Olfactory schwannomas - an enigmatic clinical entity.

Olfactory Schwannomas (OS) are a rare, benign tumour entity. Throughout literature, only few cases have been reported. We describe here a case of a 75-year-old female with a contrast enhanced mass lesion in the anterior fossa, who underwent a surgical removal and its histopathological analysis was consistent with a schwannoma. The description of the origin of this tumour is intriguing and enigmatic. Although rare, this type of tumour should always be included in the differential diagnosis of anterior fossa lesions. Further research on the pathogenesis and the natural course of OS is needed.

Robot-assisted versus navigated transpedicular spine fusion: A comparative study.

BACKGROUND: The aim of this study was to compare the intraoperative and postoperative outcomes between a robot-assisted versus a navigated transpedicular fusion technique. METHODS: This retrospective analysis included patients who underwent transpedicular posterior fusion of the spine due to trauma, pyogenic spondylodiscitis and osteoporosis. Surgery was done either with a robot-assisted or a percutaneous navigated transpedicular fusion technique. The outcome analysis included the duration of surgery, the radiation exposure, the postoperative screw position and complications. RESULTS: A total of 60 patients were operated and 491 screws were analysed. No statistical difference was seen in the applied cumulative effective radiation dose per patient. The radiological assessment revealed a more accurate screw placement with robot assistance. A learning curve could be observed in robot-assisted fusion. CONCLUSION: Robot-assisted and navigated transpedicular fusion techniques are both effective and safe. Robot-assisted transpedicular spine fusion goes along with higher placement accuracy but its implementation needs an adequate learning curve.

Rare Case of Convexity Meningioma Growing into Arachnoid Cyst.

BACKGROUND: Meningioma growing into an arachnoid cyst is an extremely rare event. Only 3 cases are reported in the literature. In 2 of them, an operative procedure in or near the arachnoid cyst preceded tumor growth. CASE DESCRIPTION: We report a case of a patient requiring marsupialization of an arachnoid cyst of the middle cranial fossa. On follow-up, 3 years postoperatively he showed no signs of recurrence or tumor growth. One year later, the fourth year after surgery on the cyst, he presented with large tumor growth into the former cyst's cavity. Pathologic workup after resection revealed an atypical meningioma (World Health Organization grade II). CONCLUSIONS: We discuss the possible pathogenesis in light of the scarce published literature, as well as the differential diagnosis of this rapidly growing tumor.

Duraplasty using amniotic membrane versus temporal muscle fascia: A clinical comparative study.

In the field of neurosurgery, often the dura mater cannot be sutured, and consequently, it requires a duraplasty procedure using a dural fascial graft. Since 1890, various materials have been researched as dura mater substitutes. Amniotic membrane, for example, is suitable as a dural graft material and has been used in neurosurgery since 2012. However, there has been little research on human patient's dural healing after the use of amniotic membrane in their duraplasty procedure. To address this gap, a clinical experimental study was undertaken to evaluate the human dural healing of 16 patients who had undergone duraplasty in decompressive craniectomy surgery at Dr. Soetomo General Hospital, Surabaya. The amniotic membrane allograft, was sutured to cover the dural defect for eight randomly chosen patients (Group I). The fascial autograft from the temporal muscle had been applied for eight other patients (Group II). Between 10 and 20 weeks after surgery, the patients underwent cranioplasty and dural healing evaluation by cerebrospinal fluid (CSF) leakage testing through the edge of the dural defect. The fibrocyte infiltration around the edge of the dural defect was examined histologically. Statistical analysis, using an independent t-test, was performed with a confidence interval of 95%. The results of the clinical and histological analysis suggest that an amniotic membrane graft was able to provide watertight dural closure and adequate fibrocyte infiltration comparable with that provided by temporalis muscle fascia. This study shows that using an amniotic membrane in neurosurgery has a potential advantage over an alternative dural healing.

Clinical Outcomes of Repeated Intraventricular Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells in Chronic Haemorrhagic Stroke. A One-Year Follow Up.

