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.

Repetitive transcranial magnetic stimulation restores altered functional connectivity of central poststroke pain model monkeys.

Central poststroke pain (CPSP) develops after a stroke around the somatosensory pathway. CPSP is hypothesized to be caused by maladaptive reorganization between various brain regions. The treatment for CPSP has not been established; however, repetitive transcranial magnetic stimulation (rTMS) to the primary motor cortex has a clinical effect. To verify the functional reorganization hypothesis for CPSP development and rTMS therapeutic mechanism, we longitudinally pursued the structural and functional changes of the brain by using two male CPSP model monkeys (Macaca fuscata) developed by unilateral hemorrhage in the ventral posterolateral nucleus of the thalamus. Application of rTMS to the ipsilesional primary motor cortex relieved the induced pain of the model monkeys. A tractography analysis revealed a decrease in the structural connectivity in the ipsilesional thalamocortical tract, and rTMS had no effect on the structural connectivity. A region of interest analysis using resting-state functional magnetic resonance imaging revealed inappropriately strengthened functional connectivity between the ipsilesional mediodorsal nucleus of the thalamus and the amygdala, which are regions associated with emotion and memory, suggesting that this may be the cause of CPSP development. Moreover, rTMS normalizes this strengthened connectivity, which may be a possible therapeutic mechanism of rTMS for CPSP.

Mechanical thrombectomy in acute ischemic stroke patients with left ventricular assist device.

OBJECTIVES: As the number of patients with left ventricular assist device (LVAD) implantation has been increasing, treatment of LVAD-related ischemic stroke is becoming a critical issue. We sought to clarify the features of mechanical thrombectomy in LVAD-related stroke with large vessel occlusion. METHODS: In a multi-center, retrospective case-control study, we compared 20 LVAD-related strokes with 33 non-LVAD strokes, all of which had large vessel occlusion in the anterior circulation treated with mechanical thrombectomy. A comparative histopathological examination of the retrieved thrombi was also performed. RESULTS: Successful reperfusion was achieved in 75% of the LVAD-related strokes. The time from onset to reperfusion was similar to that of non-LVAD strokes, but the total number of device passes required for reperfusion (median, 2.5 versus 1, P = 0.01) and the incidences of post-procedural parenchymal and subarachnoid hemorrhage (25% versus 3%, P = 0.02 and 55% versus 15%, P = 0.01, respectively) were higher in LVAD-related strokes. Symptomatic intracranial hemorrhage occurred in 4 patients (20%) with LVAD-related strokes. The histopathological analysis revealed that the ratio of erythrocyte components was significantly lower in thrombi retrieved from patients with LVAD-related stroke than in those with non-LVAD stroke (19 ± 6% versus 41 ± 17%, P = 0.01). CONCLUSIONS: Mechanical thrombectomy is feasible in patients with LVAD-related stroke. However, repetitive device passes are needed to achieve successful reperfusion mainly because of the structurally organized thrombi, and the higher risk of hemorrhagic complications should be considered, while offering this therapeutic alternative.

Endovascular treatment for large vessel occlusion stroke in patients with ventricular assist devices.

BACKGROUND: Embolic stroke with large vessel occlusion (LVO) is a major adverse event during ventricular assist device (VAD) support. In this study we aimed to clarify the efficacy of, and problems associated with, endovascular treatment (EVT) of LVO in patients with VAD support. METHODS: We retrospectively reviewed EVT for LVO in patients with VAD support between 2006 and 2017 at our institute and evaluated baseline characteristics, treatment variables, outcomes, and complications. RESULTS: The study cohort comprised 12 consecutive patients (age 35.4±20.4 years), with 15 LVO events involving 20 arterial occlusions, who had undergone EVT. The median Alberta Stroke Program Early CT score was 10 and good collaterals were observed in 10 of 17 occluded middle cerebral artery areas. No study patients had received intravenous thrombolysis therapy. EVT was performed on 18 of the 20 occluded arteries and mechanical thrombectomy on 13 vessels. The successful reperfusion (modified Thrombolysis in Cerebral Infarction grade ≥2 b) rate was 67% in all EVTs and 85% with mechanical thrombectomy. Histological analysis showed fibrin-rich thrombi in four of five samples. Seven of 12 patients (58%) maintained their neurological function (modified Rankin Scale score ≤2 or equal to pre-stroke score) at 90 days. Periprocedural complications comprised two symptomatic intracranial hemorrhages and the 90-day mortality rate was 13%. Seven of 10 cardiac transplant candidates (70%) returned to the waiting list and three of them received transplants. CONCLUSIONS: Endovascular therapy for acute LVO stroke is feasible even in patients with VAD support.

Transarterial Sinus Embolization for a Dural Arteriovenous Fistula in a Sinus of the Lesser Sphenoid Wing: A Case Report.

