This retrospective study compared the clinical and radiographic outcomes of vertebral body sliding osteotomy (n = 26) and anterior cervical corpectomy with fusion (n = 17) in 43 patients with K-line negative cervical ossification of the posterior longitudinal ligament. Clinical and radiographic parameters were evaluated preoperatively, postoperatively, and at the final follow-up. Within this cohort, the vertebral body sliding osteotomy group was associated with shorter hospital stays (p < 0.001) and greater postoperative Visual Analog Scale improvement (p = 0.048). While the anterior cervical corpectomy with fusion group achieved significantly larger immediate postoperative segmental lordosis correction, no significant difference was observed between groups in the long-term maintenance of overall segmental alignment. However, subgroup analysis suggested that in patients experiencing postoperative kyphotic progression, vertebral body sliding osteotomy was associated with less subsequent loss of segmental lordosis correction compared to anterior cervical corpectomy with fusion (p = 0.021). Both techniques effectively achieved decompression for K-line negative ossification of the posterior longitudinal ligament, with similar safety profiles and equivalent fusion rates. These preliminary findings suggest that vertebral body sliding osteotomy may be considered a potentially viable alternative to anterior cervical corpectomy with fusion, offering comparable outcomes and potential merits in early recovery and alignment maintenance for select patients.
BACKGROUND:Syringomyelia, secondary to adhesive arachnoiditis, is an intractable disease characterized by progressive extension cranially and caudally, resulting in severe neurological deficits. Subarachnoid-subarachnoid bypass has recently been reported for syringomyelia from trauma or spinal tumor surgery. METHODS:We investigated whether subarachnoid-subarachnoid bypass is a salvage treatment for refractory adhesive arachnoiditis of various etiologies, including arachnoid abnormality and hemorrhage. Patients who underwent subarachnoid-subarachnoid bypass between 2021 and 2025 for recurrent adhesive syringomyelia after conventional treatments were retrospectively reviewed. The primary outcome was the change in syrinx length from baseline to follow-up. Secondary outcomes included neurological outcomes and surgical complications. RESULTS:Six patients (median age 55 years; 2 men) were included. Patients had undergone a median of 2.5 conventional treatments, such as arachnoidolysis or intradural shunt placement, before subarachnoid-subarachnoid bypass. The syrinx showed temporary regression followed by re-expansion in all cases, attributed to extensive adhesions. Two patients presented with upper extremity paresis and pain, two with paraparesis, and two with severe paresthesia of the body trunk and lower extremities. After subarachnoid-subarachnoid bypass, the syrinx length showed a significant overall reduction (median, preoperative vs. postoperative: 9.5 vs. 5.0 levels; p = 0.014) in the median follow-up of 36 months. Neurological symptoms improved in five patients. Two patients were complicated with tube occlusion, which resolved with re-operation. CONCLUSIONS:Subarachnoid-subarachnoid bypass may be an effective option for refractory cases of syringomyelia not only from trauma or spinal tumor surgery but also from adhesive arachnoiditis due to arachnoid abnormality and hemorrhage.
Accurate differentiation of intracranial atherosclerotic disease-related large vessel occlusion from cardioembolic large vessel occlusion is important for understanding stroke etiology and optimizing endovascular treatment strategies. Although computed tomography-based diagnostic models have been proposed, magnetic resonance imaging-based models remain less well established. This study investigated the diagnostic value of border-zone infarction on diffusion-weighted imaging and evaluated predictive models incorporating border-zone infarction for identifying intracranial atherosclerotic disease-related large vessel occlusion. We retrospectively analyzed consecutive patients who underwent endovascular treatment for anterior circulation large vessel occlusion between April 2015 and April 2025. Intracranial atherosclerotic disease-related large vessel occlusion was defined as >50% residual stenosis after thrombectomy, or when dynamic intraprocedural re-occlusion occurred after initial reperfusion that was indicative of in situ thrombosis. Diagnostic performance of the ABC2D score was evaluated and compared with models incorporating border-zone infarction. Among 149 patients, 24 (16%) had intracranial atherosclerotic disease-related large vessel occlusion. Multivariable analysis identified absence of atrial fibrillation, absence of the hyperdense artery sign, and presence of border-zone infarction as independent predictors of intracranial atherosclerotic disease-related large vessel occlusion. Border-zone infarction indicated high specificity (94%) and the highest positive predictive value (64%). The ABC2D model achieved an area under the curve of 0.837, which improved to 0.912 with the addition of border-zone infarction. Furthermore, a simplified 2-variable model comprising only the absence of atrial fibrillation and the presence of border-zone infarction showed a high practical discriminative ability (area under the curve, 0.883). Border-zone infarction on diffusion-weighted imaging is a highly specific marker for intracranial atherosclerotic disease-related large vessel occlusion that significantly improves established computed tomography-based diagnostic models. A simplified 2-variable model (atrial fibrillation absence and border-zone infarction) offers a practical tool for rapid etiological triage. Prospective multicenter validation is warranted.
