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The tau protein aggregates in aging and Alzheimer disease and may lead to memory loss through disruption of medial temporal lobe (MTL)-dependent memory systems. Here, we investigated tau-mediated mechanisms of hippocampal dysfunction that underlie the expression of episodic memory decline using fMRI measures of hippocampal local coherence (regional homogeneity; ReHo), distant functional connectivity and tau-PET. We show that age and tau pathology are related to higher hippocampal ReHo. Functional disconnection between the hippocampus and other components of the MTL memory system, particularly an anterior-temporal network specialized for object memory, is also associated with higher hippocampal ReHo and greater tau burden in anterior-temporal regions. These associations are not observed in the posteromedial network, specialized for context/spatial information. Higher hippocampal ReHo predicts worse memory performance. These findings suggest that tau pathology plays a role in disconnecting the hippocampus from specific MTL memory systems leading to increased local coherence and memory decline. Deposition of tau protein aggregates occurs during aging and Alzheimer disease. Here, the authors show that tau burden in the anterior-temporal memory network is associated with disrupted fMRI connectivity and functional isolation of the hippocampus from other memory network components.

BackgroundThe primary goal of the CLARYS study is to assess the protection against rebleeding when treating ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) device.MethodsThe CLARYS study is a prospective, multicenter study conducted in 13 European centers. Patients with ruptured bifurcation aneurysms were consecutively included between February 2016 and September 2017. The primary endpoint was defined as the rebleeding rate of the target aneurysm treated with the WEB within 30 days postprocedure. Secondary endpoints included periprocedural and postprocedural adverse events, total procedure and fluoroscopy times, and modified Rankin Scale score at 1 month and 1 year.ResultsSixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. A WEB device was successfully implanted in 93.3%. The rebleeding rate at 1 month and 1 year was 0%. The mean fluoroscopy time was 27.0 min. Twenty-three periprocedural complications were observed in 18 patients and resolved without sequelae in 16 patients. Two of these complications were attributed to the procedure and/or the use of the WEB, leading to a procedure/device-related intraoperative complication rate of 3.3%. Overall mortality at 1 month and 1 year was 1.7% and 3.8%, respectively and overall morbidity at 1 month and 1 year was 15% and 9.6%, respectively. WEB-related 1-month and 1-year morbidity and mortality was 0%.ConclusionsThe interim results of CLARYS show that the endovascular treatment of ruptured bifurcation aneurysms with the WEB is safe and effective and, in particular, provides effective protection against rebleeding. It may induce profound change in the endovascular management of ruptured bifurcation aneurysms.

In recent years, the clinical usefulness of the Wada test (WT) has been debated among researchers in the field. Therefore, we aimed to assess its contribution to the prediction of change in verbal learning and verbal memory function after epilepsy surgery. Data from 56 patients with temporal lobe epilepsy who underwent WT and subsequent surgery were analyzed retrospectively. Additionally, a standard neuropsychological assessment evaluating attentional, learning and memory, visuospatial, language, and executive function was performed both before and 12 months after surgery. Hierarchical linear regression analyses were used to determine the incremental value of WT results over socio-demographic, clinical, and neuropsychological characteristics in predicting postsurgical change in patients’ verbal learning and verbal memory function. The incorporation of WT results significantly improved the prediction models of postsurgical change in verbal learning ( ∆R 2  = 0.233, p  = .032) and verbal memory function ( ∆R 2  = 0.386, p  = .005). Presurgical performance and WT scores accounted for 41.8% of the variance in postsurgical change in verbal learning function, and 51.1% of the variance in postsurgical change in verbal memory function. Our findings confirm that WT results are of significant incremental value for the prediction of postsurgical change in verbal learning and verbal memory function. Thus, the WT contributes to determining the risks of epilepsy surgery and, therefore, remains an important part of the presurgical work-up of selected patients with clear clinical indications.

