Ruptured distal anterior inferior cerebellar artery aneurysm years after stereotactic radiosurgery for vestibular schwannoma: A case report and literature review.

Background: Aneurysmal formation after stereotactic radiosurgery (SRS) for vestibular schwannoma (VS) is a rare complication. Its characteristics and the best treatment strategies remain controversial, and the clinical course is especially unknown because reported aneurysms are first incidentally detected, or aneurysmal rupture occurs suddenly, and they are treated immediately. Case Description: A 68-year-old man who underwent SRS for VS 20 years ago presented with subarachnoid hemorrhage (SAH) due to rupture of a radiation-induced fusiform anterior inferior cerebellar artery aneurysm. He was treated with parent artery occlusion, resulting in a modified Rankin scale grade 2. This report illustrates the first case of detected aneurysm formation before rupture with retrospective magnetic resonance imaging evaluation. Conclusion: We describe the possible risk of rapid progression and rupture of aneurysms, focusing on the interval from SRS to aneurysmal formation. The period of formation of SRS-induced aneurysms is suspected to vary from years to decades regardless of radiation doses; however, aneurysms estimated as pseudoaneurysms have an extremely high risk of rupture within a few years, even when small in size. If aneurysms are discovered unruptured, there are some advantages in not only the prevention of poor prognosis due to SAH but also in the availability of optional therapeutic strategies using revascularization. Long-term annual follow-up, including vessel examination, is warranted not only to assess tumor status but also for early detection of any vascular lesions.

SARS-CoV-2 Testing of the Maxillary Sinus Immediately after COVID-19 Recovery.

We report the case of a 19-year-old woman with left orbital floor fracture after a motorcycle accident. She presented with headache and diplopia; computed tomography showed herniation of the inferior rectus muscle into the maxillary sinus with orbital floor fracture. She was admitted for observation of her concussion and tested positive for coronavirus disease 2019 (COVID-19) half a day after admission. Her COVID-19 symptoms were mild; the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigen quantification test was below the standard value on the 10th day of hospitalization, and her isolation was lifted. She had diplopia with vertical eye motion disorder and underwent reconstruction of her orbital floor fracture on the 11th day. Although the orbital floor was connected to the maxillary sinus due to the orbital floor fracture, the presence and the viral load of SARS-CoV-2 in the maxillary sinus were unknown. The surgeons performed the operation while wearing N95 masks. A SARS-CoV-2 antigen quantification test and PCR test were performed on a sample from the maxillary sinus mucosa obtained through the orbital floor fracture before reconstruction of orbital floor with a titanium mesh implant; both were negative. To our knowledge, this is the first report of SARS-CoV-2 testing from the maxillary sinus immediately after COVID-19 recovery. We believe that the risk of SARS-CoV-2 infection from the maxillary sinus is small if the antigen test from the nasopharynx is negative.

Epidemiology of Subarachnoid Hemorrhage in Isolated Islands in Japan: A Population-based Study in the Miyako Islands.

The Miyako Islands (with a population of approximately 50,000) are located in southwestern Japan, with a subtropical oceanic climate. This isolated location permitted a retrospective population-based epidemiological study of subarachnoid hemorrhage. We retrospectively enrolled 110 consecutive patients from 2010 to 2019 using the subarachnoid hemorrhage database at Okinawa Miyako Hospital, which is the only local facility with neurosurgeons. We calculated the incidence of subarachnoid hemorrhage standardized to the entire Japanese population. The seasonal distribution of subarachnoid hemorrhage onset and patients' epidemiological characteristics were also investigated. The standardized annual incidence of subarachnoid hemorrhage was 21.4 per 100,000 population, as reported previously in Japan. The patients' mean age was 62.1 ± 15.4 years, and women constituted 60.9%. Anterior communicating artery aneurysms were most common. The endovascular treatment for ruptured aneurysms was increasing as standard levels in Japan. The rates of symptomatic vasospasm and secondary hydrocephalus requiring additional neurosurgical treatment were 2.7% and 19.1%, respectively. The mortality rate was 23.6%. The percentage of patients with a modified Rankin scale score of 0-2 at discharge was 55.5%. There were no differences in the frequency of subarachnoid hemorrhage associated with seasonal distribution or climatic factors. The incidence, baseline characteristics, and clinical outcomes of subarachnoid hemorrhage in the Miyako Islands were similar to those in other regions of Japan. There are preferable epidemiological backgrounds for further practical clinical research.

Delayed brain infarction caused by mechanical compression of the anterior choroidal artery after coil embolization for a large internal carotid-posterior communicating artery aneurysm: A case report.

