Correlation Between Sea-Level Rise and Aspects of Future Tropical Cyclone Activity in CMIP6 Models.

Future coastal flood hazard at many locations will be impacted by both tropical cyclone (TC) change and relative sea-level rise (SLR). Despite sea level and TC activity being influenced by common thermodynamic and dynamic climate variables, their future changes are generally considered independently. Here, we investigate correlations between SLR and TC change derived from simulations of 26 Coupled Model Intercomparison Project Phase 6 models. We first explore correlations between SLR and TC activity by inference from two large-scale factors known to modulate TC activity: potential intensity (PI) and vertical wind shear. Under the high emissions SSP5-8.5, SLR is strongly correlated with PI change (positively) and vertical wind shear change (negatively) over much of the western North Atlantic and North West Pacific, with global mean surface air temperature (GSAT) modulating the co-variability. To explore the impact of the joint changes on flood hazard, we conduct climatological-hydrodynamic modeling at five sites along the US East and Gulf Coasts. Positive correlations between SLR and TC change alter flood hazard projections, particularly at Wilmington, Charleston and New Orleans. For example, if positive correlations between SLR and TC changes are ignored in estimating flood hazard at Wilmington, the average projected change to the historical 100 years storm tide event is under-estimated by 12%. Our results suggest that flood hazard assessments that neglect the joint influence of these factors and that do not reflect the full distribution of GSAT change may not accurately represent future flood hazard.

Anatomical study of the internal carotid venous plexus: new findings with application to skull base surgery.

OBJECTIVE: The venous plexus (internal carotid venous plexus) surrounding the petrous part of the internal carotid artery (ICAp) is said to be one drainage pathway of the cavernous sinus. These veins have many potential clinical implications including iatrogenic hemorrhage during surgical approaches to the skull base and carotid-cavernous fistulas. Because there are few morphological data about this venous plexus at the skull base, this descriptive/quantitative study was performed to elucidate its anatomy. METHODS: Six latex-injected cadaveric heads (twelve sides) were dissected via a superior craniotomy approach in which the ICAp was exposed by drilling away the overlying bone. A venous plexus surrounding parts of the ICAp in all sides was documented along with the positions of its major tributaries and their connections. RESULTS: The veins were most concentrated near the junction of the ICAp and the cavernous part of the internal carotid artery, and usually along the medial and lateral sides of the ICAp. Tributaries included branches joining the basilar venous plexus posteriorly and branches joining the veins surrounding the foramen ovale anteriorly. CONCLUSION: Detailed knowledge of the anatomy of this venous plexus surrounding the ICAp is useful for interpreting imaging of the skull base and valuable for surgeons operating in this part of the cranium.

Middle Fossa Encephaloceles Treated via the Transmastoid Approach: A Case Series and Review of the Literature.

BACKGROUND: Middle fossa (MF) encephaloceles are rare lesions resulting from herniation through defects in the tegmen tympani or mastoideum. Underlying etiologies and clinical presentations are variable. Surgical goals include fistula obliteration, resection of nonfunctioning parenchyma, and dehiscence repair. The middle cranial fossa approach (MCFA), transmastoid approach (TMA), and combined (MCFA + TMA) approaches have been described. The minimally invasive TMA provides excellent exposure of the pathology and allows for ample working room to repair the defect. OBJECTIVE: To present short-term follow-up results in patients treated via the TM repair at our institution. METHODS: A retrospective review of patients with symptomatic encephaloceles treated via the TMA by our multidisciplinary team. Patient demographics, clinical presentations, intraoperative findings, repair technique, and outcomes were highlighted. RESULTS: A total of 16 encephaloceles in 13 patients were treated. Defect etiologies included spontaneous (50.0%), secondary to chronic infection (25.0%), or cholesteatoma (18.8%). Defects were most often within the tegmen mastoideum (68.8%). Average length of surgery was 3.3 h (95% CI: 2.86-3.67) and length of stay 3.9 d (95% CI: 3.09-4.79). On short-term follow-up (average 11.5 mo), no patients experienced postoperative cerebrospinal fluid leak or recurrence. The majority of patients (83.3%) experienced confirmed improvement or stabilization of hearing. CONCLUSION: MF encephaloceles present with various clinical manifestations and result from multiple underlying etiologies. The TMA is an alternative to craniotomy and our short-term results suggest that this approach may be utilized effectively in appropriately selected cases.

Transradial access for anterior circulation deployment of pipeline embolization device: A case report, literature review, and technical note.