OBJECT: Stroke, one of the most devastating diseases, is a leading cause of death and disability throughout the world and is also associated with emotional and economic problems. The main goal of this study was to investigate the clinical outcome of the intraventricular transplantation of bone marrow mesenchymal stem cells (BM-MSCs) in post-haemorrhagic stroke patients. METHOD: This study was done consisting of eight patients with supratentorial haemorrhagic stroke, who had undergone 24 weeks of standard treatment of stroke with stable neurological deficits. All of the patients received stem cell transplantation intraventricularly using autologous BM-MSCs. Six months and Twelve months after stem cells treatment, the clinical outcomes were measured using the National Institute of Health Stroke Scale (NIHSS) and adverse effect also observed. RESULT: The results of this study showed improvement of NIHSS score values before and after the treatment in five patients. No adverse effects or complications were detected during the 1-year observation. CONCLUSION: Intraventricular transplantation of BM-MSCs has shown benefits in improving the functional status of post-haemorrhagic stroke patients with no adverse effect.

Continuous selective intra-arterial application of nimodipine in refractory cerebral vasospasm due to aneurysmal subarachnoid hemorrhage.

BACKGROUND: Cerebral vasospasm is one of the leading courses for disability in aneurysmal subarachnoid hemorrhage. Effective treatment of vasospasm is therefore one of the main priorities for these patients. We report about a case series of continuous intra-arterial infusion of the calcium channel antagonist nimodipine for 1-5 days on the intensive care unit. METHODS: In thirty patients with aneurysmal subarachnoid hemorrhage and refractory vasospasm continuous infusion of nimodipine was started on the neurosurgical intensive care unit. The effect of nimodipine on brain perfusion, cerebral blood flow, brain tissue oxygenation, and blood flow velocity in cerebral arteries was monitored. RESULTS: Based on Hunt & Hess grades on admission, 83% survived in a good clinical condition and 23% recovered without an apparent neurological deficit. Persistent ischemic areas were seen in 100% of patients with GOS 1-3 and in 69% of GOS 4-5 patients. Regional cerebral blood flow and computed tomography perfusion scanning showed adequate correlation with nimodipine application and angiographic vasospasm. Transcranial Doppler turned out to be unreliable with interexaminer variance and failure of detecting vasospasm or missing the improvement. CONCLUSION: Local continuous intra-arterial nimodipine treatment for refractory cerebral vasospasm after aSAH can be recommended as a low-risk treatment in addition to established endovascular therapies.

How to perform indexing of extravascular lung water: a validation study.

BACKGROUND: Extravascular lung water is a quantitative marker of the amount of fluid in the thoracic cavity besides the vasculature. Indexing to both predicted and actual body weight have been proposed to compare different individuals and provide a uniform range of normal. OBJECTIVE: We explored extravascular lung water measured by single-indicator transpulmonary thermodilution in a large cohort of patients without cardiopulmonary instability, in order to evaluate current and alternative indexing methods. DESIGN: Prospective, observational. SETTING: Neurosurgical ICU in a tertiary referral academic teaching hospital. PATIENTS: One hundred and one consecutive patients requiring elective brain tumor surgery and postoperative ICU surveillance. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Indexed to predicted body weight, females had a mean extravascular lung water of 9.1 (SD=3.1, range: 5-23) mL/kg and males of 8.0 (SD=2.0, range: 4-19) mL/kg (p<0.001). Values indexed to predicted body weight were inversely correlated with the patient's height (p<0.001). Indexed to the traditionally used actual body weight, data showed a significant relationship to weight (p<0.001) and gender (p<0.05). In contrast, indexing to body height presented a method without dependencies on height, weight, or gender, yielding a uniform 95% confidence interval of 218-430 mL/m. Extravascular lung water increased with positive perioperative fluid balance (p=0.04). CONCLUSIONS: Using either predicted or actual body weight for indexing extravascular lung water does not lead to independence of height, weight, and gender of the patient. Specifying a fixed range of normal or a uniform upper threshold for all patients is misleading for either method, despite widespread use. Our data suggest that indexing extravascular lung water to height is superior to weight-based methods. As we are not aware of any abnormal hemodynamic profile for brain tumor patients, we propose our findings to be a close approximation to normal values.

Meningioma surgery in the elderly: outcome and validation of 2 proposed grading score systems.

