bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual representations in visual working memory inherit ensemble properties
Authors: Utochkin Igor , Brady Timothy F.
Published: April 2019

Prevailing theories of visual working memory assume that each encoded item is stored or forgotten as a separate unit independent from other items. Here, we show that items are not independent and that the recalled orientation of an individual item is strongly influenced by the summary statistical representation of all items (ensemble representation). We find that not only is memory for an individual orientation substantially biased toward the mean orientation, but the precision of memory for an individual item also closely tracks the precision with which people store the mean orientation (which is, in turn, correlated with the physical range of orientations). Thus, individual items are reported more precisely when items on a trial are more similar. Moreover, the narrower the range of orientations present on a trial, the more participants appear to rely on the mean orientation as representative of all individuals. This can be observed not only when the range is carefully controlled, but also shown even in randomly generated, unstructured displays, and after accounting for the possibility of location-based ‘swap’ errors. Our results suggest that the information about a set of items is represented hierarchically, and that ensemble information can be an important source of information to constrain uncertain information about individuals.
'Effing Consciousness' - Or, How to Use New Symbols to Get Qualia Into the Hard Sciences
Authors: Rosseinsky Nicholas Martin
Published: April 2019

Opinions differ - wildly - about the scientific study of subjective conscious experience. To start to shed some light on this contested issue, this Chapter offers an accessible introduction to the application of new qualia-valued symbols. I explain how these 'angle-bracket' symbols can mediate a conflict between 'no science of consciousness' physicists, the 'conscious experience is ineffable' camp, and 'reconstructionists' (who believe verbal reports of experience can ground a rigorous science). I start to discuss the problem of experience-to-brain coupling as a methodological requirement, and how 'The One Experiment' can determine if that requirement is met in our inhabited Universe. [Chapter 2, from 'The Science We Need - One Experiment to Change the World'.]
Clinical Profile and Outcome of Neonates Admitted to Neonatal Intensive Care Unit of NGMC
Authors: KM Roma , Pyakurel Manita , Gupta Veena , Kanodia Piush
Published: April 2019

Background: Neonatal period is a period from birth to under 28 days of life. The common causes of mortality and morbidity in our region are preventable, among which neonatal sepsis is the commonest one. Most of the deaths occur within 7 days of life.

Objectives: To study the clinical profile, pattern of diseases, causes of morbidity and mortality amongst newborns.

Materials and methods: A hospital based descriptive study was done among total 967 newborns including both inborn and out born admitted in NICU, NGMC from January 2016 to December 2016. Age, sex, gestational age, diagnosis at admission, outcome of admitted th newborns were the main variables under study. Data was entered in Excel and analyzed using SPSS 20th version. Data were presented through pie, bar graph and table with frequency and percentage.

Results: Male were predominant in the study (65%). One third of the admitted newborns were preterms. Half of the admitted newborns were admitted on their first day of life. Neonatal sepsis was the most common cause of admission. Deaths occured in 7.4%of total babies. Seventy-six percent got improved after treatment. Only 2.8% were referred to higher center.

Conclusions: Most of the neonates got admitted in first day of life with commonest cause being neonatal sepsis. Recovery rate was satisfactory. To reduce the mortality and morbidity of neonates, we need to increase awareness level in general population and proper aseptic practices in medical practitioners.
Rethinking Political Representation from the Perspective of Rhetorical Genres
Authors: Palonen Kari
Published: April 2019

This article is a thought experiment. It constructs ideal types of
political representation in the sense of Max Weber. Inspired by Quentin
Skinner and others, the aim is to give a rhetorical turn to contemporary
debates on representation. The core idea is to claim an ‘elective affinity’
(Wahlverwandschaft, as Weber says following Goethe) between forms
of representation and rhetorical genres of their justification. The four
ideal types of political representation are designated as plebiscitary,
diplomatic, advocatory, and parliamentary, corresponding to the epideictic,
negotiating, forensic, and deliberative genres of rhetoric as the
respective ways to plausibly appeal to the audience. I discuss historical
approximations of each type of representation and apply the combination
of representation and rhetorical genres to the understanding of the
European Union’s unconventional system of ‘separation of powers’. I
conclude with supporting parliamentary representation, based on dissensus
and debate, with complements from other types.
Republican Freedom in the Labour Market
Authors: Corvino Fausto
Published: April 2019

In this article, I query whether participation in the labour market
can hinder neo-republican freedom as non-domination. I briefly
present the view of Philip Pettit on the topic, based on the distinction
between offering a reward and threatening a punishment. I compare it
to the analysis of labour republicans, recently reconstructed by Alex
Gourevitch, according to whom, the exclusion of a group of individuals
from the control of productive assets represents a form of structural
domination. Then, I explain why I take a position that is different from
both. I hold that capitalist structural domination leads only to exploitation,
not interpersonal domination. In doing this, I consider two objections
that might be raised against my argument. The first one is based on
incomplete contracts and on a possible ideal benchmark for job offers.
The second one challenges the supposed arbitrariness of unequal property
relations within the capitalist social system.
Local tumor response and survival outcomes after combined stereotactic radiosurgery and immunotherapy in non–small cell lung cancer with brain metastases
Authors: Singh Charu , Qian Jack M. , Yu James B. , Chiang Veronica L.
Published: April 2019

OBJECTIVE

Concurrent use of anti-PD-1 therapies with stereotactic radiosurgery (SRS) have been shown to be beneficial for survival and local lesional control in melanoma patients with brain metastases. It is not known, however, if immunotherapy (IT) confers the same outcome advantage in lung cancer patients with brain metastases treated with SRS.

