Publications by authors named "Motoyuki Umekawa"
Article Synopsis
- * In a study of 569 patients treated with SRS, only one case of RIM (gliosarcoma) was found, leading to a very low overall incidence rate of 0.12 per 1,000 patient-years over a long follow-up period (average of 12.5 years).
- * A systematic review of 14 studies indicated RIM incidence rates between 0.00% and 0.24%, with glioblastoma being
Article Synopsis
- The study evaluated how age impacts patient outcomes in those undergoing microsurgical clipping for WFNS grade I/II aneurysmal subarachnoid hemorrhage (SAH), analyzing data from 176 patients over a decade.
- Results indicated that younger patients (≤70 years) had significantly better outcomes (84%) compared to older patients (>70 years) who had only a 46% favorable outcome, making age a crucial prognostic factor.
- The researchers developed a prognostic model based on age and surgical complications, suggesting that tailored postoperative care, especially for older patients, can improve outcomes, highlighting age as a more significant factor than initial WFNS grading in these cases.
Article Synopsis
- Fibrous dysplasia (FD) is mostly symptomless but can lead to rare neurological issues, like abducens nerve palsy, particularly in older patients.
- A case was reported involving a 76-year-old woman who developed left abducens nerve palsy due to pressure from an FD-related cyst, which was successfully treated through endoscopic surgery.
- The case highlights that while FD usually affects younger individuals, it can cause serious complications such as nerve palsy in older patients, especially when cysts form and create pressure that necessitates surgical intervention.
Background And Objectives: Patients with brain arteriovenous malformations (BAVMs) sometimes experience migraine-like chronic headaches. Reportedly, this symptom is common in occipital lobe BAVMs; however, the exact prevalence has not been clarified, and the details of visual auras have been scarcely reported. Furthermore, no comprehensive studies exist on the improvement of migraine associated with visual auras in occipital lobe BAVMs after stereotactic radiosurgery (SRS).
View Article and Find Full Text PDFBackground: The emergence of flow disruptors has brought a dynamic transition in the selection of treatment for middle cerebral artery (MCA) aneurysms, and the number of MCA aneurysms clipped is acceleratingly decreasing. Still, retreatment after endovascular treatment is still a dilemma, which may necessitate surgical clipping. It is all the more important to elucidate characteristics of MCA aneurysms that make clipping unfavorable.
View Article and Find Full Text PDFBackground: Although arterial stiffness is known as a biomarker for cardiovascular events and stroke, there is limited information in the literature regarding the stiffness of intracranial aneurysms. In this study, we aim to assess the stiffness of intracranial aneurysms using 4D Flow MRI.
Methods: A total of 27 aneurysms in 25 patients with internal carotid artery aneurysms were included in this study.
Background: Vagal paragangliomas (VPs) are rare tumors in the upper cervical region. Although surgical resection is the standard treatment for these tumors, it carries significant risks due to the tumor's high vascularity and proximity to vital structures. Stereotactic radiosurgery (SRS) for skull base paraganglioma could be a minimally invasive alternative.
View Article and Find Full Text PDFBackground: The locations of pituitary neuroendocrine tumor (PitNET) and anterior clinoid meningioma (ACM) appear to be very close but essentially different, as the former is inside the sella turcica while the latter is in the intradural space. A collision tumor thus requires a specific treatment strategy but has been rarely reported.
Observations: A 77-year-old woman presented with progressive visual impairment due to significant compression of the optic apparatus by a collision of PitNET and ACM.
Article Synopsis
- Recent studies indicate that an endoscopic endonasal approach for accessing the middle fossa is feasible, though there have been few clinical applications reported.
- A case involving an 8-year-old boy with a middle fossa epidural abscess linked to sphenoid sinusitis was successfully treated using this method, leading to complete drainage and significant symptom relief.
- The procedure highlighted the importance of the maxillary strut in enabling access to the middle fossa, suggesting this approach could be beneficial for similar cases in the future.
Objective: This study compared the effectiveness of the endoscopic endonasal approach (EEA) with the conventional transcranial approach (TCA) for treating tuberculum sellae meningiomas (TSMs), aiming to identify the superior surgical method and the risk factors affecting outcomes.
Methods: Patients treated for TSM from 1998 to 2023 at our institution were retrospectively analyzed, evaluating patient characteristics, tumor features, outcomes, and complications. A novel grading system for preoperative evaluation of TSMs was proposed.
Background And Purpose: The impact of cobalt-60 dose rate (Co-60 DR) on outcomes of stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs) remains fully elucidated. This study explored the association between Co-60 DR and SRS outcomes in AVM treatment.
Materials And Methods: 772 AVM patients from 1990 to 2020 were included.
Article Synopsis
- - Chordomas are rare tumors that originate from remnants of the notochord and usually affect the axial skeleton; intrasellar chordomas are particularly uncommon and can mimic pituitary tumors.
- - An 87-year-old woman experienced acute mental changes and vision loss due to an intrasellar chordoma, leading to cortisol replacement therapy and surgical removal, which revealed characteristic displacement of the pituitary gland and absence of bony structures.
