Non-enhanced head computed tomography is widely used for patients presenting with head trauma or stroke, given acute intracranial hemorrhage significantly influences clinical decision-making. This study aimed to develop a deep learning algorithm, referred to as DeepCT, to detect acute intracranial hemorrhage on non-enhanced head computed tomography images and evaluate its clinical applicability. We retrospectively collected 1,815 computed tomography image sets from a single center for model training. Additional computed tomography sets from 3 centers were used to construct an independent validation dataset (VAL) and 2 test datasets (GPS-C and DICH). A third test dataset (US-TW) comprised 150 cases, each from 1 hospital in Taiwan and 1 hospital in the United States of America. Our deep learning model, based on U-Net and ResNet architectures, was implemented using PyTorch. The deep learning algorithm exhibited high accuracy across the validation and test datasets, with overall accuracy ranging from 0.9343 to 0.9820. Our findings show that the deep learning algorithm effectively identifies acute intracranial hemorrhage in non-enhanced head computed tomography studies. Clinically, this algorithm can be used for hyperacute triage, reducing reporting times, and enhancing the accuracy of radiologist interpretations. The evaluation of the algorithm on both United States and Taiwan datasets further supports its universal reliability for detecting acute intracranial hemorrhage.

Adjacent vertebral fractures after balloon kyphoplasty are speculated to occur in association with increased mechanical pressure due to rigid cement-augmented vertebrae. This study aimed to clarify whether adjacent vertebral fractures are more likely to occur after balloon kyphoplasty for osteoporotic vertebral fractures when the intervening adjacent disc degeneration is advanced. We retrospectively reviewed the findings for 99 patients who underwent balloon kyphoplasty for the first-ever osteoporotic vertebral fracture at the thoracolumbar junction levels (T11-L2). Radiological parameters and clinical data were compared for the cranial and caudal vertebrae between the groups with and without adjacent vertebral fractures within 1 year postoperatively. Postoperative adjacent vertebral fractures occurred in 20 patients (12 cranial adjacent vertebral fractures and eight caudal adjacent vertebral fractures). The cranial mean disc height was 5.87 ± 1.48 mm in the cranial adjacent vertebral fracture group and 7.98 ± 1.73 mm in the non-cranial adjacent vertebral fracture group (p < 0.01), and the caudal mean disc height was 6.24 ± 1.83 mm in the caudal adjacent vertebral fracture group and 9.55 ± 2.03 mm in the non-caudal adjacent vertebral fracture group (p < 0.01). According to receiver operating characteristic analysis, the optimized cutoff values of cranial mean disc height for cranial adjacent vertebral fracture occurrence and caudal mean disc height for caudal adjacent vertebral fracture occurrence were 6.37 mm and 7.70 mm, respectively. Multiple logistic regression models showed increased odds ratios for low disc height and large cement volume for cranial adjacent vertebral fractures and low disc height and cement leakage for caudal adjacent vertebral fractures. In conclusion, patients with advanced preoperative degeneration of the adjacent disc showed a higher incidence of adjacent vertebral fracture after balloon kyphoplasty.

