Treatment of postoperative vasospasm with intraarterial verapamil after removal of intracranial tumor: patient series

BACKGROUND

The authors report on four clinical cases with intraarterial verapamil administration to resolve vasospasm in patients who underwent surgery for intracranial tumors. Iatrogenic subarachnoid hemorrhage after tumor resection and subsequent vasospasm (an increase in the systolic linear velocity of blood flow through the M1 segment of the middle cerebral artery of more than 250 cm/sec; Lindegaard index: 4.1) were observed in four patients during the early postoperative period after the removal of intracerebral tumors. Each vasospasm case was confirmed by angiography data, was clinically significant, and manifested as the development of a neurological deficit.

OBSERVATIONS

Resolution of vasospasm with the intraarterial administration of verapamil was achieved in all four cases as confirmed by angiographic data in all four cases and complete regression of neurological symptoms in two cases. In all four presented cases, vasospasm was resolved; unfortunately, the resolution did not always lead to significant clinical improvement. However, lethal outcomes were avoided in two cases, and almost full recoveries were achieved in the other two.

LESSONS

The authors believe that the removal of intracranial tumors can cause expected and potential complications, such as cerebral vasospasm, which must be diagnosed and treated in a timely manner.

Endovascular treatment of a ruptured posterior fossa pure arterial malformation: illustrative case

BACKGROUND

Pure arterial malformations (PAMs) are rare vascular anomalies that are commonly mistaken for other vascular malformations. Because of their purported benign natural history, PAMs are often conservatively managed. The authors report the case of a ruptured PAM leading to subarachnoid hemorrhage (SAH) with intraventricular extension that was treated endovascularly.

OBSERVATIONS

A 38-year-old man presented with a 1-day history of headaches and nausea. A computed tomography scan demonstrated diffuse SAH with intraventricular extension, and angiography revealed a right posterior inferior cerebellar artery-associated PAM. The PAM was treated with endovascular Onyx embolization.

LESSONS

To the authors' knowledge, only 2 other cases of SAH associated with PAM have been reported. In those 2 cases, surgical clipping was pursued for definitive treatment. Here, the authors report the first case of a ruptured PAM treated using an endovascular approach, showing its feasibility as a treatment option particularly in patients in whom open surgery is too high a risk.

Diffusion tensor magnetic resonance imaging of the optic nerves in pediatric hydrocephalus

OBJECTIVE

While conventional imaging can readily identify ventricular enlargement in hydrocephalus, structural changes that underlie microscopic tissue injury might be more difficult to capture. MRI-based diffusion tensor imaging (DTI) uses properties of water motion to uncover changes in the tissue microenvironment. The authors hypothesized that DTI can identify alterations in optic nerve microstructure in children with hydrocephalus.

METHODS

The authors retrospectively reviewed 21 children (< 18 years old) who underwent DTI before and after neurosurgical intervention for acute obstructive hydrocephalus from posterior fossa tumors. Their optic nerve quantitative DTI metrics of mean diffusivity (MD) and fractional anisotropy (FA) were compared to those of 21 age-matched healthy controls.

RESULTS

Patients with hydrocephalus had increased MD and decreased FA in bilateral optic nerves, compared to controls (p < 0.001). Normalization of bilateral optic nerve MD and FA on short-term follow-up (median 1 day) after neurosurgical intervention was observed, as was near-complete recovery of MD on long-term follow-up (median 1.8 years).

CONCLUSIONS

DTI was used to demonstrate reversible alterations of optic nerve microstructure in children presenting acutely with obstructive hydrocephalus. Alterations in optic nerve MD and FA returned to near-normal levels on short- and long-term follow-up, suggesting that surgical intervention can restore optic nerve tissue microstructure. This technique is a safe, noninvasive imaging tool that quantifies alterations of neural tissue, with a potential role for evaluation of pediatric hydrocephalus.

Outcome following postneurosurgical Acinetobacter meningitis: an institutional experience of 72 cases

OBJECTIVE

The authors aimed to evaluate the antimicrobial susceptibility pattern of Acinetobacter isolates responsible for nosocomial meningitis/ventriculitis in the neurosurgical ICU. The authors also sought to identify the risk factors for mortality following Acinetobacter meningitis/ventriculitis.

METHODS

This was a retrospective study of 72 patients admitted to the neurosurgical ICU between January 2014 and December 2018 with clinical and microbiological diagnosis of nosocomial postneurosurgical Acinetobacter baumanii meningitis/ventriculitis. Electronic medical data on clinical characteristics, underlying pathology, CSF cytology, antibiotic susceptibilities, and mortality were recorded. To evaluate the outcome following nosocomial postneurosurgical Acinetobacter meningitis/ventriculitis, patients were followed up until discharge or death in the hospital. Kaplan-Meier survival analysis and multivariable Cox proportional hazards models were used to compute factors affecting survival.

RESULTS

The study population was divided into two groups depending on the final outcome of whether the patient died or survived. Forty-three patients (59.7%) were included in the survivor group and 29 patients (40.3%) were included in the nonsurvivor group. Total in-hospital mortality due to Acinetobacter meningitis/ventriculitis was 40.3% (29 cases), with a 14-day mortality of 15.3% and a 30-day mortality of 25%. The 43 (59.7%) patients who survived had a mean length of hospital stay of 44 ± 4 days with a median Glasgow Outcome Scale-Extended score at discharge of 6. On univariate analysis, age > 40 years (p = 0.078), admission Glasgow Coma Scale (GCS) score ≤ 8 (p = 0.003), presence of septic shock (p = 0.011), presence of external ventricular drain (EVD) (p = 0.03), CSF white blood cell (WBC) count > 200 cells/mm3 (p = 0.084), and comorbidities (diabetes, p = 0.036; hypertension, p = 0.01) were associated with poor outcome. Carbapenem resistance was not a risk factor for mortality. According to a multivariable Cox proportional hazards model, age cutoff of 40 years (p = 0.016, HR 3.21), GCS score cutoff of 8 (p = 0.006, HR 0.29), CSF WBC count > 200 cells/mm3 (p = 0.01, HR 2.76), presence of EVD (p = 0.001, HR 5.42), and comorbidities (p = 0.017, HR 2.8) were found to be significant risk factors for mortality.

CONCLUSIONS

This study is the largest case series reported to date of postneurosurgical Acinetobacter meningitis/ventriculitis. In-hospital mortality due to Acinetobacter meningitis/ventriculitis was high. Age older than 40 years, GCS score less than 8, presence of EVD, raised CSF WBC count, and presence of comorbidities were risk factors for mortality.

Reduction of ventriculostomy-associated CSF infection with antibiotic-impregnated catheters in pediatric patients: a single-institution study

OBJECTIVE

External ventricular drains (EVDs) are commonly used in the neurosurgical population. However, very few pediatric neurosurgery studies are available regarding EVD-associated infection rates with antibiotic-impregnated EVD catheters. The authors previously published a large pediatric cohort study analyzing nonantibiotic-impregnated EVD catheters and risk factors associated with infections. In this study, they aimed to analyze the EVD-associated infection rate after implementation of antibiotic-impregnated EVD catheters.

METHODS

A retrospective observational cohort of pediatric patients (younger than 18 years of age) who underwent a burr hole for antibiotic-impregnated EVD placement and who were admitted to a quaternary care ICU between January 2011 and January 2019 were reviewed. The ventriculostomy-associated infection rate in patients with antibiotic-impregnated EVD catheters was compared to the authors' historical control of patients with nonantibiotic-impregnated EVD catheters.

RESULTS

Two hundred twenty-nine patients with antibiotic-impregnated EVD catheters were identified. Neurological diagnostic categories included externalization of an existing shunt (externalized shunt) in 34 patients (14.9%); brain tumor (tumor) in 77 patients (33.6%); intracranial hemorrhage (ICH) in 27 patients (11.8%); traumatic brain injury (TBI) in 6 patients (2.6%); and 85 patients (37.1%) were captured in an "other" category. Two of 229 patients (0.9% of all patients) had CSF infections associated with EVD management, totaling an infection rate of 0.99 per 1000 catheter days. This is a significantly lower infection rate than was reported in the authors' previously published analysis of the use of nonantibiotic-impregnated EVD catheters (0.9% vs 6%, p = 0.00128).

CONCLUSIONS

In their large pediatric cohort, the authors demonstrated a significant decline in ventriculostomy-associated CSF infection rate after implementation of antibiotic-impregnated EVD catheters at their institution.

A novel grading system for the prediction of the need for cerebrospinal fluid drainage following posterior fossa tumor surgery

OBJECTIVE

Prophylactic placement of an external ventricular drain (EVD) is often performed prior to resection of a posterior fossa tumor (PFT); however, there is no general consensus regarding the indications. The purpose of this study was to establish a novel grading system for the prediction of required CSF drainage due to symptomatic elevated intracranial pressure (ICP) after resection of a PFT to identify patients who require an EVD.

METHODS

The authors performed a retrospective analysis of data from a prospective database. All patients who had undergone resection of a PFT between 2012 and 2017 at the University Hospital, Goethe University Frankfurt, were identified and data from their cases were analyzed. PFTs were categorized as intraparenchymal (iPFT) or extraparenchymal (ePFT). Prior to resection, patients underwent EVD placement, prophylactic burr hole placement, or neither. The authors assessed the amount of CSF drainage (if applicable), rate of EVD placement at a later time point, and complication rate and screened for factors associated with CSF drainage. By applying those factors, they established a grading system to predict the necessity of CSF drainage for elevated ICP.

RESULTS

A total of 197 patients met the inclusion criteria. Of these 197, 70.6% received an EVD, 15.7% underwent prophylactic burr hole placement, and 29.4% required temporary CSF drainage. In the prophylactic burr hole group, 1 of 32 patients (3.1%) required EVD placement at a later time. Independent predictors for postoperative need for CSF drainage due to symptomatic intracranial hypertension in patients with iPFTs were preoperative hydrocephalus (OR 2.9) and periventricular CSF capping (OR 2.9), whereas semi-sitting surgical position (OR 0.2) and total resection (OR 0.3) were protective factors. For patients with ePFTs, petroclival/midline tumor location (OR 12.2/OR 5.7), perilesional edema (OR 10.0), and preoperative hydrocephalus (OR 4.0) were independent predictors of need for CSF drainage. According to our grading system, CSF drainage after resection of iPFT or ePFT, respectively, was required in 16.7% and 5.1% of patients with a score of 0, in 21.1% and 12.5% of patients with a score of 1, in 47.1% and 26.3% of patients with a score of 2, and in 100% and 76.5% of patients with a score ≥ 3 (p < 0.0001). The rate of relevant EVD complications was 4.3%, and 10.1% of patients were shunt-dependent at 3-month follow-up.

CONCLUSIONS

This novel grading system for the prediction of need for CSF drainage following resection of PFT might be of help in deciding in favor of or against prophylactic EVD placement.