Orbital and cranio-orbital lesions are often benign, but postoperative ocular misalignment or diplopia can impair the quality of life. Eye movement monitoring has mainly been used for intermittent mapping for localization; however, serial, stimulus-evoked surveillance with prompt alerts remains challenging. We report an initial consecutive case series evaluating feasibility, safety, and early outcomes of continuous, stimulus-evoked electro-oculography monitoring using repetitive direct stimulation through an electrode placed adjacent to the superior orbital fissure. We retrospectively reviewed 17 consecutive orbital and cranio-orbital lesion surgeries over 2 years. Continuous electro-oculography monitoring was attempted when superior orbital fissure access was allowed, using periocular recording electrodes and serial stimulation (typically 1 Hz) via a superior orbital fissure-adjacent stimulating electrode. Outcomes were assessed preoperatively and 3-9 months postoperatively, focusing on ocular motility deficits, diplopia, perioperative adverse events, and monitoring-related complications. Continuous electro-oculography monitoring was implemented in 9/17 cases (53%) and was feasible in all monitored cases, providing serial responses throughout lesion resection. Non-implementation reflected lack of superior orbital fissure access in endoscopic transnasal procedures (n = 5) or a supraorbital keyhole approach (n = 1), clinical non-necessity (n = 1), or absent evoked responses with complete preoperative palsy (n = 1). No trigeminocardiac reflex events or monitoring-related complications occurred. The exploratory final amplitude preservation ratio was ≥50% in all monitored cases. No monitored patient had postoperative worsening of ocular motility (0/9) or diplopia; one non-monitored patient experienced mild recurrent diplopia, improving on follow-up. Continuous superior orbital fissure-adjacent stimulation-evoked electro-oculography monitoring was feasible and safe when superior orbital fissure access was obtained and it provided serial eye movement surveillance signals in this initial consecutive case series.
Rapid provision of mechanical thrombectomy for acute large-vessel occlusion is indispensable for favorable outcomes; however, only a minority of eligible patients receive timely treatment. This health services research study examined the daily distribution of mechanical thrombectomy procedures within a regional system to provide a basis for estimating the treatment capacity required to meet demand. We collected daily mechanical thrombectomy case counts in Kochi prefecture, Japan, from January 2016 through December 2023. Assuming that mechanical thrombectomy cases occur independently and at random, we compared observed daily case distributions with a Poisson distribution. After confirming distributional fit, we estimated the daily mechanical thrombectomy capacity required to achieve 95% and 99% coverage of demand. To assess flexibility for emergency neuroendovascular care, we also analyzed daily admission counts for subarachnoid hemorrhage during the same period using identical methods. The mean annual number of mechanical thrombectomy cases was 161, corresponding to an overall rate of 23.2 cases per 100,000 persons per year. Daily mechanical thrombectomy case counts closely followed a Poisson distribution, with a maximum of 4 cases per day. Subarachnoid hemorrhage admissions exhibited a similar Poisson distribution. The estimated required daily mechanical thrombectomy capacity was 2-3 cases for 95% coverage and 3-4 cases for 99% coverage. Analysis of historical daily case counts enables estimation of region-specific mechanical thrombectomy demand and provides a practical framework for regional allocation of mechanical thrombectomy-capable physicians and facilities, although intraday timing data would allow more precise capacity modeling.