Common femoral artery (CFA) transfemoral access (TFA) has been the traditional route for neuroendovascular intervention with flow diversion including the pipeline embolization device (PED) for the treatment of wide-necked aneurysms. Successful deployment requires significant catheter support, thus making alternative access challenging. A 56-year-old-female presented with subarachnoid hemorrhage secondary to a large ruptured posterior communicating artery (PCOM) aneurysm as well as found to have an unruptured left superior cerebellar artery (SCA) aneurysm. Endovascular embolization of PCOM aneurysm via TFA was complicated by a right CFA pseudoaneurysm. The SCA aneurysm was treated 8 weeks later via left TFA with consequent development of a left CFA pseudoaneurysm. Contrasted magnetic resonance angiography revealed recurrence at the neck of the PCOM aneurysm at 4-month follow-up, treated via transradial access (TRA) PED flow diversion to avoid additional groin complications. Anatomic, procedural, and clinical considerations for TRA anterior circulation flow diversion using the PED are reviewed.

Anatomical Study of the Posterior Spinal Artery Branches to the Medulla Oblongata.

BACKGROUND: The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically. METHODS: We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata. RESULTS: All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted. CONCLUSIONS: Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.

Comprehensive review of the mastoid foramen.

Anatomical variations of the mastoid foramen have been observed to vary in a number of qualities including size, number, and location. These variants have the potential to become problematic during surgical approaches to the posterior cranial fossa and mastoid part of the temporal bone, and should thus be appreciated by the surgeon. Herein, we discuss the mastoid foramen in detail including issues with such foramina that should be known to the neurosurgeon.

Anatomic Study Quantifying the Relationship Between the Arcuate Eminence and the Root of the Zygoma: Application to Skull Base Surgery.

OBJECTIVE: The aim of this study was to define the structural relationship between the arcuate eminence (AE) and a known fixed external bony landmark, the root of the zygoma (ZR), and to determine its reliability as a consistent guide for guiding surgical approaches. To our knowledge, this is the only anatomic study to quantify the relationship between the AE and ZR. METHODS: Twenty-one dry temporal bones were measured using digital calipers. The distance from the posterior aspect of the ZR to the midpoint of the AE was measured. Additionally, the anteroposterior distance between the ZR and AE and vertical distance between the 2 structures were measured. Student's t-test was used to compare the left and right sides. RESULTS: An AE was found in every specimen. The mean ZR to AE distance was 30.9 mm. On most sides (91%), the ZR was located more inferiorly than the AE with a mean distance of 3 mm between the 2 structures. The mean distance between the AE and ZR was 17 mm. On all sides, the AE was located posterior to the ZR. No significant differences were found between sides. No anatomic variations or pathologic conditions were noted in any of the specimens. CONCLUSIONS: The ZR is an easily identifiable and consistent bony landmark often used by skull base surgeons. In this investigation, we measured the anatomic relationships between the ZR and AE. Such data might assist in planning surgical trajectories and minimizing complications when skull base pathologies are approached.

Adult Pineal Region Atypical Teratoid Rhabdoid Tumor: A Case for Aggressive Surgical and Chemoradiation Management with Comprehensive Literature Review.

BACKGROUND: Atypical teratoid rhabdoid tumor (ATRT) is a rare, highly malignant central nervous system neoplasm classified as an embryonal grade IV neoplasm by the World Health Organization. ATRT generally occurs in children younger than 3 years, with 85 pathologically confirmed cases reported in adults. It is most commonly supratentorial, with only 9 confirmed adult cases localized to the pineal region. CASE DESCRIPTION: The case is described of a 29-year-old man with a history of chronic migraines and a previously negative computed tomography scan of the head presenting with worsening headaches and new-onset diplopia with upward gaze palsy. Computed tomography and magnetic resonance imaging showed a hemorrhagic pineal mass with extension into the right thalamus. After resection, the immunohistochemical staining and cytogenetic profile proved consistent with ATRT, making it the ninth reported case of pineal ATRT in an adult, which was treated aggressively with good outcome. CONCLUSIONS: Adult ATRT is rare, especially in the pineal region, with only 9 cases reported. Because of the aggressiveness, ATRT must be considered in the differential diagnosis of pineal region lesions because early diagnosis and aggressive treatment are key to prolonged survival.

The inferior intercavernous sinus: An anatomical study with application to trans-sphenoidal approaches to the pituitary gland.

OBJECTIVES: The inferior intercavernous sinus is located below the pituitary gland in the sella turcica. Its presence has been controversial among anatomists because it is not always found on radiological imaging or during cadaveric dissections; however, it is becoming a better-known structure in the neurosurgical and radiological fields, specifically with respect to transsphenoidal surgery. Therefore, the present study was performed to better elucidate this structure at the skull base. PATIENTS AND METHODS: Fifty adult, latex injected cadavers underwent dissection. The presence or absence of the inferior cavernous sinus was evaluated and when present, measurements of its width and length were made. Its connections with other intradural venous sinuses were also documented. RESULTS: An inferior intercavernous sinus was identified in 26 % of specimens. In all specimens, it communicated with the left and right cavernous sinus. The average width and length were 3 mm and 9.5 mm, respectively. In the sagittal plane, the inferior intercavernous sinus was positioned anteriorly in 31 %, at the nadir of the sella turcica in 38 %, and slightly posterior to the nadir of the sella turcica in 31 %. In two specimens (15.4 %), the sinus was plexiform in its shape. In one specimen a diploic vein connected the basilar venous plexus to the inferior intercavernous sinus on its deep surface. CONCLUSION: An improved understanding of the variable anatomy of the inferior intercavernous sinus is important in pathological, surgical, and radiological cases.

