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In patients with hydrocephalus, prognosis and intervention are based on multiple factors. This includes, but is not limited to, time of onset, patient age, treatment history, and obstruction of cerebrospinal fluid flow. Consequently, several distinct hydrocephalus classification systems exist. The International Classification of Diseases (ICD) is universally applied, but in ICD-10 and the upcoming ICD-11, hydrocephalus diagnoses incorporate only a few factors, and the hydrocephalus diagnoses of the ICD systems are based on different clinical measures. As a consequence, multiple diagnoses can be applied to individual cases. Therefore, similar patients may be described with different diagnoses, while clinically different patients may be diagnosed identically. This causes unnecessary dispersion in hydrocephalus diagnostics, rendering the ICD classification of little use for research and clinical decision-making. This paper critically reviews the ICD systems for scientific and functional limitations in the classification of hydrocephalus and presents a new descriptive system. We propose describing hydrocephalus by a system consisting of six clinical key factors of hydrocephalus: A (anatomy); S (symptomatology); P (previous interventions); E (etiology); C (complications); T (time–onset and current age). The "ASPECT Hydrocephalus System" is a systematic, nuanced, and applicable description of patients with hydrocephalus, with a potential to resolve the major issues of previous classifications, thus providing new opportunities for standardized treatment and research. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluates the safety of laparoscopic procedures in patients with cerebrospinal fluid (CSF) catheters draining distally into the abdomen. Methods: A systematic search across PubMed, Scopus, and Ovid databases using pertinent keywords yielded 47 relevant papers, encompassing 197 cases, for analysis. Results: In the pediatric cohort (n = 129), male (49.6%) and female (34.1%) cases were reported, while gender remained unspecified in 16.3%. Shunt indications included unspecified (126 cases) and Meningomyelocele (3 cases). Laparoscopic procedures encompassed gastric (72.1%), urologic (21.7%), and other (6.2%) indications. Peri-operative shunt management included subcostal incision and clamping (1), ICP monitoring and drainage (2), and distal shunt flow confirmation (1). The prevalent complication was mechanical obstruction (10.1%), followed by pseudocyst formation (1.5%) and infection (2.3%). In the adult cohort (n = 61), males (60.6%) and females (39.3%) with a median age of 55 years were observed. Management strategies encompassed sponge packing and mobilization (11), distal shunt flow confirmation (2), shunt clamping (3), Transcranial Doppler monitoring (2), and no manipulation (30). Shunt infection emerged as the primary complication (2). Overall, 24 patients encountered VP shunt-related complications post-laparoscopy. Conclusion: This study underscores the safety of laparoscopic interventions in patients with ventriculoperitoneal or lumboperitoneal shunts when facilitated by interdisciplinary cooperation. A meticulous preoperative assessment for shunt track localization, intraoperative visualization of shunt tip with CSF flow, vigilant perioperative anesthetic monitoring, and shunt dysfunction surveillance are crucial for favorable outcomes in laparoscopic procedures for these patients. [ABSTRACT FROM AUTHOR]

Objective: A pseudomeningocele and an incisional cerebrospinal fluid leak are considered frequent complications following neurosurgical operations. The rate of these complications especially increases following neurosurgical procedures on the posterior cranial fossae. According to some publications, the rate of pseudomeningoceles has been reported as high as 40%, whereas that of incisional cerebrospinal fluid leaks is up to 17%. For the purposes of reducing the risk of these complications after a midline suboccipital craniotomy, we propose suturing the arachnoid membrane of the cisterna magna. In this paper, we present a retrospective analysis of arachnoid membrane suturing.Methods: Seventy patients underwent midline suboccipital craniotomy by the first author between 2012 and 2016 at Burdenko Neurosurgery Institute. In this group was included a consecutive group of patients with posterior fossae tumors where the approach was performed through the cisterna magna arachnoid membrane following midline suboccipital craniotomy and dural opening. The patients were divided into two groups. Group 1 included 38 patients to whom cisterna magna arachnoid membrane suturing was performed with monofilament nonabsorbable suture 7.0., and additionally, the suture was sealed with fibrin adhesive sealant TachoComb®. Group 2 included 32 patients without arachnoid membrane suturing. There was no other significant difference in terms of clinical signs and surgical procedures between these groups. In the postoperative period, the frequency of developing a pseudomeningocele and an incisional cerebrospinal fluid leak was assessed in these two groups. The results were evaluated on the basis of clinical, CT, and MRI data performed in the postoperative period.Results: In the patients who underwent arachnoid membrane suturing (group I), pseudomeningocele formation was observed in one (2.6%) and CSF leak in one (2.6%) of the 38 patients. In group II, in which patients had no arachnoid membrane suturing, we observed pseudomeningocele formation in 11 (34.4%) patients and a CSF leak in 7 (25.0%) out of 28 patients with known follow-up. Statistical analysis of the data indicates a significantly higher risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in a group of patients who did not undergo arachnoid membrane suturing (p < 0.05).Conclusions: Suturing of the arachnoid membrane of the cisterna magna and its further sealing with fibrin adhesive sealant TachoComb® create an additional barrier for preventing cerebrospinal fluid collection in the extradural space. This technique significantly reduces the risk of postoperative pseudomeningocele formation and/or an incisional cerebrospinal fluid leak in patients with midline suboccipital craniotomy. [ABSTRACT FROM AUTHOR]

Over the past 20years, improvement in surgical techniques as well advances in surgical instruments for sinus surgery has led to surgical closure of cerebrospinal fluid (CSF) leak using endoscopic approach. Minimally invasive and having lower post op morbidity, compared to traditional intracranial techniques, repairing CSF leak endoscopically has evolved to become the standard practice for management of CSF leak. Widespread use of endoscope in sinus surgery have made us more familiar with the anatomy of the sinuses as well as the skull base. In this paper, we will describe our experience of CSF repair by suturing dura under endoscopic guidance for the repair of small ethmoid roof (<1.2cm) defects. [ABSTRACT FROM AUTHOR]

Background: Elective use of intraparenchymal intracranial pressure (ICP) monitoring is a valuable resource in the investigation of hydrocephalus and other cerebrospinal fluid disorders. Our preliminary study aims to investigate ICP changes in the immediate period following dural breach, which has not yet been reported on. Method: This is a prospective cohort study of patients undergoing elective ICP monitoring, recruited between March and May 2022. ICP readings were obtained at opening and then at 5-min intervals for a 30-min duration. Results: Ten patients were recruited, mean age 45 years, with indications of a Chiari malformation (n = 5), idiopathic intracranial hypertension (n = 3) or other ICP-related pathology (n = 2). Patients received intermittent bolus sedation (80%) vs general anaesthesia (20%). Mean opening pressure was 22.9 mmHg [± 6.0], with statistically significant decreases present every 5 min, to a total reduction of 15.2 mmHg at 20 min (p = < 0.0001), whereafter the ICP plateaued with no further statistical change. Discussion: Our results highlight an intracranial opening pressure 'spike' phenomenon. This spike was 15.2 mmHg higher than the plateau, which is reached at 20 min after insertion. Several possible causes exist which require further research in larger cohorts, including sedation and pain response. Regardless of causation, this study provides key information on the use of ICP monitoring devices, guiding interpretation and when to obtain measurements. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to present an in vitro method for examining cerebral vasospasm after subarachnoid haemorrhage (SAH) which correlates to the patients' condition. The O2 consumption of the porcine carotid artery was monitored, using an oxygen electrode, after exposure to cerebrospinal fluid (CSF) from patients who had a SAH. The vessels were exposed to CSF from SAH patients at a 1 in 30 dilution. Force measurements were carried out using freeze-dried CSF, reconstituted in the organ bath equivalent to undiluted CSF. These observations were then compared to the patients' condition. We divided the patient CSF samples into those that stimulated oxygen consumption above 0.4 microM/min/g dry wt, and those that did not. It was found that there was a correlation between the stimulation of oxygen consumption and the Fisher grade as well as the World Federation of Neurosurgeons Grading System (WFNS) for the patients. Of the CSF tested, 24 stimulated oxygen consumption above our cut off, and 8 did not (0.84 +/- 0.34, n = 24 compared with the rate of 0.27 +/- 0.1 mumol/min/g dry wt, respectively; SD n = 8) at 180 minutes. We then examined the Fisher Grades of these two groups, the results were 3.21 +/- 0.88 vs 2.25 +/- 0.83 respectively (SD p < or = 0.01). When examining the WFNS System we found a similar difference between the groups that stimulated respiration and those who did not (WFNS Grades of 2.64 +/- 1.1 vs. 1.43 +/- 0.53; p < or = 0.01). The observed stimulation of oxygen consumption also correlated with tension generation in vitro. The CSF from subarachnoid haemorrhage patients stimulates the oxygen consumption of the porcine carotid artery. This stimulation correlated to the WFNS and Fisher Grades of the patients and can be performed using 1:30 dilution of CSF. We conclude that the metabolic changes that occur in the vessels during vasospasm are important parameters for assessing cerebral vasospasm.

