Dysbiosis of Gut Microbiome Is Associated With Rupture of Cerebral Aneurysms.

BACKGROUND AND PURPOSE: Environmental factors are important with respect to the rupture of cerebral aneurysms. However, the relationship between the gut microbiome, an environmental factor, and aneurysm rupture is unclear. Therefore, we compared the gut microbiome in patients with unruptured intracranial aneurysms (UIAs) and ruptured aneurysms (RAs) to identify the specific bacteria causing the rupture of cerebral aneurysms. METHODS: A multicenter, prospective case-control study was conducted over one year from 2019 to 2020. The fecal samples of patients with stable UIAs and RAs immediately after onset were collected. Their gut microbiomes were analyzed using 16S rRNA sequencing. Subsequently, a phylogenetic tree was constructed, and polymerase chain reaction was performed to identify the specific species. RESULTS: A total of 28 RAs and 33 UIAs were included in this study. There was no difference in patient characteristics between RAs and UIAs: age, sex, hypertension, dyslipidemia, diabetes status, body mass index, and smoking. No difference was observed in alpha diversity; however, beta diversity was significantly different in the unweighted UniFrac distances. At the phylum level, the relative abundance of Campylobacter in the RA group was larger than that in the UIA group. Furthermore, the gut microbiome in the RA and UIA groups exhibited significantly different taxonomies. However, Campylobacter was focused on because it is widely known as pathogenic among these bacteria. Then, a phylogenetic tree of operational taxonomic units related to Campylobacter was constructed and 4 species were identified. Polymerase chain reaction for these species identified that the abundance of the genus Campylobacter and Campylobacter ureolyticus was significantly higher in the RA group. CONCLUSIONS: The gut microbiome profile of patients with stable UIAs and RAs were significantly different. The genus Campylobacter and Campylobacter ureolyticus may be associated with the rupture of cerebral aneurysms.

[Ruptured Dissecting Distal Superior Cerebellar Artery Aneurysm Successfully Treated with Coil Embolization: A Case Report].

BACKGROUND: Ruptured dissecting superior cerebellar artery aneurysms are rare, and only 12 cases have been reported. We report a case of dissecting aneurysm of the distal superior cerebellar artery presenting with subarachnoid hemorrhage. CASE PRESENTATION: An 80-year-old man presented with a three-day history of headache and diplopia. CT revealed slight subarachnoid hemorrhage and CT angiography demonstrated a dissecting aneurysm located in the distal portion of the left superior cerebellar artery. Initially, we chose conservative therapy. Ten days later, the patient became drowsy. Repeat CT showed that the amount of the subarachnoid hematoma increased and the aneurysm enlarged. Emergent endovascular coil embolization with parent artery occlusion was performed successfully. Postoperative MRI revealed no infarction in the cerebellum or brain stem. Delayed ischemic deficits were not observed after treatment. CONCLUSION: Endovascular parent artery occlusion of the distal superior cerebellar artery is an effective method with low morbidity for treatment of ruptured dissecting distal superior cerebellar artery aneurysms.

Silicate Microfiber Scaffolds Support the Formation and Expansion of the Cortical Neuronal Layer of Cerebral Organoids With a Sheet-Like Configuration.

Cerebral organoids (COs) are derived from human-induced pluripotent stem cells in vitro and mimic the features of the human fetal brain. The development of COs is largely dependent on "self-organization" mechanisms, in which differentiating cells committed to cortical cells autonomously organize into the cerebral cortex-like tissue. However, extrinsic manipulation of their morphology, including size and thickness, remains challenging. In this study, we discovered that silicate microfiber scaffolds could support the formation of cortical neuronal layers and successfully generated cortical neuronal layers, which are 9 times thicker than conventional COs, in 70 days. These cortical neurons in the silicate microfiber layer were differentiated in a fetal brain-like lamination pattern. While these cellular characteristics such as cortical neurons and neural stem/progenitor cells were like those of conventional COs, the cortical neuronal layers were greatly thickened in sheet-like configuration. Moreover, the cortical neurons in the scaffolds showed spontaneous electrical activity. We concluded that silicate microfiber scaffolds support the formation of the cortical neuronal layers of COs without disturbing self-organization-driven corticogenesis. The extrinsic manipulation of the formation of the cortical neuronal layers of COs may be useful for the research of developmental mechanisms or pathogenesis of the human cerebral cortex, particularly for the development of regenerative therapy and bioengineering.

Percutaneous Transluminal Angioplasty and Stenting for Progressive Intracranial Carotid Artery Stenosis Secondary to Invasive Sphenoid Sinus Aspergillosis: A Case Report.