- - The diagnosis was confirmed through histological examination, and postoperative radiation therapy successfully prevented tumor progression for a year; the case emphasizes the need for neurosurgeons to recognize intrasellar chordomas and consider aggressive treatment strategies.
Patient-specific cerebral 3D vessel model reconstruction using deep learning.
Med Biol Eng Comput
October 2024
Article Synopsis
- Researchers developed a deep learning (DL) method for reconstructing 3D models of blood vessels from magnetic resonance angiography (MRA) images, reducing the need for manual adjustments.
- They used data from 40 patients with internal carotid artery aneurysms and created vessel models using a 2D U-net architecture, achieving a dice coefficient of 0.859 in testing accuracy.
- The DL-generated models not only successfully reconstructed blood vessel structures but also facilitated blood flow simulations, indicating potential for enhancing clinical decision-making and medical image processing in future studies.
Background: Acinic cell carcinomas (AcCCs), rare malignancies of the salivary glands, often recur and metastasize, particularly in the skull base. Conventional radical resection can be invasive for skull base AcCCs adjacent to cranial nerves and major vasculature, and the effectiveness of stereotactic radiosurgery (SRS) as an alternative is not well established.
Observations: This case report details the application of SRS for recurrent skull base AcCCs.
Article Synopsis
- The study assessed the geometric accuracy of radiation focal point (RFP) and cone-beam computed tomography (CBCT) in the ICON Leksell Gamma Knife system over a span of 544 days.
- It involved 269 analyses where RFP deviations from the unit center point (UCP) and positions of four ball bearings were measured, revealing minimal deviations in all three spatial dimensions.
- Notably, deviations were significantly improved after the cobalt-60 source replacement, showing consistent accuracy within 0.1 mm over the long-term period.
Objective: Chronic subdural hematoma (CSDH) is known to occur after endoscopic endonasal surgery (EES); however, the detailed clinical picture remains unclear. In this study, the authors aimed to examine the incidence of and risk factors for post-EES CSDH, with a focus on the quantitative evaluation of postoperative pneumocephalus.
Methods: The authors retrospectively collected data on consecutive patients who, between November 2016 and December 2022, had undergone EES during which intraoperative cerebrospinal fluid (CSF) leakage occurred.
Objective: This study aimed to assess the efficacy and safety of stereotactic radiosurgery (SRS) in treating transverse-sigmoid sinus dural arteriovenous fistulas (TSS DAVFs), and to investigate post-SRS sinus patency, focusing on the risk factors associated with treated sinus occlusion.
Methods: Data from 34 patients treated with SRS between January 2006 and April 2023 were analyzed. Detailed angioarchitecture was confirmed using digital subtraction angiography before SRS.
Purpose: This study investigated whether Ki-67 labeling index (LI) correlated with clinical outcomes after SRS for atypical meningiomas.
Methods: This retrospective study examined 39 patients with atypical meningiomas who underwent SRS over a 10-year study period. Ki-67 LI was categorized into 3 groups: low (< 5%), intermediate (5%-10%), and high (> 10%).
Background: Transcarotid artery revascularization (TCAR) has emerged as an alternative to carotid artery stenting (CAS). TCAR demonstrated its superiority by avoiding femoral artery puncture and establishing proximal protection without crossing the stenotic lesion. In the TCAR era, we focused on the possibility of a trans-distal radial approach (DRA).
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- Neurofibromatosis type 2 (NF2) leads to multiple nerve system tumors, making treatment challenging, and this study explores how different genetic mutations affect responses to stereotactic radiosurgery (SRS) for schwannomas.
- Researchers analyzed a small cohort of 14 NF2 patients with 22 tumors, revealing high progression-free rates (PFRs) of 95% at 5 years, but with some variations based on mutation types, particularly worse outcomes for truncating mutations.
- The study concluded that while SRS offers good PFR for less severe genetic forms of NF2, it requires cautious use in severe cases, especially those with specific mutations that may have poorer outcomes.
Objective: The aim of this study was to evaluate the effectiveness of ventriculo-cisternal irrigation (VCI) in preventing vasospasms and delayed cerebral infarction (DCI) by washing out subarachnoid clots earlier after aneurysm surgery.
Methods: We retrospectively identified 340 subarachnoid hemorrhage (SAH) patients with ruptured intracranial aneurysms treated with postoperative VCI at our institution between December 2010 and January 2020. As VCI therapy, a ventricular drain/cisternal drain was placed during aneurysm surgery, and lactated Ringer's solution was used for irrigation until day 4 of SAH, followed by intracranial pressure control at 5-10 cmHO until day 14.
Background: Recurrent cerebral aneurysms have complex shapes and are often technically challenging to treat with a single microcatheter. This study evaluates the clinical characteristics and treatment outcomes of patients who received double-catheter coil embolization for recurrent cerebral aneurysms.
Methods: Patients who underwent double-catheter coil embolization at our institution between April 2011 and March 2022 for recurrent aneurysms were included in the study.
Objective: With the increasing incidence of malignancies, the importance of cancer-associated stroke is emphasized. Although moyamoya disease is a leading cause of stroke, no reports have documented cancer-associated stroke in patients with this condition. We aimed to investigate cerebrovascular events during malignancy treatments in patients with moyamoya disease.
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