Background: The study of the distinct structure and function of the human central nervous system, both in healthy and diseased states, is becoming increasingly significant in the field of neuroscience. Typically, cortical and subcortical tissue is discarded during surgeries for tumors and epilepsy. Yet, there is a strong encouragement to utilize this tissue for clinical and basic research in humans. Here, we describe the technical aspects of the microdissection and immediate handling of viable human cortical access tissue for basic and clinical research, highlighting the measures needed to be taken in the operating room to ensure standardized procedures and optimal experimental results. Methods: In multiple rounds of experiments (n = 36), we developed and refined surgical principles for the removal of cortical access tissue. The specimens were immediately immersed in cold carbogenated N-methyl-D-glucamine-based artificial cerebrospinal fluid for electrophysiology and electron microscopy experiments or specialized hibernation medium for organotypic slice cultures. Results: The surgical principles of brain tissue microdissection were (1) rapid preparation (<1 min), (2) maintenance of the cortical axis, (3) minimization of mechanical trauma to sample, (4) use of pointed scalpel blade, (5) avoidance of cauterization and blunt preparation, (6) constant irrigation, and (7) retrieval of the sample without the use of forceps or suction. After a single round of introduction to these principles, multiple surgeons adopted the technique for samples with a minimal dimension of 5 mm spanning all cortical layers and subcortical white matter. Small samples (5–7 mm) were ideal for acute slice preparation and electrophysiology. No adverse events from sample resection were observed. Conclusion: The microdissection technique of human cortical access tissue is safe and easily adoptable into the routine of neurosurgical procedures. The standardized and reliable surgical extraction of human brain tissue lays the foundation for human-to-human translational research on human brain tissue. [ABSTRACT FROM AUTHOR]

Purpose : Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. Method : Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). Results : Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. Conclusion : This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted. [ABSTRACT FROM AUTHOR]

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a neurodegenerative disease and dementia subtype involving disturbed cerebrospinal fluid (CSF) homeostasis. Patients with iNPH may improve clinically following CSF diversion through shunt surgery, but it remains a challenge to predict which patients respond to shunting. It has been proposed that CSF and blood biomarkers may be used to predict shunt response in iNPH. Objective: To conduct a systematic review and meta-analysis to identify which CSF and venous biomarkers predict shunt-responsive iNPH most accurately. Methods: Original studies that investigate the use of CSF and venous biomarkers to predict shunt response were searched using the following databases: Embase, MEDLINE, Scopus, PubMed, Google Scholar, and JSTOR. Included studies were assessed using the ROBINS-I tool, and eligible studies were evaluated utilising univariate meta-analyses. Results: The study included 13 studies; seven addressed lumbar CSF levels of amyloid-β 1–42, nine studies CSF levels of Total-Tau, six studies CSF levels of Phosphorylated-Tau, and seven studies miscellaneous biomarkers, proteomics, and genotyping. A meta-analysis of six eligible studies conducted for amyloid-β 1–42, Total-Tau, and Phosphorylated-Tau demonstrated significantly increased lumbar CSF Phosphorylated-Tau (− 0.55 SMD, p = 0.04) and Total-Tau (− 0.50 SMD, p = 0.02) in shunt-non-responsive iNPH, though no differences were seen between shunt responders and non-responders for amyloid-β 1–42 (− 0.26 SMD, p = 0.55) or the other included biomarkers. Conclusion: This meta-analysis found that lumbar CSF levels of Phosphorylated-Tau and Total-Tau are significantly increased in shunt non-responsive iNPH compared to shunt-responsive iNPH. The other biomarkers, including amyloid-β 1–42, did not significantly differentiate shunt-responsive from shunt-non-responsive iNPH. More studies on the Tau proteins examining sensitivity and specificity at different cut-off levels are needed for a robust analysis of the diagnostic efficiency of the Tau proteins. [ABSTRACT FROM AUTHOR]

Background: External ventricular drainage (EVD) is one of the most common neurosurgical procedures in emergencies. This study aims to find out which factors influence the occurrence of EVD-related complications in a comparative investigation of metal needles and polyurethane catheters. This is the first clinical study comparing these two systems. Methods: Adult patients undergoing pre-coronal EVD placement via freehand burr hole trepanation were included in this prospective study. The exclusion criteria were the open EVD insertion and/or a pre-existing infectious disease of the central nervous system. Results: Two hundred consecutive patients were enrolled. Of these, 100 patients were treated by using metal EVD (group 1) and 100 patients with polyurethane catheters (group 2). The overall complication rate was 26% (misplacement 13.5%, hemorrhage 12.5%, infection 2.5%, and dislocation 1%) without statistically significant differences between both groups. Generalized brain edema and midline shift had a significant influence on misplacements (generalized brain edema: p = 0.0002, Cramer-V: 0.307, OR = 7.364, 95% CI: 2.691–20.148; all patients: p = 0.001, Cramer-V: 0.48, OR = 43.5, 95% CI: 4.327–437.295; group 1: p = 0.047, Cramer-V: 0.216, OR = 3.75, 95% CI: 1.064–13.221; group 2: midline shift: p = 0.038, Cramer-V: 0.195, OR = 3.626, 95% CI: 1.389–9.464) all patients: p = 0.053, Cramer-V: 0.231, OR = 5.533, 95% CI 1.131–27.081; group 1: p = 0.138, Cramer-V: 0.168, OR = 2.769, 95% CI: 0.813–9.429 group 2. Hemorrhages were associated with the use of oral anticoagulants or antiplatelet therapy (p = 0.002; Cramer-V: 0.220, OR = 3.798, 95% CI: 1.572–9.175) with a statistically similar influence in both groups. Conclusion: Generalized brain edema has a significant influence on misplacements in both groups. Midline shift lost its significance when considering only the patients in group 2. Patients under oral anticoagulation and antiplatelet therapy have increased odds of EVD-associated hemorrhage. Metal needles and polyurethane catheters are equivalent in terms of patient safety when there are no midline shift and generalized brain edema. [ABSTRACT FROM AUTHOR]

Object. Numerous types of materials have been evaluated over the past decades in the quest for the ideal dural replacement, but no product fully meets all the applicable criteria. This paper presents the long-term results of an animal trial of a collagen biomatrix (TISSUDURA™, Baxter AG, Vienna/Austria) for the repair and regeneration of dural defects. This product provides a matrix with a special layer structure and consists of pure naturally cross-linked collagen of equine origin. The comparable material is Tutoplast Dura®, a human cadaveric-derived dural graft preserved in a multiple stage chemical process. Methods. Bihemispheric parietotoccipital dural defects of a defined size were induced in 25 sheep and subsequently closed with the collagen graft or Tutoplast Dura®, respectively. Results. Postoperative neurological abnormalities did not occur in any animal. There were no signs of graft rejection or formation of cerebrospinal fluid fistulae. The collagen graft site displayed histological signs as early as 2 weeks postoperatively consistent with a moderate Iymphocytic inflammatory response and infiltration with fibroblasts and macrophages. The graft subsequently developed a neodura-like connective tissue architecture. The Tutoplast Dura® showed only minimal cellular infiltration, and again the surrounding structures displayed a mild inflammatory response. 24 weeks postoperatively, the dura and neomembrane were barely distinguishable at the collagen biomatrix site, but the Tutoplast Dura® displayed inadequate fusion with the dural border and was encapsulated in a connective tissue layer. Conclusion. The outcomes demonstrate that the collagen graft can be used for dura reconstruction as a temporary dural replacement and at the same time as a biomatrix for dural regeneration. [ABSTRACT FROM AUTHOR]

Objective: The authors report their experience with 44 consecutive patients who underwent cyst fenestration and wall repair or cerebrospinal fluid communication closure for the management of sacral Tarlov cysts. Methods: The procedure was performed on 32 women and 12 men with a mean age of 42 years. Clinical complaints in all patients included lumbar-sacral aching, sphincter dysfunction perineal pain, and sexual intercourse pain. The patients' symptoms had developed within a mean time period of 45 months. Five patients had a previous cyst puncture. In all patients, the cyst was exposed through a sacral laminectomy. In 30 patients, the cyst was partially resected its wall repaired, and in the remaining patients, the cyst was fenestrated, and the cerebrospinal fluid communication was located and tamponaded. Thirty-seven patients had intraoperative EMG monitoring. While the perineal pain, urinary, or sexual dysfunction improved in all patients, eleven patients reported lasting pain control following surgery. The cyst was reduced in all resected cases and seven of 14 patients with CSF tamponade. The mean length of the follow-up period was 57 months. Conclusions: Either cyst repair or CSF tamponade can be sufficient for alleviating symptoms in patients with Tarlov cyst. Advice should be given to patients regarding expectations for pain improvement after surgery. [ABSTRACT FROM AUTHOR]

