Recommendations for Quality Assurance Guidelines for Gamma Knife Radiosurgery in Republic of Korea : A Multi-institutional Survey.

Objective: The Leksell Gamma Knife (LGK) is one of the most precise radiosurgical tools available. However, the quality assurance (QA) practices for LGK vary considerably across institutions in Korea. In this study, we aim to identify and standardize key QA items, categorized into daily, monthly, biannual, and annual protocols, based on a nationwide survey conducted at 16 medical centers.

Changes in Patient Marker Coordinates with High-Definition Motion Management System during Frameless Gamma Knife Radiosurgery.

Objective: The Leksell Gamma Knife (LGK) Icon™ facilitates frameless (mask-based) fixation through its high-definition motion management (HDMM) system. However, the HDMM only records the intra-fractional motion values of patient marker without specifying changes along the X, Y, and Z axes. This study investigates the coordinate shifts in patient markers using the HDMM system during frameless gamma knife radiosurgery (GKRS) in patients with meningioma and metastases.

Brain structure comparison among Parkinson disease, essential tremor, and healthy controls using 7T MRI.

Both Parkinson disease (PD) and Essential tremor (ET) are movement disorders causing tremors in elderly individuals. Although PD and ET are different disease, they often present with similar initial symptoms, making their differentiation challenging with magnetic resonance imaging (MRI) techniques. This study aimed to identify structural brain differences among PD, ET, and health controls (HCs) using 7-Tesla (T) MRI.

Can we predict overall survival using machine learning algorithms at 3-months for brain metastases from non-small cell lung cancer after gamma knife radiosurgery?

Gamma knife radiosurgery (GRKS) is widely used for patients with brain metastases; however, predictions of overall survival (OS) within 3-months post-GKRS remain imprecise. Specifically, more than 10% of non-small cell lung cancer (NSCLC) patients died within 8 weeks of post-GKRS, indicating potential overtreatment. This study aims to predict OS within 3-months post-GKRS using machine learning algorithms, and to identify prognostic features in NSCLC patients.

Validation of real-time inside-out tracking and depth realization technologies for augmented reality-based neuronavigation.

Purpose: Concomitant with the significant advances in computing technology, the utilization of augmented reality-based navigation in clinical applications is being actively researched. In this light, we developed novel object tracking and depth realization technologies to apply augmented reality-based neuronavigation to brain surgery.

Methods: We developed real-time inside-out tracking based on visual inertial odometry and a visual inertial simultaneous localization and mapping algorithm.

Optimal mask fixation method for frameless radiosurgery with Leksell Gamma Knife Icon.

The Leksell Gamma Knife (LGK) Icon is used for mask-based and frame-based fixation. The mask fixation provides a noninvasive method. However, an optimal mask fixation method is yet to be established.

Avoiding a Collision in Gamma Knife Radiosurgery : A Modified Mask Fixation Method.

Objective: The latest version of the Leksell Gamma Knife IconTM allows for mask- and frame-based fixation. Although mask fixation provides fractionated treatment and immobilization using a noninvasive method, it is not free from collision. The authors investigated the collision problem with a modified mask fixation method.

Volume prediction for large brain metastases after hypofractionated gamma knife radiosurgery through artificial neural network.

The effectiveness of single-session gamma knife radiosurgery (GKRS) for small metastatic brain tumors has been proven, but hypofractionated GKRS (hfGKRS) for large brain metastases (BM) from the linear quadratic (LQ) model is uncertain. The purpose of this study was to investigate volume changes large BM after hfGKRS from the LQ model and predict volume changes using artificial neural network (ANN). We retrospectively investigated the clinical findings of 28 patients who underwent hfGKRS with large BM (diameter >3 cm or volume >10 cc).

Navigation of frameless fixation for gamma knife radiosurgery using fixed augmented reality.

Augmented reality (AR) offers a new medical treatment approach. We aimed to evaluate frameless (mask) fixation navigation using a 3D-printed patient model with fixed-AR technology for gamma knife radiosurgery (GKRS). Fixed-AR navigation was developed using the inside-out method with visual inertial odometry algorithms, and the flexible Quick Response marker was created for object-feature recognition.

Transplantation of human embryonic stem cells alleviates motor dysfunction in AAV2-Htt171-82Q transfected rat model of Huntington's disease.

Background: Human embryonic stem cells (hESCs) transplantation had shown to provide a potential source of cells in neurodegenerative disease studies and lead to behavioral recovery in lentivirus transfected or, toxin-induced Huntington's disease (HD) rodent model. Here, we aimed to observe if transplantation of superparamagnetic iron oxide nanoparticle (SPION)-labeled hESCs could migrate in the neural degenerated area and improve motor dysfunction in an AAV2-Htt171-82Q transfected Huntington rat model.

Methods: All animals were randomly allocated into three groups at first: HD group, sham group, and control group.

Optogenetic Stimulation of the Anterior Cingulate Cortex Modulates the Pain Processing in Neuropathic Pain: A Review.

Neuropathic pain is characterized by hypersensitivity, hyperalgesia, and allodynia, which is caused by damage to the somatosensory nervous system. It substantially impairs the quality of life. The management of neuropathic pain is challenging and should comprise alternative therapies.

Development of an inside-out augmented reality technique for neurosurgical navigation.

Objective: With the advancement of 3D modeling techniques and visualization devices, augmented reality (AR)-based navigation (AR navigation) is being developed actively. The authors developed a pilot model of their newly developed inside-out tracking AR navigation system.

Methods: The inside-out AR navigation technique was developed based on the visual inertial odometry (VIO) algorithm.