METHODS

The authors retrospectively reviewed 85 non–small cell lung cancer (NSCLC) patients with brain metastases who were treated with SRS between January 2006 and December 2016. Thirty-nine PD-L1 antibody–positive patients received anti-PD-1 therapy with SRS (IT group) and 46 patients received chemotherapy (CT) with SRS (CT group). Results were obtained using chi-square, Kaplan-Meier, and Mann-Whitney U tests and Cox regression analyses.

RESULTS

Median survival following first radiosurgical treatment in the whole study group was 11.6 months (95% CI 8–15.5 months). Median survival times in the IT group and CT group were 10 months (95% CI 8.3–13.2 months) and 11.6 months (95% CI 7.7–15.6 months), respectively (p = 0.23). A Karnofsky Performance Status (KPS) score < 80 (p = 0.001) and lung-specific molecular marker Graded Prognostic Assessment (lungmol GPA) score < 1.5 (p = 0.02) were found to be predictive of worse survival.

Maximal percent lesional shrinkage and time to maximal shrinkage were not significantly different between the CT and IT groups. Of the lesions for which a complete response occurred, 94.8% had pre-SRS volumes < 500 mm3. The amount of lesion shrinkage and time to maximal shrinkage were not different between the IT and CT groups for lesions with volumes < 500 mm3. However, in lesions with volume > 500 mm3, 90% of lesions shrank after radiosurgery in the IT group compared with 47.8% in the CT group (p = 0.001). Median times to initial response and times to maximal shrinkage were faster in the IT group than in the CT group: initial response 49 days (95% CI 33.7–64.3 days) versus 84 days (95% CI 28.1–140 days), p = 0.001; maximal response 105 days (95% CI 59–150 days) versus 182 days (95% CI 119.6–244 days), p = 0.12.

CONCLUSIONS

Unlike patients with melanoma, patients with NSCLC with brain metastases undergoing SRS showed no significant benefit—either in terms of survival or total amount of lesional response—when anti-PD-1 therapies were used. However, in lesions with volume > 500 mm3, combining SRS with IT may result in a faster and better volumetric response which may be particularly beneficial in lesions causing mass effect or located in neurologically critical locations.
Detailed standardized protocol to prevent cerebrospinal fluid shunt infection
Authors: Okamura Yuma , Maruyama Keisuke , Fukuda Shin , Horikawa Hiroshi , Sasaki Nobuyoshi , Noguchi Akio , Nagane Motoo , Shiokawa Yoshiaki
Published: April 2019

OBJECTIVE

While cerebrospinal fluid (CSF) shunt surgery plays an essential role in the treatment of hydrocephalus, postoperative infection due to the implantation of foreign materials is still one of the most common and potentially serious complications of this procedure. Because no previously reported protocol has been proven to prevent postoperative infection after CSF shunt surgeries in adults, the authors investigated the effectiveness of a protocol introduced in their institution.

METHODS

A detailed standardized surgical protocol to prevent infection in patients undergoing CSF shunt surgeries was introduced in the authors’ institution in December 2011. The protocol included a series of detailed rules regarding the surgical procedure, the surgical environment to minimize contamination from air, double gloving, local injection of antibiotics, and postoperative management. The rate of CSF shunt infection during the 3 years after surgery before and after implementation of the protocol was compared in patients undergoing their first CSF shunt surgeries. The inclusion periods were from January 2006 to November 2011 for the preprotocol group and from December 2011 to December 2014 for the postprotocol group.

RESULTS

The study included 124 preprotocol patients and 52 postprotocol patients. The mean patient age was 59 years in both groups, ranging from 40 days to 88 years. Comparison of patient background factors, including known risk factors for surgical site infections, showed no significant difference between the patient groups before and after implementation of the protocol. While 9 patients (7.3%) developed shunt infections before protocol implementation, no shunt infections (0%) were observed in patients who underwent surgery after protocol implementation. The difference was statistically significant (p = 0.047).

CONCLUSIONS

The authors’ detailed protocol for CSF shunt surgeries was effective in preventing postoperative infection regardless of patient age.
Outcomes of decompressive surgery for cavernous sinus meningiomas: long-term follow-up in 50 patients
Authors: Gozal Yair M. , Alzhrani Gmaan , Abou-Al-Shaar Hussam , Azab Mohammed A. , Walsh Michael T. , Couldwell William T.
Published: April 2019

OBJECTIVE

Cavernous sinus meningiomas are complex tumors that offer a perpetual challenge to skull base surgeons. The senior author has employed a management strategy for these lesions aimed at maximizing tumor control while minimizing neurological morbidity. This approach emphasizes combining “safe” tumor resection and direct decompression of the roof and lateral wall of the cavernous sinus as well as the optic nerve. Here, the authors review their experience with the application of this technique for the management of cavernous sinus meningiomas over the past 15 years.

