For secondary prevention of ischemic stroke, making an appropriate diagnosis of stroke subtype based on its mechanism and applying the appropriate medical management are the most important factors. In particular, antithrombotic therapy plays a crucial role among them. In selecting the best management strategies for an individual patient with a given condition, we should consider the impact of antithrombotic therapy not only on outcome, but also the risk-benefit ratio. To satisfy these conditions, the appropriate timing and dosage of the antithrombotic agents are important.

  For acute stroke patients, more aggressive treatment, such as dual antiplatelet therapy following loading-dose administration, is recommended. However, in the chronic period, discontinuation of dual therapy is recommended in the same Japanese guidelines. Although the optimal timing to start anticoagulant therapy after stroke is still not completely clear, we hope that detailed guidelines like those used in the field of coronary interventions are established soon.

  Although current consensus is that intravenous tPA thrombolysis should be administered for ischemic stroke patients within 4.5 hours after onset, early recanalization is expected limitedly. On the other hand, for cases with large vessel occlusion (LVO) in anterior circulation within 4.5 hours after onset, mechanical thrombectomy (MT) is proved to be effective compared to medical treatment alone after five randomized controlled trials and meta-analysis. Moreover, in the treatment of cases even with 6 to 16 hours after onset, with perfusion images to identify ischemic penumbra and selecting candidates, it is also shown that MT is effective recently. However, so far, there is no evidence about MT for cases with relatively small vessel such as M2 branch of the middle cerebral artery or LVO in posterior circulation.

  In intravenous tPA thrombolysis and MT, the important point is that the shorter the time from onset to recanalization, the more cases with favorable outcome with modified Rankin Scale 0-2. Therefore, after patient admission to hospital, we should pay attention to the timeline such as Door to Picture, Door to Needle, Door to Puncture, and Puncture to Recanalization time, and shorten each time using stroke algorithm.

  Now, LVO in anterior circulation is disease with high possibility to recover by these intravenous tPA thrombolysis and MT. At the next stage, shortening Onset to Door time become more important. In the near future, we have to construct prehospital emergency system that can select adaptive cases appropriately and start to treat patients promptly.

  Various randomized controlled trials have been conducted with regard to the effectiveness of surgical treatment for carotid artery stenosis. Carotid endarterectomy (CEA) was compared to best medical treatment since the 1990s, and carotid artery stenting (CAS) was then compared to CEA since the 2000s. These trials proved the effectiveness of both CEA and CAS especially for the symptomatic patients with high-grade stenosis. However, it is important to validate the necessity of surgical treatment in the asymptomatic patients in this era of developed medical management. In the future, it is necessary to establish the risk factors of each surgical treatment to clarify the appropriate surgical indications. It is also important to develop educational system for surgeons involved in both treatment strategies to improve the overall surgical outcomes.

  As a result of the recent advances in research of moyamoya disease, diagnostic criteria in Japan were revised in 2015. Several studies have proved that direct extracranial-intracranial (EC-IC) bypass plays essential role not only for reduction of ischemic stroke, but also of rebleeding risks in adult patients. Subanalysis of Japan Adult Moyamoya Trial indicates that patients with bleeding in the posterior circulation territory are particularly at higher risk of rebleeding and obtain greater benefits from a direct EC-IC bypass. However, some topics related to direct EC-IC bypass for patients of moyamoya disease remain still unsolved. It is difficult to distinguish the presence of intracranial arteriosclerosis in some patients of supposed moyamoya disease unless RNF213 is clarified as a susceptibility gene. The surgical management in patients of rapidly progressing moyamoya disease who suffer from repeated ischemic stroke in a short period of time remains unsolved. Direct EC-IC bypass provably allows to prevent aggravating ischemic stroke, however perioperative ischemic complications cannot be ignored and best treatment including direct EC-IC bypass cannot completely prevent ischemic stroke, especially in some young pediatric patients. Hyperperfusion has been reported to be one of the essential phenomena which causes focal intracranial hemorrhage or some other postoperative complications. Recently some specific radiographical changings after direct EC-IC bypass in patients of moyamoya disease, such as vasogenic edema, high intensity in the sulcus on fluid-attenuated inversion recovery (FLAIR) images, and subcortical low intensity on FLAIR images have been reported. These radiographical changes appear within several days after operation with or without transient neurologic events and disappear within several weeks. The mechanism of these findings and their relationship to postoperative complications such as transient neurologic events, ischemic stroke, and focal intracerebral hemorrhage remains unclear. A future study of cognitive impairment in patients of moyamoya disease and effectiveness of direct EC-IC bypass to improve it should be conducted. After an accurate evaluation of cognitive impairment including radiographical findings in patients of moyamoya disease, appropriate indication of direct EC-IC bypass to improve that deficit may be established. A future study of the natural history of asymptomatic moyamoya disease will also be of value to clarify indications of direct EC-IC bypass.

