bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probabilistic machine learning for the evaluation of presurgical language dominance
Authors: Gazit Tomer , Andelman Fani , Glikmann-Johnston Yifat , Gonen Tal , Solski Aliya , Shapira-Lichter Irit , Ovadia Moran , Kipervasser Svetlana , Neufeld Miriam Y. , Fried Itzhak , Hendler Talma , Perry Daniella 
Published: January 2016

OBJECTIVE
Providing a reliable assessment of language lateralization is an important task to be performed prior to neurosurgery in patients with epilepsy. Over the last decade, functional MRI (fMRI) has emerged as a useful noninvasive tool for language lateralization, supplementing or replacing traditional invasive methods. In standard practice, fMRI-based language lateralization is assessed qualitatively by visual inspection of fMRI maps at a specific chosen activation threshold. The purpose of this study was to develop and evaluate a new computational technique for providing the probability of each patient to be left, right, or bilateral dominant in language processing.

METHODS
In 76 patients with epilepsy, a language lateralization index was calculated using the verb-generation fMRI task over a wide range of activation thresholds (from a permissive threshold, analyzing all brain regions, to a harsh threshold, analyzing only the strongest activations). The data were classified using a probabilistic logistic regression method.

RESULTS
Concordant results between fMRI and Wada lateralization were observed in 89% of patients. Bilateral and right-dominant groups showed similar fMRI lateralization patterns differentiating them from the left-dominant group but still allowing classification in 82% of patients.

CONCLUSIONS
These findings present the utility of a semi-supervised probabilistic learning approach for presurgical language-dominance mapping, which may be extended to other cognitive domains such as memory and attention.
A decade of emerging indications: deep brain stimulation in the United States
Authors: Youngerman Brett E. , Chan Andrew K. , Mikell Charles B. , McKhann Guy M. , Sheth Sameer A. 
Published: January 2016

OBJECTIVE
Deep brain stimulation (DBS) is an emerging treatment option for an expanding set of neurological and psychiatric diseases. Despite growing enthusiasm, the patterns and implications of this rapid adoption are largely unknown. National trends in DBS surgery performed for all indications between 2002 and 2011 are reported.

METHODS
Using a national database of hospital discharges, admissions for DBS for 14 indications were identified and categorized as either FDA approved, humanitarian device exempt (HDE), or emerging. Trends over time were examined, differences were analyzed by univariate analyses, and outcomes were analyzed by hierarchical regression analyses.

RESULTS
Between 2002 and 2011, there were an estimated 30,490 discharges following DBS for approved indications, 1647 for HDE indications, and 2014 for emerging indications. The volume for HDE and emerging indications grew at 36.1% annually in comparison with 7.0% for approved indications. DBS for emerging indications occurred at hospitals with more neurosurgeons and neurologists locally, but not necessarily at those with the highest DBS caseloads. Patients treated for HDE and emerging indications were younger with lower comorbidity scores. HDE and emerging indications were associated with greater rates of reported complications, longer lengths of stay, and greater total costs.

CONCLUSIONS
DBS for HDE and emerging indications underwent rapid growth in the last decade, and it is not exclusively the most experienced DBS practitioners leading the charge to treat the newest indications. Surgeons may be selecting younger and healthier patients for their early experiences. Differences in reported complication rates warrant further attention and additional costs should be anticipated as surgeons gain experience with new patient populations and targets.
In vivo visualization of the facial nerve in patients with acoustic neuroma using diffusion tensor imaging–based fiber tracking
Authors: Song Fei , Hou Yuanzheng , Sun Guochen , Chen Xiaolei , Xu Bainan , Huang Jason H. , Zhang Jun 
Published: January 2016

OBJECTIVE
Preoperative determination of the facial nerve (FN) course is essential to preserving its function. Neither regular preoperative imaging examination nor intraoperative electrophysiological monitoring is able to determine the exact position of the FN. The diffusion tensor imaging–based fiber tracking (DTI-FT) technique has been widely used for the preoperative noninvasive visualization of the neural fasciculus in the white matter of brain. However, further studies are required to establish its role in the preoperative visualization of the FN in acoustic neuroma surgery. The object of this study is to evaluate the feasibility of using DTI-FT to visualize the FN.

