High-speed k-linear swept laser using acousto-optic deflectors with Doppler shift compensation for optical coherence tomography.

Swept laser based on the acousto-optic deflector (AOD) is a promising swept source in optical coherence tomography (OCT) applications for its high wavenumber linear sweep without mechanical motion. However, the poor coherence length and the elongated cavity of the laser imposed limitations on the acquisition of high-quality images with adequate imaging depth and high imaging speed. In this Letter, we demonstrate a compact high-speed wavenumber linear swept laser based on AOD using Doppler shift compensation, achieving a high linearity of Pearson's R of 0.

Precise management system for chronic intractable pain patients implanted with spinal cord stimulation based on a remote programming platform: study protocol for a randomized controlled trial (PreMaSy study).

Background: Spinal cord stimulation (SCS) is a surgical technique used in patients with chronic intractable pain, and its effectiveness and safety have been validated by multiple studies. However, to maintain an optimal and steady long-term effect is still challenging. Here, we report a new management paradigm integrating smartphone application and remote programming.

Polarization-isolated stretched-pulse mode-locked swept laser for 10.3-MHz A-line rate optical coherence tomography.

Stretched-pulse mode-locked (SPML) lasing based on a chirped fiber Bragg grating (CFBG) has proven to be a powerful method to generate wavelength-swept lasers at speeds of tens of megahertz. However, light transmitted through the CFBG may lead to undesirable laser oscillation that disrupts the mechanism of the laser active mode locking in the theta ring cavity. In this Letter, we demonstrate a simple and low-cost approach to suppress the transmitted light and achieve an effective duty cycle of ∼100% with only one CFBG and no need for intra-cavity semiconductor optical amplifier (SOA) modulation, extra-cavity optical buffering, and post amplification.

Multimodal-based machine learning strategy for accurate and non-invasive prediction of intramedullary glioma grade and mutation status of molecular markers: a retrospective study.

Background: Determining the grade and molecular marker status of intramedullary gliomas is important for assessing treatment outcomes and prognosis. Invasive biopsy for pathology usually carries a high risk of tissue damage, especially to the spinal cord, and there are currently no non-invasive strategies to identify the pathological type of intramedullary gliomas. Therefore, this study aimed to develop a non-invasive machine learning model to assist doctors in identifying the intramedullary glioma grade and mutation status of molecular markers.

Emotional Problems, Quality of Life and Symptom Burden in Patients with Chordoma.

Chordomas are very rare malignant bone tumors. Following surgery, their effects on neurological, physical, psychological, social, and emotional functioning are substantial and can have a major impact on a patients' quality of life (QOL). In this survey, we aimed to characterize the postoperation health-related QOL and emotional problem in patients with chordoma using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30 (EORTC QLQ-C30) and Hamilton Depression Rating Scale (HAMD).

Improved Ultrafast Power Doppler Imaging by Using Spatiotemporal Non-Local Means Filtering.

The change of microvasculature is associated with the occurrence and development of many diseases. Ultrafast power Doppler imaging (uPDI) is an emerging technology for the visualization of microvessels due to the development of ultrafast plane wave (PW) imaging and advanced clutter filters. However, the low signal-to-noise ratio (SNR) caused by unfocused transmit of PW imaging deteriorates the subsequent imaging of microvasculature.

A rare case of atypical spinal neurocytoma with EGFR mutation in a 12-year-old boy.

Spinal neurocytoma (SN), although frequently reportedly as tumors of the central nervous system (CNS), are a distinct class of tumors, which can achieve a better prognosis following subtotal or gross total tumor resection. Nonetheless, even with the premise of successful treatment after tumor resection, poor prognosis after treatment due to the SN high proliferation index (typically known as atypical SN) have been reported. Over the past two decades, atypical SN was only reported in four pediatric cases, amidst the lingering controversy surrounding its postoperative adjuvant therapy.

Clinical Features and Outcomes of Primary Spinal Cord Glioblastoma: A Single-Center Experience and Literature Review.

Objective: We aim to elucidate the clinical characteristics of patients with primary spinal cord glioblastoma (PSC GBM) and prognostic factors for their outcomes.

Methods: A cohort of 11 patients with pathologically diagnosed PSC GBM from our center were retrospectively reviewed. The clinical, radiologic, operative, and molecular information were recorded, and univariate analysis was performed to identify prognostic factors.

Fluorescein-guided surgery for spinal gliomas: Analysis of 220 consecutive cases.

Objective: Sodium fluorescein (FL) is widely used as a fluorescent tracer for brain tumor resection. However, FL-guided resection of spinal gliomas has been reported only occasionally. To evaluate the safety, characteristics, and usefulness of FL-guided surgery in the resection of spinal glioma.

Dual-modality optical diagnosis for precise identification of tumors in neurosurgery.

In neurosurgery, the precise diagnosis and treatment of tumor diseases are challenging to realize. Current clinical diagnoses lack fast and accurate intraoperative information. Therefore, the development of new methods and techniques to assist neurosurgeons intraoperatively is necessary.

Intramedullary Spinal Cord Ganglioglioma Presenting as Hyperhidrosis: A Rare Case Report and Literature Review.

Background: Hyperhidrosis is caused by sympathetic dysfunction of the central or peripheral nervous system. However, intramedullary spinal cord tumors presenting with hyperhidrosis as an initial symptom have been rarely reported in the literature.

Case Description: This case involves an 18-year-old man who presented with abnormal enhanced sweating and flushing on the bilateral side of his face and neck that had persisted for 6 years.

Accuracy of pedicle screw placement in the thoracic and lumbosacral spines using O-arm-based navigation versus conventional freehand technique.

