In recent years, artificial intelligence (AI) technology has attracted attention owing to new developments, such as machine learning technology with deep learning at its core and the increasing availability of large amounts of data (big data). The U.S. FDA has approved more than 100 AI-based medical devices. In Japan, several AI-based medical devices have also been approved and are in use in clinical practice. This review describes the current status of medical AI research and development in Japan and the associated challenges. It also discusses the future direction of medical AI research and development.

  Robotic surgery, which has been introduced to the field of neurosurgery, has the potential to improve the safety, accuracy, and dexterity of surgery compared to conventional methods. Currently, accuracy-enhancing robotic systems for stereotactic and spinal neurosurgery are used. In particular, stereotactic depth electrode placement using a robotic system has shown clinical benefits over conventional frame-based placements. Several microsurgery systems for dexterity-enhancing systems are available. Our trials aimed to develop the following two systems : 1) a deep endonasal robotic system that supports endonasal procedures, including dural suturing at the anterior cranial base and complicated vascular procedures and 2) a super-microsurgery system that enables anastomosis of 0.3mm diameter vessels. Our systems showed a rapid learning curve for surgical beginners and enhanced the accuracy of left-hand procedures. In future, we aim to improve the user-friendly control and durability of these systems. At the same time, robotics engineering can enhance surgical science by digitalizing all dimensions of surgical procedures and introducing artificial intelligence for sensor- and image-guided automated surgical developments. In the near future, robotic surgery will be routinely applied in complex and daily surgical procedures to improve surgical outcomes without significant variance between occasions and surgical or hospital experiences.

  Glocal is a linguistic hybrid of global and local. This paper discusses neuroendovascular therapy and stroke treatment by comparing the differences in the world, Japan, and the Ibaraki Prefecture, where the University of Tsukuba is located. Neuroendovascular therapy was developed by neuroradiologists in Europe and the United States using newly developed devices, which expanded its indications. It plays an important role in the surgical treatment of stroke. In Japan, neurosurgeons are mainly in-charge. The previous device lag has improved. Due to the wide availability of doctors in-charge and the associated facilities, the experience of each doctor is limited. In Japan, board-certified neuroendovascular therapy specialists are trained via a rigorous curriculum and examination process. This strict curriculum ensures that doctors maintain their knowledge and skills. The Ibaraki Prefecture has a serious shortage of doctors and a high stroke mortality rate. Hence, we are addressing this problem through cooperation with stroke centers using information and communication technology and using educational activities for elementary school students.

  A prerequisite for improving the outcomes of aneurysmal subarachnoid hemorrhage (SAH) is to stabilize the general condition of the patient and perform aneurysmal obliteration as soon as possible. Surgical modalities and strategies should be selected to minimize treatment complications, including additional brain damage. Moreover, postoperative management is required to stabilize the intracranial environment, including the intracranial pressure, and prevent secondary brain injury. To further improve the outcomes of SAH, it is necessary not only to improve surgical or endovascular treatment outcomes but also to develop new therapies for early brain injury and delayed cerebral ischemia. Currently, several phase 3 trials aimed at preventing secondary brain injury are being conducted, and the results are expected to be available shortly.

  Trigeminal neuralgia (TN) caused by the primitive trigeminal artery (PTA) and PTA variants is very unusual, accounting for 0.2-0.6% of TN cases, particularly the intermediate PTA type which is extremely rare and has only been reported twice in previous studies. We describe a case of TN caused by an anomalous artery originating directly from the PTA.

  A 68-year-old woman with a 4-year history of TN in the right V2 distribution visited our hospital. The patient's pain was poorly controlled with oral medicine. The 3D MRI/MRA fusion and MR constructive interference in steady state (CISS) images revealed an abnormal artery branching from the PTA compressing the trigeminal nerve in the cerebellopontine angle. During microvascular decompression (MVD), the offending artery was transposed at two points on the trigeminal nerve, the root entry zone, and the cisternal portion. The patient's TN improved immediately after surgery. The patient's postoperative course was uneventful.

  Both, 3T MRI/MRA 3D fusion and CISS images were useful in identifying the anatomical relationship between the PTA and the trigeminal nerve, thus, allowing the optimal operative strategy.

  In certain cases, high-grade tumors arising in the cerebral hemispheres of young adults contain H3F3A G34R/V mutations.

  A 24-year-old woman was referred to our hospital following a tonic seizure. MRI resonance imaging revealed a mass lesion in the left frontal lobe. Preoperative radiological examinations revealed embryonal tumors and high-grade gliomas as differential diagnoses, Subsequently, craniotomy was performed. Histologically, the tumor was characteristic of glioblastoma with PNET-like morphology. Additional pyrosequencing and Sanger sequencing identified the H3.3 G34R mutation and led to a definitive diagnosis of diffuse hemispheric glioma, with the H3 G34-mutant.