METHODS

A retrospective analysis was performed for patients with cavernous sinus meningiomas treated over a 15-year period (2002–2017) with this approach. Patient outcomes, including cranial nerve function, tumor control, and surgical complications were recorded.

RESULTS

The authors identified 50 patients who underwent subtotal resection via frontotemporal craniotomy concurrently with decompression of the cavernous sinus and ipsilateral optic nerve. Of these, 25 (50%) underwent adjuvant radiation to the remaining tumor within the cavernous sinus. Patients most commonly presented with a cranial nerve (CN) palsy involving CN III–VI (70%), a visual deficit (62%), headaches (52%), or proptosis (44%). Thirty-five patients had cranial nerve deficits preoperatively. In 52% of these cases, the neuropathy improved postoperatively; it remained stable in 46%; and it worsened in only 2%. Similarly, 97% of preoperative visual deficits either improved or were stable postoperatively. Notably, 12 new cranial nerve deficits occurred postoperatively in 10 patients. Of these, half were transient and ultimately resolved. Finally, radiographic recurrence was noted in 5 patients (10%), with a median time to recurrence of 4.6 years.

CONCLUSIONS

The treatment of cavernous sinus meningiomas using surgical decompression with or without adjuvant radiation is an effective oncological strategy, achieving excellent tumor control rates with low risk of neurological morbidity.
Development of a novel frameless skull-mounted ball-joint guide array for use in image-guided neurosurgery
Authors: Sudhakar Vivek , Mahmoodi Amin , Bringas John R. , Naidoo Jerusha , Kells Adrian , Samaranch Lluis , Fiandaca Massimo S. , Bankiewicz Krystof S.
Published: April 2019

OBJECTIVE

Successful convection-enhanced delivery of therapeutic agents to subcortical brain structures requires accurate cannula placement. Stereotactic guiding devices have been developed to accurately target brain nuclei. However, technologies remain limited by a lack of MRI compatibility, or by devices’ size, making them suboptimal for direct gene delivery to brain parenchyma. The goal of this study was to validate the accuracy of a novel frameless skull-mounted ball-joint guide array (BJGA) in targeting the nonhuman primate (NHP) brain.

METHODS

Fifteen MRI-guided cannula insertions were performed on 9 NHPs, each targeting the putamen. Optimal trajectories were planned on a standard MRI console using 3D multiplanar baseline images. After cannula insertion, the intended trajectory was compared to the final trajectory to assess deviation (euclidean error) of the cannula tip.

RESULTS

The average cannula tip deviation was 1.18 ± 0.60 mm (mean ± SD) as measured by 2 independent reviewers. Topological analysis showed a superior, posterior, and rightward directional bias, and the intra- and interclass correlation coefficients were > 0.85, indicating valid and reliable intra- and interobserver evaluation.

CONCLUSIONS

The data demonstrate that the BJGA can be used to reliably target subcortical brain structures by using MRI guidance, with accuracy comparable to current frameless stereotactic systems. The size and versatility of the BJGA, combined with a streamlined workflow, allows for its potential applicability to a variety of intracranial neurosurgical procedures, and for greater flexibility in executing MRI-guided experiments within the NHP brain.
Deep brain stimulation modulates hypothalamic-brainstem fibers in cluster headache: case report
Authors: Dantas Sérgio A. F. , Alho Eduardo J. L. , da Silva Juliano J. , Mendes Neto Nilson N. , Fonoff Erich Talamoni , Hamani Clement
Published: April 2019

Hypothalamic deep brain stimulation (DBS) has been used for more than a decade to treat cluster headache (CH) but its mechanisms remain poorly understood. The authors have successfully treated a patient with CH using hypothalamic DBS and found that the contact used for chronic stimulation was located in a white matter region posterior to the mammillary bodies. Fiber tracts crossing that region were the medial forebrain bundle and those interconnecting the hypothalamus and brainstem, including the dorsal longitudinal fasciculus. Because the stimulation of axons is an important mechanism of DBS, some of its clinical effects in CH may be related to the stimulation of fibers interconnecting the hypothalamus and brainstem.
Intraoperative localization of spatially and spectrally distinct resting-state networks in Parkinson’s disease
Authors: Belardinelli Paolo , Azodi-Avval Ramin , Ortiz Erick , Naros Georgios , Grimm Florian , Weiss Daniel , Gharabaghi Alireza
Published: April 2019

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for symptomatic Parkinson’s disease (PD); the clinical benefit may not only mirror modulation of local STN activity but also reflect consecutive network effects on cortical oscillatory activity. Moreover, STN-DBS selectively suppresses spatially and spectrally distinct patterns of synchronous oscillatory activity within cortical-subcortical loops. These STN-cortical circuits have been described in PD patients using magnetoencephalography after surgery. This network information, however, is currently not available during surgery to inform the implantation strategy.

The authors recorded spontaneous brain activity in 3 awake patients with PD (mean age 67 ± 14 years; mean disease duration 13 ± 7 years) during implantation of DBS electrodes into the STN after overnight withdrawal of dopaminergic medication. Intraoperative propofol was discontinued at least 30 minutes prior to the electrophysiological recordings. The authors used a novel approach for performing simultaneous recordings of STN local field potentials (LFPs) and multichannel electroencephalography (EEG) at rest. Coherent oscillations between LFP and EEG sensors were computed, and subsequent dynamic imaging of coherent sources was performed.

