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.
Flow diverter braid deformation is occasionally observed after flow diverter placement. However, the frequency and clinical significance of flow diverter braid deformation in non-drawn filled tube wire devices remain unclear. This retrospective, single-center study analyzed 139 consecutive patients (median age, 60 years; 82.7% women) who underwent flow diverter placement for intracranial aneurysms between 2017 and 2024. Follow-up angiography and cone-beam computed tomography images were compared with those obtained immediately after flow diverter deployment to identify flow diverterrelated morphologic changes. The identified morphologic changes were classified into 4 major patterns (fish mouthing, bump, collapse, and shortening) as flow diverter braid deformation and 2 variants (distal tapering and edge flare) as minor morphologic changes. Cases with fish mouthing or collapse were classified as a high-risk flow diverter braid deformation category because of their association with thromboembolic complications. Flow diverter-related morphologic changes were detected in 31 patients (22.3%), including flow diverter braid deformation in 24 patients (17.3%), at the first angiographic follow-up, and no progression was detected during subsequent observations. The most common pattern was shortening (12.9%), followed by distal tapering (5.0%), and high-risk flow diverter braid deformation was rare (fish mouthing, 1.4%; collapse, 1.4%). Neointimal hyperplasia was more frequent in the flow diverter braid deformation group, whereas the rates of in-stent stenosis, aneurysm occlusion (O'Kelly-Marotta grades C-D), retreatment, and favorable functional outcomes (modified Rankin Scale, 0-2) did not differ significantly between the groups. Younger age and proximal stent oversizing were independent predictors of flow diverter braid deformation. Given the rarity of the high-risk category and the absence of adverse outcomes, flow diverter braid deformation represents a benign and stable morphological change in non-drawn filled tube wire flow diverters.
It remains unclear whether frailty and white matter lesions are risk factors for surgical treatment of unruptured intracranial aneurysms in older adults. We conducted a prospective multicenter study of 397 patients aged >= 60 years with unruptured intracranial aneurysms enrolled from 20 hospitals in Japan. Unruptured intracranial aneurysms were treated by either microsurgical clipping or endovascular treatment according to institutional protocols. The primary endpoint was functional outcome at discharge assessed using the modified Rankin scale (mRS). Poor outcome was defined as a deterioration of 1 or more points in the mRS score at discharge compared with the preoperative baseline. Unruptured intracranial aneurysm size ranged from 2.1 to 26 mm (mean, 6.93 mm). Poor outcome occurred in 52 patients (13.1%). There was no significant association between poor outcome and age (p = 0.089) or treatment modality (clipping vs. coiling, p = 0.4739). In multivariate regression analysis, poor outcome was significantly associated with larger unruptured intracranial aneurysm size (p = 0.033), higher Clinical Frailty Scale score (p = 0.006), higher preoperative mRS score (p = 0.039), lower hemoglobin level (p = 0.016), absence of regular exercise (p = 0.046), slower walking speed (p = 0.002), severe white matter lesions (p = 0.001), and lower intraoperative blood pressure (p = 0.032). Severe white matter lesions were associated with a higher risk of postoperative ischemia (p <= 0.042) and intracranial hemorrhage (p = 0.0017). These findings indicate that preoperative frailty and severe white matter lesions are significant predictors of poor outcomes after unruptured intracranial aneurysm surgery in older adults. Trial registration: umin.ac.jp/ctr Identifier: UMIN 000029977
Intramedullary spinal cord tumors/lesions are rare, but they present significant surgical challenges owing to the high risk of spinal cord injury during myelotomy. Conventional techniques are often limited by positional discrepancies and anatomical variations. Indocyanine green videoangiography provides real-time fluorescence imaging of the lesion vasculature. This study aimed to evaluate the safety and efficacy of intraoperative indocyanine green videoangiography and to determine which pathological subtypes are most amenable to this technique. We enrolled patients with intramedullary spinal cord tumors, excluding those with hemangioblastoma. A 2-step approach was used for lesion localization: initial delineation using conventional methods, followed by indocyanine green videoangiography, in which indocyanine green was administered intravenously, and lesion boundaries were re-marked using fluorescence imaging. The outcome measure was the prediction error distance