We retrospectively studied the T2 star (T2*)-weighted magnetic resonance imaging (MRI) of a 40-year-old patient diagnosed with symptomatic early-onset cerebral amyloid angiopathy (CAA), occurring 34 years following childhood neurosurgery using a cadaveric dural patch. Our findings revealed that CAA associated with cadaveric dural transplantation could progress rapidly, sometimes with bilateral bleeding. This microbleed evolution is suggestive of water-soluble amyloid-β transmission via cerebrospinal fluid alongside perivascular drainage pathways with deposition in the cerebral artery walls due to clearance disturbances. Multiple intracerebral hemorrhages associated with CAA with a childhood cadaveric dural graft should be considered a life-threatening medical complication. [ABSTRACT FROM AUTHOR]

The author reflects on the neurosurgery for visual loss, that is caused by chiasmal compression from pituitary adenomas. He suggests that transsphenoidal surgery for tumors is very effective in majority of cases, and returns about half of the normal eye sight. He argues that the main risk of surgery is the damage of the normal gland function and from the leakage of cerebrospinal fluid.

Background: Precise placement of electrodes in deep brain stimulation (DBS) may be influenced by brain shift caused by cerebrospinal fluid leaking or air inflow. We compared accuracy and treatment outcomes between a standard technique and one aiming at reducing brain shift. Methods: We retrospectively reviewed 46 patients (92 targets) treated with bilateral subthalamic-DBS for Parkinson's disease. The patients were divided into two groups: group A surgery was performed in supine position with standard burr hole, dural opening, fibrin glue and gelfoam plugging. Group B patients were operated in a semi-sitting position with direct dural puncture to reduce CSF loss. We analysed target deviation on head CT performed immediately after surgery and at 1 month merged with preoperative MRI planning. We recorded pneumocephalus volume, brain atrophy and target correction by intraoperative neurophysiology (ION). Results: In group A, the mean pneumocephalus volume was 10.55 cm3, mean brain volume 1116 cm3, mean target deviation 1.09 mm and ION corrected 70% of targets. In group B, mean pneumocephalus was 7.60 cm3 (p = 0.3048), mean brain volume 1132 cm3 (p = 0.6526), mean target deviation 0.64 mm (p = 0.0074) and ION corrected 50% of targets (p = 0.4886). Most leads' deviations realigned to the planned target after pneumocephalus reabsorbtion suggesting a deviation caused by displacement of anatomical structures due to brain shift. Definitive lead position was always decided with ION. Conclusions: The modified DBS technique significantly reduced errors of electrode placement, though such difference was clinically irrelevant. ION corrected a high amount of trajectories in both groups (70% vs 50%). The choice of either strategy is acceptable. [ABSTRACT FROM AUTHOR]

Background: For the segmentation of medical imaging data, a multitude of precise but very specific algorithms exist. In previous studies, we investigated the possibility of segmenting MRI data to determine cerebrospinal fluid and brain volume using a classical machine learning algorithm. It demonstrated good clinical usability and a very accurate correlation of the volumes to the single area determination in a reproducible axial layer. This study aims to investigate whether these established segmentation algorithms can be transferred to new, more generalizable deep learning algorithms employing an extended transfer learning procedure and whether medically meaningful segmentation is possible. Methods: Ninety-five routinely performed true FISP MRI sequences were retrospectively analyzed in 43 patients with pediatric hydrocephalus. Using a freely available and clinically established segmentation algorithm based on a hidden Markov random field model, four classes of segmentation (brain, cerebrospinal fluid (CSF), background, and tissue) were generated. Fifty-nine randomly selected data sets (10,432 slices) were used as a training data set. Images were augmented for contrast, brightness, and random left/right and X/Y translation. A convolutional neural network (CNN) for semantic image segmentation composed of an encoder and corresponding decoder subnetwork was set up. The network was pre-initialized with layers and weights from a pre-trained VGG 16 model. Following the network was trained with the labeled image data set. A validation data set of 18 scans (3289 slices) was used to monitor the performance as the deep CNN trained. The classification results were tested on 18 randomly allocated labeled data sets (3319 slices) and on a T2-weighted BrainWeb data set with known ground truth. Results: The segmentation of clinical test data provided reliable results (global accuracy 0.90, Dice coefficient 0.86), while the CNN segmentation of data from the BrainWeb data set showed comparable results (global accuracy 0.89, Dice coefficient 0.84). The segmentation of the BrainWeb data set with the classical FAST algorithm produced consistent findings (global accuracy 0.90, Dice coefficient 0.87). Likewise, the area development of brain and CSF in the long-term clinical course of three patients was presented. Conclusion: Using the presented methods, we showed that conventional segmentation algorithms can be transferred to new advances in deep learning with comparable accuracy, generating a large number of training data sets with relatively little effort. A clinically meaningful segmentation possibility was demonstrated. [ABSTRACT FROM AUTHOR]

Background: In the treatment of childhood hydrocephalus, 3D volumetry seems to have many advantages over classical planar index measurements for dedicated monitoring of changes in cerebrospinal fluid and brain volume. Nevertheless, this method requires extensive technical effort and access to the complete three-dimensional data set. Against this background, we evaluated the possibility of planar area determination in a single plane and the correlation to volumetry. Methods: 138 routinely performed true FISP MRI sequences (1 mm isovoxel) were analyzed retrospectively in 68 patients with pediatric hydrocephalus. After preprocessing, the 3D-data sets were skull stripped to estimate the inner skull volume. A 2-class segmentation into different tissue types (brain matter and CSF) was performed, and the volumes of CSF (VCSF) and brain matter (VBrain) were calculated. A plane at the level of the foramina of Monro was manually identified in the ac-pc oriented data. In this plane, the areas of brain (ABrain) and CSF (ACSF) in cm2 were calculated and used for further correlation analysis. Results: Mean VCSF was 340 ± 145 cm3 and VBrain 1173 ± 254 cm3. In the selected plane, ACSF was 26 ± 14 cm2, and ABrain was 107 ± 25 cm2. There was a very strong positive correlation between both ACSF and VCSF (r = 0.895) and between ABrain and VBrain (r = 0.846). The prediction equations for VBrain and VCSF were highly significant. Conclusion: Planar area determination of brain and CSF correlates excellently with both VCSF and VBrain. Thus, areas can serve as a surrogate marker for total brain and CSF volumes for a quantitated objective tracking of changes during treatment of childhood hydrocephalus. [ABSTRACT FROM AUTHOR]

Background: Skull base reconstruction after extended endoscopic endonasal approaches (EEAs) can be challenging. In addition to the nasoseptal flap, which has been adopted by most centers, autologous fascia lata is also often utilized. Harvesting of fascia lata requires a separate thigh incision, may prolong recovery, and results in a visible scar. In principal, the use of non-autologous materials would be preferable to avoid a second incision and maintain the minimally invasive nature of the approach, assuming the CSF leak rate is not compromised. Objective: To assess the efficacy of acellular dermal matrix (ADM) as a non-autologous alternative to autologous fascia lata graft for watertight closure of the cranial base following EEAs. Methods: A retrospective chart review of extended EEAs performed before and after the transition from fascia lata to ADM was performed. Cases were frequency matched for approach, pathology, BMI, use of lumbar drainage, and tumor volume. Power analysis was performed to estimate the sample size needed to demonstrate non-inferiority. Results: ADM was used for watertight closure of the cranial base in 19 consecutive extended endoscopic endonasal approaches (16 gasket-seals and 3 buttons) with 1 postoperative CSF leak at the last follow-up (median 5.3, range 1.0–12.6 months). All patients had high-flow intraoperative leaks. The cohort included 8 meningiomas, 8 craniopharyngiomas, 2 chordomas, and 1 pituicytoma ranging in size from 0.2 to 37.2cm3 (median 5.5, IQR 2.8–13.3 cm3). In 19 historical controls who received fascia lata, there were 2 postoperative CSF leaks. Conclusions: Preliminary results suggest that ADM provides a non-inferior non-autologous alternative to fascia lata for watertight gasket-seal and button closures following extended EEAs, potentially reducing or eliminating the need to harvest autologous tissue. [ABSTRACT FROM AUTHOR]