In vitro and in vivo testing of a novel local nicardipine delivery system to the brain: a preclinical study

OBJECTIVE

The management of patients with aneurysmal subarachnoid hemorrhage (aSAH) remains a highly demanding challenge in critical care medicine. Despite all efforts, the calcium channel antagonist nimodipine remains the only drug approved for improving outcomes after aSAH. However, in its current form of application, it provides less than optimal efficacy and causes dose-limiting hypotension in a substantial number of patients. Here, the authors tested in vitro the release dynamics of a novel formulation of the calcium channel blocker nicardipine and in vivo local tolerance and tissue reaction using a chronic cranial window model in mice.

METHODS

To characterize the release kinetics in vitro, dissolution experiments were performed using artificial cerebrospinal fluid over a time period of 21 days. The excipients used in this formulation (NicaPlant) for sustained nicardipine release are a mixture of two completely degradable polymers. A chronic cranial window in C57BL/6 mice was prepared, and NicaPlant slices were placed in proximity to the exposed cerebral vasculature. Epifluorescence video microscopy was performed right after implantation and on days 3 and 7 after surgery. Vessel diameter of the arteries and veins, vessel permeability, vessel configuration, and leukocyte-endothelial cell interaction were quantified by computer-assisted analysis. Immunofluorescence staining was performed to analyze inflammatory reactions and neuronal alterations.

RESULTS

In vitro the nicardipine release profile showed an almost linear curve with about 80% release at day 15 and full release at day 21. In vivo epifluorescence video microscopy showed a significantly higher arterial vessel diameter in the NicaPlant group due to vessel dilatation (21.6 ± 2.6 µm vs 17.8 ± 1.5 µm in controls, p < 0.01) confirming vasoactivity of the implant, whereas the venous diameter was not affected. Vessel dilatation did not have any influence on the vessel permeability measured by contrast extravasation of the fluorescent dye in epifluorescence microscopy. Further, an increased leukocyte-endothelial cell interaction due to the implant could not be detected. Histological analysis did not show any microglial activation or accumulation. No structural neuronal changes were observed.

CONCLUSIONS

NicaPlant provides continuous in vitro release of nicardipine over a 3-week observation period. In vivo testing confirmed vasoactivity and lack of toxicity. The local application of this novel nicardipine delivery system to the subarachnoid space is a promising tool to improve patient outcomes while avoiding systemic side effects.

Quantitative versus qualitative blood amount assessment as a predictor for shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage

OBJECTIVE

Reliable tools are lacking to predict shunt-dependent hydrocephalus (SDHC) development after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative volumetric measurement of hemorrhagic blood is a good predictor of SDHC but might be impractical in the clinical setting. Qualitative assessment performed using scales such as the modified Fisher scale (mFisher) and the original Graeb scale (oGraeb) is easier to conduct but provides limited predictive power. In between, the modified Graeb scale (mGraeb) keeps the simplicity of the qualitative scales yet adds assessment of acute hydrocephalus, which might improve SDHC-predicting capabilities. In this study the authors investigated the likely capabilities of the mGraeb and compared them with previously validated methods. This research also aimed to define a tailored mGraeb cutoff point for SDHC prediction.

METHODS

The authors performed retrospective analysis of patients admitted to their institution with the diagnosis of aSAH between May 2013 and April 2016. Out of 168 patients, 78 were included for analysis after the application of predefined exclusion criteria. Univariate and multivariate analyses were conducted to evaluate the use of all 4 methods (quantitative volumetric assessment and the mFisher, oGraeb, and mGraeb scales) to predict the likelihood of SDHC development based on clinical data and blood amount assessment on initial CT scans.

RESULTS

The mGraeb scale was demonstrated to be the most robust predictor of SDHC, with an area under the curve (AUC) of 0.848 (95% CI 0.763-0.933). According to the AUC results, the performance of the mGraeb scale was significantly better than that of the oGraeb scale (χ2 = 4.49; p = 0.034) and mFisher scale (χ2 = 7.21; p = 0.007). No statistical difference was found between the AUCs of the mGraeb and the quantitative volumetric measurement models (χ2 = 12.76; p = 0.23), but mGraeb proved to be the simplest model since it showed the lowest Akaike information criterion (66.4), the lowest Bayesian information criterion (71.2), and the highest R2Nagelkerke coefficient (39.7%). The initial mGraeb showed more than 85% specificity for predicting the development of SDHC in patients presenting with a score of 12 or more points.

CONCLUSIONS

According to the authors' data, the mGraeb scale is the simplest model that correlates well with SDHC development. Due to limited scientific evidence of treatments aimed at SDHC prevention, we propose an mGraeb score higher than 12 to identify patients at risk with high specificity. This mGraeb cutoff point might also serve as a useful prognostic tool since patients with SDHC after aSAH have worse functional outcomes.

The effect of ICP monitoring in severe traumatic brain injury: a propensity score-weighted and adjusted regression approach

OBJECTIVE

The use of intracranial pressure (ICP) monitoring has been postulated to be beneficial in patients with severe traumatic brain injury (TBI), although studies investigating this hypothesis have reported conflicting results. The objective of this study was to evaluate the effect of inserting an ICP monitor on survival in patients with severe TBI.

METHODS

The Oslo University Hospital trauma registry was searched for the records of all patients admitted between January 1, 2002, and December 31, 2013, who fulfilled the Brain Trauma Foundation criteria for intracranial hypertension and who survived at least 24 hours after admission. The impact of ICP monitoring was investigated using both a logistic regression model and a multiple imputed, propensity score-weighted logistic regression analysis.

RESULTS

The study involved 1327 patients, in which 757 patients had an ICP monitor implanted. The use of ICP monitors significantly increased in the study period (p < 0.01). The 30-day overall mortality was 24.3% (322 patients), divided into 35.1% (200 patients, 95% confidence interval [CI] 31.3%-39.1%) in the group without an ICP monitor and 16.1% (122 patients, 95% CI 13.6%-18.9%) in the group with an ICP monitor. The impact of ICP monitors on 30-day mortality was found to be beneficial both in the complete case analysis logistic regression model (odds ratio [OR] 0.23, 95% CI 0.16-0.33) and in the adjusted, aggregated, propensity score-weighted imputed data sets (OR 0.22, 95% CI 0.15-0.35; both p < 0.001). The sensitivity analysis indicated that the findings are robust to unmeasured confounders.

CONCLUSIONS

The authors found that the use of an ICP monitor is significantly associated with improved survival in patients with severe head injury.

Two-year mortality and functional outcomes in combat-related penetrating brain injury: battlefield through rehabilitation

OBJECTIVEThere are limited data concerning the long-term functional outcomes of patients with penetrating brain injury. Reports from civilian cohorts are small because of the high reported mortality rates (as high as 90%). Data from military populations suggest a better prognosis for penetrating brain injury, but previous reports are hampered by analyses that exclude the point of injury. The purpose of this study was to provide a description of the long-term functional outcomes of those who sustain a combat-related penetrating brain injury (from the initial point of injury to 24 months afterward).METHODSThis study is a retrospective review of cases of penetrating brain injury in patients who presented to the Role 3 Multinational Medical Unit at Kandahar Airfield, Afghanistan, from January 2010 to March 2013. The primary outcome of interest was Glasgow Outcome Scale (GOS) score at 6, 12, and 24 months from date of injury.RESULTSA total of 908 cases required neurosurgical consultation during the study period, and 80 of these cases involved US service members with penetrating brain injury. The mean admission Glasgow Coma Scale (GCS) score was 8.5 (SD 5.56), and the mean admission Injury Severity Score (ISS) was 26.6 (SD 10.2). The GOS score for the cohort trended toward improvement at each time point (3.6 at 6 months, 3.96 at 24 months, p > 0.05). In subgroup analysis, admission GCS score ≤ 5, gunshot wound as the injury mechanism, admission ISS ≥ 26, and brain herniation on admission CT head were all associated with worse GOS scores at all time points. Excluding those who died, functional improvement occurred regardless of admission GCS score (p < 0.05). The overall mortality rate for the cohort was 21%.CONCLUSIONSGood functional outcomes were achieved in this population of severe penetrating brain injury in those who survived their initial resuscitation. The mortality rate was lower than observed in civilian cohorts.

Optic pathway-hypothalamic glioma hemorrhage: a series of 9 patients and review of the literature

OBJECTIVEHemorrhage (also known as apoplexy) in optic pathway gliomas (OPGs) is rare. Because of the variable presentations and low incidence of OPG hemorrhages, little is known about their clinical course and the best treatment options. The aim of this work was to review risk factors, clinical course, and treatment strategies of optic glioma hemorrhages in the largest possible number of cases.METHODSA total of 34 patients were analyzed. Nine new cases were collected, and 25 were identified in the literature. Data regarding demographics, radiological and histological features, treatment, and outcome were retrospectively reviewed.RESULTSThe majority of patients were younger than 20 years. Only 3 patients were known to have neurofibromatosis. The histopathological diagnosis was pilocytic astrocytoma in the majority of cases. Five patients had intraorbital hemorrhages, whereas 29 patients had intracranial hemorrhage; the majority of intracranial bleeds were treated surgically. Six patients, all with intracranial hemorrhage, died due to recurrent bleeding, hydrocephalus, or surgical complications. No clear risk factors could be identified.CONCLUSIONSIntracerebral OPG hemorrhages have a fatal outcome in 20% of cases. Age, hormonal status, neurofibromatosis involvement, and histopathological diagnosis have been suggested as risk factors for hemorrhage, but this cannot be reliably established from the present series. The goals of surgery should be patient survival and prevention of further neurological and ophthalmological deterioration.

Reduction of shunt dependency rates following aneurysmal subarachnoid hemorrhage by tandem fenestration of the lamina terminalis and membrane of Liliequist during microsurgical aneurysm repair

OBJECTIVEShunt-dependent hydrocephalus is an important cause of morbidity following aneurysmal subarachnoid hemorrhage (aSAH) in excess of 20% of cases. Hydrocephalus leads to prolonged hospital and ICU stays, well as to repeated surgical interventions, readmissions, and complications associated with ventriculoperitoneal (VP) shunts, including shunt failure and infection. Whether variations in surgical technique at the time of aneurysm treatment may modify rates of shunt dependency remains a matter of debate. Here, the authors report on their experience with tandem fenestration of the lamina terminalis (LT) and membrane of Liliequist (MoL) at the time of open microsurgical repair of the ruptured aneurysm.METHODSThe authors conducted a retrospective review of 663 consecutive patients with aSAH treated from 2005 to 2015 by open microsurgery via a pterional or orbitozygomatic craniotomy by the senior author (M.T.L.). Data collected from review of the electronic medical record included age, Hunt and Hess grade, Fisher grade, need for an external ventricular drain, and opening pressure. Patients were stratified into those undergoing no fenestration and those undergoing tandem fenestration of the LT and MoL at the time of surgical repair. Outcome variables, including VP shunt placement and timing of shunt placement, were recorded and statistically analyzed.RESULTSIn total, shunt-dependent hydrocephalus was observed in 15.8% of patients undergoing open surgical repair following aSAH. Tandem microsurgical fenestration of the LT and MoL was associated with a statistically significant reduction in shunt dependency (17.9% vs 3.2%, p < 0.01). This effect was confirmed with multivariate analysis of collected variables (multivariate OR 0.09, 95% CI 0.03-0.30). Number-needed-to-treat analysis demonstrated that tandem fenestration was required in approximately 6.8 patients to prevent a single VP shunt placement. A statistically significant prolongation in days to VP shunt surgery was also observed in patients treated with tandem fenestration (26.6 ± 19.4 days vs 54.0 ± 36.5 days, p < 0.05).CONCLUSIONSTandem fenestration of the LT and MoL at the time of open microsurgical clipping and/or bypass to secure ruptured anterior and posterior circulation aneurysms is associated with reductions in shunt-dependent hydrocephalus following aSAH. Future prospective randomized multicenter studies are needed to confirm this result.