BACKGROUND: Although population age increases, published evidence on meningioma treatment in the elderly is scarce. OBJECTIVE: In order to improve selection for surgery, we investigated our patients' collective, using 2 proposed risk assessment systems, the Clinical-Radiological Grading System (CRGS) and the SKALE score (sex, Karnofsky, American Society of Anesthesiology [ASA] score, location, edema). METHODS: We retrospectively assessed morbidity and mortality in 164 patients aged ≥ 65, operated on for an intracranial meningioma. Medical and surgical records were reviewed and analyzed. CRGS and SKALE scores were calculated. The ability of both CRGS and SKALE and all single factors to predict death within 12 months was analyzed by the use of multivariate logistic regression modeling. RESULTS: Eleven patients died (6.7%). Logistic regression for CRGS/SKALE showed a significant relationship with 12 months mortality. Age, Simpson resection grade, and sex were not significant predictors when investigated alone. In multivariate logistic regression, including all proposed factors, only concomitant disease and edema (CRGS) as well as ASA score and preoperative Karnofsky Performance Scale (SKALE) showed a significant relationship to mortality. After stepwise reduction of the full multivariate regression model to its significant terms, only concomitant disease and ASA remained significant for CRGS (P < .001) and SKALE (P = .003), respectively. CONCLUSION: Meningioma resection in the elderly is possible with some mortality. We were unable to reproduce the utility of 2 proposed grading systems for mortality prediction when extending to younger patients. In single-factor analysis, only concomitant disease and ASA score remained significant. The decision whether to operate should be taken individually. Patients with severe concomitant disease or high ASA score should be advised not to undergo surgical therapy independently from other factors.

Modern management of rare brain metastases in adults.

Brain metastases (BM) represent the main cause of intracranial neoplasms in adults, while being relatively less common in children. Today, better treatment options of the primary malignancy lead to higher remission rates as well as prolonged stable clinical conditions. This may in part explain the increased incidence of BM. Morbidity and mortality rates in patients with malignancies deteriorate significantly in cases of metastatic involvement of the central nervous system. Nowadays, especially modern management using surgical, medical, and radiotherapeutic options for treatment of BM tends to improve survival rates and enhance quality of life. Nonetheless, almost all treatment options are considered as palliative. In this review, we outline current knowledge of the incidence, diagnostic facilities, and therapeutic management of rare BM, with consideration of the basic aspects of the primary malignancy.

Stereotactic fractionated radiotherapy and LINAC radiosurgery in the treatment of vestibular schwannoma-report about both stereotactic methods from a single institution.

PURPOSE: To evaluate tumor control and side effects associated with radiosurgery (RS) and stereotactic fractionated radiotherapy (SFR) for vestibular schwannomas (VSs) in a group of patients treated at the same institution. METHODS AND MATERIALS: Between May 1997 and June 2007, 115 consecutive cases of VS were treated in our department. The SFR group (47 patients), including larger tumors (maximum diameter >1.5 cm), received a total dose of 54 Gy at 1.8 Gy per fraction. The RS group (68 patients, maximum diameter <1.5 cm) received a total dose of 12 Gy at the 100% isodose. Evaluation included serial imaging tests (magnetic resonance imaging) and neurologic and functional hearing examinations. RESULTS: The tumor control rate was 97.9% in the SFR group for a mean follow-up time of 32.1 months and 98.5% in the RS group for a mean follow-up time of 30.1 months. Hearing function was preserved after RS in 85% of the patients and after SFR in 79%. Facial and trigeminal nerve function remained mostly unaffected after SFR. After RS, new trigeminal neuropathy occurred in 9 of 68 patients (13%). CONCLUSIONS: A high tumor control rate and low number of side effects are registered after SFR and RS of VS. These results confirm that considering tumor diameter, both RS and SFR are good treatment modalities for VS.

The new aneurysm clip system for particularly complex aneurysm surgery: technical note.

BACKGROUND: Currently, there is an ongoing debate regarding the best treatment option for ruptured aneurysms. The International Subarachnoid Aneurysm Trial study suggests that an endovascular procedure is the best treatment. In some complex cases, or in patients with an additional large intracerebral hemorrhage, aneurysms require further microsurgical clipping. OBJECTIVE: We introduce a new clip system to improve clipping procedures in especially complex aneurysms. METHODS: The inverted opening mechanism of the clip in combination with the special clip applier provides the surgeon with a good overview in the operating field. The new design also enables a wider opening of the clip jaws in contrast to all other well-known titanium aneurysm clips. This should provide a better and safer application and decrease the danger of premature rupture. RESULTS: From January 2006 to July 2008, 55 aneurysms were clipped in 45 patients. The most common aneurysm location was the anterior communicating artery (20 patients) followed by the M1 segment of the middle cerebral artery (16 patients). Four patients had 2, one had 3, and one had 5 aneurysms. Two clipping procedures were performed for an arteriovenous malformation-associated aneurysm. All aneurysms were clipped without any technical complication. CONCLUSION: The use of the new clip system, especially in complex aneurysm surgery, has potential benefits because of the better surgical vision during clip application and the wider opening of the clip jaws. It is easy to handle and compatible with magnetic resonance imaging.