Background: In childhood hydrocephalus, both the amount of cerebrospinal fluid and the brain volume are relevant for the prognosis of the development and for therapy monitoring. Since classical planar measurements of ventricular size are subject to strong limitations, imprecise and neglect brain volume, 3D volumetry is most desirable. We used and evaluated the robust segmentation algorithms of the freely available FSL-toolbox in paediatric hydrocephalus patients before and after specific therapy. Methods: Retrospectively 76 pre- and postoperative high-resolution T2-weighted MRI sequences (true FISP, 1 mm isovoxel) were analyzed in 38 patients with paediatric hydrocephalus (mean 4.4 ± 5.1 years) who underwent surgical treatment (ventriculo-peritoneal (VP) shunt n = 22, endoscopic third ventriculostomy (ETV) n = 16). After preprocessing, the 3D-datasets were skull stripped to estimate the inner skull surface. Following, a 2 class segmentation into different tissue types (brain matter and CSF) was performed. The volumes of CSF and brain were calculated. Results: The method could be implemented in an automated fashion in all 76 MRIs. In the VP shunt cohort, the amount of CSF (p < 0.001) decreased. Consecutively brain volume increased significantly (p < 0.001). Following ETV, CSF volume (p = 0.019) decreased significantly (p = 0.012) although the reduction was less pronounced than after shunt implantation. Brain volume expanded (p = 0.02). Conclusion: A reliable automated segmentation of CSF and brain could be performed with the implemented algorithm. The method was able to track changes after therapy and detected significant differences in CSF and brain volumes after shunting and after ETV. [ABSTRACT FROM AUTHOR]

Intra-abdominal pressure (IAP) is a physiological parameter that has gained considerable attention during the last few decades. The incidence of complications arising from increased IAP, known as intra-abdominal hypertension (IAH) or abdominal compartment syndrome in critically ill patients, is high and its impact is significant. The effects of IAP in neurological conditions and during surgical procedures are largely unexplored. IAP also appears to be relevant during neurosurgical procedures (spine and brain) in the prone position, and in selected cases, IAH may affect cerebrospinal fluid drainage after a ventriculoperitoneal shunt operation. Furthermore, raised IAP is one of the contributors to intracranial hypertension in patients with morbid obesity. In traumatic brain injury, case reports described how abdominal decompression lowers intracerebral pressure. The anatomical substrate for transmission of the IAP to the brain and venous system of the spine is the extradural neural axis compartment; the first reports of this phenomenon can be found in anatomical studies of the sixteenth century. In this review, we summarize the available knowledge on how IAP impacts the cerebrospinal venous system and the jugular venous system via two pathways, and we discuss the implications for neurosurgical procedures as well as the relevance of IAH in neurological disorders. [ABSTRACT FROM AUTHOR]

Introduction: Tinnitus is a symptom commonly associated with idiopathic intracranial hypertension (IIH) that can have a profound effect on quality of life. We aim to determine tinnitus symptom response after dural venous sinus stenting (DVSS) or CSF diversion with a shunt, in patients with both pulsatile (PT) and non-pulsatile tinnitus (NPT).Methods: Single-centre cohort of IIH patients (2006-2016) who underwent 24-h ICP monitoring (ICPM). An un-paired t test compared ICP and pulse amplitude (PA) values in IIH patients with PT vs. NPT.Results: We identified 59 patients with IIH (56 F:3 M), mean age 32.5 ± 9.49 years, 14 of whom suffered from tinnitus. Of these 14, seven reported PT and seven reported NPT. Patients with tinnitus had a mean 24-h ICP and PA of 9.09 ± 5.25 mmHg and 6.05 ± 1.07 mmHg respectively. All 7 patients with PT showed symptom improvement or resolution after DVSS (n = 4), secondary DVSS (n = 2) or shunting (n = 1). In contrast, of the 7 with NPT, only 1 improved post intervention (DVSS), despite 2 patients having shunts and 5 having DVSS.Conclusions: NPT and PT were equally as common in our group of IIH patients. DVSS appears to be an effective management option for IIH patients with a clear history of pulsatile tinnitus. However, non-pulsatile tinnitus was more persistent and did not respond well to either DVSS or CSF diversion. [ABSTRACT FROM AUTHOR]

Idiopathic spinal cord herniation (ISCH) through an anterior dural defect is rare and the cause is uncertain. Recently, through interpreting imaging studies, disc herniation was proposed to be a major cause for ISCH. We describe the case of a 50-year-old woman with progressive myelopathy who was diagnosed with a thoracic spinal cord herniation. Microsurgical exploration revealed an anterior vertical dural defect and a small concomitant disc herniation, occult on the preoperative imaging, which caused the dural defect and led to ISCH. This intraoperative finding corroborates the emerging notion that disc herniation is the underlying cause of ISCH. [ABSTRACT FROM AUTHOR]

Background: Ayub Ommaya proposed a surgical technique for subcutaneous reservoir and pump placement in 1963 to allow access to intraventricular cerebrospinal fluid (CSF). Currently, the most common indication for Ommaya reservoir insertion (ORI) in adults is for patients with hematologic or leptomeningeal disorders requiring repeated injection of chemotherapy into the CSF space. Historically, the intraventricular catheter has been inserted blindly based on anatomical landmarks. The purpose of this study was to examine short-term complication rates with ORI with image guidance (IG) and without image guidance (non-IG).Methods: We retrospectively evaluated all operative cases of ORI from 2000 to 2014 by the senior author. Patient demographic data, surgical outcomes, and peri-operative complications were collected. Accurate placement and early (30-day) morbidity or mortality were considered primary outcomes.Results: Fifty-five consecutive patients underwent ORI by the senior author over the study period (43.5 ± 16.6 years; 40.0% female). Indications for placement included acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and leptomeningeal carcinomatosis. There were seven (12.7%) total complications: three (37.5%) with no-IG versus four (8.5%) with IG. Catheter malpositions were significantly higher in the non-IG group at 37.5% compared to 2.1%. Catheters were also more likely to require multiple passes with non-IG at 25% compare to 0% with IG. There were no early infections in either group.Conclusions: We demonstrate improved accuracy and decreased complications using an image-guided approach compared with a traditional approach. Our results support routine use of intra-operative image guidance for proximal catheter insertion in elective ORI for intraventricular chemotherapy. [ABSTRACT FROM AUTHOR]

Object: In the past decade, the endonasal transsphenoidal approach (eTSA) has become an alternative to the microsurgical transcranial approach (mTCA) for tuberculum sellae meningiomas (TSMs) and olfactory groove meningiomas (OGMs). The aim of this meta-analysis was to evaluate which approach offered the best surgical outcomes. Methods: A systematic review of the literature from 2004 and meta-analysis were conducted in accordance with the PRISMA guidelines. Pooled incidence was calculated for gross total resection (GTR), visual improvement, cerebrospinal fluid (CSF) leak, intraoperative arterial injury, and mortality, comparing eTSA and mTCA, with p-interaction values. Results: Of 1684 studies, 64 case series were included in the meta-analysis. Using the fixed-effects model, the GTR rate was significantly higher among mTCA patients for OGM (eTSA: 70.9% vs. mTCA: 88.5%, p-interaction < 0.01), but not significantly higher for TSM (eTSA: 83.0% vs. mTCA: 85.8%, p-interaction = 0.34). Despite considerable heterogeneity, visual improvement was higher for eTSA than mTCA for TSM (p-interaction < 0.01), but not for OGM (p-interaction = 0.33). CSF leak was significantly higher among eTSA patients for both OGM (eTSA: 25.1% vs. mTCA: 10.5%, p-interaction < 0.01) and TSM (eTSA: 19.3%, vs. mTCA: 5.81%, p-interaction < 0.01). Intraoperative arterial injury was higher among eTSA (4.89%) than mTCA patients (1.86%) for TSM (p-interaction = 0.03), but not for OGM resection (p-interaction = 0.10). Mortality was not significantly different between eTSA and mTCA patients for both TSM (p-interaction = 0.14) and OGM resection (p-interaction = 0.88). Random-effect models yielded similar results. Conclusion: In this meta-analysis, eTSA was not shown to be superior to mTCA for resection of both OGMs and TSMs. [ABSTRACT FROM AUTHOR]