Factors predicting reoperation of chronic subdural hematoma following primary surgical evacuation

OBJECTIVEChronic subdural hematoma (CSDH) is commonly encountered in neurosurgical practice. However, surgical evacuation remains complicated by a high rate of reoperation. The optimal surgical approach to reduce the reoperation rate has not been determined. In the current study, the authors evaluated the prognostic value of clinical and radiographic factors to predict reoperation in the context of CSDH.METHODSA retrospective review of 325 CSDH patients admitted to an academic medical center in the United States, between 2006 and 2016, was performed. Clinical and radiographic factors predictive of the need for CSDH reoperation were identified on univariable and multivariable analyses.RESULTSUnivariable analysis showed that warfarin use, clopidogrel use, mixed hypo- and isointensity on T1-weighted MRI, greater preoperative midline shift, larger hematoma/fluid residual on first postoperative day CT, lesser decrease in hematoma size after surgery, use of monitored anesthesia care (MAC), and lack of intraoperative irrigation correlated with a significantly higher rate of reoperation. Multivariable analysis, however, showed that only the presence of loculation, clopidogrel or warfarin use, and percent of hematoma change after surgery significantly predicted the need for reoperation. Our results showed that 0% (no reduction), 50%, and 100% hematoma maximum thickness change (complete resolution of hematoma after surgery) were associated with a 41%, 6%, and < 1% rate of reoperation, respectively. The use of drains, either large diameter or small caliber, did not have any effect on the likelihood of reoperation.CONCLUSIONSAmong many factors, clopidogrel or warfarin use, hematoma loculation on preoperative CT, and the amount of hematoma evacuation on the first postoperative CT were the strongest predictors of reoperation.

Surgical treatment of falcotentorial meningiomas: a retrospective review of a single-institution experience

OBJECTIVE

Meningiomas at the falcotentorial junction represent a rare subgroup of complex meningiomas. Debate remains regarding the appropriate treatment strategy for and optimal surgical approach to these tumors, and surgical outcomes have not been well described in the literature. The authors reviewed their single-institution experience in the management, approach selection, and outcomes for patients with falcotentorial meningiomas.

METHODS

From the medical records, the authors identified all patients with falcotentorial meningiomas treated with resection at the Barrow Neurological Institute between January 2007 and October 2017. Perioperative clinical, surgical, and radiographic data were retrospectively collected. For patients who underwent the supracerebellar infratentorial approach, the tentorial angle was defined as the angle between the line joining the nasion with the tuberculum sellae and the tentorium in the midsagittal plane.

RESULTS

Falcotentorial meningiomas occurred in 0.97% (14/1441) of the patients with meningiomas. Most of the patients (13/14) were female, and the mean patient age was 59.8 ± 11.3 years. Of 17 total surgeries (20 procedures), 11 were single-stage primary surgeries, 3 were two-stage primary surgeries (6 procedures), 2 were reoperations for recurrence, and 1 was a reoperation after surgery had been aborted because of brain edema. Hydrocephalus was present in 5 of 17 cases, 4 of which required additional treatment. Various approaches were used, including the supracerebellar infratentorial (4/17), occipital transtentorial/transfalcine (4/17), anterior interhemispheric transsplenial (3/17), parietal transventricular (1/17), torcular (2/17), and staged supracerebellar infratentorial and occipital transtentorial/transfalcine (3/17) approaches. Of the 17 surgeries, 9 resulted in Simpson grade IV resection, and 3, 1, and 4 surgeries resulted in Simpson grades III, II, and I resection, respectively. The tentorial angle in cases with Simpson grade I resection was significantly smaller than in those with an unfavorable resection grade (43.3° ± 4.67° vs 54.0° ± 3.67°, p = 0.04). Complications occurred in 10 of 22 approaches (17 surgeries) and included visual field defects (6 cases, 2 permanent and 4 transient), hemiparesis (2 cases), hemidysesthesia (1 case), and cerebellar hematoma (1 case).

CONCLUSIONS

Falcotentorial meningiomas are challenging lesions. A steep tentorial angle is an unfavorable preoperative radiographic factor for achieving maximal resection with the supracerebellar infratentorial approach. Collectively, the study findings show that versatility is required to treat patients with falcotentorial meningiomas and that treatment goals and surgical approach must be individualized to obtain optimal surgical results.

Prevention of surgical site infections after brain surgery: the prehistoric period to the present

In this historical vignette, the authors discuss the prevention of surgical site infections (SSIs) after brain surgery from the prehistoric period to the present. Although the mechanism for infection was not fully understood until the 19th century, records demonstrate that as early as 10,000 bc, practitioners used gold, a biocidal material, for cranioplasties and attempted to approximate wounds by tying a patient's hair across the incision. Written records from the Egyptian and Babylonian period depict the process of soaking head dressings in alcohol, an antibacterial agent. In the Greek and Early Byzantine period, Hippocrates argued against the formation of pus in wounds and continued to champion the use of wine in wound management. In the 16th century, intracranial silver drains were first utilized in an effort to prevent postoperative infections. The turning point of SSI prevention was in 1867, when Joseph Lister illustrated the connection between Louis Pasteur's discovery of the fermentation process and the suppuration of wounds. Today, there are ongoing investigations and debates about the optimal techniques to prevent SSI after brain surgery. Although tremendous progress in the field of SSI prevention since the prehistoric period has been made, SSI continues to affect morbidity and mortality after brain surgery.

Variation in hospital charges in patients with external ventricular drains: comparison between the intensive care and surgical floor settings

OBJECTIVE

Placement of an external ventricular drain (EVD) is a common and potentially life-saving neurosurgical procedure, but the economic aspect of EVD management and the relationship to medical expenditure remain poorly studied. Similarly, interinstitutional practice patterns vary significantly. Whereas some institutions require that patients with EVDs be monitored strictly within the intensive care unit (ICU), other institutions opt primarily for management of EVDs on the surgical floor. Therefore, an ICU burden for patients with EVDs may increase a patient's costs of hospitalization. The objective of the current study was to examine the expense differences between the ICU and the general neurosurgical floor for EVD care.

METHODS

The authors performed a retrospective analysis of data from 2 hospitals within a single, large academic institution-the University of Washington Medical Center (UWMC) and Seattle Children's Hospital (SCH). Hospital charges were evaluated according to patients' location at the time of EVD management: SCH ICU, SCH floor, or UWMC ICU. Daily hospital charges from day of EVD insertion to day of removal were included and screened for days that would best represent baseline expenses for EVD care. Independent-samples Kruskal-Wallis analysis was performed to compare daily charges for the 3 settings.

RESULTS

Data from a total of 261 hospital days for 23 patients were included in the analysis. Ten patients were cared for in the UWMC ICU and 13 in the SCH ICU and/or on the SCH neurosurgical floor. The median values for total daily hospital charges were $19,824.68 (interquartile range [IQR] $12,889.73-$38,494.81) for SCH ICU care, $8,620.88 (IQR $6,416.76-$11,851.36) for SCH floor care, and $10,002.13 (IQR $8,465.16-$12,123.03) for UWMC ICU care. At SCH, it was significantly more expensive to provide EVD care in the ICU than on the floor (p < 0.001), and the daily hospital charges for the UWMC ICU were significantly greater than for the SCH floor (p = 0.023). No adverse clinical event related to the presence of an EVD was identified in any of the settings.

CONCLUSIONS

ICU admission solely for EVD care is costly. If safe EVD care can be provided outside of the ICU, it would represent a potential area for significant cost savings. Identifying appropriate patients for EVD care on the floor is multifactorial and requires vigilance in balancing the expenses associated with ICU utilization and optimal patient care.

Hydrocephalus-induced neurogenic stunned myocardium and cardiac arrest in a child: completely reversed with CSF diversion

Neurogenic stunned myocardium (NSM) is a potentially fatal cause of sudden cardiogenic dysfunction due to an acute neurological event, most commonly aneurysmal subarachnoid hemorrhage in adults. Only two pediatric cases of hydrocephalus-induced NSM have been reported. Here the authors report a third case in a 14-year-old boy who presented with severe headache, decreased level of consciousness, and shock in the context of acute hydrocephalus secondary to fourth ventricular outlet obstruction 3 years after standard-risk medulloblastoma treatment. He was initially stabilized with the insertion of an external ventricular drain and vasopressor treatment. He had a profoundly reduced cardiac contractility and became asystolic for 1 minute, requiring cardiopulmonary resuscitation when vasopressors were inadvertently discontinued. Over 1 week, his ventricles decreased in size and his cardiac function returned to normal. All other causes of heart failure were ruled out, and his impressive response to CSF diversion clarified the diagnosis of NSM secondary to hydrocephalus. He was unable to be weaned from his drain during his time in the hospital, so he underwent an endoscopic third ventriculostomy and has remained well with normal cardiac function at more than 6 months' follow-up. This case highlights the importance of prompt CSF diversion and cardiac support for acute hydrocephalus presenting with heart failure in the pediatric population.

Secondary hemorrhagic complications in aneurysmal subarachnoid hemorrhage: when the impact hits hard

OBJECTIVE

Clinical data on secondary hemorrhagic complications (SHCs) in patients with aneurysmal subarachnoid hemorrhage (SAH) are sparse and mostly limited to ventriculostomy-associated SHCs. This study aimed to elucidate the incidence, risk factors, and impact on outcome of SHCs in a large cohort of SAH patients.

METHODS

All consecutive patients with ruptured aneurysms treated between January 2003 and June 2016 were eligible for this study. Patients' charts were reviewed for clinical data, and imaging studies were reviewed for radiographic data. SHCs were divided into those associated with ventriculostomy and those not associated with ventriculostomy, as well as into major and minor bleeding forms, depending on clinical impact.