BackgroundThe CLinical Assessment of WEB device in Ruptured aneurYSms (CLARYS) study has shown that the endovascular treatment of ruptured bifurcation aneurysms with the Woven EndoBridge (WEB) is safe and effective and provides protection against rebleeding at 1 month and 1 year. The 12-month angiographic follow-up is an important endpoint of the study.MethodsThe CLARYS study is a prospective multicenter study conducted in 13 European centers. The study enrolled 60 patients with 60 ruptured aneurysms of the anterior and posterior circulation. The study was conducted with an independent assessment of safety outcomes and imaging.ResultsSixty patients with 60 ruptured bifurcation aneurysms to be treated with the WEB were included. Fifty-three aneurysms (88.3%) had a broad base with a dome to neck ratio <2 (mean 1.6). Of these, 46 patients were evaluated by an independent core laboratory with follow-up imaging performed at 12 months or before eventual retreatment. At 1 year, 19/46 aneurysms (41.3%) were completely occluded (Raymond–Roy grade I), 21/46 (45.7%) had a residual neck and 6/46 (13.0%) had residual aneurysm filling. Adequate occlusion was reported in 40/46 (87%) aneurysms. Six patients underwent target aneurysm retreatment.ConclusionsThe CLARYS study has previously shown that the use of the WEB in the endovascular treatment of ruptured bifurcation aneurysms provides effective protection against rebleeding with a good safety profile. The angiographic occlusion rates at 1 year reported here are comparable to those already seen in previous multicenter studies which primarily included unruptured aneurysms.

BACKGROUND:Aneurysms of the internal carotid artery (ICA) bifurcation are rare, and no studies have compared patient outcomes after endovascular vs surgical treatment. OBJECTIVE:To report the safety, efficacy, and follow-up outcome of these 2 treatment options for patients with ICA bifurcation aneurysms. METHODS:Patient and aneurysm characteristics, treatment results, and follow-up outcomes (at 30 months) were analyzed from patient records and review of imaging findings. RESULTS:A total of 58 patients with ICA bifurcation aneurysms were treated. By interdisciplinary consensus, 30 aneurysms were assigned for coiling and 28 for clipping. Patients who underwent surgical clipping were younger and had larger aneurysms. More patients were assigned to coiling if their aneurysms originated only from the ICA bifurcation or projected superiorly. For the combined angiographic endpoint, complete and nearly complete occlusion (Raymond-Roy I + II), similar rates of 96% (coiling) or 100% (clipping) could be achieved. Raymond-Roy I occlusion occurred more often after clipping (79% vs 41% coiling). Follow-up of the endovascular group showed minor recanalization of the aneurysm neck (Raymond-Roy II) in 42%. One patient (4%) showed a major recanalization (Raymond-Roy III) and needed re-treatment. For incidental findings, no bleeding complications or new persistent neurological deficits occurred during follow-up. CONCLUSION:Treatment of ICA bifurcation aneurysms after interdisciplinary assignment to clipping or coiling is effective and safe. Despite significantly more minor recanalizations after coiling, the re-treatment rate was very low, and no bleeding was observed during follow-up. Multivariate analysis revealed that origin only from the ICA bifurcation was an independent predictor of aneurysm recanalization after endovascular treatment. ABBREVIATIONS:CI, confidence intervalDSA, digital subtraction angiographyF/U, follow-upISAT, International Subarachnoid Aneurysm TrialICA, internal carotid arterymRS, modified Rankin Scale

Neuromodulation techniques such as deep brain stimulation (DBS) are a promising treatment for memory-related disorders including anxiety, addiction, and dementia. However, the outcomes of such treatments appear to be somewhat paradoxical, in that these techniques can both disrupt and enhance memory even when applied to the same brain target. In this article, we hypothesize that disruption and enhancement of memory through neuromodulation can be explained by the dropout of engram nodes. We used a convolutional neural network (CNN) to classify handwritten digits and letters and applied dropout at different stages to simulate DBS effects on engrams. We showed that dropout applied during training improved the accuracy of prediction, whereas dropout applied during testing dramatically decreased the accuracy of prediction, which mimics enhancement and disruption of memory, respectively. We further showed that transfer learning of neural networks with dropout had increased the accuracy and rate of learning. Dropout during training provided a more robust \"skeleton\" network and, together with transfer learning, mimicked the effects of chronic DBS on memory. Overall, we showed that the dropout of engram nodes is a possible mechanism by which neuromodulation techniques such as DBS can both disrupt and enhance memory, providing a unique perspective on this paradox.

