Chronic subdural hematoma is a common disease in the field of neurosurgery, and the number of cases is expected to continue increasing in an aging society. At our hospital, minimally invasive percutaneous subdural perforation (the Aoki method) is the first-line treatment. We investigated the recurrence rate associated with the Aoki method, factors related to recurrence, and the complication risks. Among the cases treated with the Aoki method between June 2007 and December 2020, 383 (431 lesions) for which image analysis and recurrence tracking were possible were included. On the basis of the preoperative patient background (sex, age, history of taking antiplatelet and anticoagulant drugs, preoperative neurological findings, imaging findings (preoperative hematoma volume and hematoma density), surgical details, and postoperative use of concomitant drugs), we retrospectively analyzed the recurrence rate, factors related to recurrence, and complication risk. The recurrence rate was 23.7%, which is within the same range as that of burr-hole hematoma irrigation. Multivariate analysis showed that age and a large preoperative hematoma volume were associated with recurrence. One of the 3 cases with postoperative epidural and 2 of the 3 cases with subdural hematomas required craniotomy. The incidence of complications requiring additional surgery was approximately 1%, which is comparable to that of burr-hole irrigation. The Aoki method is efficient because it is minimally invasive and has a therapeutic effect equivalent to that of burr-hole irrigation, which is the current standard of care.

In adult isthmic spondylolysis/spondylolisthesis, a fibrocartilaginous mass, ragged edge, and decrease in disk height cause radiculopathy with intervertebral foraminal stenosis. There are few reports on the outcomes of full-endoscopic spine surgery for isthmic spondylolisthesis because of difficulty in the ragged edge resection. This study evaluated the short-term outcomes of our original full-endoscopic spine surgery technique in patients with isthmic spondylolisthesis with a focus on the "pars crisscross." An important landmark, the pars crisscross consist of the superior articular process at S1, floating lamina, inferior articular process at L4, and pars ragged edge. The exiting nerve root can only be decompressed by complete resection of the ragged edge after confirmation of the pars crisscross. This case series includes 6 patients (mean age 63.2 ± 14.3 years) who underwent full-endoscopic spine surgery under local anesthesia for radiculopathy. The leg pain improved immediately after surgery in all patients and the mean visual analog scale score improved from 8.2 ± 1.3 preoperatively to 1.2 ± 1.1 at 2 weeks postoperatively. The neuroforaminal area at the inlet and center expanded dramatically from 184 ± 41 mm² and 192 ± 45 mm², respectively, before surgery to 340 ± 55 mm² and 338 ± 80 mm² postoperatively. No patient experienced a recurrence of leg pain, aggravation of low back pain, or spinal instability during the 3 months after surgery. full-endoscopic spine surgery pars crisscross decompression had excellent short-term clinical and radiographic outcomes. Patients who are unsuitable for general anesthesia and instrumentation surgery could be candidates for this procedure.

Early brain injury after a subarachnoid hemorrhage is an important prognostic factor. Aging is also an important prognostic factor of subarachnoid hemorrhage. However, the association between early brain injury and aging remains unclear. Older patients have comorbidities and frailty that can affect early brain injury severity. The purpose of this retrospective study was to clarify the differences in early brain injury severity between young and older patients by adjusting for comorbidities and frailty using propensity score matching. Between 2013 and 2021, 433 patients with subarachnoid hemorrhage who presented within 72 hrs of onset were included. The patients were divided into 2 groups: those aged 18-65 years (young group) and those aged ≥75 years (older group). The primary end point was early brain injury, which comprised the clinical, radiological, and laboratory findings on admission. We used propensity score matching to adjust for histories, comorbidities, and frailty. We analyzed early brain injury in the 2 groups for both non-propensity score matching and propensity score matching cohorts. Within the non-propensity score matching cohort, 260 patients were included in the young group and 173 in the older group. The propensity score matching cohort comprised 98 patients from both groups. The older group showed a higher World Federation of Neurosurgical Societies grade (p < 0.001), higher Hijdra scale (p < 0.01), and higher proportion of acute hydrocephalus (p < 0.001) in both cohorts. The study indicated exacerbated early brain injury among older patients, with worsening neurological damage, increasing subarachnoid hemorrhage volume, and causing hydrocephalus. Clarifying the impact of aging on early brain injury may help develop therapeutic interventions for subarachnoid hemorrhage.

Negative remodeling, characterized by a decrease in the outer diameter of the terminal (C1) segment of the internal carotid artery and the proximal (M1) segment of the middle cerebral artery, is a hallmark of moyamoya disease. However, the role of the disease-susceptibility gene RNF213 in negative remodeling in moyamoya disease remains unclear. This study investigated the effect of RNF213 p.R4810K polymorphism on the degree of negative remodeling in moyamoya disease. We analyzed 70 hemispheres of 38 adult patients with moyamoya disease who underwent RNF213 p.R4810K gene analysis. Vascular outer diameters of the distal C1 and proximal M1 segments were measured using constructive interference in steady-state images obtained from 3-tesla magnetic resonance imaging. Suzuki stages were determined via cerebral angiography, and comparisons were made between RNF213-mutant and wild-type hemispheres. Among the analyzed hemispheres, 39 (56%) were RNF213-mutant, and 31 were wild-type. Suzuki stages were distributed as follows: 0 in 8 hemispheres, 1-2 in 15, 3-4 in 40, and 5-6 in 7. At stage 3-4, the C1 outer diameter was significantly smaller in RNF213-mutant hemispheres compared to wild-type (median 2.1 vs 2.6 mm, p < 0.05). A significant reduction in vascular outer diameters in the advanced disease stage was observed only in the mutant group between stages 0 and 3-4 (C1: median 3.0 vs 2.1 mm, p < 0.05; M1: median 2.2 vs 1.5 mm, p < 0.001). These findings suggest the association between RNF213 p.R4810K polymorphism and the progression of negative remodeling at the carotid fork in advanced disease stages of moyamoya disease.

Despite the recognized usefulness of a portable table-top microscope in microsurgical training, its effectiveness is limited when training involves anatomical models and long surgical instruments. This limitation arises from the microscope's exclusive mobility to an up-and-down direction and the restricted working space beneath it. To address these challenges, we customized the table-top microscope by attaching its scope body and focusing rack to a Visual Electronics Standards Association (San Jose, CA, USA) monitor arm, originally designed for mounting computer monitors. A multipurpose metal plate, known as a "cheese plate" and designed for use with photography cameras, was customized to function as an adapter between the microscope and the monitor arm. The plate has Visual Electronics Standards Association-standard screw holes, which allowed the connection between the microscope focusing rack and the Visual Electronics Standards Association monitor arm. This assembly, referred to as a focusing rack-adapter plate complex, was then mounted on the Visual Electronics Standards Association monitor arm. To evaluate the modified microscope, its view was compared with that of a traditional microscope using concentric circles and gauze on the slope models. The modified microscope, mounted on the Visual Electronics Standards Association monitor arm, exhibited remarkable flexibility in its working area, height, and angles. The total cost of the modification was approximately $140. The advantages of the modified microscope over the traditional one, shown by a comparative study, were primarily attributed to the enhanced mobility of the modified microscope. With its simple modification process and affordable cost, this upgraded microscope has the potential to greatly benefit neurosurgeons who undergo microsurgical training.