Revascularization surgery for moyamoya disease poses risks of complications, requiring appropriate management. Although precise prediction is difficult, the systemic immune-inflammation index is a calculable marker that reflects systemic inflammatory conditions. We aimed to investigate the association between postoperative complications and the systemic immune-inflammation index. We included 91 hemispheres from 71 patients who underwent combined revascularization surgery for moyamoya disease. Symptomatic cerebral hyperperfusion, radiological ischemic and hemorrhagic complications, and temporal muscle swelling that caused brain shift were assessed. The systemic immune-inflammation index ratio was calculated from blood test results from the preoperative day and the day after surgery. The association between the systemic immune-inflammation index ratio and postoperative complications was assessed using univariate and multivariate analyses. A receiver operating characteristic analysis was performed to evaluate the diagnostic value of the systemic immune-inflammation index ratio for postoperative complications. The frequencies of postoperative symptomatic cerebral hyperperfusion, ischemic and hemorrhagic complications, and temporal muscle swelling were detected in 24 (26%), 15 (16%), 11 (12%), and 5 (5%) hemispheres, respectively. The systemic immune-inflammation index ratio was higher in the group with postoperative complications than in the group without (median 4.6 vs. 2.7). Multivariate analysis demonstrated the systemic immune-inflammation index ratio as an independent factor associated with symptomatic cerebral hyperperfusion (odds ratio 2.4, 95% confidence interval 1.5-4.0). The receiver operating characteristic analysis demonstrated that the optimal threshold of the systemic immune-inflammation index ratio was 4.3, with a specificity of 0.96 and sensitivity of 0.63. The systemic immune-inflammation index ratio is an indicator of postoperative complications, including symptomatic cerebral hyperperfusion in moyamoya disease, and can be used for effective postoperative management.

Some studies showed a gender difference with the predominance of men in the prevalence of Parkinson's disease, and such a trend in Asia, particularly in Japan, is opposite to that in Western countries. Hence, the gender difference in the outcome of subthalamic nucleus-deep brain stimulation has stimulated the interest. The aim of this study was to clarify the gender difference in the outcome of Parkinson's disease in Japanese patients. The subjects were 57 patients with Parkinson's disease. The gender difference in outcome was studied retrospectively on the basis of the Unified Parkinson's Disease Rating Scale score and score improvement rate in the short- (1 month) and long-term (5 years). In the postoperative state, statistically significant gender differences were noted in the improvement rates of Unified Parkinson's Disease Rating Scale total and part III scores during the off-period in the short term. There was no significant gender difference in the long term. This study is the first on the gender difference in the outcome of Parkinson's disease in Japan. Some significant gender differences were noted in the short term with a higher improvement rate in women.

Pediatric patients with moyamoya disease frequently show rapid progression with a high risk of stroke. Indirect revascularization is widely accepted as a surgical treatment for pediatric moyamoya disease, but it does not augment cerebral blood flow immediately, which leaves patients at risk for stroke peri-operatively. This delay in flow augmentation may make adding direct bypass the better option. This study documents our cases of direct bypass failure that underwent indirect bypass supplemented with superficial temporal artery-middle cerebral artery bypass to evaluate the adverse effects of direct bypass failure. A retrospective review of all surgeries for pediatric moyamoya disease after introducing intraoperative indocyanine green videoangiography to confirm direct bypass patency identified 78 surgical hemispheres. Direct bypass failure was defined as failure to confirm blood flow from the superficial temporal artery to the middle cerebral artery on indocyanine green videoangiography. The occurrence of ischemic complications was evaluated by magnetic resonance imaging. During the period, postoperative ischemic complications were seen in 3 surgical hemispheres (3.8%) and one contralateral hemisphere (1.3%). One case in which hyperventilation was difficult to control postoperatively developed extensive cerebral infarction. Direct bypass failure was seen in 3 patients (3.8%), none of whom had additional cerebral infarction on magnetic resonance imaging. The results of this study indicate that failure of direct bypass surgery does not necessarily lead to cerebral infarction. Based on these results, surgeons can safely attempt to add a direct bypass to an indirect bypass, with special attention to perioperative patient management.

