Augmented Reality in Stereotactic Neurosurgery: Current Status and Issues.

Stereotactic neurosurgery is an established technique, but it has several limitations. In frame-based stereotaxy using a stereotactic frame, frame setting errors may decrease the accuracy of the procedure. Frameless stereotaxy using neuronavigation requires surgeons to shift their view from the surgical field to the navigation display and to advance the needle while assuming a physically uncomfortable position.

Evaluation of augmented-reality based navigation for brain tumor surgery.

To date, several researchers have introduced augmented reality navigation (ARN) into neurological surgery. While its application in brain tumor surgery seems promising, reports on its utility have been limited, thus warranting further evaluation. To clarify the stages and approaches in which ARN is useful and assess the effect of presurgical discussion with surgeons, we assessed usefulness using a hand-held ARN system we had developed, which displays three-dimensional (3D) virtual structures overlaid on a real-time image of the surgical field via a tablet PC monitor.

Preoperative simulation of a middle cerebral artery aneurysm clipping using a rotational three-dimensional digital subtraction angiography.

Background: In recent years, young neurosurgeons have had few opportunities to gain experience with clipping surgeries. The first author was sometimes surprised that she could not predict the anatomical relationships between the aneurysm and vessels during actual surgery. This study investigated the differences between the expected and actual operative findings during clipping surgery for aneurysms of the middle cerebral artery.

Application of Augmented Reality to Stereotactic Biopsy.

Both frame-based stereotaxy and frameless stereotaxy are established surgical procedures. However, they each have their respective disadvantages when used in the biopsy of a deep-seated lesion. To overcome the drawbacks associated with these procedures, we evaluated the feasibility of applying augmented reality (AR) to stereotactic biopsy.

Comprehensive Metabolomic Analysis of IDH1 Clinical Glioma Samples Reveals Suppression of β-oxidation Due to Carnitine Deficiency.

Gliomas with Isocitrate dehydrogenase 1 (IDH1) mutation have alterations in several enzyme activities, resulting in various metabolic changes. The aim of this study was to determine a mechanism for the better prognosis of gliomas with IDH mutation by performing metabolomic analysis. To understand the metabolic state of human gliomas, we analyzed clinical samples obtained from surgical resection of glioma patients (grades II-IV) with or without the IDH1 mutation, and compared the results with U87 glioblastoma cells overexpressing IDH1 or IDH1.

Hippocampal GAD67 Transduction Using rAAV8 Regulates Epileptogenesis in EL Mice.

Gene therapy has been employed as a therapeutic approach for intractable focal epilepsies. Considering the potential of focal GABAergic neuromodulation in regulating epileptogenesis, the GABA-producing enzyme, γ-aminobutyric acid decarboxylase 67 (GAD67), is highly suitable for epilepsy therapy. The EL/Suz (EL) mouse is a model of multifactorial temporal lobe epilepsy.

Individual optimal attentional strategy during implicit motor learning boosts frontoparietal neural processing efficiency: A functional near-infrared spectroscopy study.

Introduction: Optimal focus of attention is a crucial factor for improving motor learning. Most previous studies have shown that directing attention to movement outcome (external focus; EF) is more effective than directing attention to body movement itself (internal focus; IF). However, our recent studies demonstrated that the optimal attentional strategy in healthy and clinical populations varies depending on individual motor imagery ability.

[The Current Status of Corpus Callosotomy for Epilepsies].

Surgery is considered a therapeutic option for drug-resistant epilepsies. As a first step, the epileptic focus is carefully examined using extra- and intra-cranial EEG and various neurodiagnostic imaging techniques, such as magnetic resonance imaging, intra-ictal single photon emission computed tomography, magnetoencephalography, and functional near-infrared spectoroscopy. Only when the epileptogenic focus can not be identified, callosotomy is considered as a palliative surgical method.

Recovery of brain abscess-induced stuttering after neurosurgical intervention.

Stuttering occurs in approximately 5% of all children and 1% of adults. One type, neurogenic stuttering, is usually attributable to strokes or other structural damages to the brain areas that are responsible for language fluency. Here, we present the first case of neurogenic stuttering caused by a brain abscess.

Smart Glasses for Neurosurgical Navigation by Augmented Reality.

Background: Wearable devices with heads-up displays or smart glasses can overlay images onto the sight of the wearer. This technology has never been applied to surgical navigation.

Objective: To assess the applicability and accuracy of smart glasses for augmented reality (AR)-based neurosurgical navigation.

Morphological changes indicative of brain hemisphere development and handedness in fixed brains and on CT/MRI images.

We measured the lengths of some parts of the right and left hemispheres (HEs) in 70 formalin-fixed brains and on 15 computed tomography/magnetic resonance imaging (CT/MRI) images (7 left-handed and 8 right-handed cases) to clarify the morphological changes indicating which HE developed earlier and handedness. In many cases of the fixed brains, 1) the distance from the frontal pole to the occipital pole was longer in the left HE than in the right HE, 2) the distance from the middle plane to the lateral-most portion of the HE was wider in the right HE than in the left HE, 3) the left occipital pole elongated more posteriorly and covered the right occipital pole, and 4) the volume of each HE was nearly the same. The results indicate that the left HE develops and grows slightly earlier in the larger semi-cranium (half of the cranium) than the right HE which develops later in the smaller semi-cranium.