Iatrogenic tension pneumothorax resulting in pneumocephalus after insertion of a ventriculoperitoneal shunt: an unusual complication.

We report the case of an iatrogenic tension pneumothorax related to the placement of a ventriculoperitoneal shunt, followed by pneumocephalus. The patient was pending cranioplasty and shunt placement after decompressive craniectomy for acute subdural hematoma and posttraumatic hydrocephalus. Facilitating the severe and potential life-threatening complication was a severe obesity of the patient as well as incorrect surgical technique.

Global end-diastolic volume acquired by transpulmonary thermodilution depends on age and gender in awake and spontaneously breathing patients.

INTRODUCTION: Volumetric parameters acquired by transpulmonary thermodilution had been repeatedly proven superior to filling pressures for estimation of cardiac preload. Up to now, the proposed normal ranges were never studied in detail. We investigated the relationship of the global end-diastolic volume (GEDV) acquired by transpulmonary thermodilution with age and gender in awake and spontaneously breathing patients. METHODS: Patients requiring brain tumor surgery were equipped prospectively with a transpulmonary thermodilution device. On postoperative day one, thermodilution measurements were performed in 101 patients ready for discharge from the ICU. All subjects were awake, spontaneously breathing, hemodynamically stable and free of catecholamines. RESULTS: Main finding was a dependence of GEDV on age and gender, height and weight of the patient. Age was a highly significant non-linear coefficient for GEDV with large inter-individual variance (p < 0.001). On average, GEDV was 131.1 ml higher in males (p = 0.027). Each cm body height accounted for 13.0 ml additional GEDV (p < 0.001). GEDV increased by 2.90 ml per kg actual body weight (p = 0.043). Each cofactor, including height and weight, remained significant after indexing GEDV to body surface area using predicted body weight. CONCLUSIONS: The volumetric parameter GEDV shows a large inter-individual variance and is dependent on age and gender. These dependencies persist after indexing GEDV to body surface area calculated with predicted body weight. Targeting resuscitation using fixed ranges of preload volumes acquired by transpulmonary thermodilution without concern to an individual patient's age and gender seems not to be appropriate.

Matrix metalloproteinase expression levels suggest distinct enzyme roles during lumbar disc herniation and degeneration.

The disruption of the extracellular disc matrix is a major hallmark of disc degeneration. This has previously been shown to be associated with an up-regulation of major matrix metalloproteinase (MMP) expression and activity. However, until now hardly any data are available for MMP/TIMP regulation and thereby no concept exists as to which MMP/TIMP plays a major role in disc degeneration. The objective of this study was, therefore, to identify and quantify the putative up-regulation of MMPs/TIMPs on the mRNA and protein level and their activity in disc material in relation to clinical data and histological evidence for disc degeneration. A quantitative molecular analysis of the mRNA expression levels for the MMPs (MMPs-1, -2, -3, -7, -8, -9, -13) and the MMP inhibitors (TIMPs-1 and -2) was performed on 37 disc specimens obtained from symptomatic disc herniation or degeneration. In addition, disc specimens from patients without disc degeneration/herniation (=controls) were analyzed. Expression of MMPs-1, -2, -3, -7, -8, -9, -13 and TIMPs-1, -2 was analyzed using quantitative RT-PCR, normalized to the expression level of a house keeping gene (GAPDH). Gene expression patterns were correlated with MMP activity (in situ zymography), protein expression patterns (immunohistochemistry), degeneration score (routine histology) and clinical data. MMP-3 mRNA levels were consistently and substantially up-regulated in samples with histological evidence for disc degeneration. A similar but less pronounced up-regulation was observed for MMP-8. This up-regulation was paralleled by the expression of TIMP-1 and to a lesser extent TIMP-2. In general, these findings could be confirmed with regard to protein expression and enzyme activity. This study provides data on the gene and protein level, which highlights the key role of MMP-3 in the degenerative cascade leading to symptomatic disc degeneration and herniation. Control of the proteolytic activity of MMP-3 may, therefore, come into the focus when aiming to develop new treatment options for early disc degeneration.