METHODS
Data from 15 patients with acoustic neuromas were collected using 3-T MRI. The visualized FN course and its position relative to the tumors were determined using DTI-FT with 3D Slicer software. The preoperative visualization results of FN tracking were verified using microscopic observation and electrophysiological monitoring during microsurgery.

RESULTS
Preoperative visualization of the FN using DTI-FT was observed in 93.3% of the patients. However, in 92.9% of the patients, the FN visualization results were consistent with the actual surgery.

CONCLUSIONS
DTI-FT, in combination with intraoperative FN electrophysiological monitoring, demonstrated improved FN preservation in patients with acoustic neuroma. FN visualization mainly included the facial-vestibular nerve complex of the FN and vestibular nerve.
Preoperative external tissue expansion for complex cranial reconstructions
Authors: Reinard Kevin A. , Zakaria Hesham M. , Qatanani Ahmad , Lee Ian Y. , Rock Jack P. , Houin Herman P. 
Published: January 2016

OBJECTIVE
Reconstruction of large solitary cranial defects after multiple craniotomies is challenging because scalp contraction generally requires more than simple subcutaneous undermining to ensure effective and cosmetically appealing closure. In plastic and reconstructive surgery, soft tissue expansion is considered the gold standard for reconstructing scalp defects; however, these techniques are not well known nor are they routinely practiced among neurosurgeons. The authors here describe a simple external tissue expansion technique that is associated with low morbidity and results in high cosmetic satisfaction among patients.

METHODS
The authors reviewed the medical records of patients with large cranial defects (> 5 cm) following multiple complicated craniotomies who had undergone reconstructive cranioplasty with preoperative tissue expansion using the DermaClose RC device. In addition to gathering data on patient age, sex, primary pathology, number of craniotomies and/or craniectomies, history of radiation therapy, and duration of external scalp tissue expansion, the authors screened patient charts for cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess formation, dermatitis, and patient satisfaction rates.

RESULTS
The 6 identified patients (5 female, 1 male) had an age range from 36 to 70 years. All patients had complicating factors such as recalcitrant scalp infections after multiple craniotomies or cranial radiation, which led to secondary scalp tissue scarring and retraction. All patients were deemed to be potential candidates for rotational flaps with or without skin grafts. All patients underwent the same preoperative tissue expansion followed by standard cranial bone reconstruction. None of the patients developed CSF leak, meningitis, intracranial abscess, dermatitis, or permanent cosmetic defects. None of the patients required a reoperation. Mean follow-up was 117 days.

CONCLUSIONS
Preoperative scalp tissue expansion with the DermaClose RC device allows for simple and reliable completion of complicated cranial reconstruction with low morbidity rates and high cosmetic satisfaction among patients.
Intracranial MR-guided laser-induced thermal therapy: single-center experience with the Visualase thermal therapy system
Authors: Patel Purvee , Patel Nitesh V. , Danish Shabbar F. 
Published: January 2016

OBJECTIVE
MR-guided laser-induced thermal therapy (MRgLITT) can be used to treat intracranial tumors, epilepsy, and chronic pain syndromes. Here, the authors report their single-center experience with 102 patients, the largest series to date in which the Visualase thermal therapy system was used.

METHODS
A retrospective analysis of all patients who underwent MRgLITT between 2010 and 2014 was performed. Pathologies included glioma, recurrent metastasis, radiation necrosis, chronic pain, and epilepsy. Laser catheters were placed stereotactically, and ablation was performed in the MRI suite. Demographics, operative parameters, length of hospital stay, and complications were recorded. Thirty-day readmission rates were calculated by using the standard method according to America's Health Insurance Plans Center for Policy and Research guidelines.