Background: An external ventricular drain (EVD) is used to measure intracranial pressure (ICP) and to drain cerebrospinal fluid (CSF). The procedure is generally safe, but parenchymal sequelae are reported as a possible side effect, with variable incidence. We investigated the mechanical sequelae of EVD insertion and their clinical significance in acute brain-injured patients, with a special focus on hemorrhagic lesions. Methods: Mechanical sequelae of EVD insertion were detected in patients by computed tomography (CT) and magnetic resonance imaging (MRI), performed for clinical purposes. Results: In 155 patients we studied the brain tissue surrounding the EVD by CT scan (all patients) and MRI (16 patients); 53 patients were studied at three time points (day 1-2, day 3-10, >10 days after EVD placement) to document the lesion time course. Small hemorrhages, with a hyperdense core surrounded by a hypodense area, were identified by CT scan in 33 patients. The initial average (hyper- + hypodense) lesion volume was 8.16 ml, increasing up to 15 ml by >10 days after EVD insertion. These lesions were not accompanied by neurologic deterioration or ICP elevation. History of arterial hypertension, coagulation abnormalities and multiple EVD insertions were significantly associated with hemorrhages. In 122 non-hemorrhagic patients, we detected very small hypodense areas (average volume 0.38 ml) surrounding the catheter. At later times these hypodensities slightly increased. MRI studies in 16 patients identified both intra- and extracellular edema around the catheters. The extracellular component increased with time. Conclusion: EVD insertion, even when there are no clinically important complications, causes a tissue reaction with minimal bleedings and small areas of brain edema. [ABSTRACT FROM AUTHOR]

The authors reflect on the study "Hydrocephalus in vein of Galen malformation: etiologies and therapeutic management implications," by D. Meila and colleagues in the 2016 issue. Topics discussed include the treatment options for hydrocephalus in vein of Galen malformation (VGM), development of hydrocephalus, and dual mechanism and absorption of cerebrospinal fluid (CSF).

Background: Skull base and posterior fossa surgeries are sometimes complicated by cerebrospinal fluid (CSF) fistulae, which may be challenging to treat. They can lead to meningitis, increasing global morbidity and mortality. In case of failed medical treatment, revision surgery may be required. 'Fat packing' (adipose tissue grafts) is usually used to close the communication between the intracranial contents and the cutaneous tissue, and to fill the dead space created by the skull base surgery. Vascularised flaps can also be used. They seem more efficient, especially in multi-operated patients or after radiotherapy, when cutaneous tissue is adhesive and fragile. Methods: Temporoparietal fascia (TPF) flap is a regional flap; it has reliable blood supply and can cover temporal and retroauricular defects. Folded into a ball, it can fill small dead spaces and can be skin grafted in case of cutaneous defect. Results and Conclusions: We present a simple surgical solution to manage recurrent retroauricular CSF fistulae after posterior fossa surgery using a pedicled TPF flap folded into a ball. [ABSTRACT FROM AUTHOR]

Background: Only a few reports have been published on the natural history of non-shunted patients suspected of having NPH. The aim of this study is to follow up a group of such cases. Methods: It was possible to follow up 27 patients who had not been qualified for shunting after the primary diagnosis. An assessment of Hakim's triad was performed, together with an analysis of radiological parameters and the results of lumbar infusion tests (LITs), both on admission and at the later date (on average, after 5.6 months). All parameters were analyzed with respect to periventricular lucency (PVL), atrophy, type of NPH, and the age of the patients. Results: There were no deteriorations and six patients improved. Those who were over 50 and who had no PVL or secondary NPH tended to improve more frequently. Significant improvement of dementia was noted ( p = 0.042) in all cases, and in the group of patients without PVL ( p = 0.04). The size of the ventricles did not change significantly. The values of the resistance to outflow (R), elastance (E), and ICP remained stable. Conclusions: Analysis of our series revealed that the patients suspected of having NPH who had not been qualified for shunting did not deteriorate, while some of them even improved significantly as far as the level of dementia was concerned. As the CT and LIT parameters remained stable, there were no indications for repeating these examinations, at least within the period of nearly 6 months, which followed the primary diagnosis. [ABSTRACT FROM AUTHOR]

Background: Cerebrospinal fluid disturbance (CSFD) is a well-known complication after occipitocervical decompression (OCD) in patients with Chiari malformation type I (CMI). There is scarce data focusing on preoperative patients' factors predisposing to development of CSF disturbance. The aim of this study is to evaluate a prognostic value of some patients' factors in the prediction of CSFD after OCD in CMI patients. Materials and methods: We undertook a 10-year (2003-2013) retrospective study of all OCD in patients with CMI performed at Sahlgrenska IC, Sahlgrenska University Hospital, Sweden. A total of 52 consecutive patients were obtained from the operation database and we excluded one patient who was previously diagnosed with normal-pressure hydrocephalus. Data regarding preoperative age, body mass index, gender, degree of tonsillar herniation and syrinx were registered. Development of CSFD after OCD was noted. Results: Of the 51 patients reviewed, six had CSFD after OCD and were managed using a form of CSF diversion procedure. All of the patients who developed CSFD were females. They had a mean body mass index of 32.3 compared to a mean of 24.3 in patients without CSFD ( p = 0.0011). There was no difference between the two groups with regard to the other examined patient factors. Conclusions: CSF diversion was needed in six consecutive adult Chiari malformation type I patients who underwent occipitocervical decompression. All patients with postoperative CSFD were female and their mean BMI was significantly higher than patients without this complication. [ABSTRACT FROM AUTHOR]

Background: Patients with Chiari malformation type 1 (CMI) often present with elevated pulsatile and static intracranial pressure (ICP). The preferred treatment of CMI, foramen magnum decompression (FMD), is assumed to normalise ICP and craniospinal pressure dissociation. In order to further explore the mechanisms behind FMD, the present study investigated whether or not pulsatile and static ICP normalises immediately after FMD. Method: The study included CMI patients undergoing FMD with perioperative ICP monitoring as a part of clinical management. The pulsatile and static ICP scores were retrieved from the department's ICP database, and the clinical and radiological data from the patient records. Results: Eleven patients were included in the study. During the first 3 days following FMD, mixed model analysis revealed no significant time-dependent differences of preoperatively elevated either pulsatile (mean wave amplitude, MWA; p = 0.85) and/or static (mean ICP, p = 0.90) ICP. Percentage of mean ICP >15 mmHg increased during days 2 and 3 after FMD. Two patients from the present series had to receive ventriculoperitoneal shunt after FMD in the early postoperative period. Conclusions: The present observations suggest that anatomical restoration of cerebrospinal fluid pathways by FMD does not lead to immediate normalisation of preoperatively altered pulsatile and static ICP in patients with CMI. This finding may explain persistent symptoms during the early period after FMD. [ABSTRACT FROM AUTHOR]

Leptomeningeal cysts are commonly seen in children usually following trauma and associated with bulging leptomeninges at the site of fracture. Intradiploic leptomeningeal cyst is an important differential for an expansile lytic lesion in the bony calvarium especially in a patient with a previous history of trauma. Here we present a case of intradiploic leptomeningeal cyst and describe the usefulness of retrograde cisternogram by CT-guided direct percutaneous cyst puncture where a CT cisternogram after intrathecal contrast injection could not demonstrate the dural defect and communication of the subarachnoid space with the intradiploic leptomeningeal cyst. [ABSTRACT FROM AUTHOR]

Subependymal giant cell tumor (SGCT) is a benign intraventricular tumor, usually located near the foramen of Monro. It is almost always associated with tuberous sclerosis complex (TSC). SGCTs may obstruct cerebrospinal fluid (CSF) pathways. Rarely, they may secrete a protein-rich exudate, causing communicating hydrocephalus. Surgery is indicated for symptomatic lesions or growing asymptomatic lesions. The operative approach to SGCT has shifted from simple shunt placement to a more aggressive approach, leading to early attempts at gross total resection. Recently, the mTOR inhibitor everolimus has been approved for treating SGCT. In this article, we present two cases of recurrent shunt malfunctions in adult TSC patients with protein-secreting SGCTs. We describe the complexity of treating such patients with an emphasis on the role mTOR inhibitors may have in their management. We also review the literature on surgical management of SGCT-related hydrocephalus. [ABSTRACT FROM AUTHOR]

Background: Postoperative cerebrospinal fluid (CSF) leaks and headaches remain potential complications after retrosigmoid approaches for lesions in the posterior fossa and cerebellopontine angle. The authors describe a simple repair technique with an autologous fat graft-assisted Medpor Titan cranioplasty and investigate the incidence of postoperative CSF leaks and headaches using this technique. Methods: A retrospective chart review was conducted on all cases ( n = 60) of retrosigmoid craniectomy from September 2009 to May 2014 in patients who underwent fat graft-assisted cranioplasty. After obtaining a watertight dural closure and sealing off any visible mastoid air cells with bone wax, an autologous fat graft was placed over the dural suture line and up against the waxed-off air cells. The fat graft filled the retrosigmoid cranial defect and was then bolstered with a Medpor Titan (titanium mesh embedded in porous polyethylene) cranioplasty. A postoperative mastoid pressure dressing was applied for 48 h, and prophylactic lumbar drainage was not used. Factors examined in this study included postoperative CSF leak (incisional, rhinorrhea, otorrhea), pseudomeningocele formation, incidence and severity of postoperative headache, length of hospital stay, and length of follow-up. Results: No patients developed postoperative CSF leaks (0 %), pseudomeningoceles (0 %), or new-onset postoperative headaches (0 %) with the described repair technique. There were no cases of graft site morbidity such as hematoma or wound infection. Mean duration of postoperative hospital stay was 3.8 days (range 2-10 days). Mean postoperative follow-up was 12.4 months (range 2.0-41.1 months). Conclusions: Our multilayer repair technique with a fat graft-assisted Medpor Titan cranioplasty appears effective in preventing postoperative CSF leaks and new-onset postoperative headaches after retrosigmoid approaches. Postoperative lumbar drainage may not be necessary. [ABSTRACT FROM AUTHOR]