The authors identified coherent activity in the upper beta range (21–35 Hz) between the STN and the ipsilateral mesial (pre)motor area. Coherence in the theta range (4–6 Hz) was detected in the ipsilateral prefrontal area.

These findings demonstrate the feasibility of detecting frequency-specific and spatially distinct synchronization between the STN and cortex during DBS surgery. Mapping the STN with this technique may disentangle different functional loops relevant for refined targeting during DBS implantation.
Clinical utility of routine postoperative morning cortisol monitoring in detecting new hypothalamic-pituitary-adrenal axis insufficiency following endoscopic transsphenoidal surgery for sellar lesions
Authors: Jackanich Anna , Tavakol Sherwin , Strickland Ben A. , Rutkowski Martin , Kamel Dina , Carmichael John D. , Weiss Martin , Zada Gabriel
Published: April 2019

OBJECTIVE

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction is a well-documented complication of transsphenoidal craniotomy (TSC) for sellar lesions. The authors aimed to assess their multidisciplinary approach to the diagnosis and treatment of postoperative hypocortisolemia utilizing conservative screening methods.

METHODS

The authors performed a retrospective review of 257 patients who underwent TSC for pituitary adenoma (PA) or Rathke cleft cyst (RCC) at the University of Southern California between 2012 and 2017. Patients with preoperative adrenal insufficiency, Cushing’s disease, or < 3 months of postoperative follow-up were excluded. Patient demographics, pathology, tumor characteristics, and complications were recorded. Postoperative day 1 (POD1) morning serum cortisol was assessed in all patients. Hypocortisolemia on POD1 (serum cortisol < 5 μg/dl) prompted a 7 am cortisol level measurement on POD 2 (POD2). Clinical signs and symptoms of hypocortisolemia were consistently monitored. After two serum cortisol levels < 5 μg/dl, or one serum level < 5 μg/dl plus a high clinical suspicion for HPA dysfunction, high-risk patients received glucocorticoid supplementation.

RESULTS

Data on 165 patients were included in the analysis; there were 101 women (61.2%) and 64 men (38.7%). Preoperative diagnoses included nonfunctional adenoma (n = 97, 58.7%), growth hormone–secreting adenoma (n = 37, 22.4%), RCC (n = 18, 10.9%), prolactinoma (n = 8, 4.8%), and other (n = 5, 3.0%). One hundred thirty-eight patients (63.0%) had either suprasellar extension or cavernous sinus invasion. POD1 hypocortisolemia was diagnosed in 8 patients (4.8%). Of these patients, 2 (1.2%) were clinically asymptomatic and had normalized POD2 cortisol levels. Six patients (3.6%) had clinical symptoms and POD2 cortisol levels confirming HPA axis deficiency. Of these 6 patients treated with early glucocorticoid replacement, 2 patients recovered HPA axis function during follow-up, making the incidence of new, permanent HPA axis deficiency 2.5%.

CONCLUSIONS

In the authors’ institutional review, all patients warranting postoperative glucocorticoid replacement had both complicated surgical courses and associated clinical symptoms of hypocortisolemia. The authors’ algorithm of withholding steroids until patients demonstrate clear evidence of postoperative hypocortisolemia is safe and clinically efficacious. Their data further suggest that routine postoperative cortisol screening may not be necessary following an uncomplicated operative resection, with gland preservation and the absence of clinical symptoms indicative of HPA dysfunction.
Diagnostic and therapeutic values of intraoperative electrophysiological neuromonitoring during resection of intradural extramedullary spinal tumors: a single-center retrospective cohort and meta-analysis
Authors: Ishida Wataru , Casaos Joshua , Chandra Arun , D’Sa Adam , Ramhmdani Seba , Perdomo-Pantoja Alexander , Theodore Nicholas , Jallo George , Gokaslan Ziya L. , Wolinsky Jean-Paul , Sciubba Daniel M. , Bydon Ali , Witham Timothy F. , Lo Sheng-Fu L.
Published: April 2019

OBJECTIVE

With the advent of intraoperative electrophysiological neuromonitoring (IONM), surgical outcomes of various neurosurgical pathologies, such as brain tumors and spinal deformities, have improved. However, its diagnostic and therapeutic value in resecting intradural extramedullary (ID-EM) spinal tumors has not been well documented in the literature. The objective of this study was to summarize the clinical results of IONM in patients with ID-EM spinal tumors.

METHODS

A retrospective patient database review identified 103 patients with ID-EM spinal tumors who underwent tumor resection with IONM (motor evoked potentials, somatosensory evoked potentials, and free-running electromyography) from January 2010 to December 2015. Patients were classified as those without any new neurological deficits at the 6-month follow-up (group A; n = 86) and those with new deficits (group B; n = 17). Baseline characteristics, clinical outcomes, and IONM findings were collected and statistically analyzed. In addition, a meta-analysis in compliance with the PRISMA guidelines was performed to estimate the overall pooled diagnostic accuracy of IONM in ID-EM spinal tumor resection.