Clazosentan (CLA), an endothelin-A receptor antagonist, is used to prevent cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH). Although its efficacy has been demonstrated in large-scale clinical trials, the effects of CLA on cytokine and chemokine profiles in cerebrospinal fluid (CSF) after SAH remain unclear. Twenty-two patients with SAH were enrolled. Ten patients received fasudil hydrochloride (FH), a Rho kinase inhibitor, and 12 received CLA. CSF samples were collected on days 1, 3, 5, 7, 10, and 14. Concentrations of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), interferon-γ-inducible protein-10 (IP-10), and monokine induced by interferon-γ (MIG) were measured using enzyme-linked immunosorbent assay. IL-6 levels were significantly suppressed during the acute phase in the CLA group compared with the FH group, whereas MCP-1 levels were upregulated on day 1. The peak expression of IP-10 and MIG was delayed in the CLA group relative to the FH group. A strong correlation between IP-10 and MIG was observed on day 5 in the FH group and on day 7 in the CLA group. CLA suppressed IL-6 expression during the acute phase, which may contribute to delayed upregulation of IP-10 and MIG. Suppression of IL-6 may represent a key mechanism underlying the anti-inflammatory effects of CLA following SAH.
Fourth ventricular arachnoid cysts are rare and optimal surgical management remains unclear. We describe a flexible endoscopic trans-third ventricular technique for the treatment of fourth ventricular arachnoid cysts associated with obstructive hydrocephalus. Through a frontal approach, a flexible neuroendoscope is advanced via the foramen of Monro and third ventricle into the dilated cerebral aqueduct, allowing access to the fourth ventricle. Cyst fenestration is performed using biopsy forceps and a balloon catheter, and communication with surrounding cerebrospinal fluid spaces can be established. Endoscopic third ventriculostomy is performed concomitantly to ensure cerebrospinal fluid diversion. In selected cases, additional caudal fenestration toward the cisterna magna can be achieved to enhance cerebrospinal fluid circulation. This minimally invasive technique avoids posterior fossa craniotomy and enables simultaneous treatment of hydrocephalus. The approach is particularly suitable for cases with sufficient aqueductal dilation and offers a safe and effective alternative in selected patients.
Minimally invasive surgery for intracerebral hemorrhage is typically performed in the acute phase; however, in frail older adults, the risks of general anesthesia may outweigh the benefits of an early intervention. This study evaluated a "consistency-guided" strategy, in which hematoma evacuation is delayed until liquefaction allows endoscopic removal under local anesthesia. We retrospectively analyzed patients aged ≥70 years with lobar hemorrhages of ≥30 mL, excluding deep-seated types. Patients were categorized into 3 groups: subacute endoscopic surgery performed between days 7 and 14 based on hematoma consistency, acute craniotomy performed for neurological deterioration, and conservative management. The hematoma evacuation rate, operative metrics, complications, and functional outcomes were assessed using the modified Rankin Scale at 90 days and Functional Independence Measure gain. Among the 43 patients (endoscopic: 18, craniotomy: 11, conservative: 14), baseline hemorrhage severity was comparable across groups, with mean intracerebral hemorrhage scores of 3.07, 2.27, and 2.64, respectively. The endoscopic group achieved a high evacuation rate (median 88%) with significantly shorter operative times than the craniotomy group (50 vs. 180 min) and had no postoperative respiratory complications. Although the median 90-day modified Rankin Scale score was 5 across all groups, the endoscopic group demonstrated significantly greater Functional Independence Measure gain compared with conservative management, particularly among patients with hematoma volumes ≥40 mL. Delayed endoscopic evacuation under local anesthesia appears to be a feasible and safe strategy for older adults with frailty and may contribute to improved functional recovery in this population.