RESULTS
A total of 133 lasers were placed in 102 patients who required intervention for intracranial tumors (87 patients), chronic pain syndrome (cingulotomy, 5 patients), or epilepsy (10 patients). The procedure was completed in 98% (100) of these patients. Ninety-two patients (90.2%) had undergone previous treatment for their intracranial tumors. The average (± SD) total procedural time was 170.5 ± 34.4 minutes, and the mean laser-on time was 8.7 ± 6.8 minutes. The average intensive care unit (ICU) and hospital stays were 1.8 and 3.6 days, respectively, and the median length of stay for both the ICU and the hospital was 1 day. By postoperative Day 1, 54% of the patients (n = 55) were neurologically stable for discharge. There were 27 cases of morbidity, including new-onset neurological deficits, and 2 perioperative deaths. Fourteen patients (13.7%) developed new deficits after the MRgLITT procedure, and of those 14 patients, 64.3% (n = 9) had complete resolution of deficits within 1 month, 7.1% (n = 1) had partial resolution of symptoms within 1 month, 14.3% (n = 2) had not had resolution of symptoms at the most recent follow-up, and 14.3% (n = 2) died without resolution of symptoms. The 30-day readmission rate was 5.6%

CONCLUSIONS
MRgLITT, although minimally invasive, must be used with caution. Thermal damage to critical and eloquent structures can occur despite MRI guidance. Once the learning curve is overcome, the overall procedural complication rate is low, and most patients can be discharged within 24 hours, with a relatively low readmission rate. In cases in which they occurred, most neurological deficits were temporary. The therapeutic role of MRgLITT in various intracranial diseases will require larger and more rigorous studies.
Surgically resected skull base meningiomas demonstrate a divergent postoperative recurrence pattern compared with non–skull base meningiomas
Authors: Mansouri Alireza , Klironomos George , Taslimi Shervin , Kilian Alex , Gentili Fred , Khan Osaama H. , Aldape Kenneth , Zadeh Gelareh 
Published: January 2016

OBJECTIVE
The objective of this study was to identify the natural history and clinical predictors of postoperative recurrence of skull base and non–skull base meningiomas.

METHODS
The authors performed a retrospective hospital-based study of all patients with meningioma referred to their institution from September 1993 to January 2014. The cohort constituted both patients with a first-time presentation and those with evidence of recurrence. Kaplan-Meier curves were constructed for analysis of recurrence and differences were assessed using the log-rank test. Cox proportional hazard regression was used to identify potential predictors of recurrence.

RESULTS
Overall, 398 intracranial meningiomas were reviewed, including 269 (68%) non–skull base and 129 (32%) skull base meningiomas (median follow-up 30.2 months, interquartile range [IQR] 8.5–76 months). The 10-year recurrence-free survival rates for patients with gross-total resection (GTR) and subtotal resection (STR) were 90% and 43%, respectively. Skull base tumors were associated with a lower proliferation index (0.041 vs 0.062, p = 0.001), higher likelihood of WHO Grade I (85.3% vs 69.1%, p = 0.003), and younger patient age (55.2 vs 58.3 years, p = 0.01). Meningiomas in all locations demonstrated an average recurrence rate of 30% at 100 months of follow-up. Subsequently, the recurrence of skull base meningiomas plateaued whereas non–skull base lesions had an 80% recurrence rate at 230 months follow-up (p = 0.02). On univariate analysis, a prior history of recurrence (p < 0.001), initial WHO grade following resection (p < 0.001), and the inability to obtain GTR (p < 0.001) were predictors of future recurrence. On multivariate analysis a prior history of recurrence (p = 0.02) and an STR (p < 0.01) were independent predictors of a recurrence. Assessing only patients with primary presentations, STR and WHO Grades II and III were independent predictors of recurrence (p < 0.001 for both).

CONCLUSIONS
Patients with skull base meningiomas present at a younger age and have less aggressive lesions overall. Extent of resection is a key predictor of recurrence and long-term follow-up of meningiomas is necessary, especially for non–skull base tumors. In skull base meningiomas, recurrence risk plateaus approximately 100 months after surgery, suggesting that for this specific cohort, follow-up after 100 months can be less frequent.
Resting-state functional MRI in an intraoperative MRI setting: proof of feasibility and correlation to clinical outcome of patients
Authors: Roder Constantin , Charyasz-Leks Edyta , Breitkopf Martin , Decker Karlheinz , Ernemann Ulrike , Klose Uwe , Tatagiba Marcos , Bisdas Sotirios 
Published: January 2016

OBJECTIVE
The authors' aim in this paper is to prove the feasibility of resting-state (RS) functional MRI (fMRI) in an intraoperative setting (iRS-fMRI) and to correlate findings with the clinical condition of patients pre- and postoperatively.