Significance of intraoperative motor function monitoring using transcranial electrical motor evoked potentials (MEP) in patients with spinal and cranial lesions near the motor pathways.

Intraoperative motor evoked potential (MEP) monitoring in patients with spinal and cranial lesions is thought to be a valuable tool for prevention of postoperative motor deficits. Aim of this study was to investigate its diagnostic value in a spinal and a cranial patient group. Ninety-six patients, 31 with spinal and 65 with intracranial lesions, were studied. Transcranial stimulation was performed with a high-frequency electrical train stimulation using two subdermal needle electrodes. MEPs were recorded from the pathology-related muscles. Decreasing amplitudes of 50% or more, increasing stimulus intensities of 20% or more or increased latencies were taken as warning criteria. MEP recording was possible in 90% of the spinal and 98% of the cranial group. With two further exclusions, 28 patients of the spinal and 62 of the cranial group were analyzed. We saw a temporary maximum amplitude reduction of 50% or more and an increase in stimulation intensity of 20% or more in 8 spinal and 29 cranial patients. Five of the spinal and nine of the cranial patients deteriorated in motor function postoperatively. One patient with normal MEP monitoring showed a temporary motor weakness postoperatively. Latencies were normal in all patients. Given both warning criteria, intraoperative MEP changes had a sensitivity of 83%/ 100% and a specificity of 86%/ 62% (spinal/ cranial group). The positive predictive value of MEP changes for postoperative motor function deterioration was 63%/ 31%, and the negative predictive value was 95%/ 100%. Transcranial electrical monitoring of MEP is a practicable and safe method. However, there are many events, which can cause amplitude changes of MEP independent from surgical manipulations. Although sensitivity is high for both groups, this results in a moderate specificity for the cranial group and a low positive predictive value for both groups.

Secondary intracranial hypertension with acute intracranial pressure crisis in superficial siderosis.

Superficial siderosis of the central nervous system is a very rare disease related to hemosiderin deposits in the brain, brainstem, cerebellum and spinal cord due to chronic subarachnoid hemorrhage. Chronic increased intracranial pressure develops in about one-third of affected cases. We report a patient with superficial siderosis and sudden intracranial pressure crisis. A 29-year-old man experienced a subacute episode of headache, tinnitus and blurred vision. Magnetic resonance imaging of the brain revealed hemosiderin deposits characteristic of superficial siderosis. Extensive diagnostic work-up excluded causative pathologies of bleeding. Lumbar puncture and continuous intra-ventricular cerebrospinal fluid (CSF) pressure monitoring revealed continuous CSF pressure increase. Implantation of a ventriculo-peritoneal shunt led to complete clinical recovery. Our case emphasizes that patients with superficial siderosis may present with sudden elevation of intracranial pressure due to chronic intracranial hypertension. In this situation permanent CSF drainage provides a useful therapeutic option.

Pullout test with three lumbar interbody fusion cages.

STUDY DESIGN: In vitro biomechanical testing was performed on 12 cadaveric human lumbar spines. OBJECTIVE: To determine the initial dislocation resistance, as quantified by the pullout force of three different cage designs. SUMMARY OF BACKGROUND DATA: Interbody cage devices frequently are used as stand-alone cages in the surgical treatment of degenerative conditions in the lumbar spine. In contrast to the wide clinical acceptance of interbody fusion cages, there are only a few biomechanical studies of posterior pullout trials. METHODS: Cylindrical threaded cages (Ray TFC Surgical Dynamics), bullet-shaped cages (Stryker), and newly designed rectangular titanium cages with an endplate anchorage device (Marquardt) were used for posterior interbody implants. For each device, the pullout test was performed in four specimens on both sides (L3-L4). RESULTS: In the pullout test, the Stryker cages required a median pullout force of 130 N (minimum, 100 N; maximum, 220 N), as compared with the higher pullout force of the Marquardt cages (median, 605 N; minimum, 450 N; maximum, 680 N), and the Ray cages (median, 945 N; minimum, 125 N; maximum, 2230 N). CONCLUSIONS: Differences in pullout resistance were noted depending on the cage design. A cage design with threads or a hook device provides superior stability, as compared with ridges. The initial pullout resistance was highest for the Ray cages and lowest for the Stryker cages.