Degenerative lumbar canal stenosis is characterized by fibrosis-driven thickening of the ligamentum flavum, which is a key factor in the pathology of the disease and is responsible for clinical symptoms. Given the central role of transforming growth factor-β/Small mothers against decapentaplegic (Smad) signaling in fibrosis, this study aimed to investigate its role in ligamentum flavum remodeling in patients with degenerative lumbar canal stenosis. Ligamentum flavum tissue samples were obtained from 27 patients undergoing surgery for either degenerative lumbar canal stenosis (n = 18) or lumbar disc herniation (n = 9). The lumbar disc herniation patients served as the control group. The severity of the fibrosis was quantified using Masson trichrome and hematoxylin-eosin staining, and radiological measurement of ligamentum flavum thickness. Quantitative reverse transcription-polymerase chain reaction was used to analyze gene expression levels of transforming growth factor-β, transforming growth factor-β receptor, Smad2, Smad3, and Smad4. Changes at the protein level were verified using Western blot analysis. All statistical analyses were conducted post-normalization. Based on histological evaluation, the degenerative lumbar canal stenosis group showed a significantly higher degree of fibrosis compared to the control group. Radiological measurements also revealed increased ligamentum flavum thickness in the degenerative lumbar canal stenosis group (p < 0.0001). Significant upregulation (p < 0.05) of the Ski, transforming growth factor-β, transforming growth factor-β receptor, Smad2, Smad3, and Smad4 genes was detected, as confirmed by Western blot results. Collective analysis indicated that reduced SnoN gene expression in degenerative lumbar canal stenosis undermined the inhibition of target proteins on Smad2 and Smad3, resulting in elevated levels of phosphorylated Smad2/3. These findings suggest that downregulating SnoN may enhance the activation of the transforming growth factor-β/transforming growth factor-β receptor/Smad2/3 signaling pathway, thereby promoting ligamentum flavum fibrosis in patients with degenerative lumbar canal stenosis.
Tumor stiffness strongly influences exposure, extent of resection, operative time, and approach in meningioma surgery, but magnetic resonance imaging-based prediction still relies mainly on qualitative assessment. We evaluated whether a diffusion-derived stiffness surrogate calculated from diffusion-weighted magnetic resonance imaging-based virtual elastography correlates with intraoperative quantitative tumor stiffness in meningiomas and assessed its usefulness for preoperative stiffness prediction. Of 33 patients who underwent meningioma surgery between May 2022 and January 2025, 22 with both preoperative virtual elastography and intraoperative stiffness measurements were analyzed. Preoperative 3-Tesla diffusion-weighted magnetic resonance imaging with 2 b values was used to generate shifted apparent diffusion coefficient maps, and a single-slice volume of interest with a 5.51 mm slice thickness was manually delineated on the axial slice showing the largest tumor cross-sectional area. Intraoperative tumor stiffness of approximately 1-cm3 fresh specimens was measured with a rheometer and expressed as Young's modulus. The relationship between the diffusion-derived stiffness surrogate and stiffness was examined using Pearson correlation and multivariate linear regression. The diffusion-derived stiffness surrogate showed a significant negative correlation with tumor stiffness (r = -0.655, p = 0.00094), and this association remained significant after exclusion of embolized cases. Lower diffusion-derived stiffness surrogate values were associated with firmer tumors, whereas higher values were associated with softer tumors. These findings indicate that diffusion-weighted magnetic resonance imaging-based virtual elastography may provide a noninvasive, quantitative preoperative surrogate marker for estimating the stiffness of selected solid components of meningiomas and may offer adjunctive information for surgical planning.
