Female sex is an independent risk factor for subarachnoid hemorrhage. Additionally, the global decline in the incidence rate of subarachnoid hemorrhage is more apparent in men than in women, except in Japan. We examined sex-specific trends in the incidence rates of subarachnoid hemorrhage in four Japanese regions. An epidemiological study was conducted to identify the estimated age-adjusted incidence rate of subarachnoid hemorrhage per 100,000 person-years by sex in Aomori, Akita, Kochi, and Shimane Prefectures from 2000 to 2017, calculated by the age-adjusted mortality and case-fatality rates (assumed to be 35%). The estimated age-adjusted incidence rate of subarachnoid hemorrhage in each region decreased in both sexes between 2000 and 2017; the rates of change were significantly higher in women (43.1%) than in men (36.6%; p = 0.021). This study revealed declining trends in the estimated age-adjusted incidence rate of subarachnoid hemorrhage in four Japanese prefectures from 2000 to 2017; this was more apparent in women. The underlying etiology for the female-dominant declining trend in the estimated age-adjusted incidence rate of subarachnoid hemorrhage should be further investigated.

Current magnetic resonance vessel wall imaging enables the detection of atherosclerotic changes in the walls of intracranial aneurysms. Lipid accumulation in the intracranial aneurysm wall is involved in aneurysm neovascularization and chronic inflammation and may lead to aneurysm enlargement and rupture. Therefore, in the present study, we examined the relationship between atherosclerotic changes identified by vessel wall imaging and systemic atherosclerosis-related risk factors. A total of 111 patients with 156 unruptured intracranial aneurysms who underwent magnetic resonance vessel wall imaging and atherosclerotic protein examinations between April 2021 and November 2023 were reviewed. Data on atherosclerotic proteins were obtained from peripheral blood samples. The relationships between aneurysm wall enhancement and patient demographic data, aneurysm morphology, and atherosclerosis-related risk factors were assessed. Fifty-seven of 156 unruptured intracranial aneurysms (36.5%) showed aneurysm wall enhancement. In a univariate logistic regression analysis, age (p = 0.007), male sex (p = 0.023), morphological factors such as maximum diameter (p < 0.001) and irregular shape (p < 0.001), and the levels of apolipoprotein A1 (<0.001) and apolipoprotein B/apolipoprotein A1 (0.004) correlated with aneurysm wall enhancement. In the multivariate logistic regression analysis, age (odds ratio: 1.05, 95% confidence interval: 1.02-1.10), male sex (odds ratio: 3.83, 95% confidence interval: 1.46-10.01), maximum diameter (odds ratio: 1.19, 95% confidence interval: 1.01-1.45), irregular shape (odds ratio: 5.01, 95% confidence interval: 2.10-12.73), and apolipoprotein A1 levels (odds ratio: 0.97, 95% confidence interval: 0.94-0.99) correlated with aneurysm wall enhancement. Low levels of apolipoprotein A1, which may function as an atherosclerotic protein, were associated with specific aneurysm wall features in vessel wall imaging. In future studies, these results will contribute to the identification of factors that promote the destabilization of unruptured intracranial aneurysms.

Japan has become a super-aging society compared with other countries, with many healthy super-older people surpassing the average life expectancy. Among this population, there are some patients aged >90 years with cervical fracture. However, few clinical studies have investigated cervical fracture among patients aged >90 years, and its clinical features and outcomes have not been fully elucidated. Therefore, this study aimed to explore the descriptive epidemiology of cervical fracture among patients aged >90 years in Japan using a nationwide database. This retrospective study used the Diagnosis Procedure Combination database, which is a nationwide inpatient database covering more than half of all acute-care hospitals in Japan. A total of 977 patients aged >90 years with a confirmed diagnosis of cervical fracture were included in this study. Data were collected, including medical history, diagnoses, treatments, complications, and outcomes. The results showed that the complication rates among patients aged >90 years with cervical fracture were almost the same as those in previous studies, whereas in-hospital mortality in patients with cervical fracture was higher (15.5%). Furthermore, half of the patients aged >90 years with cervical fracture had polytrauma. Older patients with head and spinal cord injuries and cardiac and respiratory complications were more likely to have a poor prognosis. These findings should be considered when treating patients at high risk regardless of surgery. These novel findings provide valuable insights into cervical fracture in patients aged >90 years based on extensive real-world data from Japan, a country with a rapidly aging population.

Brain tumor biopsies are essential for pathological diagnosis. However, hemorrhagic complications after biopsies may occur, leading to suboptimal outcomes. This study evaluated the relationship between intraoperative blood pressure, especially anesthesia awakening, and hemorrhagic complications after brain tumor biopsies. We retrospectively collected data on consecutive patients with brain tumors (malignant lymphoma or glioma) who underwent a biopsy from 2011 to 2020. During the first half of the study period (until 2015), we managed patients with a mild blood pressure-lowering policy during awakening from general anesthesia, while in the latter half (after 2016), we aggressively lowered blood pressure below 140 mmHg. This blood pressure management was performed as a best practice. After propensity score matching using logistic regression analysis, 122 patients were included. With the aggressive blood pressure-lowering policy, the values of blood pressure-related parameters during the recovery from general anesthesia were drastically reduced (median maximum blood pressures were 165 [mmHg] until 2015 vs. 135 after 2016, p < 0.001). Accordingly, the overall bleeding rate decreased after 2016 (ALL bleeding, 54.1 vs. 31.1%, p = 0.017; symptomatic bleeding, 16.4% vs. 6.6%, p = 0.154). Abrupt blood pressure rise during anesthesia awakening (mmHg/min) was significantly associated with symptomatic postsurgical hemorrhages (p = 0.012). An aggressive blood pressure-lowering policy reduced blood pressure during recovery from general anesthesia and the overall bleeding rates. Avoiding rapid blood pressure rises during anesthesia awakening may be necessary by focusing on both blood pressure and the speed of any changes.

Moyamoya disease is associated with the formation of collateral pathways, including transdural anastomosis, such as vault and ethmoidal moyamoya. However, temporal base transdural anastomosis remains unrecognized. This study investigates the imaging characteristics and features of temporal base transdural anastomosis in moyamoya disease. This retrospective review was conducted on 164 hemispheres from 82 patients with moyamoya disease admitted to our institution between 2012 and 2024. Digital subtraction angiography helped identify temporal base transdural anastomosis, which is classified as "obvious" or "faint" types based on digital subtraction angiography findings. Affected hemispheres and patients were grouped based on the presence or absence of temporal base transdural anastomosis, and their clinical characteristics were analyzed. Both types of temporal base transdural anastomosis were found in 10 of 164 hemispheres (6.1%) and 10 of 82 patients (12.2%). The obvious-type temporal base transdural anastomosis was detected in three hemispheres (1.8%) among three patients (3.7%). Temporal base transdural anastomosis was predominantly associated with advanced-stage moyamoya disease (Suzuki stage ≥4) and posterior cerebral artery involvement (p < 0.01). Although no significant association was found between the presence of temporal base transdural anastomosis and previous bypass surgery (p = 0.26), obvious temporal base transdural anastomosis was frequently found in cases without bypass surgery (two of three cases; 66.7%), and all obvious temporal base transdural anastomosis cases received no direct bypass surgery. Temporal base transdural anastomosis is considered to compensate for blood flow to the temporal lobe and is associated with posterior cerebral artery involvement. In addition, temporal base transdural anastomosis may receive high hemodynamic stress due to blood flow from the middle meningeal artery main trunk that may be related to aneurysmal formation or an unknown origin intracranial hemorrhage.