A 65-year-old male received coil embolization for a large internal carotid-posterior communicating artery aneurysm. Pre- and postoperative angiography at surgery demonstrated that the ipsilateral anterior choroidal artery branched from the internal carotid artery near the distal side of the aneurysm, and elevated and expanded on the aneurysmal dome, but was clearly visualized. Three days following endovascular treatment, the patient presented hemiparesis on the left side, with brain infarction in the territory of the right anterior choroidal artery despite antithrombotic therapy. The delayed brain infarction was likely caused by a reduction in anterior choroidal artery perfusion caused by mechanical compression following a postoperative increase in internal carotid-posterior communicating artery aneurysmal volume during intra-aneurysmal thrombosis. Transient volume expansion after coil embolization for intracranial aneurysms is rarely reported as a cause of brain infarction. It is important to recognize these arteries as potential postoperative complication risks, and consider the use of open surgery to avoid this risk.

Risk of fatal sinus arrest induced by low-grade subarachnoid hemorrhage: A case of a young patient with obstructive sleep apnea.

BACKGROUND: Sleep apnea syndrome (SAS) and subarachnoid hemorrhage (SAH) are both considered possible causes of secondary arrhythmias. However, there are limited reports on the increased risk of bradyarrhythmia for arrhythmia-free SAS patients with SAH. CASE DESCRIPTION: A 31-year-old woman with SAS developed low-grade SAH and underwent coil embolization on postbleed day 1. Following a coiling procedure, she experienced worsening episodes of sinus arrest lasting up to 12 s and required a temporary pacemaker. Frequent episodes of sinus arrest were detected for the next 4 days. Thereafter, all types of arrhythmias gradually decreased, and she eventually recovered to be arrhythmia free. CONCLUSION: Acceleration of sympathetic nervous activity caused by acute SAH may predispose patients to bradyarrhythmia with SAS and elicit asystole. The coexistence of SAS and SAH should be recognized as a cause of life-threatening sinus arrest, even if the severity of SAH is low grade.

Feasibility and Safety of Endoscopic Procedure in Burr-Hole Surgery for Chronic Subdural Hematoma in Patients of Very Advanced Age.

OBJECTIVE: The usefulness of endoscopic procedures for chronic subdural hematoma (CSDH) has been described, but the indications in patients of very advanced age have not been analyzed. The aim of this study was to evaluate the feasibility, safety, and usefulness of introduction of an endoscopic procedure for such patients. METHODS: We retrospectively analyzed the data of 540 CSDHs treated by burr-hole surgery with endoscopic examination. The safety of the endoscopic procedure was assessed according to postoperative complications, morbidity, and mortality. The outcome was evaluated by statistical comparison among 4 different age-groups, and the recurrence rate and risk factors for recurrence was investigated in patients of very advanced age. RESULTS: Postoperative complications occurred in 7 cases (1.5%). The 6-month morbidity and mortality were 13.5% and 4.5%. No complications, morbidity, or mortality associated with the additional endoscopic procedure occurred even in patients of very advanced age. The endoscopic features of trabecular structures and residual septa separating the cavity were also risk factors for recurrence in patients of very advanced age. Releasing of the septa showed the possibility of decreasing the risk of recurrence to 6.6% in patients aged ≥85 years as well as in younger patients. There were some inevitable problems such as prolongation of the surgical time and inadequate endoscopic surgical skill. CONCLUSIONS: An endoscopic procedure for CSDH can be safely indicated and useful even in patients aged ≥85 years. However, clinicians should carefully select the patients based on clinical information associated with risk factors for recurrence.

Toward Inter-isolated Island Cooperation for the Drip, Ship, and Retrieve Method in the Sakishima Islands: A Case Report.

Objective: Based on the findings of preferable outcomes from recanalization therapy in recent studies, regional partnerships for the endovascular treatment of acute ischemic stroke are being promoted. However, reports of inter-island cooperation between remote islands located far from high-volume centers on the mainland are rare. Case Presentation: A 63-year-old man experienced an acute ischemic stroke on a small, isolated island in Okinawa, Japan. He was transferred by helicopter to the primary emergency hospital on Ishigaki Island, which was the nearest island on which he could be administered recombinant tissue plasminogen activator (rtPA). After this, he was carried again by helicopter and ambulance to the primary stroke center on Miyako Island using the drip and ship method. Mechanical thrombectomy with a stent retriever achieved recanalization of the occluded major vessels and improved the neurological disturbance. The patient became neurologically independent and could be discharged only 11 days after onset. Conclusion: Building a local area network that includes hospitals providing mechanical thrombectomy is a meaningful approach to treating acute ischemic stroke occurring on isolated islands. It is necessary to recognize the specific restrictions imposed by helicopter transportation and to make efforts to shorten the time required for key processes to provide faster treatment.

Analysis of Endoscopic Findings in the Chronic Subdural Hematoma Cavity: Bleeding Factors in Chronic Subdural Hematoma Natural History and as Predictors of Recurrence.