RESULTS

No intergroup differences were discovered between the groups regarding baseline characteristics and operative data. In multivariate analysis, significant IONM changes (p < 0.001) and tumor location (thoracic vs others, p = 0.018) were associated with new neurological deficits at the 6-month follow-up. In predicting these changes, IONM yielded a sensitivity of 82.4% (14/17), specificity of 90.7% (78/86), positive predictive value (PPV) of 63.6% (14/22), negative predictive value (NPV) of 96.3% (78/81), and area under the curve (AUC) of 0.893. The diagnostic value slightly decreased in patients with schwannomas (AUC = 0.875) and thoracic tumors (AUC = 0.842). Among 81 patients who did not demonstrate significant IONM changes at the end of surgery, 19 patients (23.5%) exhibited temporary intraoperative exacerbation of IONM signals, which were recovered by interruption of surgical maneuvers; none of these patients developed new neurological deficits postoperatively. Including the present study, 5 articles encompassing 323 patients were eligible for this meta-analysis, and the overall pooled diagnostic value of IONM was a sensitivity of 77.9%, a specificity of 91.1%, PPV of 56.7%, and NPV of 95.7%.

CONCLUSIONS

IONM for the resection of ID-EM spinal tumors is a reasonable modality to predict new postoperative neurological deficits at the 6-month follow-up. Future prospective studies are warranted to further elucidate its diagnostic and therapeutic utility.
Embolized cerebral arteriovenous malformations: a multivariate analysis of 101 excised specimens
Authors: Tailor Chetna , Ashby W. Spencer , Gorassini Donald R. , Lownie Stephen P. , Walsh Kimberley , Pelz David , Hammond Robert R.
Published: April 2019

OBJECTIVE

Endovascular approaches have evolved from a technique practiced at very few centers to a widely available option in the management of arteriovenous malformations (AVMs) of the central nervous system. Embolization can be employed as definitive therapy or as an adjunct to surgical excision. A wide variety of embolic agents have been successfully developed and used in the clinical setting. In addition to facilitating vascular occlusion, embolic agents induce a number of reactive and destructive changes in vessel walls and the surrounding tissue. However, studies examining the pathological changes induced by different embolic agents and varying times of exposure are scarce. The goal of the present study was to compare embolic agents and time of exposure on the pathology in excised specimens.

METHODS

The records of the Department of Pathology at the London Health Sciences Centre were searched for embolized AVMs for the 35-year period 1980–2015. All cases were reevaluated for clinical and technical variables and standardized histopathological findings. Cases were grouped by embolic agent, volume of agent used, and time to excision.

RESULTS

A total of 101 specimens were identified. Embolic agents were invariably associated with a range of pathological findings, some of which may affect the integrity of vessel walls or the reestablishment of flow, thrombosis, acute and chronic inflammatory changes, angionecrosis, extravasation, and recanalization. The type of embolic agent did not predict differences in the incidence or severity of histopathological changes. Larger volumes of embolic agent were associated with a greater proportion of vessels containing embolic material. AVMs excised early (< 1 week postembolization) contained more acute vasculitis, while those excised later (≥ 1 week postembolization) were more likely to exhibit recanalization and foreign body giant cell infiltrates.

CONCLUSIONS

Embolic agents induce a predictable range and temporal progression of pathological changes in cerebral AVMs. The embolic agents studied are indistinguishable in terms of the range and frequency of pathological reactions induced. Greater volumes of embolic agent are associated with more abundant agent within the lesion, but the proportion of vessels and vascular cross-sectional areas containing agent is small. Several changes are significantly associated with time postembolization. Acute vasculitis is a more common finding in the 1st week, while recanalization and foreign body–type granulomatous inflammation are more common at 1 week and beyond.
Proliferation-dominant high-grade astrocytoma: survival benefit associated with extensive resection of FLAIR abnormality region
Authors: Jiang Haihui , Cui Yong , Liu Xiang , Ren Xiaohui , Li Mingxiao , Lin Song
Published: April 2019

OBJECTIVE

The aim of this study was to investigate the relationship between extent of resection (EOR) and survival in terms of clinical, molecular, and radiological factors in high-grade astrocytoma (HGA).

METHODS

Clinical and radiological data from 585 cases of molecularly defined HGA were reviewed. In each case, the EOR was evaluated twice: once according to contrast-enhanced T1-weighted images (CE-T1WI) and once according to fluid attenuated inversion recovery (FLAIR) images. The ratio of the volume of the region of abnormality in CE-T1WI to that in FLAIR images (VFLAIR/VCE-T1WI) was calculated and a receiver operating characteristic curve was used to determine the optimal cutoff value for that ratio. Univariate and multivariate analyses were performed to identify the prognostic value of each factor.

RESULTS

Both the EOR evaluated from CE-T1WI and the EOR evaluated from FLAIR could divide the whole cohort into 4 subgroups with different survival outcomes (p < 0.001). Cases were stratified into 2 subtypes based on VFLAIR/VCE-T1WI with a cutoff of 10: a proliferation-dominant subtype and a diffusion-dominant subtype. Kaplan-Meier analysis showed a significant survival advantage for the proliferation-dominant subtype (p < 0.0001). The prognostic implication has been further confirmed in the Cox proportional hazards model (HR 1.105, 95% CI 1.078–1.134, p < 0.0001). The survival of patients with proliferation-dominant HGA was significantly prolonged in association with extensive resection of the FLAIR abnormality region beyond contrast-enhancing tumor (p = 0.03), while no survival benefit was observed in association with the extensive resection in the diffusion-dominant subtype (p = 0.86).