  “Precision medicine” is an emerging approach for disease treatment and prevention that considers the implications of individual variations in genes, environment, and lifestyle. Recent genetic analysis studies in the field of ischemic cerebrovascular diseases have achieved much progress due to the remarkable innovation of comprehensive genetic analysis technology. Elucidation of the genetic background of ischemic cerebrovascular diseases is likely to lead to the development of novel therapeutic approaches against specific molecular targets, and enables accurate diagnosis and prediction of the onset of the cerebrovascular diseases. This article describes recent progress in the genetic analysis of monogenic and multifactorial disorders in the field of ischemic cerebrovascular diseases, and reviews the clinical importance of the cerebrovascular disease-associated gene RNF213. Unsolved problems and future areas for investigation will be discussed necessary for the establishment of “precision medicine.”

  The incidence of brain metastases has increased over time as a result of improvements in the treatment of primary tumor and systemic disease. Being aware of both the significant heterogeneity in prognosis and therapeutic options for patients with brain metastasis is crucial for appropriate management, with greater attention to developing individual patient treatment plans based on predicted outcomes.

  Brain metastases are often surgically resected, especially for large lesion with mass effect, improving survival in some patient populations. Stereotactic radiosurgery (SRS) to the surgical cavity results in no significant difference in survival and improved preservation of quality of life and cognitive outcomes compared with whole brain radiotherapy. SRS is increasingly used in newly diagnosed and recurrent brain metastases. Targeted therapies, which show activity in the primary tumor, are increasingly investigated as an upfront treatment in patients with asymptomatic or small brain metastases. The combination of radiotherapy and targeted agents/immune check point inhibitors could increase the efficacy, but data on the risks of toxicity are needed.

  Most meningiomas arising in anterior skull base are prone to proceed asymptomatic, and are found as “giant” when some neurological deficits are manifested. The size of the tumor and brain edema make surgical treatment difficult. We presented 2 cases of giant anterior skull base meningiomas and discuss our surgical strategy. The patients are a 50-year-old man and a 58-year-old woman. The maximal diameters of the tumor are 7 cm and 6 cm, respectively. Contrast-enhanced fast imaging employing steady-state acquisition (CE-FIESTA) images show significant compression of both optic nerves and major arteries in the both. The interhemispheric approach was adopted for the removal. However, brain edema was serious, resulting in difficulty to obtain enough surgical space. For decompression of the brain, opening of bilateral Sylvian fissure and drainage of cerebrospinal fluid (CSF) were performed using subfrontal approach. Thereafter, sufficient working spaces were obtained. In addition, bilateral optic nerves and major arteries were able to be identified, and dissected those structures from the tumor. As a result, complete removal of the tumor was achieved. The anterior skull base was repaired using vascularized pericranial flap, fat tissue, muscle fascia, polygliocolic acid sheet, and fibrin glue. Postoperatively, the patients’ conditions were uneventful and discharged without any deficits. For surgical treatment of giant anterior skull base meningiomas, preoperative precise evaluation of the relation between tumor and surrounding vital structures using CE-FIESTA is extremely important. Furthermore, opening Sylvian fissure and CSF aspiration to control brain swelling in the early surgical stage is inevitable. Precise frontal repair to prevent CSF leak is necessary for successful surgery.