Dural arteriovenous fistula (DAVF) in a sinus of the lesser sphenoid wing (SLSW) is rarely reported. Here, we report a case of an isolated SLSW DAVF treated by coils placed into the sinus through the feeding artery. A 68-year-old man was admitted to our hospital with headache. Magnetic resonance images and an angiogram showed a varix in the right middle cranial fossa. A DAVF, consisting of three main feeders and the isolated SLSW, was diagnosed based on the angiogram findings. Retrograde leptomeningeal venous drainage to the deep middle cerebral vein was observed. Given the remarkable extent of cortical venous ectasia together with the presence of headache and right abducens nerve paralysis, endovascular treatment was initiated. A transvenous approach through the right inferior petrosal sinus was not feasible because of difficulty associated with inserting the microcatheter into the SLSW. Thus, we tried a transarterial approach and were able to advance the microcatheter beyond the fistula into the isolated SLSW, through the artery of the foramen rotundum. The isolated sinus and feeding arteries were embolized with coils. The postoperative angiogram showed the total occlusion of the SLSW DAVF. This case demonstrates the feasibility of transarterial sinus packing for an isolated SLSW DAVF.

Brachial-Ankle Pulse Wave Velocity as a Predictor of Silent Cerebral Embolism after Carotid Artery Stenting.

BACKGROUND: In neuroendovascular therapy, the effect of arterial stiffness on postprocedural cerebral thromboembolism is unknown. In this observational study, we examined the relationship between cerebral thromboembolism after carotid artery stenting and arterial stiffness. METHODS: From April 2015 to February 2017, we enrolled consecutive patients undergoing scheduled carotid artery stenting in our institution. In all patients, preprocedural brachial-ankle pulse wave velocity was used to assess arterial stiffness, whereas the number of new cerebral ischemic lesions on diffusion-weighted magnetic resonance imaging was assessed after treatment. We also analyzed patient data and details of procedures in patients with carotid artery stenting. RESULTS: Twenty-one patients completed the study. The mean brachial-ankle pulse wave velocity was 1879 cm/s. There was no association of cerebral thromboembolisms with age, unstable plaque, protection device, or type of stent. However, the brachial-ankle pulse wave velocity was an independent predictor of cerebral thromboembolisms (P = .0017). CONCLUSIONS: Brachial-ankle pulse wave velocity is predictive of silent cerebral embolisms on diffusion-weighted magnetic resonance imaging after carotid artery stenting.

Endovascular and Surgical Treatment of Spinal Dural Arteriovenous Fistulas: Assessment of Post-treatment Clinical Outcome.

Spinal dural arteriovenous fistulas (DAVFs) are the most commonly encountered vascular malformation of the spinal cord and a treatable cause of progressive para- or tetraplegia. It is an elusive pathology that tends to be under-diagnosed, due to lack of awareness among clinicians, and affects males more commonly than females, typically between the fifth and eighth decades. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality. The purpose of our retrospective, single-center study was to determine the long-term clinical and radiographic outcome of patients who have received endovascular or surgical treatment of a spinal DAVF. In particular, during a 6-year period (2009-2014) 14 patients with a spinal DAVF were treated at our department either surgically (n = 4) or endovascularly (n = 10) with detachable coils and/or glue. There was no recurrence in the follow-up period (mean: 36 months, range 3-60 months) after complete occlusion with the endovascular treatment (n = 9; 90%), while only one patient (10%) had residual flow both post-treatment and at 3-month follow-up. All four surgically treated patients (100%) had no signs of residual DAVF on follow-up magnetic resonance angiography (MRA) and/or angiography (mean follow-up period of 9 months). Since improvement or stabilization of symptoms may be seen even in patients with delayed diagnosis and substantial neurological deficits, either endovascular or surgical treatment is always justified.

Direct aspiration first pass technique for a middle cerebral artery occlusion with a hidden aneurysm.

Hidden aneurysms within occluded vessels present a challenge for interventionists because vessel perforation can lead to life-threatening complications. We present a case of middle cerebral artery ischemic stroke, refractory to thrombolysis. A direct aspiration first pass technique (ADAPT) was employed for revascularization. Following thrombectomy, an aneurysm of the occluded vessel was revealed. Despite this, the patient recovered without hemorrhagic complication. ADAPT permits the minimal insertion of endovascular devices and might be a safe procedure when hidden aneurysms are suspected.

A symptomatic spinal extradural arachnoid cyst with lumbar disc herniation.

Spinal epidural arachnoid cyst (EAC) is a rare, usually asymptomatic condition of unknown origin, which typically involves the lower thoracic spine. We report a case of posttraumatic symptomatic EAC with lumbar disc herniation. A 22-year-old man experienced back pain and sciatica after a traffic accident. Neurological examination revealed a right L5 radiculopathy. Magnetic resonance imaging demonstrated a cystic lesion at the L3 to L5 level and an L4-5 disc herniation; computed tomography myelography showed that the right L5 root was sandwiched between the cyst and the herniation. A dural defect was identified during surgery. The cyst was excised completely and the defect was repaired. A herniation was excised beside the dural sac. Histology showed that the cyst wall consisted of collagen and meningothelial cells. Postoperatively the symptoms resolved. Lumbar spinal EACs are rare; such cysts may arise from a congenital dural crack and grow gradually. The 6 cases of symptomatic lumbar EAC reported in the literature were not associated with disc herniation or trauma. In this case, the comorbid disc herniation was involved in symptom progression. Although many EACs are asymptomatic, comorbid spinal disorders such as disc herniation or trauma can result in symptom progression.