between conventional localization and indocyanine green videoangiography localization, and the impact of lesion characteristics on localization accuracy. This study included 15 patients with intramedullary spinal cord tumors. The mean prediction error distance was 3.63 mm for the conventional method and 2.77 mm for indocyanine green videoangiography. The mean prediction error distance difference between the 2 methods was 0.87 mm (p = 0.047). Tumor size correlated with greater reductions in prediction error distance using indocyanine green videoangiography (height, p = 0.005). Larger tumors (23.4 mm in height) tended to demonstrate a mean prediction error distance reduction of 2.0 mm (p = 0.085). Minor adverse events that could be related to indocyanine green videoangiography were observed in 3 cases, all of which resolved spontaneously. Intraoperative indocyanine green videoangiography performed before myelotomy may improve the accuracy of tumor localization with minimal risk in patients with intramedullary spinal cord tumors/lesions. It might be particularly effective at minimizing errors in large intramedullary spinal cord tumors. By reducing unnecessary myelotomy, indocyanine green videoangiography may improve surgical outcomes.
Vertebral artery dissection is a rare but potentially life-threatening condition. However, many cases of mild vertebral artery dissection-an early disease stage-may be overlooked. 3-dimensional T1-weighted black-blood magnetic resonance imaging has recently emerged as a promising diagnostic tool, yet it remains underutilized. This study investigated the impact of vertebral artery dissection screening in patients presenting with headache, the most common chief complaint encountered in general neurosurgery outpatient clinics, and an initial symptom of vertebral artery dissection, in a real-world clinical setting. We retrospectively reviewed 3,049 consecutive patients with headache who visited a neurosurgical outpatient center in Chiba, Japan (October 2021-October 2023). In the first year, 1,527 patients underwent brain magnetic resonance imaging and magnetic resonance angiography. In the second year, 1,522 patients received these examinations as well as brain and neck black-blood magnetic resonance imaging. Vertebral artery dissection detection rates were compared between the 2 groups.Vertebral artery dissection was diagnosed in 0.5% and 1.6% of the former and latter groups, respectively (relative risk: 3.42, 95% confidence interval 1.48-7.92, p = 0.003), indicating an over threefold increase in detection. Among patients with intracranial vertebral artery dissection, 96% reported occipital headache rather than nonspecific/generalized headache. Among high-risk individuals aged 40-55 years with occipital or posterior neck pain, the detection rate reached 7.5%. Vertebral artery dissection accounted for 93% of head and neck arterial dissections. The addition of black-blood magnetic resonance imaging significantly improved early detection and may enhance screening accuracy for patients presenting with headache at elevated risk.
Temporary zygomatic arch removal (zygomectomy) in the orbitozygomatic approach is sometimes used in surgeries involving complex lesions. Although the orbitozygomatic approach provides wider exposure than the pterional approach, it is more invasive and carries a higher risk of complications. We hypothesized that adequate exposure could be achieved without zygomectomy when the zygomatic arch lies well below the floor of the middle cranial fossa. This study introduces the concept of "Low-set Zygoma" and examines its clinical and anatomical relevance. High-resolution cranial computed tomography scans from 105 adults without craniofacial anomalies (210 sides) were analyzed to measure the vertical distance from the superior margin of the zygomatic arch to the middle cranial fossa floor (middle cranial fossa height). In this study, a Low-set Zygoma was defined as a middle cranial fossa height of ≥ -3.0 mm. Participants were stratified into 2 groups [Low-set Zygoma (≥ -3.0 mm) and non-Low-set Zygoma (< -3.0 mm) ], and demographic variables were assessed using univariate and multivariate statistical analyses. We performed 3 pterional approaches in patients with Low-set Zygoma, where orbitozygomatic approach was typically indicated. Adequate exposure was achieved in all patients, with no complications. Based on computed tomography data, the mean vertical distance from the zygomatic arch to the middle cranial fossa floor was -2.36 mm. Body height was the only independent predictor of a Low-set Zygoma (p = 0.037); individuals shorter than 162.5 cm were significantly more likely to exhibit this anatomical feature. A Low-set Zygoma appears to be a reliable anatomical indicator for avoiding unnecessary zygomectomy and may support more individualized preoperative planning.