RESULTS

Sixty-two (6.6%) of the 939 patients included in the final analysis developed SHCs. Ventriculostomy-associated bleedings (n = 16) were independently predicted by mono- or dual-antiplatelet therapy after aneurysm treatment (p = 0.028, adjusted odds ratio [aOR] = 10.28; and p = 0.026, aOR = 14.25, respectively) but showed no impact on functional outcome after SAH. Periinterventional use of thrombolytic agents for early effective anticoagulation was the only independent predictor (p = 0.010, aOR = 4.27) of major SHCs (n = 38, 61.3%) in endovascularly treated patients. In turn, a major SHC was independently associated with poor outcome at the 6-month follow-up (modified Rankin Scale score > 3). Blood thinning drug therapy prior to SAH was not associated with SHC risk.

CONCLUSIONS

SHCs present a rare sequela of SAH. Antiplatelet therapy during (but not before) SAH increases the risk of ventriculostomy-associated bleedings, but without further impact on the course and outcome of SAH. The use of thrombolytic agents for early effective anticoagulation carries relevant risk for major SHCs and poor outcome.

The role of lumboperitoneal shunts in managing chronic hydrocephalus with slit ventricles

OBJECTIVELumboperitoneal (LP) shunts have a role not only in pseudotumor cerebri, but also in patients with slit-like ventricles who are treated with CSF shunting on a chronic basis. Hesitation to utilize LP shunts is based on previous conventional beliefs including the tendency for overdrainage, difficulties accessing the shunt to tap or revise, and risk of progressive cerebellar tonsillar herniation. The authors hypothesized that the use of horizontal-vertical (HV) valves may reduce the risk of these complications, particularly overdrainage and development of Chiari malformation.METHODSAll pediatric cases involving patients treated with an LP shunt at the Children's Hospital of Michigan were reviewed in this retrospective case series. A total of 143 patients with hydrocephalus were treated with LP shunts from 1997-2015 (follow-up range 8 months-8 years, median 4.2 years). Patients with pseudotumor cerebri underwent placement of an LP shunt as a primary procedure. In patients with slit ventricles from chronically treated hydrocephalus or repeated shunt malfunctions from proximal catheter obstruction, a lumbar drain was inserted to assess candidacy for conversion to an LP shunt. In patients who tolerated the lumbar drain and demonstrated communication of the ventricles with the spinal cisterns, treatment was converted to an LP shunt. All patients included in the series had undergone initial shunt placement between birth and age 16 years.RESULTSIn 30% of patients (n = 43), LP shunts were placed as the initial shunt treatment; in 70% (n = 100), treatment was converted to LP shunts from ventriculoperitoneal (VP) shunts. The patients' age at insertion of or conversion to an LP shunt ranged from 1 to 43 years (median 8.5 years). Of the patients with clear pre-LP and post-LP shunt follow-up imaging, none were found to develop an acquired Chiari malformation. In patients with pre-existing tonsillar ectopia, no progression was noted on follow-up MRIs of the brain in these patients after LP shunt insertion. In our LP shunt case series, no patient presented with acute deterioration from shunt malfunction.CONCLUSIONSConversion to an LP shunt may minimize acute deterioration from shunt malfunction and decrease morbidity of repeated procedures in patients with chronically shunt-treated hydrocephalus and small ventricles. In comparison to previously published case series of LP shunt treatment, the use of LP shunts in conjunction with HV valves may decrease the overall risk of cerebellar tonsillar herniation. The use of an LP shunt may be an alternative in the management of slit ventricles when VP shunting repeatedly fails.

Pediatric silent corticotroph pituitary adenoma and role for proton therapy: case report

Tumors involving the sella are commonly craniopharyngiomas, optic pathway gliomas, or pituitary adenomas. Functioning adenomas are expected, with prolactinomas topping the differential. The authors present the case of a silent corticotroph adenoma, which has not been described in the pediatric population, and they detail the use of proton therapy, which is also novel.

Intraventricular tigecycline for the treatment of shunt infection: a case in pediatrics

Ventriculoperitoneal (VP) shunt infections are seen in 3%-17% of patients with VP shunts. These infections may cause severe morbidity and mortality. Staphylococci are the most common cause of CSF shunt-associated infections, although gram-negative bacteria (especially multidrug-resistant [MDR] and extensive drug-resistant [XDR] bacteria) also play an important role. Due to increased antibiotic resistance, sometimes off-label usage of antibiotics is considered. Tigecycline is one of these antibiotics. It should not be used unless there are no other antibiotic treatment options available, especially in children. It belongs to the glycylcycline class of antibiotic agents and inhibits protein translation in bacteria by binding to the 30S ribosomal subunit. The authors describe the case of a patient who had an XDR Klebsiella pneumoniae-positive VP shunt infection. After removal of his VP shunt, an external ventricular drain was inserted, and the patient was treated with a combination of intravenous (1.2 mg/kg/day) and intraventricular (4 mg/day) tigecycline in addition to his meropenem (120 mg/kg/day) treatment. On the 7th day of the combined therapy, his CSF culture was sterile. Because tigecycline distribution into the tissues is not sufficient with intravenous administration, combining it with intraventricular infusion can provide new treatment methods. However, further studies are needed for its use as a treatment method in children.

Management of hydrocephalus in infants with severe hemophilia A: report of 2 cases

The authors report on the clinical course of two infants with severe hemophilia A (HA) and concomitant progressive hydrocephalus that required management with a ventriculoperitoneal shunt. The first child, with known HA, presented with a spontaneous intracranial hemorrhage and acquired hydrocephalus. He underwent cerebrospinal fluid diversion with a temporary external ventricular drain, followed by placement of a ventriculoperitoneal shunt. The second child had hydrocephalus secondary to a Dandy-Walker malformation and was diagnosed with severe HA during preoperative evaluation. He underwent placement of a ventriculoperitoneal shunt after progression of the hydrocephalus. The authors also review the treatment of hydrocephalus in patients with HA and describe the perioperative protocols used in their two cases. Treatment of hydrocephalus in infants with HA requires unique perioperative management to avoid complications.

Pipeline-assisted coil embolization of a large middle cerebral artery pseudoaneurysm in a 9-month-old infant: experience from the youngest flow diversion case

Intracranial aneurysms in the pediatric population are rare entities. The authors recently treated a 9-month-old infant with a 19-mm recurrent, previously ruptured, and coil-embolized left middle cerebral artery (MCA) pseudoaneurysm, which was treated definitively with single-stage Pipeline-assisted coil embolization. The patient was 5 months old when she underwent resection of a left temporal Grade 1 desmoplastic infantile ganglioglioma at an outside institution, which was complicated by left MCA injury with a resultant 9-mm left M1 pseudoaneurysm. Within a month, the patient had two aneurysmal rupture events and underwent emergency craniectomy for decompression and evacuation of subdural hematoma. The pseudoaneurysm initially underwent coil embolization; however, follow-up MR angiography (MRA) revealed aneurysm recanalization with saccular enlargement to 19 mm. The patient underwent successful flow diversion-assisted coil embolization at 9 months of age. At 7 months after the procedure, follow-up MRA showed complete aneurysm occlusion without evidence of in-stent thrombosis or stenosis. Experience with flow diverters in the pediatric population is still in its early phases, with the youngest reported patient being 22 months old. In this paper the authors report the first case of such a technique in an infant, whom they believe to be the youngest patient to undergo cerebral flow diversion treatment.

Clinical evaluation and surveillance imaging of children with myelomeningocele and shunted hydrocephalus: a follow-up study

OBJECTIVEThe majority of children with myelomeningocele undergo implantation of CSF shunts. The efficacy of adding surveillance imaging to clinical evaluation during routine follow-up as a means to minimize the hazard associated with future shunt failure has not been thoroughly studied.METHODSA total of 300 spina bifida clinic visits during the calendar years between 2012 and 2016 were selected for this study (defined as the index clinic visit). Each index visit was preceded by a 6-month period during which no shunt evaluation of any kind was performed. At the index clinic visit, all patients were evaluated by a neurosurgeon. Seventy-four patients underwent previously scheduled surveillance CT or shunt series scans in addition to clinical evaluation (surveillance imaging group), and 226 patients did not undergo surveillance imaging (clinical evaluation group). Subsequent unexpected events, defined as emergency department visits, caregiver-requested clinic visits, and shunt revision surgeries were reviewed. The timing and likelihood of an unexpected event in each of the 2 groups were compared using Cox proportional hazard survival analysis. The rate of shunt revision surgery in the follow-up period as well as the associated outcomes and rate of complications were analyzed.RESULTSThe clinical characteristics of the 2 groups were similar. In the clinical evaluation group, 4 of 226 (1.8%) patients underwent shunt revision based on clinical findings during the index visit, compared to 8 of 74 (10.8%) patients in the surveillance imaging group who underwent shunt revision based on clinical and imaging findings at that visit (p < 0.05). In the subsequent follow-up period, there were 74 unexpected events resulting in 10 shunt revisions in the clinical evaluation group, for an event rate of 33% and operation rate of 13.5%. In the surveillance imaging group there were 23 unexpected events resulting in 2 shunt revisions, for an event rate of 34.8% and an operation rate of 8.7%; neither difference was statistically significant. The complication rate for shunt revision surgery was also not different between the groups.CONCLUSIONSObtaining predecided, routine surveillance imaging in children with myelomeningocele and shunted hydrocephalus resulted in more shunt revisions in asymptomatic patients. For patients who had negative results on surveillance imaging, the rate of shunt revision in the follow-up period was not significantly decreased compared to patients who underwent clinical examination only at the index visit.

Ruptured intracranial aneurysm in a patient with autosomal recessive polycystic kidney disease

Aneurysmal rupture can result in devastating neurological consequences and can be complicated by comorbid disease processes. Patients with autosomal recessive polycystic kidney disease (ARPKD) have a low rate of reported aneurysms, but this may be due to the relative high rate of end-stage illnesses early in childhood. Authors here report the case of a 10-year-old boy with ARPKD who presented with a Hunt and Hess grade V subarachnoid hemorrhage requiring emergency ventriculostomy, embolization, and decompressive craniectomy. Despite initial improvements in his neurological status, the patient succumbed to hepatic failure. Given the catastrophic outcomes of subarachnoid hemorrhage in young patients, early radiographic screening in those with ARPKD may be warranted.

Temporal response profiles of serum ubiquitin C-terminal hydrolase-L1 and the 145-kDa alpha II-spectrin breakdown product after severe traumatic brain injury in children

OBJECTIVE

Traumatic brain injury (TBI) is the leading cause of acquired disability among children. Brain injury biomarkers may serve as useful diagnostic and prognostic indicators for TBI. Levels of ubiquitin C-terminal hydrolase-L1 (UCH-L1) and the 145-kDa alpha II-spectrin breakdown product (SBDP-145) correlate with outcome in adults after severe TBI. The authors conducted a pilot study of these biomarkers in children after severe TBI to inform future research exploring their utility in this population.