Underlying atherosclerotic stenosis is more common in acute basilar artery occlusion than in anterior circulation, and often necessitates additional procedures such as balloon angioplasty or stent placement during endovascular revascularization. Preoperative recognition of underlying basilar artery stenosis may be clinically relevant, but reliable imaging indicators remain unclear. This study aimed to identify preoperative magnetic resonance imaging findings associated with underlying basilar artery stenosis in patients undergoing acute endovascular revascularization. We retrospectively analyzed patients at three institutions between 2018 and 2023. Patients were divided into stenosis and non-stenosis groups based on post-recanalization angiographic findings. Stenosis was identified in 13 patients and was found to be absent in 35 patients. Pontine hyperintensity on diffusion-weighted imaging was more frequent in the stenosis group and remained independently associated with preexisting basilar artery stenosis after adjustment for preoperative National Institutes of Health Stroke Scale score. Non-visualization of the proximal basilar artery on magnetic resonance angiography was also more frequent in the stenosis group, but did not remain independently associated after adjustment. Additional endovascular procedures were more frequently required in the stenosis group, whereas recanalization was achieved with mechanical thrombectomy alone in the non-stenosis group. Functional outcomes at discharge were comparable between the groups. In acute basilar artery occlusion, pontine hyperintensity on diffusion-weighted imaging was independently associated with preexisting basilar artery stenosis. Its absence may help exclude underlying stenosis, whereas concordant positivity of pontine hyperintensity and proximal basilar artery non-visualization may support suspicion of stenosis before treatment.
Long-term functional independence after shunt surgery for idiopathic normal pressure hydrocephalus varies widely, particularly in older patients with multiple comorbidities. We aimed to develop and prospectively validate a frailty-integrated prognostic prediction tool to support patient selection and preoperative decision-making. A retrospective cohort of 82 patients with idiopathic normal pressure hydrocephalus who underwent shunt surgery between 2005 and 2014 was used to develop a weighted idiopathic normal pressure hydrocephalus-specific frailty index based on multivariable logistic regression. The index incorporated neurological and non-neurological comorbidities, including dementia, cancer, depression, and movement disorders. The weighted idiopathic normal pressure hydrocephalus-specific frailty index was combined with preoperative modified Rankin Scale scores to estimate the probability of achieving functional independence (modified Rankin Scale ≤2) at 1, 2, and mid- to long-term follow-up (up to 4 years). Prospective validation was performed in an independent cohort of 30 patients treated between 2018 and 2023. The weighted idiopathic normal pressure hydrocephalus-specific frailty index demonstrated improved predictive performance, particularly for mid- to long-term outcomes (2-4 years), compared with conventional frailty indices, with higher correlation coefficients and lower Akaike Information Criterion values. Predicted probabilities of long-term independence declined stepwise with increasing frailty burden. In the validation cohort, predicted and observed outcomes showed good agreement, with adequate calibration confirmed by the Hosmer-Lemeshow test. This frailty-integrated prognostic prediction tool provides individualized estimates of long-term postoperative independence, particularly in the context of frailty and comorbidity burden. By incorporating comorbidity burden into preoperative assessment, the tool supports patient selection and shared decision-making and may facilitate realistic counseling and long-term care planning in older patients.
Japan is undergoing rapid population aging, and glioblastoma is increasingly diagnosed in older adults. However, nationwide data on regional variation in age distribution, surgical volume, population-adjusted incidence, and treatment selection for newly diagnosed glioblastoma remain limited. Using anonymized data from the Japan Neurosurgical Database between 2018 and 2023, we analyzed patients with newly diagnosed glioblastoma who underwent initial tumor resection or biopsy and examined inter-prefectural heterogeneity in surgical practice patterns. Patient age was categorized into 5-year groups and stratified as <75 and ≥75 years, and prefecture-specific population data from the 2020 national census were used to calculate population-adjusted incidence.Across all 47 prefectures, the age distribution of surgically treated patients differed significantly from that of the general population, with older patients being consistently overrepresented. The magnitude of this difference varied substantially among prefectures, indicating marked regional heterogeneity in the age profile of patients undergoing surgical management. Significant inter-prefectural differences were also observed in the surgical volume, the population-adjusted incidence, and the balance between resection and biopsy. Patients undergoing biopsy were older than those undergoing resection, although the magnitude of this difference varied regionally. The proportion of tumor resection ranged widely across regions and persisted even among patients aged ≥75 years. Importantly, baseline functional status (modified Rankin Scale) and admission consciousness level (Japan Coma Scale) were largely comparable across the prefectures.These findings demonstrate substantial regional heterogeneity in the initial surgical management of glioblastoma in Japan that cannot be fully explained by population aging or patient condition alone.