Introduction: Early surgical series of shunt insertion for idiopathic normal-pressure hydrocephalus reported a low rate of short-term improvement with a relatively high rate of mortality and morbidity; subsequently shunt insertion was recommended for patients in whom there is favourable risk-to-benefit ratio. Methods: Bibliographic search for studies that objectively assessed the outcome following shunt insertion in idiopathic normal-pressure hydrocephalus was done; the aim was to estimate the outcome of shunt insertion in terms of improvement rates and associated mortality and morbidity. Results: A total of 64 studies of 3,063 patients were reviewed. Positive improvement following shunt insertion was reported in an average of 71 % of patients with an average 1 % mortality. Results from studies published in the last 5 years showed 82 % improvement following shunt insertion, mortality of 0.2 %, and combined common complications rate of 8.2 %. Conclusion: When patients are properly selected, shunt insertion is a safe and effective management of idiopathic normal-pressure hydrocephalus with a prolonged positive outcome. [ABSTRACT FROM AUTHOR]

Background: Shunt infection markedly impairs the clinical result of shunt surgery. The infection rate can be reduced by dedicated protocols. This study was undertaken to determine the efficacy of introducing a perioperative protocol for control of shunt infections. Method: The shunt infection rate and risk factors for shunt infection were determined for two periods, namely the period 2001-2002 (Patient Material A), and the period 2005-2008 (Patient Material B). The perioperative protocol was introduced in 2005 before the second period. Results: The total patient material includes 901 patients, in whom 1,404 shunt procedures were performed during the study periods. While the overall infection rate dropped nonsignificantly from 6.5 % to 4.3 %, infection rate dropped markedly and significantly from 18.4 % to 5.7 % among the children younger than 1 year ( p = 0.016). The significant risk factors for shunt infection were in Patient Material A age below 1 year ( p < .001), and in Patient Material B premature birth ( p = 0.045), postoperative cerebrospinal fluid (CSF) leakage ( p < .001) and high American Society of Anaesthesiologists (ASA) score ( p = 0.039). Of the protocol steps, only the lack of preoperative wash with 4 % clorhexidine gluconate (Hibiscrub®) showed a tendency of influencing the shunt infection rate ( p = 0.051). Conclusions: This study showed that implementation of a perioperative protocol markedly and significantly reduced shunt infection rate in children younger than 1 year, even though no significant overall reduction in shunt infection rate was found. [ABSTRACT FROM AUTHOR]

Background: This study was designed to investigate the clinical characteristics and risk factors of hydrocephalus after gamma knife radiosurgery (GKRS) for vestibular schwannoma. Methods: The authors retrospectively reviewed clinical and neuroimaging findings of 221 patients who underwent GKRS for newly diagnosed vestibular schwannoma. Mean patient age was 54.1 years (range 7-83 years), mean tumor volume was 3,010.4 mm (range 34.7 to 14,300 mm), mean marginal dose was 12.5 Gy (range 11 to 15 Gy), and mean follow-up duration was 31.9 months (range 1 to 107.6 months). Results: Surgical intervention for cerebrospinal fluid (CSF) diversion after GKRS was necessary in 11 (5 %) of the patients. Median time between GKRS and ventriculoperitoneal (VP) shunt placement was 15.5 months (range 1.8-37.8 months). These 11 patients showed female predominance (11 females) and mean tumor volume was significantly larger than in the other without hydrocephalus (6,509 vs. 2,726 mm; p < 0.01). Decreases in tumor enhancement and swelling were observed in all 221 patients, and CSF protein was found to be elevated in five of nine patients with available data at the time of the shunt procedure. Hydrocephalic symptoms improved after VP shunt and tumor sizes further decreased at last follow-up in all patients. Conclusions: Hydrocephalus after radiosurgery may co-occur with a temporary change of tumor volume after radiation treatment. Therefore, hydrocephalus should be kept in mind during the time of tumor volume transition. Furthermore, the authors suggest that frequent patient monitoring for hydrocephalus be maintained for up to 3-4 years after GKRS. [ABSTRACT FROM AUTHOR]

Objective: In the present study an attempt was made to quantify and characterise the changes in the intracranial pressure (ICP) waveform over the wide pressure range covered during infusion studies by means of the central tendency measure (CTM). CTM is a non-linear approach using continuous chaotic modelling that summarises the degree of variability in a signal. Methods: CTM of the ICP wave in the lumbar subarachnoid space was analysed in 77 infusion studies performed in patients with idiopathic and secondary forms of normal pressure hydrocephalus (median age 74 years, range 22-88). Four artefact-free epochs were selected during the baseline, infusion, plateau and relaxation stages of every infusion study. The average pressure, pulse amplitude and CTM were determined for each epoch. Correlations among these parameters were explored. Results: CTM of the ICP waveform decreases, i.e. variability increases, as infusion studies progress from baseline pressure to the plateau stage. Significant correlations were found during all phases of infusion testing, except at baseline, between CTM and pressure, CTM and amplitude and pressure and amplitude. Partial correlations emphasised the relationship between CTM and amplitude. When pulse amplitude is held constant, CTM and the pressure range do not correlate. Conclusions: Volume loading leads to increased variability of the ICP signal measured by means of CTM. This finding summarises numerically the long-established phenomenon of increasing amplitude and rounding of ICP pulses associated with ICP elevation during infusion studies. CTM could be a suitable approach to quantify and characterise the pulsatile nature of the ICP wave. [ABSTRACT FROM AUTHOR]

Background: In the past, sporadic demonstrations of the existence of a subarachnoid subdiaphragmatic cistern have been published. The aim of this study was to evaluate the anatomical characteristics of the subdiaphragmatic cistern of the pituitary gland. Methods: After a complete review of the literature published on the topic, we report anatomical observations of the subdiaphragmatic cistern and its relationship to the pituitary gland and to the chiasmatic cistern. Ten cadaveric heads were studied using different techniques and surgical methods (plastination, plastic casts of the subarachnoid spaces, microscopic and transsphenoidal endoscopic approaches). Moreover, 3-T magnetic resonance images of ten healthy volunteers were analyzed to investigate the presence and anatomical variability of the subdiaphragmatic cistern. Results: By means of our qualitative radioanatomic study, we found that the roof of the subdiaphragmatic cistern is formed by the diaphragma sellae, the floor by the superior face of the pituitary gland, the lateral walls by the arachnoidea extending laterally through the medial walls of the cavernous sinus, and the medial walls by the infundibular stem. The subdiaphragmatic cistern communicates by means of the ostium of the diaphragm with the chiasmatic cistern. Conclusion: We confirmed the existence of the subdiaphragmatic cistern. The overused term 'suprasellar cistern' refers more to a complex of cisterns, formed by the subdiaphragmatic cistern, below the diaphragma sella, and by the chiasmatic cistern, above it, in direct communication with the lamina terminalis and carotid cisterns. [ABSTRACT FROM AUTHOR]

Background: Subarachnoid hemorrhage (SAH) has been recognized as a risk factor for ventriculostomy-related infections (VRI). In addition to the hemorrhagic cerebrospinal fluid (CSF), the potential need for prolonged catheterization may contribute to the increased CSF infection rate in this population. The use of antibiotic-impregnated catheters (AIC) has effectively reduced the risk of VRI. Herein, we examined specifically the impact of systematic insertion of AIC on the timing of CSF infections in SAH patients. Methods: Retrospective review of patients admitted between April 2006 to March 2009 with a non-traumatic SAH who required an external ventriculostomy. Only patients with AIC were included. A meningitis or ventriculitis was diagnosed according to the published criteria of the Center for Disease Control and Prevention. Results: This study includes 75 patients in which 97 drains were inserted. Seven infections (7/75 = 9.3%) occurred over 1,024 drainage days (DD), resulting in a rate of 6.8 infections/1,000 DD. The mean drainage time was 15.4 days in the infected AIC group compared with 10.2 days in the non-infected AIC group. No infection occurred before day 9 of drainage and 71% (5/7) occurred after more than 2 weeks of drainage. The observed timing of infections is delayed in comparison with that reported in series using non-AIC, which typically occur prior to the 10th day of drainage. Conclusions: In the high-risk population of non-traumatic SAH, the use of AIC delays the occurrence of infection compared with that reported with non-antibiotic-impregnated catheters. This may orient management strategies in SAH patients requiring a ventriculostomy. [ABSTRACT FROM AUTHOR]