We report a case of invasive sphenoid sinus aspergillosis with progressive internal carotid artery (ICA) stenosis and contralateral carotid occlusion that was successfully treated with percutaneous transluminal angioplasty and stenting (PTAS). A 70-year-old man presented with right-sided visual disturbance, ptosis, and left hemiparesis. Magnetic resonance imaging of the head revealed a space-occupying lesion within the sphenoid sinus with infiltration of the bilateral cavernous sinuses, right ICA occlusion, and multiple watershed cerebral infarcts involving the right cerebral hemisphere. The patient was diagnosed with invasive sinus aspergillosis based on transnasal biopsy findings. Despite intensive antifungal therapy using voriconazole, rapidly progressive aspergillosis led to a new stenotic lesion in the left ICA, which increased the risk of bilateral cerebral hypoperfusion. We performed successful PTAS to prevent critical ischemic events. Finally, aspergillosis was controlled with voriconazole treatment, and the patient was discharged. He showed a favorable outcome, with a patent left ICA observed at a 3-year follow-up. PTAS may be feasible in patients with ICA stenosis and invasive sinus aspergillosis.

Association of Gut Microbiome with Early Brain Injury After Subarachnoid Hemorrhage: an Experimental Study.

The occurrence of early brain injury (EBI) following subarachnoid hemorrhage (SAH) is crucial in the prognosis of SAH; however, no effective treatment for EBI has been developed. Gut microbiome (GM) composition influences the outcome of various diseases, including ischemic stroke. Here, we evaluated whether prior GM alteration could prevent EBI following SAH. We altered the GM of 7-week-old male rats by administering antibiotic-containing water for 2 weeks and performing fecal microbiome transplantation after antibiotic induction. Composition of the GM was profiled using 16S rRNA. We induced SAH by injecting blood in the subarachnoid space of control rats and rats with altered GM. We evaluated EBI indicators such as neurological score, brain water content, Evans blue extravasation, and neuronal injury. Additionally, we studied inflammatory cells using immunohistochemistry, immunocytochemistry, quantitative PCR, and flow cytometry. EBI was significantly averted by alterations in GM using antibiotics. The altered GM significantly prevented neutrophil infiltration into the brain among inflammatory cells, and this anti-inflammatory effect was observed immediately following SAH onset. The altered GM also prevented neutrophil extracellular trap formation in the brain and blood, indicating the systemic protective effect. The cause of the protective effect was attributed to a significant decrease in aged neutrophils (CXCR4high CD62Llow) by the altered GM. These protective effects against EBI disappeared when the altered GM was recolonized with normal flora. Our findings demonstrated that EBI following SAH is associated with GM, which regulated neutrophil infiltration.

Ophthalmic Artery Flow Pattern-related Stump Pressure and Ischemic Tolerance during Balloon Test Occlusion of the Internal Carotid Artery.

Very few studies have described the blood flow pattern in the ipsilateral ophthalmic artery (OphA) during internal carotid artery (ICA) balloon test occlusion performed to estimate the risk of cerebral ischemia associated with therapeutic ICA sacrifice. This study aimed to investigate the relationship between ipsilateral OphA flow patterns just after ICA temporary occlusion and balloon test occlusion findings. We retrospectively reviewed 32 balloon test occlusion procedures performed at our institution between 2010 and 2019, and analyzed the OphA flow patterns and the conventional balloon test occlusion assessment items: neurological symptoms, stump pressure, stump-pressure ratio, collateral circulations, and venous phase delay. The flow patterns were categorized as type I (retrograde flow reaching the middle cerebral artery [MCA]), type II (retrograde flow to the ICA not reaching the MCA), or type III (no retrograde flow). Tolerance to balloon test occlusion was observed in 4/21 patients (19.0%), 4/6 patients (66.7%), and all five patients with types I, II, and III flows, respectively. The mean pressure ratios during balloon test occlusion in flow types I, II, and III were 35.6% ± 3.5%, 56.4% ± 6.5%, and 69.4% ± 7.1%, respectively (P <0.001). The mean stump pressures in flow types I, II, and III were 36.2 ± 3.6 mmHg, 46.6 ± 6.7 mmHg, and 66.6 ± 7.3 mmHg, respectively (P = 0.003). The mean venous phase delay in flow types I, II, and III were 0.99 ± 0.14 s, 0.25 ± 0.25 s, and 0.0 ± 0.28 s, respectively (P = 0.004). All the above variables showed significant flow-related differences. These results suggest that the OphA flow patterns may provide an additional diagnostic criterion for balloon test occlusion.

Endovascular Treatment for Middle Cerebral Artery Aneurysms: Single-Center Experience and Review of Literatures.