Triaging and prioritising patients for RT-PCR test had been essential in the management of COVID-19 in resource-scarce countries. In this study, we applied machine learning (ML) to the task of detection of SARS-CoV-2 infection using basic laboratory markers. We performed the statistical analysis and trained an ML model on a retrospective cohort of 5148 patients from 24 hospitals in Hong Kong to classify COVID-19 and other aetiology of pneumonia. We validated the model on three temporal validation sets from different waves of infection in Hong Kong. For predicting SARS-CoV-2 infection, the ML model achieved high AUCs and specificity but low sensitivity in all three validation sets (AUC: 89.9–95.8%; Sensitivity: 55.5–77.8%; Specificity: 91.5–98.3%). When used in adjunction with radiologist interpretations of chest radiographs, the sensitivity was over 90% while keeping moderate specificity. Our study showed that machine learning model based on readily available laboratory markers could achieve high accuracy in predicting SARS-CoV-2 infection.

BackgroundData on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience.MethodsA retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted.ResultsWe identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5–20) and 9 (IQR 7–10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis.ConclusionOur study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Objectives: To review the angiographic and clinical outcome of patients with unruptured intracranial aneurysm(s) (UIA) with regard to complications and successful obliteration by surgical clipping or endovascular coiling. Methods: Data were derived from a prospective database of intracranial aneurysms from June 1999 to May 2005. All patients were followed-up for 6 months using the modified Rankin Scale (mRS). Favourable outcome was classified as mRS 0–2. From a total of 691 patients included in the database, 173 harboured 206 UIA of whom 118 patients (133 UIA) were treated. Results: Primary treatment assignment was surgical repair in 91 UIA and endovascular treatment in 42. In 3 UIA (7.1%), endovascular treatment was not feasible and had to be abandoned. Definite treatment was surgery in 94 UIA (81 patients) and endovascular obliteration in 39 UIA (37 patients). There were no deaths related to any treatment. Immediately after treatment, 6.4% of the surgical and 7.7% of the endovascular patients showed new neurological deficits, mainly related to cerebral ischaemia. After 6 months, 3 (2.3%) patients had a treatment related unfavourable outcome, defined as mRS >2, 2 patients after surgical and 1 patient after endovascular aneurysm repair (not statistically different, p = 0.3; Fisher’s exact test). This led to an overall satisfactory outcome in 97.9% of surgically and 97.4% of endovasculary treated UIA. After surgical clipping, complete occlusion of the aneurysm was achieved in 88 (93.6%) and near complete (small residual neck) in 4 (4.3%) of 94 UIA. Two small posterior communicating artery aneurysms with a fetal type posterior communicating artery were wrapped. After endovascular treatment, obliteration was complete in 26 (66.7%). Small residual neck was seen in 13 (33.3%), but none of the UIA showed residual aneurysm filling. Five patients in the endovascular group (13.9%) underwent repeated endovascular treatment after aneurysm recanalisation. Conclusions: If patients are carefully selected and individually assigned to their optimum treatment modality, UIA can be obliterated by surgery or endovascular treatment in the majority of patients, with a low percentage of unfavourable outcomes. In this series, the outcome was not dependent on treatment. However, the rate of recanalisation of UIA is higher after endovascular obliteration. After diagnosis of an UIA, an individual interdisciplinary decision is essential for each patient to provide the optimum management.

Introduction The introduction of the Woven Endobridge (WEB) device increases the feasibility of endovascular treatment of wide-neck bifurcation aneurysms with limitations given by currently available sizes and shapes of the device. Parallel to other studies, we used the new device for selected patients who were no optimal candidates for established techniques like neurosurgical clipping or endovascular coiling. We aimed to report the angiographic and clinical results of WEB implantations or combinations between WEB and coiling or intracranial stents. Methods We reviewed the records of n  = 23 interventions in 22 patients with unruptured wide-neck aneurysms (UIA) who were assigned for aneurysm treatment with the use of the WEB or adjunctive techniques. Interventional procedures and clinical and angiographic outcomes are reported for the periprocedural phase and in mid-term FU. Results Of the included 22 patients, six patients needed additional coiling, intracranial stenting, or implantation of a flow diverter. WEB implantation was technically feasible in 22 out of the 23 interventions. Follow-up angiographic imaging proved total or subtotal occlusion of the aneurysm in 19 of 22 cases. Two minor recurrences remained stable during a period of 15 months. One patient with a partially thrombosed giant MCA aneurysm had a major recurrence and was retreated with a second WEB in combination with coiling. Conclusion Despite of unfavorable anatomic conditions, broad-based and large UIA endovascular treatment with the WEB and adjunctive techniques was feasible with a low risk of complications and promising occlusion rates in mid-term follow-up.