The cerebrospinal fluid tap test is commonly used to select shunt candidates in idiopathic normal pressure hydrocephalus; however, it is invasive and has limited predictive value, as a substantial proportion of patients who tested positive on tap test do not improve after shunt surgery. This limitation highlights the need for noninvasive imaging markers to support preoperative decision-making. We retrospectively analyzed 80 patients with ventriculomegaly evaluated at a single center between 2014 and 2022, including 40 patients with idiopathic normal pressure hydrocephalus who tested positive on tap test and underwent shunt surgery, and 40 control patients with ventriculomegaly without idiopathic normal pressure hydrocephalus. Shunt responsiveness was defined as an improvement of at least 1 point on the idiopathic normal pressure hydrocephalus grading scale at 6-12 months. Evans index, zEvans index, callosal angle, disproportionately enlarged subarachnoid-space hydrocephalus, and the coronal hydrocephalic index (Eo index =z-Evans index/Evans index) were measured on magnetic resonance imaging. Among patients who underwent shunt surgery, 28/40 (70%) demonstrated clinical improvement. In univariate analyses within the shunted subgroup, Evans index and z-Evans index were not associated with shunt responsiveness, whereas callosal angle, disproportionately enlarged subarachnoid-space hydrocephalus, and the coronal hydrocephalic index were significant discriminators. The discriminative performance of the coronal hydrocephalic index was comparable to callosal angle and was complementary to disproportionately enlarged subarachnoid-space hydrocephalus. In the full ventriculomegaly cohort, the coronal hydrocephalic index also discriminated patients with idiopathic normal pressure hydrocephalus who were shunt-responsive from others who were not. Receiver operating characteristic analyses were used to derive within-sample cut-off values for scenariobased clinical decision support. The coronal hydrocephalic index is a simple, noninvasive magnetic resonance imaging-derived parameter that may support stratification of shunt responsiveness in patients with idiopathic normal pressure hydrocephalus, and requires external validation in independent cohorts before broader clinical application.
Electroencephalogram-based objective assessment of surgical skill remains underexplored in neurosurgical training. We investigated whether electroencephalogram spectral features can discriminate surgical expertise during microvascular anastomosis training and identify neural markers associated with task performance. We conducted a prospective observational study in 29 right-handed male participants (neurosurgeons, residents, and medical students) performing a 10-minute interrupted anastomosis on a 1.0-mm hydrophilic tube under an operating microscope. Electroencephalogram under the 10-20 system was recorded during the task, segmented into 3 procedural phases (needle insertion, knot tying, thread cutting), and epoched into 2-second windows. Participants were stratified post hoc into Skilled (>= 6 units) and Less-skilled (<= 5 units) groups based on task throughput. Power spectral density from 4 to 22 Hz was summarized into 6 frequency bands across 7 regions of interest, yielding 42 features per epoch. Classification models were trained using a nested cross-validation framework with a leave-one-subject-out outer loop, and epoch-level predictions of Skilled-class probability were aggregated into subject-level scores, from which phase-specific area under the receiver operating characteristic curve values were calculated. A total of 7,201 artifact-free epochs (76.3%) were included. Subject-level discrimination performance varied by phase, with area under the receiver operating characteristic curve values of 0.736 for needle insertion, 0.678 for knot tying, and 0.788 for thread cutting. Feature attribution and group-level analyses consistently revealed increased frontal alpha power and reduced midline theta power in Skilled participants, particularly during needle insertion and thread cutting. These findings support the feasibility of electroencephalogram-based objective assessment of microsurgical expertise and identify candidate neural markers of proficiency.