METHODS
Twelve patients underwent intraoperative MRI-guided resection of lesions in or directly adjacent to the central region and/or pyramidal tract. Intraoperative RS (iRS)–fMRI was performed pre- and intraoperatively and was correlated with patients' postoperative clinical condition, as well as with intraoperative monitoring results. Independent component analysis (ICA) was used to postprocess the RS-fMRI data concerning the sensorimotor networks, and the mean z-scores were statistically analyzed.

RESULTS
iRS-fMRI in anesthetized patients proved to be feasible and analysis revealed no significant differences in preoperative z-scores between the sensorimotor areas ipsi- and contralateral to the tumor. A significant decrease in z-score (p < 0.01) was seen in patients with new neurological deficits postoperatively. The intraoperative z-score in the hemisphere ipsilateral to the tumor had a significant negative correlation with the degree of paresis immediately after the operation (r = −0.67, p < 0.001) and on the day of discharge from the hospital (r = −0.65, p < 0.001). Receiver operating characteristic curve analysis demonstrated moderate prognostic value of the intraoperative z-score (area under the curve 0.84) for the paresis score at patient discharge.

CONCLUSIONS
The use of iRS-fMRI with ICA-based postprocessing and functional activity mapping is feasible and the results may correlate with clinical parameters, demonstrating a significant negative correlation between the intensity of the iRS-fMRI signal and the postoperative neurological changes.
Densitometric comparison of 3 occipital regions for suitability of fixation
Authors: Das Chandan , Newcomb Anna G. U. S. , Gaudin Daniel P. , Crawford Neil R. 
Published: January 2016

OBJECTIVE
Atlantooccipital fixation is an important technique in the treatment of upper cervical spine instability. Important considerations for implant devices are obtrusiveness and propagation of torque through the device caused by cervical rotation. The authors evaluated the feasibility of 3 regions of the occiput as sites for occipitocervical fixation by examining bone mineral density at these locations.

METHODS
Unembalmed occiputs of 9 male and 4 female cadavers were used (mean age at time of death was 61.6 years, range 36–68 years). Studies were undertaken using caliper measurements and dual-energy x-ray absorptiometry of the superior nuchal line (SNL), the external occipital protuberance (EOP), and the inferior nuchal line (INL).

RESULTS
Data indicate that the bone at the INL has a similar volumetric bone density as the bone at the SNL, despite having half the thickness. Also, the volumetric bone density increases laterally along the nuchal lines.

CONCLUSIONS
Most hardware fixation is centered on stabilization at the EOP and the SNL. On the basis of these radiological results, the INL shows promise as a potential alternative site for screw placement in occipitocervical fixation.
Percutaneous biportal endoscopic decompression for lumbar spinal stenosis: a technical note and preliminary clinical results
Authors: Hwa Eum Jin , Hwa Heo Dong , Son Sang Kyu , Park Choon Keun 
Published: January 2016

OBJECTIVE
The use of conventional uniportal spinal endoscopic decompression surgery for lumbar spinal stenosis can be limited by technical difficulties and a restricted field of vision. The purpose of this study is to describe the technique for percutaneous biportal endoscopic decompression (PBED) for lumbar spinal stenosis and analysis of clinical postoperative results.

METHODS
The authors performed a unilateral laminotomy with bilateral foraminal decompression using a unilateral biportal endoscopic system in patients with single-level lumbar stenosis. The authors enrolled only patients who underwent follow-up for longer than 12 months after PBED. Fifty-eight patients were enrolled in this study. This approach was based on 2 portals: one portal was used for continuous irrigation and endoscopic viewing and the other portal was used to manipulate the instruments used in the decompression procedures. Clinical parameters such as the Oswestry Disability Index (ODI), Macnab criteria, and postoperative complications were analyzed.

RESULTS
Neural decompression was effectively performed in all enrolled patients. The mean ODI was significantly lower after PBED. Of 58 patients, 47 (81.0%) had a good or excellent result according to the Macnab criteria. Postoperative ODI and visual analog scale scores were significantly improved compared with preoperative values.

