Nimodipine was given perioperatively (48 mg i.v./day for 10 to 14 days). Cases of symptomatic vasospasm were treated with selective intra-arterial administration of papaverine, sometimes combined with angioplasty. Outcome at discharge and 3 months later is good recovery in 61% and 75%, and death in 6% and 7%. The incidence of symptomatic vasospasm was 17%. Devastating vasospasms were observed in 5%. One-third of patients had mean flow velocities exceeding 120 cm/sec determined by transcranial Doppler sonography between days 4 and 14. Communicating hydrocephalus necessitating ventriculoperitoneal shunt occurred in 9%. Our results clearly show a favorable outcome compared with previous reports, especially with respect to the reduced occurrence of fatal vasospasm, hydrocephalus, and technical insufficiency.

Radicular compression by gas in a spinal extra dural cyst. Report on two cases.

The authors describe two cases of secondary sciatica due to radicular compression by a gas containing cyst in the extra dural space. The diagnosis was realized with CT-Scan and magnetic resonance imaging. In both cases removal of the cyst provided relief. The pathogenesis of the presence of epidural gas is discussed and the literature reviewed.