Herniation of orbital fat through the inferior orbital fissure and into the infratemporal fossa: a cadaveric case report and review.

Orbital fat herniation is primarily in a subconjunctival location. However, herniation through the inferior orbital fissure (IOF) has been scantly reported. Here, we report a cadaveric case of herniation of orbital fat through the inferior orbital fissure and into the infratemporal fossa. The cadaver's orbital anatomy and orbital fat herniation were found during routine dissection. The details of this case are reported. We also discuss anatomical variations of the inferior orbital fissure as well as the related vascular and nervous system structures related to orbital fat herniation. This is a rare case of a cadaver with this anatomical abnormality.

Endovascular Management of a Ruptured Basilar Perforator Artery Aneurysm Associated with a Pontine Arteriovenous Malformation: Case Report and Review of the Literature.

BACKGROUND: Arteriovenous malformation (AVM)-associated aneurysms are common, reported in 15% of cases. Regarding the ruptured posterior fossa AVMs, associated aneurysms are present in 48% of cases and are the cause of the bleed in 37%. We present a 75-year-old female who presented with a subarachnoid hemorrhage secondary to a ruptured aneurysm arising from a flow-related basilar perforator artery feeder of an anterior pontine AVM. We report the successful treatment of the aneurysm with coil embolization. CASE DESCRIPTION: A 75-year-old female presented with subarachnoid hemorrhage primarily contained within the posterior fossa. Angiography demonstrated a 2 × 3-mm fusiform aneurysm arising from a basilar perforator feeding pedicle of an anterior 1 × 2-cm pontine AVM. Venous drainage from the AVM was predominantly to the superior petrosal vein. Under roadmap guidance, super-selective catheterization of the basilar perforator aneurysm was performed. Three HydroSoft 3D coils were deployed within the aneurysm, resulting in complete obliteration. The patient was discharged on postbleed day 15 to an inpatient rehabilitation facility. Follow-up angiography at 5 months demonstrated stable complete obliteration. The patient made a complete recovery and was living independently at the time of this report. CONCLUSIONS: Basilar trunk perforator aneurysms are rare lesions, particularly in the setting of brainstem AVMs. We report successful endovascular treatment of a flow-related ruptured basilar perforator aneurysm associated with an anterior pontine AVM. To the best of our knowledge, this is the second report addressing this scenario. We hope that the information presented here serves to guide future surgical decision making and management.

Endovascular Management of Multiple Dysplastic Aneurysms in a Young Man with an Unknown Underlying Cause: A Case Report and Review of the Literature.

BACKGROUND: Intracranial aneurysms are the leading cause of nontraumatic subarachnoid hemorrhage and are most commonly associated with the anterior cerebral artery (ACA) and anterior communicating artery complex. We describe the presentation and management of a 27-year-old man with concurrent bilateral A1-2 junction aneurysms and fusiform intraorbital ophthalmic artery (OA) aneurysms. CASE DESCRIPTION: A 27-year-old man with no past medical history presented with 3 months of headaches. Imaging showed a large dysplastic left A1-2 junction aneurysm and a smaller saccular right A1-2 junction aneurysm, with potentially adherent domes. Two fusiform aneurysms of the intraorbital segment of the left OA were also identified. The patient underwent coil-assisted pipeline embolization of the left A1-A2 aneurysm, with complete obliteration and reconstitution of the normal parent vessel. The patient underwent coil embolization of the right A1-2 aneurysm 3 weeks later, which was found to have grown significantly at the time of treatment. Three-month follow-up showed spontaneous resolution of the OA aneurysms, persistent obliteration of the left aneurysm, and significant recurrence of the right aneurysm, which was treated with stent-assisted coil embolization. A second recurrence 3 months later was successfully treated with repeat coiling. At the time of this treatment, the patient was also found to have 2 de novo distal middle cerebral artery and ACA dysplastic aneurysms, which were not treated. Follow-up angiography 6 weeks later showed stable complete obliteration of the right A1-2 aneurysm and interval complete resolution of the dysplastic middle cerebral artery aneurysm. The distal ACA aneurysm was observed to have minimally increased in size; however, the parent vessel showed signs of interval partial thrombosis with contrast stasis within the aneurysm. This final aneurysm is being followed with serial imaging. The patient remains neurologically intact with complete resolution of his headaches. CONCLUSIONS: We report the case of a young man with no past medical history who presented with multiple dysplastic aneurysms. Successful staged endovascular intervention resulted in obliteration of aneurysms with spontaneous obliteration of the intraorbital OA aneurysms observed at 3 months. We present this case to review the multiple challenges of managing complex ACA aneurysms and to highlight the usefulness of endovascular intervention in their treatment.