CONCLUSIONS
From a surgical point of view, percutaneous biportal endoscopy is very similar to microscopic spinal surgery, permitting good visualization of the contralateral sublaminar and medial foraminal areas. The authors suggest that the PBED, which is a minimally invasive procedure, is an alternative treatment option for degenerative lumbar stenosis.
Reoperation rates for symptomatic nonunions in posterior cervical (subaxial) fusions with and without bone morphogenetic protein in a cohort of 1158 patients
Authors: Guppy Kern H. , Harris Jessica , Chen Jason , Paxton Elizabeth W. , Alvarez Julie , Bernbeck Johannes 
Published: January 2016

OBJECTIVE
Bone morphogenetic protein (BMP) was first approved in 2002 for use in single-level anterior lumbar fusions as an alternative to iliac crest grafts. Subsequent studies have concluded that BMP provides superior fusions rates and therefore reduces reoperations for nonunions. The purpose of this study was to determine the reoperation rates for symptomatic nonunions in posterior cervical (subaxial) spinal fusions with and without the use of BMP and to determine if the nonunion rates are statistically significantly different between the two groups.

METHODS
Between January 2009 and September 2013, the authors identified 1158 posterior cervical spinal fusion cases in the subaxial spine (C2–7) from a large spine registry (Kaiser Permanente). Patient characteristics, diagnoses, operative times, lengths of stay, and reoperations were extracted from the registry. Reoperations for symptomatic nonunions were adjudicated via chart review. Logistic regression was conducted to produce estimates of odds ratios (OR) and 95% confidence intervals (CIs). Kaplan-Meier curves for the non-BMP and BMP groups were generated and compared using the log-rank test.

RESULTS
In this cohort there were 1158 patients (19.3% with BMP) with a median follow up of 1.7 years (interquartile range [IQR] 0.7–2.9 years) and median duration to operative nonunion of 0.63 years (IQR 0.44–1.57 years). Kaplan-Meier curves showed no significant difference in reoperation rates for nonunions using the log-rank test (p = 0.179). In a subset of patients with more than 1 year of follow-up, 788 patients were identified (22.5% with BMP) with a median follow-up duration of 2.5 years (IQR 1.7–3.4 years) and a median time to operative nonunion of 0.73 years (IQR 0.44–1.57 years). There was no statistically significant difference in the symptomatic operative nonunion rates for posterior cervical (subaxial) fusions with BMP compared with non-BMP (1.1% vs 0.7%; crude OR 1.73, 95% CI 0.32–9.55, p = 0.527) for more than 1 year of follow-up.

CONCLUSIONS
This study presents the largest series of patients using BMP in posterior cervical (subaxial) spinal fusions. Reoperation rates for symptomatic nonunions with more than 1 year of follow-up were found to be 1.1% with BMP and 0.7% without BMP. There was no significant difference in the reoperation rates for symptomatic nonunions with or without BMP.
Questioning the need for ICU level of care in pediatric patients following elective uncomplicated craniotomy for brain tumors
Authors: Gabel Brandon C. , Martin Joel , Crawford John R. , Levy Michael 
Published: January 2016

OBJECTIVE
The object of this study is to address what factors may necessitate the need for intensive care monitoring after elective uncomplicated craniotomy in pediatric patients who are initially managed in a non–intensive care unit setting postoperatively.

METHODS
A retrospective chart review was undertaken for all patients who underwent elective craniotomy for brain tumor between April of 2007 and April of 2012 and who were directly admitted to the floor postoperatively. Factors such as age, tumor type, craniotomy location, neurological comorbidities, reason for transfer to intensive care unit (ICU) level of care (if applicable), time between admittance to floor and transfer to ICU level of care, and reason for transfer to ICU level of care were assessed.

RESULTS
Adjusted logistic regression found 2 significant positive predictors of postoperative transfer to the ICU after initial admission to the floor: primitive neuroectodermal tumor pathology (OR 44.10, 95% CI 1.24–1572.16, p = 0.04), and repeat craniotomy during the same hospitalization (OR 13.97, 95% CI 1.21–160.66, p = 0.03). Conversely, 1 negative factor was found: low-grade glioma pathology (OR 0.05, 95% CI 0.00–0.87, p = 0.04).

CONCLUSIONS
Select pediatric patients may not require ICU level of care after elective uncomplicated pediatric craniotomy. Additional studies are needed to adequately address which patients would benefit from initial ICU admittance following elective craniotomies for brain tumors.