CONCLUSIONS

VFLAIR/VCE-T1WI is an important classifier that could divide the HGA into 2 subtypes with distinct invasive features. Patients with proliferation-dominant HGA can benefit from extensive resection of the FLAIR abnormality region, which provides the theoretical basis for a personalized resection strategy.
Adverse events after clipping of unruptured intracranial aneurysms: the NSQIP unruptured aneurysm scale
Authors: Dasenbrock Hormuzdiyar H. , Rudy Robert F. , Smith Timothy R. , Gormley William B. , Patel Nirav J. , Frerichs Kai U. , Aziz-Sultan M. Ali , Du Rose
Published: April 2019

OBJECTIVE

The complex decision analysis of unruptured intracranial aneurysms entails weighing the benefits of aneurysm repair against operative risk. The goal of the present analysis was to build and validate a predictive scale that identifies patients with the greatest odds of a postsurgical adverse event.

METHODS

Data on patients who underwent surgical clipping of an unruptured aneurysm were extracted from the prospective National Surgical Quality Improvement Program registry (NSQIP; 2007–2014); NSQIP does not systematically collect data on patients undergoing intracranial endovascular intervention. Multivariable logistic regression evaluated predictors of any 30-day adverse event; variables screened included patient demographics, comorbidities, functional status, preoperative laboratory values, aneurysm location/complexity, and operative time. A predictive scale was constructed based on statistically significant independent predictors, which was validated using both NSQIP (2015–2016) and the Nationwide Inpatient Sample (NIS; 2002–2011).

RESULTS

The NSQIP unruptured aneurysm scale was proposed: 1 point was assigned for a bleeding disorder; 2 points for age 51–60 years, cardiac disease, diabetes mellitus, morbid obesity, anemia (hematocrit < 36%), operative time 240–330 minutes; 3 points for leukocytosis (white blood cell count > 12,000/μL) and operative time > 330 minutes; and 4 points for age > 60 years. An increased score was predictive of postoperative stroke or coma (NSQIP: p = 0.002, C-statistic = 0.70; NIS: p < 0.001, C-statistic = 0.61), a medical complication (NSQIP: p = 0.01, C-statistic = 0.71; NIS: p < 0.001, C-statistic = 0.64), and a nonroutine discharge (NSQIP: p < 0.001, C-statistic = 0.75; NIS: p < 0.001, C-statistic = 0.66) in both validation populations. Greater score was also predictive of increased odds of any adverse event, a major complication, and an extended hospitalization in both validation populations (p ≤ 0.03).

CONCLUSIONS

The NSQIP unruptured aneurysm scale may augment the risk stratification of patients undergoing microsurgical clipping of unruptured cerebral aneurysms.
Recent advances in the neurosurgical treatment of pediatric epilepsy
Authors: Roland Jarod L. , Smyth Matthew D.
Published: April 2019

The field of epilepsy surgery has seen tremendous growth in recent years. Innovative new devices have driven much of this growth, but some has been driven by revisions of existing products. Devices have also helped to rejuvenate existing procedures, as in the case of robotic assistance for electrode placement for stereo-electroencephalography, and these devices have brought significant attention along with their introduction. Other devices, such as responsive neurostimulators or laser interstitial thermal therapy systems, have introduced novel treatment modalities and broadened the surgical indications. Collectively, these advances are rapidly changing much of the landscape in the world of pediatric neurosurgery for medically refractory epilepsy. The foundations for indications for neurosurgical intervention are well supported in strong research data, which has also been expanded in recent years. In this article, the authors review advances in the neurosurgical treatment of pediatric epilepsy, beginning with trials that have repeatedly demonstrated the value of neurosurgical procedures for medically refractory epilepsy and following with several recent advances that are largely focused on less-invasive intervention.
Microsurgical, endoscopic, and shunt management of pediatric temporosylvian arachnoid cysts: a comparative study
Authors: Amelot Aymeric , Beccaria Kevin , Blauwblomme Thomas , Bourgeois Marie , Paternoster Giovanna , Cuny Marie-Laure , Zerah Michel , Sainte-Rose Christian , Puget Stephanie
Published: April 2019

OBJECTIVE

Arachnoid cysts (ACs) are most frequently located in the middle cranial fossa. Some patients are asymptomatic whereas others exhibit signs of increased intracranial pressure, seizures, or cognitive and behavioral symptoms. When ACs do require treatment, the optimal surgical technique remains controversial. This study was conducted to assess the most effective surgical treatment for these cysts.

METHODS

The authors retrospectively reviewed 240 temporal intracranial ACs managed over a 25-year period in their pediatric neurosurgical unit. Pre- and posttreatment results were clinically and radiologically assessed.