METHODS

The levels of UCH-L1 and SBDP-145 were measured in serum, and UCH-L1 in CSF from pediatric patients after severe TBI over 5 days after injury. Both biomarkers were also measured in age-matched control serum and CSF.

RESULTS

Adequate numbers of samples were obtained in serum, but not CSF, to assess biomarker temporal response profiles. Using patients with samples from all time points, UCH-L1 levels increased rapidly and transiently, peaking at 12 hours after injury. SBDP-145 levels showed a more gradual and sustained response, peaking at 48 hours. The median serum UCH-L1 concentration was greater in patients with TBI than in controls (median [IQR] = 361 [187, 1330] vs 147 [50, 241] pg/ml, respectively; p < 0.001). Receiver operating characteristic (ROC) analysis revealed an AUC of 0.77. Similarly, serum SBDP-145 was greater in children with TBI than in controls (median [IQR] = 172 [124, 257] vs 69 [40, 99] pg/ml, respectively; p < 0.001), with an ROC AUC of 0.85. When only time points of peak levels were used for ROC analysis, the discriminability of each serum biomarker increased (AUC for UCH-L1 at 12 hours = 1.0 and for SBDP-145 at 48 hours = 0.91). Serum and CSF UCH-L1 levels correlated well in patients with TBI (r = 0.70, p < 0.001).

CONCLUSIONS

Findings from this exploratory study reveal robust increases of UCH-L1 and SBDP-145 in serum and UCH-L1 in CSF obtained from children after severe TBI. In addition, important temporal profile differences were found between these biomarkers that can help guide optimal time point selection for future investigations of their potential to characterize injury or predict outcomes after pediatric TBI.

Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures

OBJECTIVE

Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.

METHODS

Fifty-two patients with severe TBI (median age 24 years, range 9-61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.

RESULTS

All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%-13%, p = 0.004) and young age (-0.2% of GMT with ICP > 20 mm Hg, 95% CI -0.07% to -0.3%, p = 0.002) were associated with increased ICP.

CONCLUSIONS

Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

Complications following pediatric cranioplasty after decompressive craniectomy: a multicenter retrospective study

OBJECTIVE In children, the repair of skull defects arising from decompressive craniectomy presents a unique set of challenges. Single-center studies have identified different risk factors for the common complications of cranioplasty resorption and infection. The goal of the present study was to determine the risk factors for bone resorption and infection after pediatric cranioplasty. METHODS The authors conducted a multicenter retrospective case study that included all patients who underwent cranioplasty to correct a skull defect arising from a decompressive craniectomy at 13 centers between 2000 and 2011 and were less than 19 years old at the time of cranioplasty. Prior systematic review of the literature along with expert opinion guided the selection of variables to be collected. These included: indication for craniectomy; history of abusive head trauma; method of bone storage; method of bone fixation; use of drains; size of bone graft; presence of other implants, including ventriculoperitoneal (VP) shunt; presence of fluid collections; age at craniectomy; and time between craniectomy and cranioplasty. RESULTS A total of 359 patients met the inclusion criteria. The patients' mean age was 8.4 years, and 51.5% were female. Thirty-eight cases (10.5%) were complicated by infection. In multivariate analysis, presence of a cranial implant (primarily VP shunt) (OR 2.41, 95% CI 1.17-4.98), presence of gastrostomy (OR 2.44, 95% CI 1.03-5.79), and ventilator dependence (OR 8.45, 95% CI 1.10-65.08) were significant risk factors for cranioplasty infection. No other variable was associated with infection. Of the 240 patients who underwent a cranioplasty with bone graft, 21.7% showed bone resorption significant enough to warrant repeat surgical intervention. The most important predictor of cranioplasty bone resorption was age at the time of cranioplasty. For every month of increased age the risk of bone flap resorption decreased by 1% (OR 0.99, 95% CI 0.98-0.99, p < 0.001). Other risk factors for resorption in multivariate models were the use of external ventricular drains and lumbar shunts. CONCLUSIONS This is the largest study of pediatric cranioplasty outcomes performed to date. Analysis included variables found to be significant in previous retrospective reports. Presence of a cranial implant such as VP shunt is the most significant risk factor for cranioplasty infection, whereas younger age at cranioplasty is the dominant risk factor for bone resorption.

Acute fatal hemorrhage from previously undiagnosed cerebral arteriovenous malformations in children: a single-center experience

OBJECTIVE The most significant adverse outcome of intracranial hemorrhage from an arteriovenous malformation (AVM) is death. This study reviews a single-center experience with pediatric AVMs to quantify the incidence and characterize clinical and radiographic factors associated with sudden death from the hemorrhage of previously undiagnosed AVMs in children. METHODS A single-center database review of the period from 2006 to 2017 identified all patients with a first-time intracranial hemorrhage from a previously undiagnosed AVM. Clinical and radiographic data were collected and compared between patients who survived to hospital discharge and those who died at presentation. RESULTS A total of 57 patients (average age 10.8 years, range 0.1-19 years) presented with first-time intracranial hemorrhage from a previously undiagnosed AVM during the study period. Of this group, 7/57 (12%) patients (average age 11.5 years, range 6-16 years) suffered hemorrhages that led directly to their deaths. Compared to the cohort of patients who survived their hemorrhage, patients who died were 4 times more likely to have an AVM in the posterior fossa. No clear pattern of antecedent triggering activity (sports, trauma, etc.) was identified, and 3/7 (43%) experienced cardiac arrest in the prehospital setting. Surviving patients were ultimately treated with resection of the AVM in 42/50 (84%) of cases. CONCLUSIONS Children who present with hemorrhage from a previously undiagnosed intracranial AVM had a 12% chance of sudden death in our single-institution series of pediatric cerebrovascular cases. Clinical triggers of hemorrhage are unpredictable, but subsequent radiographic evidence of a posterior fossa AVM was present in 57% of fatal cases, and all fatal cases were in locations with high risk of potential herniation. These data support a proactive, aggressive approach toward definitive treatment of AVMs in children.

Introduction of severe traumatic brain injury care protocol is associated with reduction in mortality for pediatric patients: a case study of Children's Healthcare of Atlanta's neurotrauma program

OBJECTIVE Evidence shows mixed efficacy of applying guidelines for the treatment of traumatic brain injury (TBI) in children. A multidisciplinary team at a children's health system standardized intensive care unit-based TBI care using guidelines and best practices. The authors sought to investigate the impact of guideline implementation on outcomes. METHODS A multidisciplinary group developed a TBI care protocol based on published TBI treatment guidelines and consensus, which was implemented in March 2011. The authors retrospectively compared preimplementation outcomes (May 2009 to March 2011) and postimplementation outcomes (April 2011 to March 2014) among patients < 18 years of age admitted with severe TBI (Glasgow Coma Scale score ≤ 8) and potential survivability who underwent intracranial pressure (ICP) monitoring. Measures included mortality, hospital length of stay (LOS), ventilator LOS, critical ICP elevation time (percentage or total time that ICP was > 40 mm Hg), and survivor functionality at discharge (measured by the WeeFIM score). Data were analyzed using Student t-tests. RESULTS A total of 71 and 121 patients were included pre- and postimplementation, respectively. Mortality (32% vs 19%; p < 0.001) and length of critical ICP elevation (> 20 mm Hg; 26.3% vs 15%; p = 0.001) decreased after protocol implementation. WeeFIM discharge scores were not statistically different (57.6 vs 58.9; p = 0.9). Hospital LOS (median 19.6 days; p = 0.68) and ventilator LOS (median 10 days; p = 0.24) were unchanged. CONCLUSIONS A multidisciplinary effort to develop, disseminate, and implement an evidence-based TBI treatment protocol at a children's hospital was associated with improved outcomes, including survival and reduced time of ICP elevation. This type of ICP-based protocol can serve as a guide for other institutions looking to reduce practice disparity in the treatment of severe TBI.

Complications of invasive intracranial pressure monitoring devices in neurocritical care

Intracranial pressure monitoring devices have become the standard of care for the management of patients with pathologies associated with intracranial hypertension. Given the importance of invasive intracranial monitoring devices in the modern neurointensive care setting, gaining a thorough understanding of the potential complications related to device placement-and misplacement-is crucial. The increased prevalence of intracranial pressure monitoring as a management tool for neurosurgical patients has led to the publication of a plethora of papers regarding their indications and complications. The authors aim to provide a concise review of key contemporary articles in the literature concerning important complications with the hope of elucidating practices that improve outcomes for neurocritically ill patients.

Surgical decision-making in the management of childhood tumors of the CNS disseminated at presentation

OBJECTIVE It is relatively unusual for pediatric CNS tumors to be disseminated at presentation, and the literature on the clinical features, management, and outcomes of this specific group is scarce. Surgical management in this population is often challenging, particularly in the presence of hydrocephalus. The authors present their recent experience of treating pediatric CNS tumors that were disseminated at presentation, and they compare these lesions with focal tumors. METHODS The authors performed a retrospective review of prospectively collected data on children presenting to a tertiary center between 2003 and 2016 inclusive. RESULTS Of 361 children with CNS tumors, the authors identified 53 patients with disease dissemination at presentation (male/female ratio 34:19, median age 3.8 years, age range 7 days to 15.6 years) and 308 without dissemination at presentation (male/female ratio 161:147, median age 5.8 years, age range 1 day to 16.9 years). Five tumor groups were studied: medulloblastoma (disseminated n = 29, focal n = 74), other primitive neuroectodermal tumor (n = 8, n = 17), atypical teratoid rhabdoid tumor (n = 8, n = 22), pilocytic astrocytoma (n = 6, n = 138), and ependymoma (n = 2, n = 57). The median follow-up duration in survivors was not significantly different between those with disease dissemination at presentation (64.0 months, range 5.2-152.0 months) and those without it (74.5 months, range 4.7-170.1 months) (p > 0.05). When combining data from all 5 tumor groups, dissemination status at presentation was significantly associated with a higher risk of requiring CSF diversion, a higher surgical complication rate, and a reduced likelihood of achieving gross-total resection of the targeted lesion (all variables p < 0.05). Differences between the 5 tumor groups were evident. No factors that predicted the need for permanent CSF diversion following temporary external ventricular drainage were identified on multivariate analysis, and there was no clear superiority of either ventriculoperitoneal shunt surgery or endoscopic third ventriculostomy as a permanent CSF diversion procedure. CONCLUSIONS Tumor type and dissemination status at initial presentation significantly affect outcomes across a range of measures. The management of hydrocephalus in patients with CNS tumors is challenging, and further prospective studies are required to identify the optimal CSF diversion strategy in this population.