Despite a number of various hypotheses in the literature, the pathophysiology of syringomyelia is still not well understood. In this article, we report two cases of cervical syringomyelia not associated with Chiari I malformation. Both cases had a septum-like structure in the subarachnoid space on the dorsal side of the cord at the craniovertebral junction. Cardiac-gated phase-contrast cine-mode magnetic resonance imaging (MRI) demonstrated decreased cerebrospinal fluid (CSF) flow on the dorsal side of the spinal cord. Surgical excision of this septum, restoring the CSF flow, resulted in a prompt reduction of the syrinx size in both cases. Findings in these cases contradict the currently prevailing hypothesis of syrinx formation that postulate that the piston-like movement of the cerebellar tonsils enhance the pulsatile CSF flow in the spinal subarachnoid space, driving the CSF into the syrinx through the perivascular space of Virchow and Robin. The authors propose that a mechanism based on the decreased pulsatile CSF flow in the spinal subarachnoid space will be more suitable as a hypothesis in studying the pathophyisiology of syringomyelia. These cases also provide an important lesson in managing the patients with syringomyelia not associated with Chiari I malformation. [ABSTRACT FROM AUTHOR]

Introduction: Various cranial repairs have been described to limit the incidence of cerebrospinal fluid (CSF) leak, the rate of infections, postoperative headache and local discomfort in patients undergoing cerebello-pontine angle surgery. Materials and methods: The aim of this study was to evaluate the impact of a feasible craniotomy procedure and cranial repair technique, which does not require bone replacers or filling materials, on postoperative outcome. We analysed postoperative results in a series of 34 patients undergoing cerebello-pontine angle surgery. Discussion and conclusions: We observed a statistically significant reduced incidence of local discomfort, postoperative headache and CSF leak in patients who underwent such a reconstructive technique compared to those undergoing retrosigmoid craniectomy. [ABSTRACT FROM AUTHOR]

Background: The Ommaya reservoir for intraventricular chemotherapy of leptomeningeal carcinomatosis (LMC) patients has been reported to have some complications. We introduced a Chemoport reservoir, with a solid non-collapsible, high-profile chamber as a the replacement for the Ommaya reservoir in LMC patients. Objective: To evaluate the usefulness of Chemoport as an alternative to Ommaya for the intraventricular chemotherapy of LMC. Methods: The medical records of 155 patients (89 Ommaya and 66 Chemoport) who underwent intraventricular chemotherapy via a subgaleal reservoir were reviewed. Chemoport was secured with engraving of skull. Result: Reservoir malfunction, including one intracranial hemorrhage (ICH) under the burr hole occurred, in six patients. During the course of therapy, cerebrospinal fluid (CSF) infection was diagnosed in 19 patients and intraventricular hemorrhage with ICH was evident in three patients of the Ommaya group. Incidence of the above-mentioned complications showed no difference between the two groups. CSF leakage under a galeal flap or through a wound edge occurred more frequently in the Ommaya group (12 patients) than in the Chemoport group (two patients) and the difference was statistically significant ( p = 0.03). One-hundred and four patients showed increased intracranial pressure (ICP) and 74 of them received additional CSF drainage to control increased ICP by either intermittent CSF drainage in both groups or continuous extraventricular drainage (EVD) of CSF using designated hooked needle only in the Chemoport group. Among the factors related to the control ICP, the number of chemotherapies, type of reservoir in favor of Chemoport, and EVD showed significantly improved control of ICP ( p < 0.05). Conclusion: Chemoport, as a reservoir for intraventricular chemotherapy, has superior ICP control at an equal or lower rate of complications compared with the Ommaya reservoir. [ABSTRACT FROM AUTHOR]

Background: Generally accepted reference values in CSF diagnostics are not valid in cerebrospinal fluid (CSF) containing large amounts of blood. Residual blood may obscure ventriculitis as diagnostics largely depend on parameters such as cell count, lactic acid and total protein measurement. We sought to improve the diagnostics by evaluating a cytokine panel and soluble CD62L as markers of ventriculitis. In addition, we tested an algorithm of established parameters to predict ventriculitis in a specific patient collective. Methods: Analysis was performed on ventricular CSF samples from 50 consecutive patients. Gram staining, microbiological culture, total cell count, total protein and CD62L expression on neutrophil granulocytes were analysed immediately. Cytokines and soluble CD62L were measured by flow cytometry. Findings: Positive culture was detected in ten patients. Of all parameters tested only IL1-beta, IL8 and CD62L on neutrophils were significantly different between culture-positive and -negative patients. The highest predictive value was obtained when analysing IL1-beta. The predictive value of a parameter combination (IL6 in CSF, C-reactive protein and leukocytes in periphereal blood) was comparable to IL1-beta. Half of the patients in this analysis were identified as culture positive because of the lack of inflammatory response. Conclusions: IL1-beta and perhaps also IL8 provide very good analytical performance when looking for ventriculitis in patients with residual blood in CSF. Turn-around time is short, and results could be reported within 1 h for 24 h a day. In some patients application of glucocorticoids may result in restricted inflammatory response. Even in these patients IL1-beta provides a reliable parameter for the immediate diagnosis of ventriculitis. [ABSTRACT FROM AUTHOR]

Background: Delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is a major cause of high morbidity and mortality. The reduced availability of nitric oxide (NO) in blood and cerebrospinal fluid (CSF) is well established as a key mechanism of vasospasm. Systemic administration of glyceryl trinitrate (GTN), an NO donor also known as nitroglycerin, has failed to be established in clinical settings to prevent vasospasm because of its adverse effects, particularly hypotension. The purpose of this study was to analyze the effect of intrathecally administered GTN on vasospasm after experimental SAH in the rabbit basilar artery. Methods: A single-hemorrhage model of SAH in rabbits was used to induce vasospasm. GTN (0.5 mg/ml) or saline was infused via a subcutaneous implanted osmotic pump with continuous drug release into the cerebellomedullary cistern over 5 days. The degree of vasospasm in the basilar artery was recorded with angiography on day 5 after SAH and was compared to baseline angiography on day 0. Findings: Significant reduction of basilar artery diameter was observed in the SAH group with saline infusion compared to sham-operated animals. Intrathecally administered GTN had no effect on the vessel diameter in sham-operated animals, whereas it significantly prevented vasospasm in the SAH group. Intrathecal GTN infusion did not affect arterial blood pressure. Conclusions: Prophylactic, continuous intrathecal administration of GTN prevents vasospasm of the basilar artery in the rabbit SAH model. No toxic effects could be demonstrated in this study. The clinical safety and feasibility of this strategy need to be further investigated. [ABSTRACT FROM AUTHOR]

Background: Intracranial subependymomas are rare, slow-growing and usually non-invasive tumors. The aim of this study was to analyze our experience with the surgical treatment of intracranial subependymomas. Methods: Between 1991 and 2007, 11 patients with intracranial subependymomas had surgery in our institution. Mean age of the patients was 54.4 years (ranging from 40 to 85 years). Results: Tumors were located in the fourth ventricle in seven patients and in the lateral ventricle in four patients. Most patients presented with symptoms related to intracranial hypertension and/or cerebellar signs and symptoms (headache: eight patients; dizziness: six patients; nausea: six patients; gait ataxia: four patients), one patient with cognitive decline and flattened affect, and one patient with a hemiparesis. Six patients presented with hydrocephalus, but only one needed a permanent cerebrospinal fluid (CSF) shunt. Complete removal of the tumor was possible in eight cases. Following surgery, only one patient experienced a permanent drop of his Karnofsky Performance Index (from 70 to 60). Median follow-up was 37 months. There were no true recurrences during follow-up. A second surgery was required 7 years after the first operation for progression of an incompletely resected tumor. Conclusions: Removal of symptomatic subependymomas can be performed safely. Prognosis is excellent after a complete resection. The potential for a surgical cure, low surgical complication rates and the risk of undertreatment of a more aggressive tumor together may justify surgery for asymptomatic lesions [ABSTRACT FROM AUTHOR]