RESULTS

A majority of male patients (74.6%) with an overall median age of 6.9 years were included. The mean cyst size was 107 cm3; the Galassi classification showed 99 (41.3%) type I, 77 (32.1%) type II, and 64 (26.7%) type III cysts. Forty-four ACs (18.3%) were diagnosed after rupture. Surgical management was performed by microsurgery (28.3%), endoscopic cyst fenestration (14.6%), cystoperitoneal shunting (CPS; 16.2%), or subdural shunting (10%). Furthermore, 74 children (30.8%) did not undergo operations. After a mean follow-up of 4.1 years, the mean percentage decrease in cyst volume and the overall rate of clinical improvement did not significantly differ. The endoscopy group had earlier complications and a shorter event-free survival (EFS) time (EFS at 3 years = 67.7%, vs 71.5% and 90.5% for CPS and microsurgery, respectively; p < 0.007) and presented with more subdural hematomas compared to the microsurgery group (p < 0.005). The microsurgery group also showed a tendency for longer cystocisternostomy permeability than the endoscopy group.

CONCLUSIONS

Concerning the management of unruptured symptomatic temporal ACs, microsurgery appears to be the most effective treatment, with longer EFS and fewer complications compared to shunting or endoscopy.
A pilot study of influence of pedicle screw instrumentation on immature vertebra: a minimal 5-year follow-up in children younger than 5 years
Authors: Zhang Yanbin , Peng Qifeng , Wang Shengru , Yang Yang , Lin Guanfeng , Zhang Jianguo
Published: April 2019

OBJECTIVE

Concerns remain over the influence of pedicle screw instrumentation on the growth potential of an immature spine. Previous studies have reported discrepancies between animal experiments and clinical studies. The authors’ objective was to explore the influence of pedicle screw instrumentation on the growth of an immature spine at a very young age.

METHODS

Individuals who met the authors’ criteria were included. Anteroposterior diameter of the vertebral body; pedicle length on both sides; and anteroposterior diameter, transverse diameter, and area of the spinal canal were measured on CT images before surgery and at the final follow-up. Parameters of instrumented vertebrae and adjacent noninstrumented vertebrae were compared. The growth value and growth percentage of each parameter were calculated. Subgroup comparisons were made in thoracic vertebrae and lumbar vertebrae. Statistical analyses were performed.

RESULTS

Thirteen patients with a congenital spinal deformity were included in the study. The average age at surgery was 3.4 (range 2–5) years, and the average follow-up was 7.2 (range 5–11) years. Osteotomy and short instrumentation with pedicle screws were performed in each case. A total of 69 segments were measured, including 43 instrumented vertebrae and 26 immediately adjacent noninstrumented vertebrae. Significant increases in all parameters were noted at the final follow-up. In instrumented vertebrae, growth of the pedicle length and the anteroposterior diameter and area of the spinal canal increased significantly, while growth of the anteroposterior diameter of the vertebral body decreased significantly compared with noninstrumented vertebrae. Similar results were noted in the lumbar region. The shape-change phenomenon was found in noninstrumented vertebrae but was not apparent in instrumented vertebrae.

CONCLUSIONS

Pedicle screw instrumentation may slow down growth of the vertebral body, indirectly speed up growth of the spinal canal, and hinder the shape-change phenomenon of the lumbar spinal canal. However, the influences were quite slight, and significant development did occur in instrumented vertebrae. Therefore, pedicle screw instrumentation may not have much effect on the growth of immature vertebrae in children younger than 5 years.
Does relocation of the apex after osteotomy affect surgical and clinical outcomes in patients with ankylosing spondylitis and thoracolumbar kyphosis?
Authors: Liu Zhuo-jie , Qian Bang-ping , Qiu Yong , Mao Sai-hu , Jiang Jun , Wang Bin
Published: April 2019

OBJECTIVE

Relocation of the apex is often found in patients with ankylosing spondylitis (AS)–associated thoracolumbar/lumbar kyphosis after corrective surgery. This study evaluates the influence of different postoperative apex locations on surgical and clinical outcomes of osteotomy for patients with AS and thoracolumbar kyphosis.

METHODS

Sixty-two patients with a mean age of 34.6 ± 9.7 years (range 17–59 years) and a minimum of 2 years of follow-up, who underwent 1-level lumbar pedicle subtraction osteotomy for AS-related thoracolumbar kyphosis, were enrolled in the study, as well as 62 age-matched healthy individuals. Patients were divided into 2 groups according to the postoperative location of the apex (group 1, T8 or above; group 2, T9 or below). Demographic data, radiographic measurements (including 3 postoperative apex-related parameters), and clinical outcomes were compared between the 2 groups preoperatively, postoperatively, and at the last follow-up. Furthermore, a subgroup analysis was performed among patients with a postoperative apex located at T6–11 and postoperatively the entire AS cohort was compared with normal controls regarding the apex location of the thoracic spine.

RESULTS

In the majority of the enrolled patients, the apex location changed from T12–L2 preoperatively to T6–9 postoperatively. The sagittal vertical axis (SVA) differed significantly both postoperatively (25.7 vs 59.0 mm, p = 0.001) and at the last follow-up (34.6 vs 59.9 mm, p = 0.003) between the 2 groups, and the patients in group 1 had significantly smaller horizontal distance between the C7-vertical line and the apex (DCA) than the patients in group 2 (67.5 vs 103.7 mm, p = 0.001). Subgroup analysis demonstrated similar results, showing that the patients with a postoperative apex located at T8 or above had an average SVA < 47 mm. Notably, a significant correlation was found between postoperative SVA and DCA (r = 0.642, p = 0.001). Patients who underwent an osteotomy at L3 had limited apex relocation but larger SVA correction than those at L1 or L2. However, no significant difference was found in health-related quality of life between the 2 groups.