Image guidance and improved accuracy of external ventricular drain tip position particularly in patients with small ventricles

OBJECTIVEExternal ventricular drain (EVD) insertion is one of the most common emergency neurosurgical procedures. EVDs are traditionally inserted freehand (FH) in an emergency setting, but often result in suboptimal positioning. Image-guided surgery (IGS) is selectively used to assist placement. However, the accuracy and practicality of IGS use is yet to be reported. In this study, the authors set out to assess if IGS is practical and improves the accuracy of EVD placement.METHODSCase notes and images obtained in patients who underwent frontal EVD placement were retrospectively reviewed. Ventriculomegaly was determined by the measurement of the Evans index. EVD location was classified as optimal (ipsilateral frontal horn) or suboptimal (any other location). Propensity score matching of the two groups (IGS vs FH) for the Evans index was performed. Data were analyzed for patient age, diagnosis, number of EVDs, and complications. Those without postoperative CT scans were excluded.RESULTSA total of 607 patients with 760 EVDs placed were identified; 331 met inclusion criteria. Of these, 287 were inserted FH, and 44 were placed with IGS; 60.6% of all unmatched FH EVDs were optimal compared with 75% of the IGS group (p = 0.067). The IGS group had a significantly smaller Evans index (p < 0.0001). Propensity score matching demonstrated improved optimal position in the IGS group when compared with the matched FH group (75% vs 43.2%, OR 4.6 [1.5-14.6]; p = 0.002). Patients with an Evans index of ≥ 0.36 derived less benefit (75% in IGS vs 66% in FH, p = 0.5), and those with an Evans index < 0.36 derived more benefit (75% in IGS vs 53% in FH, p = 0.024). The overall EVD complication rate was 36% in the FH group versus 18% in the IGS group (p = 0.056). Revision rates were higher in the FH group (p = 0.035), and the operative times were similar (p = 0.69). Long intracranial EVD catheters were associated with tip malposition irrespective of the group.CONCLUSIONSImage guidance is practical and improves the accuracy of EVD placement in patients with small ventricles; thus, it should be considered for these patients.

Reinfection after treatment of first cerebrospinal fluid shunt infection: a prospective observational cohort study

OBJECTIVE CSF shunt infection requires both surgical and antibiotic treatment. Surgical treatment includes either total shunt removal with external ventricular drain (EVD) placement followed by new shunt insertion, or distal shunt externalization followed by new shunt insertion once the CSF is sterile. Antibiotic treatment includes the administration of intravenous antibiotics. The Hydrocephalus Clinical Research Network (HCRN) registry provides a unique opportunity to understand reinfection following treatment for CSF shunt infection. This study examines the association of surgical and antibiotic decisions in the treatment of first CSF shunt infection with reinfection. METHODS A prospective cohort study of children undergoing treatment for first CSF infection at 7 HCRN hospitals from April 2008 to December 2012 was performed. The HCRN consensus definition was used to define CSF shunt infection and reinfection. The key surgical predictor variable was surgical approach to treatment for CSF shunt infection, and the key antibiotic treatment predictor variable was intravenous antibiotic selection and duration. Cox proportional hazards models were constructed to address the time-varying nature of the characteristics associated with shunt surgeries. RESULTS Of 233 children in the HCRN registry with an initial CSF shunt infection during the study period, 38 patients (16%) developed reinfection over a median time of 44 days (interquartile range [IQR] 19-437). The majority of initial CSF shunt infections were treated with total shunt removal and EVD placement (175 patients; 75%). The median time between infection surgeries was 15 days (IQR 10-22). For the subset of 172 infections diagnosed by CSF culture, the mean ± SD duration of antibiotic treatment was 18.7 ± 12.8 days. In all Cox proportional hazards models, neither surgical approach to infection treatment nor overall intravenous antibiotic duration was independently associated with reinfection. The only treatment decision independently associated with decreased infection risk was the use of rifampin. While this finding did not achieve statistical significance, in all 5 Cox proportional hazards models both surgical approach (other than total shunt removal at initial CSF shunt infection) and nonventriculoperitoneal shunt location were consistently associated with a higher hazard of reinfection, while the use of ultrasound was consistently associated with a lower hazard of reinfection. CONCLUSIONS Neither surgical approach to treatment nor antibiotic duration was associated with reinfection risk. While these findings did not achieve statistical significance, surgical approach other than total removal at initial CSF shunt infection was consistently associated with a higher hazard of reinfection in this study and suggests the feasibility of controlling and standardizing the surgical approach (shunt removal with EVD placement). Considerably more variation and equipoise exists in the duration and selection of intravenous antibiotic treatment. Further consideration should be given to the use of rifampin in the treatment of CSF shunt infection. High-quality studies of the optimal duration of antibiotic treatment are critical to the creation of evidence-based guidelines for CSF shunt infection treatment.

Spontaneous occult intracranial hypotension precipitating life-threatening cerebral venous thrombosis: case report

Spontaneous intracranial hypotension (SIH) is an uncommon headache etiology, typically attributable to an unprovoked occult spinal CSF leak. Although frequently benign, serious complications may occur, including cerebral venous thrombosis (CVT). The objective of this study was to examine a highly complicated case of CVT attributable to SIH as a lens for understanding the heterogeneous literature on this rare complication, and to provide useful, evidence-based, preliminary clinical recommendations. A 43-year-old man presented with 1 week of headache, dizziness, and nausea, which precipitously evolved to hemiplegia. CT venography confirmed CVT, and therapeutic heparin was initiated. He suffered a generalized seizure due to left parietal hemorrhage, which subsequently expanded. He developed signs of mass effect and herniation, heparin was discontinued, and he was taken to the operating room for clot evacuation and external ventricular drain placement. Intraoperatively, the dura was deflated, suggesting underlying SIH. Ventral T-1 CSF leak was identified, which failed multiple epidural blood patches and required primary repair. The patient ultimately made a complete recovery. Systematic review identified 29 publications describing 36 cases of SIH-associated CVT. Among 31 patients for whom long-term neurological outcome was reported, 25 (81%) recovered completely. Underlying coagulopathy/risk factors were identified in 11 patients (31%). CVT is a rare and potentially lethal sequela occurring in 2% of SIH cases. Awareness of the condition is poor, risking morbid complications. Evaluation and treatment should be directed toward identification and treatment of occult CSF leaks. Encouragingly, good neurological outcomes can be achieved through vigilant multidisciplinary neurosurgical and neurocritical care.

Relationship between external ventricular drain clamp trials and ventriculoperitoneal shunt insertion following nontraumatic subarachnoid hemorrhage: a single-center study

OBJECTIVE

Currently, there is no established standard regarding the ideal number of external ventricular drain (EVD) clamp trials performed before ventriculoperitoneal (VP) shunt insertion following nontraumatic subarachnoid hemorrhage (SAH). In this study, the authors aimed to evaluate this relationship.

METHODS

A retrospective review of all patients presenting with SAH between July 2007 and December 2016 was performed. Patients with SAH who had received an EVD within the first 24 hours of hospital admission and had undergone at least 1 clamp trial prior to EVD removal were eligible for inclusion in the study. Patient demographics, clinical presentations, SAH etiologies and grades, clamp trial data, hospital lengths of stay, and functional outcomes were recorded.

RESULTS

One hundred fourteen patients with nontraumatic SAH complicated by posthemorrhagic hydrocephalus were included in the study. The median patient age was 57 years (range 28-90 years), with a male/female ratio of 1:1.7. A ruptured aneurysm was the underlying etiology of SAH in 79.8% of patients. A majority of patients (69.4%) had a Hunt and Hess grade III-V on admission. The median number of clamp trials performed was 2 (range 1-6). A VP shunt was required in 40.4% of patients. In those who underwent 2 and 3 clamp trials, 60% and 38.9%, respectively, did not require subsequent VP shunt placement.

CONCLUSIONS

Surgical placement of a VP shunt is associated with complications. Clamp trials are routinely performed before making the decision to insert a shunt. In the present study, the authors found that a significant percentage of patients passed their second and third clamp trials without requiring subsequent shunt insertion. These data support performing multiple clamp trials prior to shunt placement.

Developing a pediatric neurosurgical training model

OBJECTIVE One of the greatest challenges of pediatric neurosurgery training is balancing the training needs of the trainee against patient safety and parental expectation. The traditional "see one, do one, teach one" approach to training is no longer acceptable in pediatric neurosurgery. The authors have developed the baby Modeled Anatomical Replica for Training Young Neurosurgeons (babyMARTYN). The development of this new training model is described, its feasibility as a training tool is tested, and a new approach of integrating simulation into day-to-day training is suggested. METHODS In part 1 (development), a prototype skull was developed using novel model-making methods. In part 2 (validation), 18 trainee neurosurgeons (at various stages in training) performed the following 4 different procedures: 1) evacuation of a posterior fossa hematoma; 2) pterional craniotomy; 3) tapping of the fontanelle to obtain a CSF specimen; and 4) external ventricular drain insertion. Completion of the procedural stages (scored using a curriculum-based checklist) was used to test the feasibility of babyMARTYN as a training tool. Likert scale-based questionnaires were used to assess the model for face and content validity. Training benefit was assessed using pre- and posttraining ratings on the Physician Performance Diagnostic Inventory Scale (PPDIS). To determine the significance of improvement in median PPDIS score, the Wilcoxon matched-pairs signed-rank test was performed. RESULTS In part 1 (development), the model was successfully developed with good fidelity. In part 2 (validation), the validation data demonstrated feasibility, face, and content validity. The PPDIS score significantly increased for all groups after babyMARTYN training, thereby indicating a potential future role for babyMARTYN in the training of pediatric neurosurgeons. CONCLUSIONS This recent collaborative neurosurgical development by the Royal College of Surgeons of England is designed to supplement current neurosurgical training. High-fidelity, portable, operation-specific models enable preoperative planning and have the potential to be used in an operating room environment prior to novel operations. A "see one, simulate one, do one" approach for pediatric neurosurgical training using babyMARTYN is suggested.

