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.

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.

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.

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.

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.

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.

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.

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.