In recent years, the Japanese neurosurgical field has been added to the guidelines for the appropriate use of antimicrobial agents for the prevention of surgical site infection; however, the awareness of neurosurgeons and specific methods for surgical site infection prevention in the Japanese neurosurgical field remains unclear. Therefore, we report a repeat survey conducted after the addition of guidelines on the appropriate use of antimicrobial agents for the prevention of surgical site infection and compare it with our previous survey on surgical site infection prevention conducted in 2018. A questionnaire-based survey was conducted via the Internet among members of the Japanese Neurosurgical Society and the Japanese Society of Chemotherapy. The survey response rate was 34.1% (270/792). More than 90% of the respondents were facility directors or specialists, and their institutions were universities and private hospitals. Cefazolin sodium was used in 88% of cases, and the percentage of cases started immediately before surgery increased to 85% (65% in the previous survey). Intraoperative administration intervals were most frequent every 3 hours (62%). Preoperative hair washing was performed by 76% of patients, a rate lower than that reported in the previous survey. Approximately 89% used partial removal, 75% used povidone-iodine for surgical field disinfection, double gloves were used by 46%, and antibacterial sutures by only 36% of surgeons. Compared with the 2018 survey, improvements were observed in the use of antibiotics for which guidelines were developed; however, other aspects of surgical site infection prevention need to be clarified, and guidelines for surgical site infection in the field of neurosurgery are necessary.

For ruptured cerebral aneurysms over 90 years of age, the outcome and the safety after endovascular treatment are not well-known. This multicenter retrospective registry enrolled patients with ruptured cerebral aneurysms after endovascular treatment from January 2015 to December 2019 in Japan. We investigated differences between the patients over 90 years (age ≥ 90) and those under 90 years of age (age <90). The primary outcome was defined as a modified Rankin scale 0-2 at 30 days. Secondary outcomes were all-cause death and returned to premorbid modified Rankin scale at 30 days. Safety outcomes were the incidence of ischemic stroke and technical complications. Among 8,024 patients with aneurysm, 204 were aged ≥ 90 years and 7,820 were <90 years, those of median age were 92 and 65 years. The proportion of females and premorbid modified Rankin scale was higher in the age ≥ 90 group (n [%]; 191 [93.6] vs. 5,395 [69.0], median [interquartile range]; 1 [0-2] vs. 0 [0-0]). The modified Rankin scale 0-2 at 30 days was lower in age ≥ 90 patients than in age <90 patients (13.2% vs. 56.2%, adjusted odds ratio [95% confidence intervals]; 0.13 [0.08-0.21]). In age ≥ 90 patients, all-cause death was significantly higher (adjusted odds ratio [95% confidence intervals]; 1.85 [1.19-2.86]) and returned to premorbid modified Rankin scale was significantly lower (adjusted odds ratio [95% confidence intervals]; 0.26 [0.17-0.39]). However, safety outcomes were not significantly different between both groups. In this population undergoing endovascular treatment for ruptured cerebral aneurysms, patients older than 90 years had a poor prognosis but no difference in having perioperative complications.

The therapeutic time window for endovascular therapy in acute stroke patients with large-vessel occlusion was extended to 24 hours from onset. Although a retrospective study showed the efficacy of endovascular therapy beyond 24 hours from the last known well, it remains unclear whether endovascular therapy is effective. Extending the time window of Endovascular therapy in the Triage of Late Presenting Strokes beyond 24 h (SKIP-EXTEND trial) aimed to clarify the efficacy of endovascular therapy compared to the best medical management. This is an investigator-initiated, multicenter, prospective, randomized, open-label, blinded end-point clinical trial. Eligibility criteria included adults and pre-stroke modified Rankin scale score ≤2 with internal carotid artery or M1 (horizontal or sphenoidal segment) occlusion beyond 24 to 72 hours of the last known well. The target enrollment is 260 patients, with 130 reeiving endovascular therapy and 130 receiving the best medical treatment. The primary outcome is the rate of favorable outcome defined as a modified Rankin scale score ≤2 at 90 days. The secondary outcomes are the ordinal logistic regression analysis of the modified Rankin scale score and the rate of recanalization at 48 hours. As safety outcomes, the rate of any and symptomatic intracranial hemorrhage at 24 hours and the rate of mortality at 90 days are assessed. This is the first randomized controlled trial to focus on the efficacy of endovascular therapy beyond 24 hours. Our results will not only benefit patients but also reduce healthcare costs. We believe that this novel study will be useful in clinical practice.