Pain modulation effect on motor cortex after optogenetic stimulation in shPKCγ knockdown dorsal root ganglion-compressed Sprague-Dawley rat model.

Neuropathic pain can be generated by chronic compression of dorsal root ganglion (CCD). Stimulation of primary motor cortex can disrupt the nociceptive sensory signal at dorsal root ganglion level and reduce pain behaviors. But the mechanism behind it is still implicit.

The Effect of Optogenetic Inhibition of the Anterior Cingulate Cortex in Neuropathic Pain Following Sciatic Nerve Injury.

Cortical disinhibition is the underlying pathological alteration contributing to neuropathic pain associated with peripheral nerve injury. Nerve injury resulting in disinhibition of the anterior cingulate cortex has been reported. However, the effect of optogenetic inhibition of the anterior cingulate cortex (ACC) on the sensory component of nerve injury-induced neuropathic pain has not been well studied.

Optical Modulation on the Nucleus Accumbens Core in the Alleviation of Neuropathic Pain in Chronic Dorsal Root Ganglion Compression Rat Model.

Objective: The role of the nucleus accumbens (NAc) in chronic neuropathic pain has been suggested, but the role of the NAc in dorsal root ganglion (DRG) neuropathic pain remains unclear. The objective of this study was to determine whether optogenetic stimulation of the NAc influences DRG compression-induced neuropathic pain.

Materials And Methods: We established sham or DRG lesions in female Sprague-Dawley rats by L4-5 DRG root compression, and the animals received unilateral injections of optogenetic virus in the NAc core.

Atrophic Changes and Diffusion Abnormalities of Affected Trigeminal Nerves in Trigeminal Neuralgia Using 7-T MRI.

Background: Magnetic resonance imaging (MRI) has been widely used for visualizing trigeminal nerves in trigeminal neuralgia.

Objective: To assess atrophy and diffusion abnormalities of affected trigeminal nerves in trigeminal neuralgia with 7-T MRI.

Methods: In this prospective study, 14 patients (mean age 49 years; range 31-64 years) with trigeminal neuralgia underwent 7-T MRI.

Characterization of Tetrodes Coated with Au Nanoparticles (AuNPs) and PEDOT and Their Application to Thalamic Neural Signal Detection .

Tetrodes, consisting of four twisted micro-wires can simultaneously record the number of neurons in the brain. To improve the quality of neuronal activity detection, the tetrode tips should be modified to increase the surface area and lower the impedance properties. In this study, tetrode tips were modified by the electrodeposition of Au nanoparticles (AuNPs) and dextran (Dex) doped poly (3,4-ethylenedioxythiophene) (PEDOT).

7 Tesla magnetic resonance imaging of caudal anterior cingulate and posterior cingulate cortex atrophy in patients with trigeminal neuralgia.

The cingulate cortex (CC) is a brain region that plays a key role in pain processing, but CC abnormalities are not unclear in patients with trigeminal neuralgia (TN). The purpose of this study was to determine the central causal mechanisms of TN and the surrounding brain structure in healthy controls and patients with TN using 7 Tesla (T) magnetic resonance imaging (MRI). Whole-brain parcellation in gray matter volume and thickness was assessed in 15 patients with TN and 16 healthy controls matched for sex, age, and regional variability using T1-weighted imaging.

7.0 Tesla MRI tractography in patients with trigeminal neuralgia.

7.0 Tesla (T) high-resolution diffusion tensor imaging (DTI) can supply information on changing microstructures in cranial nerves. We investigated DTI parameters and the feasibility of DTI criteria for diagnosing trigeminal neuralgia (TN).

Optical inactivation of the anterior cingulate cortex modulate descending pain pathway in a rat model of trigeminal neuropathic pain created via chronic constriction injury of the infraorbital nerve.

Purpose: The anterior cingulate cortex (ACC) plays a critical role in the initiation, development, and maintenance of neuropathic pain. Recently, the effects of optical stimulation on pain have been investigated, but the therapeutic effects of optical stimulation on trigeminal neuralgia (TN) have not been clearly shown. Here, we investigated the effects of optical inhibition of the ACC on TN lesions to determine whether the alleviation of pain affects behavior performance and thalamic neuron signaling.

Effect of optogenetic modulation on entopeduncular input affects thalamic discharge and behavior in an AAV2-α-synuclein-induced hemiparkinson rat model.

Objective: Neuromodulation of the globus pallidus internus(GPi) alleviates Parkinson's disease symptoms. The primate GPi is homologous to the rat entopeduncular nucleus (EP). The aim of the present study was to determine if optogenetic modulation of the EP could alter parkinsonian behavior or thalamic discharge in a hemiparkinson rat model.

Reduced GABAergic neuronal activity in zona incerta causes neuropathic pain in a rat sciatic nerve chronic constriction injury model.

Purpose: The zona incerta (ZI) is below the ventral tier of the thalamus and has a strong influence selectively in higher-order thalamic relays. Although neuropathic pain has been suggested to result from reduced gamma-aminobutyric acid (GABA) and GABAergic signaling in the ZI, the mechanisms remain unclear. Here, the role of GABA and GABAergic signaling was investigated in the ZI in neuropathic pain using sciatic nerve chronic constriction injury (CCI) rats.

Comparison of 7T and 3T MRI in patients with moyamoya disease.

Magnetic resonance imaging and magnetic resonance angiography (MRI/MRA) are widely used for evaluating the moyamoya disease (MMD). This study compared the diagnostic accuracy of 7Tesla (T) and 3T MRI/MRA in MMD. In this case control study, 12 patients [median age: 34years; range (10-66years)] with MMD and 12 healthy controls [median age: 25years; range (22-59years)] underwent both 7T and 3T MRI/MRA.