Anterior skull base meningiomas are often supplied by ethmoidal arteries branching from the ophthalmic artery. Preoperative embolization can reduce intraoperative bleeding and facilitate safer resection; however, its use is limited by the risk of visual complications. This study evaluates the safety, effectiveness, and technical considerations of embolization via the ophthalmic artery using n-butyl-2-cyanoacrylate (n-BCA). This retrospective study included patients with meningiomas who underwent preoperative embolization via the ophthalmic artery between 2017 and 2025. Demographics, clinical characteristics, technical details, surgical outcomes, and complications were analyzed. Five patients (median age of 58 years) underwent embolization. Two meningiomas were at the olfactory groove, two at the planum sphenoidale, and one at the sphenoid ridge (median diameter of 41.9 mm). Unilateral embolization was performed in four patients; one underwent bilateral embolization. The working angle was set at an anterior oblique and cranial position to optimize visualization of the central retinal and ethmoidal arteries. The microcatheter was advanced beyond the central retinal artery to cannulate the ethmoidal artery and to position it near the tumor. N-BCA, heated to 80°C, was used at concentrations ranging from 20% to 33%. All patients showed reduced tumor blush without neurological complications, including vision loss or impairment. Simpson grade II-III resection was achieved in all patients, with a median intraoperative blood loss of 350 mL. One patient demonstrated postoperative improvement in the visual field defects. Embolization via the ophthalmic artery can be safely performed to facilitate the resection of skull base meningiomas using standardized techniques and n-BCA.
Although vestibular schwannomas are common, benign intracranial tumors with similar histopathology originating from other nerves are rare. For non-vestibular schwannomas, surgery remains standard treatment, albeit associated with morbidities. Radiotherapy offers a safe and effective alternative treatment modality. Nevertheless, the previous publication had a limited follow-up period and included outcomes from both stereotactic radiosurgery and radiotherapy. To investigate our long-term results, a retrospective chart review was conducted in patients who received stereotactic radiotherapy for non-vestibular schwannomas using hypo- or conventional fractionated regimen, from 2000 to 2020, with a minimum follow-up of 24 months. Treatment failure was defined as a >= 20% tumor growth, necessitating additional treatment. Radiation-induced sequelae were also observed. During the study period, 66 patients underwent stereotactic radiotherapy for non-vestibular schwannomas. After excluding non-eligible cases, 57 patients were analyzed. The tumor's median volume was 6.5 milliliters (interquartile range 2.85-11.04). Hypofractionated stereotactic radiotherapy, delivered in 3, 5, or 10 sessions, was used in 53 patients, while 4 patients received 25-day conventional fractionated stereotactic radiotherapy. With a median follow-up of 121 months (interquartile range 54-159), tumor control was achieved in 55 subjects (96.5%), with surgical resection necessary in 2 patients after radiation. The actuarial control rates were 100%, 97%, and 92% at 5, 10, and 15 years, respectively. Tumor shrinkage was observed in 27 individuals (47.37%). Regarding complications, one patient reported worsening of facial numbness after radiation. With extended follow-up compared to prior reports, our long-term outcomes support the efficacy and safety of hypo- and conventional fractionated stereotactic radiotherapy for non-vestibular schwannomas.
Perfusion computed tomography predicts and diagnoses delayed cerebral ischemia after subarachnoid hemorrhage, but challenges in precision and interpretation limit its adoption. This study investigated whether tissue time-to-maximum analysis during the peak term of cerebral vasospasm, processed via Rapid Processing of Perfusion and Diffusion, can stratify delayed cerebral ischemia risk in patients with subarachnoid hemorrhage. In this retrospective cohort study, patients with subarachnoid hemorrhage treated surgically or endovascularly from March 2021 to March 2025 at the Japanese Red Cross Kumamoto Hospital underwent perfusion computed tomography approximately 10 days after the onset. Time-to-maximum parameters were computed via Rapid Processing of Perfusion and Diffusion and analyzed using logistic regression to assess their association with subsequent delayed cerebral ischemia. The primary endpoint was the development of delayed cerebral ischemia. Of the 181 patients initially screened, 101 were included in the study. The cohort included 81 women, with a mean age of 65 years. Among the 101 patients, 22 developed delayed cerebral ischemia. Compared with those without delayed cerebral ischemia, the delayed cerebral ischemia group had higher preoperative World Federation of Neurosurgical Societies grades and a higher frequency of significant cerebral vasospasm. The volume of time-to-maximum > 4 sec showed the strongest independent association with delayed cerebral ischemia. Receiver operating characteristic analysis identified a threshold of 31 mL for time-to-maximum > 4 sec, yielding a sensitivity of 0.91 and a specificity of 0.96. In multivariable logistic regression adjusting for World Federation of Neurosurgical Societies grade and cerebral vasospasm, time-to-maximum > 4 sec was associated with delayed cerebral ischemia development. The incorporation of time-to-maximum analysis via Rapid Processing of Perfusion and Diffusion may standardize perfusion computed tomography interpretation and enable delayed cerebral ischemia risk assessment.