CONCLUSIONS

AS patients with an apex located at T8 or above after surgery tended to have better SVA correction (within 47 mm) than those who had a more caudally located apical vertebra. For ideal postoperative apex relocation, a higher (closer to or at the preoperative apex) level of osteotomy is more likely to obtain the surgical goal.
Meningioma metastases: incidence and proposed screening paradigm
Authors: Dalle Ore Cecilia L. , Magill Stephen T. , Yen Adam J. , Shahin Maryam N. , Lee David S. , Lucas Calixto-Hope G. , Chen William C. , Viner Jennifer A. , Aghi Manish K. , Theodosopoulos Philip V. , Raleigh David R. , Villanueva-Meyer Javier E. , McDermott Michael W.
Published: April 2019

OBJECTIVE

Extracranial meningioma metastases are uncommon, occurring in less than 1% of patients diagnosed with meningioma. Due to the rarity of meningioma metastases, patients are not routinely screened for distant disease. In this series, we report their experience with meningioma metastases and results of screening for metastases in select patients with recurrent meningiomas.

METHODS

All patients undergoing resection or stereotactic radiosurgery for primary or recurrent meningioma from 2009 to 2017 at a single center were retrospectively reviewed to identify patients who were diagnosed with or underwent imaging to evaluate for systemic metastases. Imaging to evaluate for metastases was performed with CT scanning of the chest, abdomen, and pelvis or whole-body PET/CT using either FDG or 68Ga-DOTA-octreotate (DOTATATE) tracers in 28 patients. Indications for imaging were symptomatic lesions concerning for metastasis or asymptomatic screening in patients with greater than 2 recurrences being evaluated for additional treatment.

RESULTS

Of 1193 patients treated for meningioma, 922 (77.3%) patients had confirmed or presumed WHO grade I tumors, 236 (19.8%) had grade II tumors, and 35 (2.9%) had grade III tumors. Mean follow-up was 4.3 years. A total of 207 patients experienced recurrences (17.4%), with a mean of 1.8 recurrences. Imaging for metastases was performed in 28 patients; 1 metastasis was grade I (3.6%), 16 were grade II (57.1%), and 11 were grade III (39.3%). Five patients (17.9%) underwent imaging because of symptomatic lesions. Of the 28 patients screened, 27 patients had prior recurrent meningioma (96.4%), with a median of 3 recurrences. On imaging, 10 patients had extracranial lesions suspicious for metastasis (35.7%). At biopsy, 8 were meningioma metastases, 1 was a nonmeningioma malignancy, and 1 patient was lost to follow-up prior to biopsy. Biopsy-confirmed metastases occurred in the liver (5), lung (3), mediastinum (1), and bone (1). The observed incidence of metastases was 0.67% (n = 8). Incidence increased to 2% of WHO grade II and 8.6% of grade III meningiomas. Using the proposed indications for screening, the number needed to screen to identify one patient with biopsy-confirmed malignancy was 3.83.

CONCLUSIONS

Systemic imaging of patients with multiply recurrent meningioma or symptoms concerning for metastasis may identify extracranial metastases in a significant proportion of patients and can inform decision making for additional treatments.
Predictive factors for long-term clinical outcomes of deep brain stimulation in the treatment of primary Meige syndrome
Authors: Wang Xin , Mao Zhiqi , Cui Zhiqiang , Xu Xin , Pan Longsheng , Liang Shuli , Ling Zhipei , Yu Xinguang
Published: April 2019

OBJECTIVE

Primary Meige syndrome is characterized by blepharospasm and orofacial–cervical dystonia. Deep brain stimulation (DBS) is recognized as an effective therapy for patients with this condition, but previous studies have focused on clinical effects. This study explored the predictors of clinical outcome in patients with Meige syndrome who underwent DBS.

METHODS

Twenty patients who underwent DBS targeting the bilateral subthalamic nucleus (STN) or globus pallidus internus (GPi) at the Chinese People’s Liberation Army General Hospital from August 2013 to February 2018 were enrolled in the study. Their clinical outcomes were evaluated using the Burke–Fahn–Marsden Dystonia Rating Scale at baseline and at the follow-up visits; patients were accordingly divided into a good-outcome group and a poor-outcome group. Putative influential factors, such as age and course of disease, were examined separately, and the factors that reached statistical significance were subjected to logistic regression analysis to identify predictors of clinical outcomes.

RESULTS

Four factors showed significant differences between the good- and poor-outcome groups: 1) the DBS target (STN vs GPi); 2) whether symptoms first appeared at multiple sites or at a single site; 3) the sub-item scores of the mouth at baseline; and 4) the follow-up period (p < 0.05). Binary logistic regression analysis revealed that initial involvement of multiple sites and the mouth score were the only significant predictors of clinical outcome.

CONCLUSIONS

The severity of the disease in the initial stage and presurgical period was the only independent predictive factor of the clinical outcomes of DBS for the treatment of patients with Meige syndrome.