Objective: Cerebrospinal fluid (CSF) shunting can improve symptoms of elderly patients' idiopathic normal pressure hydrocephalus (iNPH). However, adjunctive means for confirming the diagnosis remain unavailable. We have previously reported the specific increase of leucine-rich alpha-2-glycoprotein (LRG) in iNPH CSF, and the present study investigates its potential clinical applications. Methods: We performed CSF tap test (TT) on 90 patients (mean age 73.4 years) and shunting in 52 patients (mean age 73.5 years), evaluating symptom improvement and higher cerebral functions-mini-mental state examination (MMSE) and Frontal Assessment Battery (FAB) before and 12 months after shunting. LRG and tau protein concentrations in TT CSF were simultaneously measured using enzyme-linked immunosorbent assay. We then compared the predictive value of these concentrations with TT results regarding successful shunting outcomes. Results: Positive combinations of TT and LRG concentrations of 67 ng/ml or higher, gave 81.6% sensitivity and 78.6% specificity. Therefore we used LRG (67 ng/ml) and tau (200 pg/ml) cut-off values, dividing patients into four groups. In group A (LRG ≥ 67 ng/ml and tau < 200 pg/ml) 31 of 34 patients (91.2%) had a positive TT and all operated 22 patients were shunt responders. Dementia MMSE and FAB scores in them increased from a baseline of 22.05(SE ± 0.96) to 25.65 (±0.85) and 11.38 (±0.68) to 13.08 (±0.57) respectively. In group B, (LRG ≥ 67 ng/ml and tau ≥ 200 pg/ml), the mean MMSE score increased from 17.62 (±2.03) to 21.62 (±1.96), and the FAB decreased slightly from 9.25 (±1.15) to 10.5 (±1.59), without improvement beyond the range of dementia. In group C, (LRG < 67 ng/ml, tau < 200 pg/ml), the mean MMSE score improved from 22.06 (±1.25) to 24.29 (±1.23) and the FAB score improved slightly from 12.0 (±0.72) to 12.87 (±0.72). Finally, in group D, (LRG < 67 ng/ml, tau ≥ 200 pg/ml), there was almost no improvement in MMSE score Conclusions: A combination of positive TT and biomarkers quantification such as LRG and tau protein, can reliably predict shunting outcome in iNPH patients. [ABSTRACT FROM AUTHOR]

Decompression of the foramen magnum for symptomatic Chiari malformation attends a small but significant risk of infratentorial subdural extra-arachnoid hygroma when an arachnoid-sparing procedure is attempted. We present three cases whereby an arachnoid-sparing procedure was carried out and resulted in infratentorial subdural hygroma and hydrocephalus. The complication was managed by re-exploration of the posterior fossa and wide arachnoidotomy. In cases whereby the decision has been made to open the dura, we recommend routine arachnoidotomy in foramen magnum decompression, avoiding the risks of infratentorial subdural hygroma. In cases where arachnoid-sparing procedures have been attempted and subdural hygroma subsequently develops, we advocate re-exploration of the posterior fossa rather than cerebrospinal fluid diversion. [ABSTRACT FROM AUTHOR]

Introduction: Many strategies have been developed with the aim of reducing external ventricular drain-related infections. Antibiotic-impregnated catheters are one of them. Material and methods: We report 648 cases of external ventricular drain from a total of 534 patients treated at the Virgen del Rocío Hospital between 1995 and 2006. Three subgroups were considered: group 1 included patients treated between 1995 and 2000, as well as a total of 190 external ventricular drains and 59 cases of infection (31.05%); group 2, with patients treated between 2000 and 2004 and managed with a minimal handling protocol, included 210 external ventricular drains and nine cases of infection (4.29%); and group 3, treated between 2004 and 2006, with 248 external ventricular drains and six cases of infection (2.41%). This latter subgroup included patients managed with a minimal handling protocol and antibiotic-impregnated catheters. Results: Infection rate was 17% when non-antibiotic-impregnated catheters were employed and 2.41% when antibiotic-impregnated catheters were inserted ( p < 0.001). This difference was statistically significant before and after the introduction of a minimal handling protocol, with percentages of 5.31% and 3.27%, respectively ( p < 0.001; odds ratio 0.08; absolute risk reduction 27.26%). However, no statistically significant difference was observed in infection rate when the impact of a minimal handling protocol was considered: 4.29% when only the protocol was introduced and 2.41% when both the protocol and antibiotic-impregnated catheters were used ( p > 0.05). Conclusion: Minimal handling protocols constitute an essential strategy in the reduction of external ventricular drain-related infections. Besides that, the use of antibiotic-impregnated catheters may reduce infection-related hospital costs. [ABSTRACT FROM AUTHOR]

Background and purpose: We describe the rationale and safety of concurrent decompression of Chiari type 1 malformation (CM1) and untethering of the spinal cord. Spinal cord traction is considered one of the pathogenic mechanisms involved in the development of CM, and 14% of patients with CM1 have tethered cord syndrome (Milhorat et al., Surg Neurol 7:20-35, ; Roth, Neuroradiology 21:133-138, ; Royo-Salvador, Rev Neurol 24:937-959, ; Royo-Salvador et al., Acta Neurochir 147:515-523, ). Therefore, intraspinal anomalies that require intervention are commonly treated before surgical decompression of Chiari malformation (Cheng et al., Neurologist 8:357-362, ; Menezes, Pediatr Neurosurg 23:260-269, ; Milhorat et al., Surg Neurol 7:20-35, ; Royo-Salvador et al., Acta Neurochir 147:515-523, ; Schijman and Steinbok, Childs Nerv Syst 20:341-348, ; Yamada et al., Neurol Res 26:719-721, ). However, in the interval between the spinal cord untethering and the decompression surgery, patients may continue to suffer from the untreated symptoms of CM. In a series of four patients with concurrent severe and progressive symptoms referable to both conditions, we performed both surgeries simultaneously. Methods: Charts of four patients who underwent concurrent Chiari decompression and spinal cord untethering were reviewed. Results: All patients tolerated the procedures well without complication. They reported significant or complete early postsurgical resolution of headaches and ambulating difficulties. On average, patients started to walk on postoperative day 3 (3 ± 1 days) and were discharged on hospital day 6 (6 ± 1 days). No patient experienced a persistent subcutaneous or transcutaneous cerebrospinal fluid leak. Subsequent postoperative courses were uneventful. Conclusion: Concurrent Chiari decompression and untethering of the spinal cord is a feasible option and in some patients may be preferred in lieu of staged procedures. [ABSTRACT FROM AUTHOR]

Purpose: Postauricular, transpetrous, presigmoid approach combines a supra/infratentorial exposure with partial petrosectomy to access third to the twelfth cranial nerves and extraaxial lesions situated anterolateral to brainstem. It provides a shorter working distance to large petrosal, petroclival, cerebellopontine, and cerebellomedullary cisternal lesions and their extensions to the subtemporal–infratemporal areas. This study reviews the surgical technique, corridors of extension, and complications encountered utilizing this approach for excising extensive lesions in these locations. Methods: The lesions ( n = 14) included petroclival meningiomas [( n = 5), including three recurrent lesions], dumbbell lower cranial nerve schwannomas ( n = 2), giant acoustic schwannomas ( n = 2), recurrent giant trigeminal nerve schwannoma ( n = 1), glomus jugulare ( n = 3), and recurrent petrous aneurysmal bone cyst ( n = 1). The approach was combined with a retrosigmoid suboccipital craniectomy ( n = 3), with an infratemporal approach ( n = 2), and with an extreme lateral transcondylar approach and a translabyrinthine approach in one patient each, respectively. External auditory canal was not ligated in nine patients, superior petrosal sinus and tentorial division was performed in all patients, and sigmoid sinus–internal jugular vein was excised in three patients (with a glomus jugulare ( n = 1) and petroclival meningioma ( n = 2), respectively). Repair was performed with fat–fascia, pedicled pericranium, and temporalis muscle. Lumbar drain was placed for three to five postoperative days. Results: Total excision was performed in nine patients. Small tumor remnants were left attached to the brainstem ( n = 3, petroclival meningioma), carotid canal and cavernous sinus ( n = 1, glomus jugulare), and sigmoid sinus–jugular bulb ( n = 1, recurrent trigeminal schwannoma). A two-staged procedure was performed in three patients. Two patients with recurrent giant petroclival meningiomas died: one with lower cranial nerve paresis due to aspiration pneumonitis and the other with cerebrospinal fluid otorrhoea and secondary meningitis. Conclusions: The approach facilitates direct tumor decompression and its retraction away from the brainstem without initially encountering the intracisternal cranial nerves and neuraxis. It provides multiple corridors for excising extensive posterior fossa tumors. Preoperative assessment of sigmoid sinus dominance, jugular bulb height, labyrinth, vein of Labbe, and space available through Trautman’s triangle considerably helps in complication avoidance. [ABSTRACT FROM AUTHOR]