Absorbable gelatin sponges are widely used as hemostatic and reconstructive materials in neurosurgery. Global discontinuation of Gelfoam and withdrawal of Spongel from the Japanese market have created an urgent need for alternatives. This study was performed to evaluate the utility of Spongostan as a substitute for Spongel and Gelfoam in sellar floor reconstruction using the fibrin glue-soaked gelatin sponge method. Two gelatin sponges (Spongel and Spongostan) and 2 fibrin sealants (Beriplast and Bolheal) were combined to prepare 4 fibrin glue-soaked gelatin sponge combinations. Adhesive strength was measured using a tensile strength test according to ASTM F2458-05 and analyzed using 2-way analysis of variance. A retrospective review was also conducted for patients who underwent endoscopic transsphenoidal surgery for pituitary adenoma between May 2024 and October 2025, in which fibrin glue-soaked gelatin sponge prepared with Spongostan was used for sellar floor reconstruction. Spongostan showed significantly higher adhesive strength than Spongel (F(1,20) = 13.72, p = 0.0014), whereas neither the fibrin sealant type nor the sponge-fibrin sealant interaction was significant (both p = 0.73). In 11 clinical cases (mean age 66 ± 16 years), intraoperative cerebrospinal fluid leakage occurred in 5 cases and postoperative leakage in one case, in a patient who had undergone prior radiotherapy. No hemorrhage, meningitis, or material-related complications occurred. These findings suggest that Spongostan may serve as a feasible alternative to Spongel for fibrin glue-soaked gelatin sponge-based sellar floor reconstruction during endoscopic transsphenoidal surgery.
Vagus nerve stimulation is an established treatment for refractory epilepsy, but predictors of treatment response remain unclear. Given that left-sided vagus nerve stimulation preferentially modulates the left thalamus and that epileptic networks induce thalamic structural damage, we investigated whether preoperative thalamic volume asymmetry predicts vagus nerve stimulation outcomes. This retrospective study included 17 patients with refractory epilepsy who underwent vagus nerve stimulation implantation. Patients were classified as responders (≥50% seizure reduction at 24 months, n = 9) or non-responders (n = 8). Thalamic volumes were manually segmented on preoperative T2-weighted magnetic resonance imaging by 2 blinded raters, and we used the rater-averaged values to calculate the left/right volume ratio and asymmetry index. The mean thalamic volume ratio (left/right) was significantly higher in responders than non-responders (1.00 [95% confidence interval 0.97-1.03] vs 0.96 [95% confidence interval 0.92-0.99], p = 0.027), and the asymmetry index also differed between groups (0.00 [95% confidence interval -0.015 to 0.017] vs -0.023 [95% confidence interval -0.040 to -0.006], p = 0.027). Inter-rater reliability was acceptable for absolute volumes but was lower for ratio-based asymmetry indices, suggesting that these derived metrics may be more suitable for group-level comparisons than for single-patient prediction. Epileptogenic laterality determined by electroencephalography did not predict thalamic asymmetry. Relative left thalamic volume reduction was associated with poor vagus nerve stimulation treatment response. Assessment of preoperative thalamic asymmetry on routine structural magnetic resonance imaging may represent a candidate biomarker for predicting vagus nerve stimulation efficacy, pending validation in larger cohorts.