Unplanned readmission within 90 days after pediatric neurosurgery

OBJECTIVE Readmission and return to operating room after surgery are increasingly being used as a proxy for quality of care. Nearly 60% of these readmissions are unplanned, which translates into billions of dollars in health care costs. The authors set out to analyze the incidence of readmission at their center, to define causes of unplanned readmission, and to determine the preoperative and surgical variables associated with readmissions following pediatric neurosurgery. METHODS A total of 536 children who underwent operations for neurosurgical diagnoses between 2012 and 2015 and who were later readmitted were included in the final analysis. Unplanned readmissions were defined to have occurred as a result of complications within 90 days after index surgery. Patient records were retrospectively reviewed to determine the primary diagnosis, surgery indication, and cause of readmission and return to operating room. The cost for index hospitalization, readmission episode, and total cost were derived based on the charges obtained from administrative data. Bivariate and multivariable analyses were conducted. RESULTS Of 536 patients readmitted in total, 17.9% (n = 96) were readmitted within 90 days. Of the overall readmissions, 11.9% (n = 64) were readmitted within 30 days, and 5.97% (n = 32) were readmitted between 31 and 90 days. The median duration between discharge and readmission was 20 days (first quartile [Q1]: 9 days, third quartile [Q3]: 36 days). The most common reason for readmission was shunt related (8.2%, n = 44), followed by wound infection (4.7%, n = 25). In the risk-adjusted multivariable logistic regression model for total 90-day readmission, patients with the following characteristics: younger age (p = 0.001, OR 0.886, 95% CI 0.824-0.952); "other" (nonwhite, nonblack) race (p = 0.024, OR 5.49, 95% CI 1.246-24.2); and those born preterm (p = 0.032, OR 2.1, 95% CI 1.1-4.12) had higher odds of being readmitted within 90 days after discharge. The total median cost for patients undergoing surgery in this study cohort was $11,520 (Q1: $7103, Q3: $19,264). For the patients who were readmitted, the median cost for a readmission episode was $8981 (Q1: $5051, Q3: $18,713). CONCLUSIONS Unplanned 90-day readmissions in pediatric neurosurgery are primarily due to CSF-related complications. Patients with the following characteristics: young age at presentation; "other" race; and children born preterm have a higher likelihood of being readmitted within 90 days after surgery. The median cost was > $8000, which suggests that the readmission episode can be as expensive as the index hospitalization. Clearly, readmission reduction has the potential for significant cost savings in pediatric neurosurgery. Future efforts, such as targeted education related to complication signs, should be considered in the attempt to reduce unplanned events. Given the single-center, retrospective study design, the results of this study are primarily applicable to this population and cannot necessarily be generalized to other institutions without further study.

Hemorrhage associated with ventriculoperitoneal shunt placement in aneurysmal subarachnoid hemorrhage patients on a regimen of dual antiplatelet therapy: a retrospective analysis

OBJECTIVE

Intracranial stenting and flow diversion require the use of dual antiplatelet therapy (DAPT) to prevent in-stent thrombosis. DAPT may significantly increase the risk of hemorrhagic complications in patients who require subsequent surgical interventions. In this study, the authors sought to investigate whether DAPT is a risk factor for hemorrhagic complications associated with ventriculoperitoneal (VP) shunt placement in patients with aneurysmal subarachnoid hemorrhage (aSAH). Moreover, the authors sought to compare VP shunt complication rates with respect to the shunt's location from the initial external ventricular drain (EVD) site.

METHODS

Patients with aSAH who presented to the authors' institution from July 2009 through November 2016 and required VP shunt placement for persistent hydrocephalus were included. The rates of hemorrhagic complications associated with VP shunt placement were compared between patients who were on a regimen of DAPT (aspirin and clopidogrel) for use of a stent or flow diverter, and patients who underwent microsurgical clipping or coiling only and were not on DAPT using a backward stepwise multivariate analysis. Rates of radiographic hemorrhage and infection-related VP shunt revision were compared between patients who underwent VP shunt placement along the same track and those who underwent VP shunt placement at a different site (contralateral or posterior) from the initial EVD.

RESULTS

A total of 443 patients were admitted for the management of aSAH. Eighty of these patients eventually required VP shunt placement. Thirty-two patients (40%) had been treated with stent-assisted coiling or flow diverters and required DAPT, whereas 48 patients (60%) had been treated with coiling without stents or surgical clipping and were not on DAPT at the time of VP shunt placement. A total of 8 cases (10%) of new hemorrhage were observed along the intracranial proximal catheter of the VP shunt. Seven of these hemorrhages were observed in patients on DAPT, and 1 occurred in a patient not on DAPT. After multivariate analysis, only DAPT was significantly associated with hemorrhage (OR 31.23, 95% CI 2.98-327.32; p = 0.0001). One patient (3%) on DAPT who experienced hemorrhage required shunt revision for hemorrhage-associated proximal catheter blockage. The remaining 7 hemorrhages were clinically insignificant. The difference in rates of hemorrhage between shunt placement along the same track and placement at a different site of 0.07 was not significant (6/47 vs 2/32, p = 0.46). The difference in infection-related VP shunt revision rate was not significantly different (1/47 vs 3/32, p = 0.2978).

CONCLUSIONS

This clinical series confirms that, in patients with ruptured aneurysms who are candidates for stent-assisted coiling or flow diversion, the risk of clinically significant VP shunt-associated hemorrhage with DAPT is low. In an era of evolving endovascular therapeutics, stenting or flow diversion is a viable option in select aSAH patients.

Dual antiplatelet therapy in aneurysmal subarachnoid hemorrhage: association with reduced risk of clinical vasospasm and delayed cerebral ischemia

OBJECTIVE Clinical vasospasm and delayed cerebral ischemia (DCI) are devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Several theories involving platelet activation have been postulated as potential explanations of the development of clinical vasospasm and DCI. However, the effects of dual antiplatelet therapy (DAPT; aspirin and clopidogrel) on clinical vasospasm and DCI have not been previously investigated. The objective of this study was to evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients. METHODS Analysis of patients treated for aSAH during the period from July 2009 to April 2014 was performed in a single-institution retrospective study. Patients were divided into 2 groups: patients who underwent stent-assisted coiling or placement of flow diverters requiring DAPT (DAPT group) and patients who underwent coiling only without DAPT (control group). The frequency of symptomatic clinical vasospasm and DCI and of hemorrhagic complications was compared between the 2 groups, utilizing univariate and multivariate logistic regression. RESULTS Of 312 aSAH patients considered for this study, 161 met the criteria for inclusion and were included in the analysis (85 patients in the DAPT group and 76 patients in the control group). The risks of clinical vasospasm (OR 0.244, CI 95% 0.097-0.615, p = 0.003) and DCI (OR 0.056, CI 95% 0.01-0.318, p = 0.001) were significantly lower in patients receiving DAPT. The rates of hemorrhagic complications associated with placement of external ventricular drains and ventriculoperitoneal shunts were similar in both groups (4% vs 2%, p = 0.9). CONCLUSIONS The use of DAPT was associated with a lower risk of clinical vasospasm and DCI in patients treated for aSAH, without an increased risk of hemorrhagic complications.

Frontal and occipital horn ratio is associated with multifocal intraparenchymal hemorrhages in neonatal shunted hydrocephalus

OBJECTIVE Placement of a cerebrospinal fluid diversion device (i.e., shunt) is a routine pediatric neurosurgical procedure, often performed in the first weeks of life for treatment of congenital hydrocephalus. In the postoperative period, shunt placement may be complicated by subdural, catheter tract, parenchymal, and intraventricular hemorrhages. The authors observed a subset of infants and neonates who developed multifocal intraparenchymal hemorrhages (MIPH) following shunt placement and sought to determine any predisposing perioperative variables. METHODS A retrospective review of the electronic medical record at a tertiary-care children's hospital was performed for the period 1998-2015. Inclusion criteria consisted of shunt placement, age < 30 days, and available pre- and postoperative brain imaging. The following data were collected and analyzed for each case: ventricular size ratios, laboratory values, clinical presentation, shunt and valve type, and operative timing and approach. RESULTS A total of 121 neonates met the inclusion criteria for the study, and 11 patients (9.1%) had MIPH following shunt placement. The preoperative frontal and occipital horn ratio (FOR) was significantly higher in the patients with MIPH than in those without (0.65 vs 0.57, p < 0.001). The change in FOR (∆FOR) after shunt placement was significantly greater in the MIPH group (0.14 vs 0.08, p = 0.04). Among neonates who developed MIPH, aqueductal stenosis was the most common etiology (45%). The type of shunt valve was associated with incidence of MIPH (p < 0.001). Preoperative clinical parameters, including head circumference, bulging fontanelle, and coagulopathy, were not significantly associated with development of MIPH. CONCLUSIONS MIPH represents an underrecognized complication of neonatal shunted hydrocephalus. Markers of severity of ventriculomegaly (FOR) and ventricular response to CSF diversion (∆FOR) were significantly associated with occurrence of MIPH. Choice of shunt and etiology of hydrocephalus were also significantly associated with MIPH. After adjusting for corrected age, etiology of hydrocephalus, and shunt setting, the authors found that ∆FOR after shunting was still associated with MIPH. A prospective study of MIPH prevention strategies and assessment of possible implications for patient outcomes is needed.

Endoscopic third ventriculostomy and repeat endoscopic third ventriculostomy in pediatric patients: the Dutch experience

OBJECTIVE After endoscopic third ventriculostomy (ETV), some patients develop recurrent symptoms of hydrocephalus. The optimal treatment for these patients is not clear: repeat ETV (re-ETV) or CSF shunting. The goals of the study were to assess the effectiveness of re-ETV relative to initial ETV in pediatric patients and validate the ETV success score (ETVSS) for re-ETV. METHODS Retrospective data of 624 ETV and 93 re-ETV procedures were collected from 6 neurosurgical centers in the Netherlands (1998-2015). Multivariable Cox proportional hazards modeling was used to provide an adjusted estimate of the hazard ratio for re-ETV failure relative to ETV failure. The correlation coefficient between ETVSS and the chance of re-ETV success was calculated using Kendall's tau coefficient. Model discrimination was quantified using the c-statistic. The effects of intraoperative findings and management on re-ETV success were also analyzed. RESULTS The hazard ratio for re-ETV failure relative to ETV failure was 1.23 (95% CI 0.90-1.69; p = 0.20). At 6 months, the success rates for both ETV and re-ETV were 68%. ETVSS was significantly related to the chances of re-ETV success (τ = 0.37; 95% bias corrected and accelerated CI 0.21-0.52; p < 0.001). The c-statistic was 0.74 (95% CI 0.64-0.85). The presence of prepontine arachnoid membranes and use of an external ventricular drain (EVD) were negatively associated with treatment success, with ORs of 4.0 (95% CI 1.5-10.5) and 9.7 (95% CI 3.4-27.8), respectively. CONCLUSIONS Re-ETV seems to be as safe and effective as initial ETV. ETVSS adequately predicts the chance of successful re-ETV. The presence of prepontine arachnoid membranes and the use of EVD negatively influence the chance of success.

Severe bilateral cerebellar edema from ingestion of ketamine: case report

The use of ketamine as a drug of abuse has increased and so too has the risk of accidental overdose. Here, the authors report the case of a 10-month-old infant who inadvertently ingested ketamine. The child demonstrated severe cerebellar swelling that required emergency surgical intervention. The authors describe the clinical course of this child and present the radiographic characteristics of the brain. The imaging characteristics were not consistent with purely anoxic injury, thus suggesting a specific effect of this drug. To the authors' knowledge, similar imaging characteristics in this context have not been described.