OBJECTIVE: Possible factors associated with bleeding from endoscopy-detected chronic subdural hematomas (CSDHs) have rarely been analyzed. We therefore evaluated intraoperative endoscopic findings to elucidate the clinical course and assess predictors of CSDH recurrence. METHODS: Altogether, 540 CSDHs were reviewed in this retrospective study. Six possible signs of bleeding were detected in the cavity: spotty bleeding on the outer membrane, hematoma clots, cerebral parenchymal suspension, stretched cortical vessels, intraluminal trabecular structures, and septa separating the cavity. We evaluated the association of each with the radiologic findings, endoscopic features, and interval from trauma to surgery and then assessed the correlation between each endoscopic feature and CSDH recurrence. RESULTS: Spotty bleeding, cerebral parenchymal suspension, and stretched cortical vessels occurred during every period. Hematoma clots exhibited a 2-peak pattern with significant resurgence during the chronic phase. Trabecular structures significantly increased 61 days after the trauma, reaching 71.2% of patients on day 91. Septa were found in the cavity in only 12.5% during the initial 30 days but subsequently increased significantly to 37.3%. At 2 months, an exacerbation stage was inferred. The multivariable analysis revealed that trabecular structures and residual septa were significant independent risk factors for recurrence. We opened most septa intraoperatively. Their recurrence rate was 7.5%, which is lower than has been previously reported. CONCLUSIONS: Evaluation of the changes in the endoscopic findings and their association with recurrence was useful for clarifying the mechanism of CSDH enlargement, the risk of recurrence, and the potential for endoscopic surgery.

[Bevacizumab-Related Hyperintense Lesions on Diffusion-Weighted Imaging at Different Locations in a Patient with Malignant Glioma].

We report the case of a 60-year-old man who first presented with transient difficulty of word recall. Subsequent MRI revealed an invasive brain tumor in the left frontal lobe. The patient underwent open biopsy, and diffuse astrocytoma(WHO grade II)was diagnosed. However, the malignant potential of this tumor was not particularly low because of a few enhancement on preoperative evaluation, and radiation therapy was initially performed. Four months after ending irradiation, temozolomide treatment was introduced for tumor regrowth. After another 2 months, combined chemotherapy with bevacizumab was also started due to tumor enlargement, which was evaluated as malignant transformation to glioblastoma. Two focal lesions with signal hyperintensity on DWI appeared in the frontal and temporal lobes at different locations 3 months after starting bevacizumab. The left temporal lesion subsequently changed to a ring-enhanced tumor, and glioblastoma(WHO grade IV)was finally diagnosed at decompressive surgery. Another frontal lesion, however, continued to maintain a favorable course without any changes in signal despite appearing as similar signal-hyperintense lesions. The temporal hyperintense lesion may undergo malignant transformation into glioblastoma with typical radiological appearance. Recent studies on image changes following bevacizumab treatment have attracted widespread attention, and the clinical significance of such hyperintense lesions has gained attention. This present case was thought to be valuable because of the contradistinctive aspects at the same time, in which the hyperintense lesions of the frontal and temporal lobes seemed to represent antitumor activity or drug refractory effects based on bevacizumab treatment.

Successfully Treated Isolated Posterior Spinal Artery Aneurysm Causing Intracranial Subarachnoid Hemorrhage: Case Report.

There are very few published reports of rupture of an isolated posterior spinal artery (PSA) aneurysm, and consequently the optimal therapeutic strategy is debatable. An 84-year-old man presented with sudden onset of restlessness and disorientation. Neuroradiological imaging showed an intracranial subarachnoid hemorrhage (SAH) with no visible intracranial vascular lesion. Spinal magnetic resonance imaging (MRI) detected a localized subarachnoid hematoma at Th10-11. Both contrast-enhanced spinal computed tomography and enhanced MRI and magnetic resonance angiography revealed an area of enhancement within the hematoma. Superselective angiography of the left Th12 intercostal artery demonstrated a faintly enhanced spot in the venous phase. Thirteen days after the onset of symptoms, a small fusiform aneurysm situated on the radiculopial artery was resected. The patient's postoperative course was uneventful and he was eventually discharged in an ambulatory condition. To our knowledge, this 84-year-old man is the oldest reported case of surgical management of a ruptured isolated PSA aneurysm. This case illustrates both the validity and efficacy of this therapeutic approach.

Management of Trigeminal Neuralgia Caused by an Intraneural Spiral Trigeminocerebellar Artery: A Case Report.