Outcome of vagus nerve stimulation for drug-resistant epilepsy: the first three years of a prospective Japanese registry.

Vagus nerve stimulation (VNS) is an established option of adjunctive treatment for patients with drug-resistant epilepsy, however, evidence for long-term efficacy is still limited. Studies on clinical outcomes of VNS in Asia are also limited. We report the overall outcome of a national, prospective registry that included all patients implanted in Japan.

A patient-specific intracranial aneurysm model with endothelial lining: a novel in vitro approach to bridge the gap between biology and flow dynamics.

Objectives: To develop an in vitro model for studying the biological effect of complex-flow stress on endothelial cells in three-dimensional (3D) patient-specific vascular geometry.

Materials And Methods: A vessel replica was fabricated with polydimethylsiloxanes using 3D printing technology from vascular image data acquired by rotational angiography. The vascular model was coated with fibronectin and immersed in a tube filled with a cell suspension of endothelium, and then cultured while being slowly rotated in three dimensions.

Training in Cerebral Aneurysm Clipping Using Self-Made 3-Dimensional Models.

Introduction: Recently, there have been increasingly fewer opportunities for junior surgeons to receive on-the-job training. Therefore, we created custom-built three-dimensional (3D) surgical simulators for training in connection with cerebral aneurysm clipping.

Methods: Three patient-specific models were composed of a trimmed skull, retractable brain, and a hollow elastic aneurysm with its parent artery.

Improved motor performance in patients with acute stroke using the optimal individual attentional strategy.

It is believed that motor performance improves when individuals direct attention to movement outcome (external focus, EF) rather than to body movement itself (internal focus, IF). However, our previous study found that an optimal individual attentional strategy depended on motor imagery ability. We explored whether the individual motor imagery ability in stroke patients also affected the optimal attentional strategy for motor control.

Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method.

Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer.

[Rapid 3-Dimensional Models of Cerebral Aneurysm for Emergency Surgical Clipping].

We developed a method for manufacturing solid models of cerebral aneurysms, with a shorter printing time than that involved in conventional methods, using a compact 3D printer with acrylonitrile-butadiene-styrene(ABS)resin. We further investigated the application and utility of this printing system in emergency clipping surgery. A total of 16 patients diagnosed with acute subarachnoid hemorrhage resulting from cerebral aneurysm rupture were enrolled in the present study.

Ultrasound-guided central venous catheterization using an optical see-through head-mounted display: A pilot study.

Purpose: We examined the feasibility of using a head-mounted display (HMD) to improve the ergonomics of sonographic-guided interventional procedures.

Methods: Five physicians with experience of more than 20 central venous catheterizations participated in this study. Each participant performed five pairs of simulated jugular vein catheterization under sonographic guidance with and without the HMD.

Preoperative Three-Dimensional Diagnosis of Neurovascular Relationships at the Root Exit Zones During Microvascular Decompression for Hemifacial Spasm.

Objective: Hemifacial spasm occurs when a blood vessel compresses against an area near the root exit zone of the facial nerve. Developments in diagnostic neuroimaging have allowed three-dimensional (3D) observation of artery and nerve locations, an effective aid for treatment selection. However, an accurate interpretation of the 3D data remains challenging because imaging representations of complex small vessels are drowned out by noise.

A New Irrigation System (Endosplash) for a Rigid Endoscope in Trans-sphenoidal Endoscopic Surgery.

Obstruction of the visual field by blood is a major hindrance during endonasal endoscopic surgery, and a rapid and effective method for cleaning the lens is needed. We developed a new lens-cleaning system that does not employ a sheath or an irrigation-suction system. It is a 20-mm long cylinder with side holes that is attached to the barrel of the endoscope and is connected to a syringe containing saline.

The Trans-Visible Navigator: A See-Through Neuronavigation System Using Augmented Reality.

Introduction: The neuronavigator has become indispensable for brain surgery and works in the manner of point-to-point navigation. Because the positional information is indicated on a personal computer (PC) monitor, surgeons are required to rotate the dimension of the magnetic resonance imaging/computed tomography scans to match the surgical field. In addition, they must frequently alternate their gaze between the surgical field and the PC monitor.

Embolization for Refractory Subacute Subdural Hematoma in a Child with Severe Hemophilia Type A.

Hemophilia is an X-linked hemorrhagic disease due to coagulation factor VIII or IX deficiency with approximately 5-10% incidence of central nervous system bleeding. We present an intriguing case of a refractory subacute subdural hematoma (SDH) controlled with endovascular embolization in a hemophilic patient. A 5-year-old severe hemophilic A boy presented with a life threatening left parietal subcortical hemorrhage, for which he underwent craniotomy and evacuation of the hematoma.

Optimization of a motor learning attention-directing strategy based on an individual's motor imagery ability.

Motor learning performance has been shown to be affected by various cognitive factors such as the focus of attention and motor imagery ability. Most previous studies on motor learning have shown that directing the attention of participants externally, such as on the outcome of an assigned body movement, can be more effective than directing their attention internally, such as on body movement itself. However, to the best of our knowledge, no findings have been reported on the effect of the focus of attention selected according to the motor imagery ability of an individual on motor learning performance.