Tractography is a technique for visualizing the trajectories of white matter pathways. The most widely used model, the diffusion tensor imaging, assumes a single fiber orientation within each voxel. In contrast, the constrained spherical deconvolution model enables the estimation of multiple fiber orientations. Recently, constrained spherical deconvolution was added to a widely used neurosurgical navigation platform alongside the diffusion tensor imaging model, allowing both approaches to be applied within the same clinical environment. In this study, we compared the volumes of white matter tracts reconstructed using these 2 models. Magnetic resonance imaging data from 37 patients were used to reconstruct 5 white matter tracts-the corpus callosum, the bilateral inferior fronto-occipital fasciculi, and the bilateral corticospinal tracts. Volumetric and visual analyses were conducted to assess differences in tract reconstruction between constrained spherical deconvolution and diffusion tensor imaging. Across all bundles, constrained spherical deconvolution consistently yielded significantly greater tract volumes, with a mean percentage volume difference of 158.6% (p < 0.001), most prominently in the inferior fronto-occipital fasciculi. Visual assessments favored constrained spherical deconvolution-based reconstructions in approximately 80% of the cases, and volumetric and visual measures demonstrated strong concordance (Spearman's ρ = -0.766, p < 0.001). In contrast, differences between constrained spherical deconvolution and diffusion tensor imaging were less pronounced in the corticospinal tracts. Lowering the fractional anisotropy threshold in diffusion tensor imaging did not improve reconstruction quality and produced anatomically implausible streamlines. Tract type was the primary determinant of inter-method differences (p < 0.001). Integration of constrained spherical deconvolution into clinical navigation can enhance visualization of white matter organization and may improve preoperative planning and risk evaluation in neurosurgical practice.
Non-ipsilateral ischemic lesions after carotid artery stenting are considered to arise from emboli originating in the aortic arch, but the quantitative contribution of aortic arch calcification to post-carotid artery stenting ischemic lesions remains unclear. This study aimed to investigate the association between volumetric aortic arch calcification and non-ipsilateral diffusion-weighted imaging hyperintense lesions after transfemoral carotid artery stenting. We retrospectively analyzed 99 consecutive transfemoral carotid artery stenting procedures performed between January 2018 and December 2023. Aortic arch calcification volume was quantified using preoperative computed tomography angiography using threshold-based segmentation. Postprocedural diffusion-weighted imaging performed within 48 h was assessed for hyperintense lesions in the contralateral hemisphere or cerebellum. Variables were evaluated using univariate and multivariate logistic regression analyses. Receiver operating characteristic curve analysis was used to determine the optimal cut-off value for predicting non-ipsilateral lesions. Non-ipsilateral high-intensity diffusion-weighted imaging lesions occurred in 14 patients (14.1%), who showed significantly higher aortic arch calcification volumes than did those without lesions (median 2.2 vs. 1.0 mL, p = 0.005). Receiver operating characteristic analysis identified an optimal cutoff of 1.3 mL (sensitivity 78.6%, specificity 62.3%, area under the curve 0.73). Both age (odds ratio 1.1 per year, p = 0.039) and aortic arch calcification volume (odds ratio 1.3 per mL, p = 0.040) were independently associated with non-ipsilateral lesions. Aortic arch type and guiding catheter size showed no significant associations. Quantitative aortic arch calcification on preoperative computed tomography angiography was independently associated with non-ipsilateral ischemic lesions after transfemoral carotid artery stenting. Incorporating calcification volume into preprocedural assessments may assist in selecting alternative access routes or protective strategies for patients at high risk.