The trigeminocerebellar artery (TCA) is a branch of the basilar artery that may have an intraneural course and may cause trigeminal neuralgia. We report a case of trigeminal neuralgia with right vertebral artery aneurysm caused by an intraneural TCA that compressed the trigeminal nerve in multiple places. We performed proximal trapping for the fusiform aneurysm with extra-intracranial bypass to preserve flow of the posterior inferior cerebellar artery, followed by microvascular decompression that successfully changed the course of the TCA. This procedure provided relief from the neuralgia without direct bisection of the trigeminal nerve that may cause severe nerve injury. Reshaping of the course of the artery can achieve good pain relief.

Endoscopic endonasal surgical approach to the oculomotor trigone from the cavernous sinus.

Knowledge of anatomy visualized endoscopically is necessary to perform endoscopic surgical procedures safely. The cavernous sinuses are complicated structures with major blood vessels and nerves seated deeply in the center of the skull base. Anatomical orientation during surgery is essential for deep and narrow skull base surgery. While performing surgery involving the cavernous sinuses, understanding of the structures identifiable via a transsphenoidal view can allow comprehension of the relationship between a lesion and the surrounding structures, thus preventing intraoperative complications. The objective of this study was to dissect the neurovascular structures in the cavernous sinus deeply inside the oculomotor trigone through a transsphenoidal view, and to determine the relationships among anatomical landmarks in the path of surgery. Ten fresh silicone-injected cadaveric heads were evaluated. Four millimeter-diameter rigid endoscopes with 0° and 30° rod-lenses were utilized to perform an endonasal transsphenoidal approach. The detailed position and course of the major components in each cavernous sinus were assessed under panoramic view. We also validated the utility of this approach by successfully excising a huge pituitary adenoma.

Endoscopic endonasal surgical approach to the oculomotor trigone from the cavernous sinus.

Knowledge of anatomy visualized endoscopically is necessary to perform endoscopic surgical procedures safely. The cavernous sinuses are complicated structures with major blood vessels and nerves seated deeply in the center of the skull base. Anatomical orientation during surgery is essential for deep and narrow skull base surgery. While performing surgery involving the cavernous sinuses, understanding of the structures identifiable via a transsphenoidal view can allow comprehension of the relationship between a lesion and the surrounding structures, thus preventing intraoperative complications. The objective of this study was to dissect the neurovascular structures in the cavernous sinus deeply inside the oculomotor trigone through a transsphenoidal view, and to determine the relationships among anatomical landmarks in the path of surgery. Ten fresh silicone-injected cadaveric heads were evaluated. Four millimeter-diameter rigid endoscopes with 0° and 30° rod-lenses were utilized to perform an endonasal transsphenoidal approach. The detailed position and course of the major components in each cavernous sinus were assessed under panoramic view. We also validated the utility of this approach by successfully excising a huge pituitary adenoma.

A pitfall of neuroendoscopic intraventricular hematoma removal - delayed obstructive hydrocephalus caused by a small remnant clot - case report - .

A 57-year-old female presented with a left putaminal hemorrhage, intraventricular hematoma (IVH), and acute obstructive hydrocephalus. Neuroendoscopic surgery was performed for the IVH. Three days after successful IVH removal and improvement of her consciousness, the patient lapsed into a comatose state due to hydrocephalus caused by obstruction of the mesencephalic aqueduct by a small remnant clot. The small clot was identified by constructive interference with steady state magnetic resonance imaging and was removed during a second-look operation. Even after the cerebrospinal fluid circulation improves following neuroendoscopic surgery for IVH, the patient may nevertheless develop a life-threatening condition without warning signs in the subacute phase. Awareness of this complication will lead to early diagnosis and correct management.

Comparison of clinical outcomes of intraventricular hematoma between neuroendoscopic removal and extraventricular drainage.

The efficacy of treatment for intraventricular hematoma by neuroendoscopic surgery and extraventricular drainage was compared in 10 patients with intraventricular hematoma and hydrocephalus who underwent neuroendoscopic surgery (endoscopic group), and eight patients with intraventricular hematoma and hydrocephalus treated with extraventricular drainage (EVD group). The outcomes in each group were assessed retrospectively using the Graeb scores on the pre- and postoperative computed tomography (CT), duration of extraventricular drainage, requirement for a shunt operation, and modified Rankin scale score at 12 months. The Graeb scores on the preoperative CT were not significantly different between the two groups, but the duration of catheter placement was significantly shorter (69.3%) in the endoscopic group (2.7 days) than in the EVD group (8.8 days). None of the patients in either group required a shunt procedure for communicating hydrocephalus 12 months after surgery. Neuroendoscopic removal is a safe and effective procedure for intraventricular hematoma. Advantages include rapid removal of hematoma in the ventricular systems and reliable improvement of non-communicating hydrocephalus in the acute phase. The procedure resulted in faster removal of the catheter in the postoperative period and earlier patient ambulation.