Background: The accuracy and safety of pedicle screw insertion was markedly improved with the introduction of intraoperative three-dimensional navigation system during the last decade. This study aimed to evaluate the accuracy of pedicle screw placement using O-arm-based navigation system versus conventional freehand technique.

Methods: We reviewed the accuracy of 341 thoracic ( = 173) and lumbosacral ( = 168) pedicle screws placed in 60 consecutive patients using either O-arm-based navigation or freehand technique in the Department of Neurosurgery of Beijing Tsinghua Changgung Hospital between January 2015 and June 2018.

Risk factor analysis of progressive spinal deformity after resection of intramedullary spinal cord tumors in patients who underwent laminoplasty: a report of 105 consecutive cases.

Objective: Laminoplasty has been used in recent years as an alternative approach to laminectomy for preventing spinal deformity after resection of intramedullary spinal cord tumors (IMSCTs). However, controversies exist with regard to its real role in maintaining postoperative spinal alignment. The purpose of this study was to examine the incidence of progressive spinal deformity in patients who underwent laminoplasty for resection of IMSCT and identify risk factors for progressive spinal deformity.

Giant Recurrent Sacral Chordoma.

A 65-year-old man presented with a giant recurrent sacral chordoma after undergoing 7 surgical resections. Neurologic examination revealed urinary incontinence. Magnetic resonance imaging showed a huge mass lesion in the bilateral gluteal regions and multiple metastatic chordomas.

Accuracy of Screw Placement and Clinical Outcomes After O-Arm-Navigated Occipitocervical Fusion.

Objective: This study aimed to evaluate the accuracy of screw placement and clinical outcomes in patients undergoing occipitocervical fusion.

Methods: Patients who underwent occipitocervical fusion with O-arm-based navigation were retrospectively reviewed between January 2015 and December 2017. The patients' characteristics, clinical and radiographic outcomes, and surgical complications were recorded and analyzed.

Microsurgical treatment and outcomes of spinal arteriovenous lesions: Learned from consecutive series of 105 lesions.

Spinal arteriovenous lesions (SAVLs), arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs), are rare and can devastatingly impair spinal cord function. This study aimed to evaluate clinical outcomes after microsurgical treatment with the aid of intraoperative indocyanine green video-angiography (ICG-VA) in a large series of patients with SAVLs. We retrospectively reviewed the cases of 95 consecutive patients with 105 SAVLs (77 spinal AVFs, 28 spinal AVMs) who had been treated surgically during 2010-2016 in two hospitals by the same experienced surgeon.

Predisposing factors for recanalization of cerebral aneurysms after endovascular embolization: a multivariate study.

Background: The recanalization of cerebral aneurysms after endovascular embolization (coiling or stent-assisted coiling) has been a matter of concern.

Objective: To systematically evaluate the predisposing factors for cerebral aneurysm recanalization using multidimensional analysis in a large patient cohort.

Methods: In 238 patients with 283 aneurysms, patient baseline characteristics, aneurysm morphological characteristics, treatment-related factors, and changes in flow hemodynamics after endovascular treatment (coiling or stent-assisted coiling) were compared between the recanalization and non-recanalization groups.

Phantom-based experimental validation of fast virtual deployment of self-expandable stents for cerebral aneurysms.

Background: Endovascular intervention using a stent is a mainstream treatment for cerebral aneurysms. To assess the effect of intervention strategies on aneurysm hemodynamics, we have developed a fast virtual stenting (FVS) technique to simulate stent deployment in patient-specific aneurysms. However, quantitative validation of the FVS against experimental data has not been fully addressed.

Rupture Risk Assessment for Mirror Aneurysms with Different Outcomes in the Same Patient.

Background: The purpose of this research was to analyze the effect of morphologic and hemodynamic characteristics on mirror aneurysms in which one ruptured and the other did not, within the same patient, and to identify reliable predictors of rupture.

Methods: We performed three-dimensional angiographic imaging in 56 patients with intracranial mirror aneurysms for computational fluid dynamic studies from January 2009 to December 2015. The ruptured aneurysm simulations were conducted with geometry obtained after rupture.

Bifurcation Type and Larger Low Shear Area Are Associated with Rupture Status of Very Small Intracranial Aneurysms.

Background: Characterization of the risk factors for rupture of very small intracranial aneurysm (VSIA, ≤3 mm) is clinically valuable, since VSIAs are implicated in subarachnoid hemorrhage. The aim of this study was to identify morphological and hemodynamic parameters that independently characterize the rupture status of VSIAs.

Methods: We conducted a retrospective study of consecutive VSIAs between September 2010 and February 2014 in our institute.

Low wall shear stress is associated with the rupture of intracranial aneurysm with known rupture point: case report and literature review.

Background: Few previous hemodynamic studies demonstrated the detailed features of rupture point of intracranial aneurysms. The hemodynamic simulation for the case that ruptured during angiography was even rare. In the present study, we studied the hemodynamic characteristics of a posterior communicating artery segment aneurysm that ruptured during angiography and detailed the hemodynamic features at the rupture point.

Successful Retreatment of Recurrent Intracranial Vertebral Artery Dissecting Aneurysms After Stent-Assisted Coil Embolization: A Self-Controlled Hemodynamic Analysis.

Background: Intracranial vertebral artery dissecting aneurysms (VADAs) tend to recur despite successful stent-assisted coil embolization (SACE). Hemodynamics is useful in evaluating aneurysmal formation, growth, and rupture. Our aim was to evaluate the hemodynamic patterns of the recurrence of VADA.