Hydrocephalus presenting as idiopathic aqueductal stenosis with subsequent development of obstructive tumor: report of 2 cases demonstrating the importance of serial imaging

The authors describe 2 cases of triventricular hydrocephalus initially presenting as aqueductal stenosis that subsequently developed tumors of the pineal and tectal region. The first case resembled late-onset idiopathic aqueductal stenosis on serial imaging. Subsequent imaging revealed a new tumor in the pineal region causing mass effect on the midbrain. The second case presented in a more typical pattern of aqueductal stenosis during infancy. On delayed follow-up imaging, an enlarging tectal mass was discovered. In both cases hydrocephalus was successfully treated by cerebrospinal fluid diversion prior to tumor presentation. The differential diagnoses, diagnostic testing, and treatment course for these unusual cases are discussed. The importance of follow-up MRI in cases of idiopathic aqueductal stenosis is emphasized by these exemplar cases.

Isolated abducens nerve palsy associated with subarachnoid hemorrhage: a localizing sign of ruptured posterior inferior cerebellar artery aneurysms

OBJECTIVE Compressive cranial nerve syndromes can be useful bedside clues to the diagnosis of an enlarging intracranial aneurysm and can also guide subsequent evaluation, as with an acute oculomotor nerve (cranial nerve [CN] III) palsy that is presumed to be a posterior communicating artery aneurysm and a surgical emergency until proven otherwise. The CN VI has a short cisternal segment from the pontomedullary sulcus to Dorello's canal, remote from most PICA aneurysms but in the hemodynamic pathway of a rupturing PICA aneurysm that projects toward Dorello's canal. The authors describe a cranial nerve syndrome for posterior inferior cerebellar artery (PICA) aneurysms that associates subarachnoid hemorrhage (SAH) and an isolated abducens nerve (CN VI) palsy. METHODS Clinical and radiological data from 106 surgical patients with PICA aneurysms (66 ruptured and 40 unruptured) were retrospectively reviewed. Data from a group of 174 patients with other aneurysmal SAH (aSAH) were analyzed in a similar manner to control for nonspecific effects of SAH. Univariate statistical analysis compared incidence and risk factors associated with CN VI palsy in subarachnoid hemorrhage. RESULTS Overall, 13 (4.6%) of 280 patients had CN VI palsy at presentation, and all of them had ruptured aneurysms (representing 13 [5.4%] of the 240 cases of ruptured aneurysms). CN VI palsies were observed in 12 patients with ruptured PICA aneurysms (12/66 [18.1%]) and 1 patient with other aSAH (1/174 [0.1%], p < 0.0001). PICA aneurysm location in ruptured aneurysms was an independent predictor for CN VI palsy on multivariate analysis (p = 0.001). PICA aneurysm size was not significantly different in patients with or without CN VI palsy (average size 4.4 mm and 5.2 mm, respectively). Within the PICA aneurysm cohort, modified Fisher grade (p = 0.011) and presence of a thick cisternal SAH (modified Fisher Grades 3 and 4) (p = 0.003) were predictors of CN VI palsy. In all patients with ruptured PICA aneurysms and CN VI palsy, dome projection and presumed direction of rupture were directed toward the ipsilateral and/or contralateral Dorello's canal, in agreement with laterality of the CN palsy. In patients with bilateral CN VI palsies, a medial projection with extensive subarachnoid blood was observed near bilateral canals. CONCLUSIONS This study establishes a localizing connection between an isolated CN VI palsy, SAH, and an underlying ruptured PICA aneurysm. CN VI palsy is an important clinical sign in aSAH and when present on initial clinical presentation may be assumed to be due to ruptured PICA aneurysms until proven otherwise. The deficit may be ipsilateral, contralateral, or bilateral and is determined by the direction of the aneurysm dome projection and extent of subarachnoid bleeding toward Dorello's canal, rather than by direct compression.

The pathophysiology of chronic noncommunicating hydrocephalus: lessons from continuous intracranial pressure monitoring and ventricular infusion testing

OBJECTIVE The pathophysiology of chronic noncommunicating hydrocephalus (ncHC) is poorly understood. This present study explored whether lessons about the pathophysiology of this clinical entity might be retrieved from results of overnight monitoring of pulsatile and static intracranial pressure (ICP) and ventricular infusion testing. METHODS The study cohort included adult patients (> 20 years of age) with chronic ncHC due to aqueductal stenosis in whom symptoms had lasted a minimum of 6 months. A reference cohort consisted of age- and sex-matched patients managed for communicating HC (cHC). Information about symptoms and clinical improvement following surgery was retrieved from a quality register, and results of overnight ICP recordings and ventricular infusion testing were retrieved from the hospital ICP database. RESULTS The cohort with ncHC consisted of 61 patients of whom 6 (10%) were managed conservatively, 34 (56%) by endoscopic third ventriculostomy (ETV), and 21 (34%) using ETV and subsequent shunt surgery. In patients responding to surgery, pulsatile ICP (mean ICP wave amplitude) was significantly increased to a similar magnitude in patients with ncHC and the reference cohort (cHC). Furthermore, intracranial compliance (ICC) was reduced in clinical responders. The results of ventricular infusion testing provided evidence that patients responding to ETV have impaired ventricular CSF absorption, while those requiring shunt placement after ETV present with impaired CSF absorption both in the intraventricular and extraventricular compartments. CONCLUSIONS The study may provide some lessons about the pathophysiology of chronic ncHC. First, increased pulsatile ICP and impaired ICC characterize patients with chronic ncHC who respond clinically to CSF diversion surgery, even though static ICP is not increased. Second, in patients responding clinically to ETV, impaired ventricular CSF absorption may be a key factor. Patients requiring shunt placement for clinical response appear to have both intraventricular and extraventricular CSF absorption failure. A subgroup of patients with ncHC due to aqueductal stenosis has normal ventricular CSF absorption and normal ICC and may not be in need of surgical CSF diversion.

Robot-assisted endoscopic third ventriculostomy: institutional experience in 9 patients

OBJECTIVE The endoscopic third ventriculostomy (ETV) is an established and effective treatment for obstructive hydrocephalus. In its most common application, surgeons plan their entry point and the endoscope trajectory for the procedure based on anatomical landmarks, then control the endoscope freehand. Recent studies report an incidence of neural injuries as high as 16.6% of all ETVs performed in North America. The authors have introduced the ROSA system to their ETV procedure to stereotactically optimize endoscope trajectories, to reduce risk of traction on neural structures by the endoscope, and to provide a stable mechanical holder of the endoscope. Here, they present their series in which the ROSA system was used for ETVs. METHODS At the authors' institution, they performed ETVs with the ROSA system in 9 consecutive patients within an 8-month period. Patients had to have a favorable expected response to ETV (ETV Success Score ≥ 70) with no additional endoscopic procedures (e.g., choroid plexus cauterization, septum pellucidum fenestration). The modality of image registration (CT, MRI, surface mapping, or bone fiducials) was dependent on the case. RESULTS Nine pediatric patients with an age range of 1.5 to 16 years, 4 girls and 5 boys, with ETV Success Scores ranging from 70 to 90, underwent successful ETV surgery with the ROSA system within an 8-month period. Their intracranial pathologies included tectal tumors (n = 3), communicating hydrocephalus from hemorrhage or meningeal disease (n = 2), congenital aqueductal stenosis (n = 1), compressive porencephalic cyst (n = 1), Chiari I malformation (n = 1), and pineal region mass (n = 1). Robotic assistance was limited to the ventricular access in the first 2 procedures, but was used for the entirety of the procedure for the following 7 cases. Four of these cases were combined with another procedural objective (3 stereotactic tectal mass biopsies, 1 Chiari decompression). A learning curve was observed with each subsequent surgery as registration and surgical times became shorter and more efficient. All patients had complete resolution of their preprocedural symptoms. There were no complications. CONCLUSIONS The ROSA system provides a stable, precise, and minimally invasive approach to ETVs.

Emergency resection of brainstem cavernous malformations

Brainstem cavernous malformations (CMs) pose significant challenges to neurosurgeons because of their deep locations and high surgical risks. Most patients with brainstem CMs present with sudden-onset cranial nerve deficits or ataxia, but uncommonly patients can present in extremis from an acute hemorrhage, requiring surgical intervention. However, the timing of surgery for brainstem CMs has been a controversial topic. Although many authors propose delaying surgery into the subacute phase, some patients may not tolerate waiting until surgery. To the best of the authors' knowledge, emergency surgery after a brainstem CM hemorrhage has not been described. In cases of rapidly progressive neurological deterioration, emergency resection may often be the only option. In this retrospectively reviewed small series of patients, the authors report favorable outcomes after emergency surgery for resection of brainstem CMs.

Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip

OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p < 0.001). Measures for CN VI were most prominently affected. The area under the curve (AUC) for eye-tracking metrics to discriminate between ICP < 12 and ≥ 12 mm Hg was 0.798. To discriminate an ICP < 15 from ≥ 15 mm Hg the AUC was 0.833, and to discriminate ICP < 20 from ≥ 20 mm Hg the AUC was 0.889. CONCLUSIONS Increasingly elevated ICP was associated with increasingly abnormal eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

Reoperations within 48 hours following 7942 pediatric neurosurgery procedures

OBJECTIVE Various indicators are used to evaluate the quality of care delivered by surgical services, one of which is early reoperation rate. The indications and rate of reoperations within a 48-hour time period have not been previously reported for pediatric neurosurgery. METHODS Between May 1, 2009, and December 30, 2014, 7942 surgeries were performed by the pediatric neurosurgery service in the operating rooms at a single institution. Demographic, socioeconomic, and clinical characteristics associated with each of the operations were prospectively collected. The procedures were grouped into 31 categories based on the nature of the procedure and underlying diseases. Reoperations within 48 hours at the conclusion of the index surgery were reviewed to determine whether the reoperation was planned or unplanned. Multivariate logistic regression was employed to analyze risk factors associated with unplanned reoperations. RESULTS Cerebrospinal fluid shunt-and hydrocephalus-related surgeries accounted for 3245 (40.8%) of the 7942 procedures. Spinal procedures, craniotomy for tumor resections, craniotomy for traumatic injury, and craniofacial reconstructions accounted for an additional 8.7%, 6.8%, 4.5%, and 4.5% of surgical volume. There were 221 reoperations within 48 hours of the index surgery, yielding an overall incidence of 2.78%; 159 of the reoperation were unplanned. Of these 159 unplanned reoperations, 121 followed index operations involving shunt manipulations. Using unplanned reoperations as the dependent variable (n = 159), index operations with a starting time after 3 pm and admission through the emergency department (ED) were associated with a two- to threefold increase in the likelihood of reoperations (after-hour surgery, odds ratio [OR] 2.01 [95% CI 1.43-2.83, p < 0.001]; ED admission, OR 1.97 (95% CI 1.32-2.96, p < 0.05]). CONCLUSIONS Approximately 25% of the reoperations within 48 hours of a pediatric neurosurgical procedure were planned. When reoperations were unplanned, contributing factors could be both surgeon related and system related. Further study is required to determine the extent to which these reoperations are preventable. The utility of unplanned reoperation as a quality indicator is dependent on proper definition, analysis, and calculation.