Objective: The efficacy of endovascular treatment for middle cerebral artery (MCA) aneurysms remains controversial. However, recent studies have reported the safety of endovascular treatment for MCA aneurysms. In this study, we studied the efficacy and clinical outcomes of endovascular treatment for MCA aneurysms in our hospital and the morphology and anatomy of MCA aneurysms that were suitable for endovascular treatment. Methods: We retrospectively analyzed 26 cases of MCA aneurysms which had undergone endovascular treatment at our institution between January 2015 and October 2018. We studied sizes and shapes of the aneurysms, clinical and angiographical outcomes one year after the treatment, and complications in these 26 patients. We also compared the differences in these parameters of the 26 patients with those of 61 other patients who were treated with clipping during the same period. Results: The median aneurysm size was 6.1 mm (1.8-29.9 mm), with the shapes of the aneurysms irregular in 8, and round in the other 18 cases. Four cases (15.4%) had ruptured aneurysms. All aneurysms were treated with assist techniques; 8 (30.8%) were treated by stent-assisted technique and 18 (69.2%) were treated by balloon-assisted technique and endovascular treatment was successfully performed in all (100%) cases. While the aneurysms were completely obliterated in 22 of them (84.6%), the remaining 4 cases (15.4%) had neck remnants. We observed periprocedural complications in 5 of the 26 (19.2%) aneurysms, all of which were transient and completely recovered during the follow-up period. The efficacy and complication rates were not different from the MCA aneurysms treated with clipping. All MCA aneurysms arising from the M1 trunk were treated with endovascular treatment, and those with a round shape with the axis not deviating from M1 were also treated with endovascular treatment. Conclusion: Endovascular treatment for MCA aneurysms is safe and effective together with adjunctive techniques such as balloon-assisted technique or stent-assisted technique. Thus, M1 trunk aneurysms and MCA bifurcation aneurysms with a round shape along the same axis of MCA may be good indications for endovascular treatment. However, long-term clinical and angiographical outcomes remain unknown. Thus, further studies are needed to address the existing limitations.

Transnasal flow reduction in endovascular treatment for anterior cranial fossa dural arteriovenous fistula.

Transarterial embolization (TAE) is a useful option for anterior cranial fossa-dural arteriovenous fistula (ACF-dAVF) as endovascular devices have progressed. Liquid agents are usually injected via a microcatheter positioned just proximal to the shunt pouch beyond the ophthalmic artery; however, high blood flow from the internal maxillary artery (IMA) often impedes penetration of embolic materials into the shunt pouch. Therefore, reducing blood flow from the IMA before embolization can increase the success rate. In the present case, to reduce blood flow from branches of the IMA, we inserted surgical gauze infiltrated with xylocaine and epinephrine into bilateral nasal cavities. Using this method, we achieved curative TAE with minimal damage to the nasal mucosa. Transnasal flow reduction is an easy, effective and minimally invasive method. This method should be considered in the endovascular treatment of ACF-dAVF, especially in patients with high blood flow from theIMA.

Conservative and Surgical Management of Spinal Cord Cavernous Malformations.

OBJECTIVES: We present a case series of spinal cord cavernous malformations (SCCMs) to describe clinical presentation and outcomes of both surgical and conservative management. METHODS: The clinical courses of patients diagnosed with SCCMs at our institution were retrospectively reviewed. Neurologic symptoms were evaluated using the Modified McCormick Scale. RESULTS: A total of 18 patients were identified. Five patients (27.8%) presented with acute onset bleeding, 4 of whom underwent immediate surgical resection. Thirteen patients (72.2%) were initially managed conservatively. Eight patients (38.9%) developed a hemorrhage during follow-up, and 8 (38.9%) required surgical resection due to bleeding or neurological worsening. The mean (range) duration from primary symptoms to subsequent hemorrhage or deterioration of symptoms was 1.42 (range: 0.25-4.33) years. The mean duration from primary symptoms to surgery was 2.10 (range: 0.25-5.0) years. No patients experienced subsequent hemorrhage after surgical resection. Eleven patients (84.6%) in the surgery group showed improved neurological status, and 2 patients (15.4%) remained unchanged. The annualized subsequent hemorrhage risk was 3.7%. Patients in the immediate surgical group had a significantly larger lesion compared with those in the conservative group. There was significance between the worst Modified McCormick Scale grades at the time of debilitating symptoms and the length of hemorrhage, but not the size of the lesion. CONCLUSIONS: Surgery for SCCMs resulted in no recurrence of hemorrhage or exacerbation of neurological symptoms, and should be considered for patients who experienced acute onset of hemorrhage or debilitating symptoms during follow-up.