Search Results (13)

Background and Objectives: Overt perioperative stroke remains a feared complication of adult cardiac surgery. Diffusion-weighted magnetic resonance imaging (DWI-MRI) has revealed a more prevalent form of cerebral injury, termed silent stroke or silent brain injury (SBI). Covert ischemic lesions occur without focal neurological deficits but are increasingly associated with postoperative delirium, cognitive decline, and elevated long-term cerebrovascular risk. Despite growing recognition, the true burden, mechanisms, and clinical relevance of SBI remain incompletely integrated into perioperative practice. Materials and Methods: We performed a narrative review of the literature published between January 2000 and December 2025, identified through PubMed/MEDLINE and Scopus. Eligible studies included prospective and retrospective cohorts, randomized trials, systematic reviews, and meta-analyses involving adult patients undergoing coronary artery bypass grafting, valve surgery, or minimally invasive cardiac procedures, with or without cardiopulmonary bypass, and reporting MRI-detected ischemic lesions or validated surrogate markers of cerebral injury. Pediatric studies, transcatheter interventions, case reports, and non-English publications were excluded. Sixty studies met the inclusion criteria. Results: Silent stroke occurred more frequently than clinically apparent stroke, with new DWI-MRI lesions detected in approximately 20–60% of patients following cardiac surgery. Lesions were typically small, multifocal, and embolic in distribution, predominantly affecting cortical and watershed regions. Cardiopulmonary bypass-related factors, including aortic manipulation, cerebral microembolization, hemodilution, hypoperfusion, and impaired oxygen delivery, emerged as key contributors. Several studies demonstrated associations between SBI burden and postoperative delirium, early cognitive dysfunction, and functional decline. Perfusion-based neuroprotective strategies showed mechanistic benefit, although no single intervention conclusively prevented SBI. Conclusions: Silent stroke represents the most frequent form of neurological injury in adult cardiac surgery. Evidence suggests that these covert lesions reflect clinically meaningful cerebral injury, with potential short- and long-term consequences. Recognition of silent stroke as a relevant neurological endpoint supports a shift toward multimodal, perfusion-driven neuroprotective strategies and the routine incorporation of MRI-based outcomes in future cardiac surgical research. Full article

Background/Objectives: Risk stratification in asymptomatic carotid stenosis has traditionally relied on the degree of luminal narrowing; however, plaque vulnerability may better predict cerebrovascular events. Ipsilateral silent brain lesions (SBLs) are considered surrogate markers of stroke risk. This study aimed to identify carotid plaque features on duplex ultrasound (DUS) and computed tomography angiography (CTA), as well as circulating biomarkers, associated with ipsilateral SBL in patients with clinically asymptomatic ≥70% internal carotid artery stenosis. Methods: This prospective observational study with cross-sectional imaging analysis included 316 clinically asymptomatic patients with ≥70% carotid stenosis treated between January 2022 and October 2024. All patients underwent cranial non-contrast CT for SBL detection, DUS plaque characterization (according to the Gray–Weale classification and plaque surface morphology), and CTA analysis, including plaque surface, composition, length, and attenuation values categorized according to Schroeder’s criteria (<50 HU lipid-rich; 51–120 HU fibrous; >120 HU calcified). Demographic, clinical, and laboratory parameters, including inflammatory biomarkers, were recorded. Multivariate logistic regression was performed to identify independent predictors of SBL. Results: SBL were detected in 72 patients (22.8%). On DUS, SBL were significantly associated with Gray–Weale class II plaques, heterogeneous composition, and irregular or ulcerated surfaces (all p < 0.001). On CTA, lipid-rich plaques (<50 HU), ulcerated surfaces, heterogeneous morphology, and lower median plaque density were significantly more frequent in the SBL group (all p < 0.001). In multivariate analysis, independent predictors of SBL were male sex (OR 2.2; 95% CI 1.2–5.7; p = 0.029), Gray–Weale class II plaques (p = 0.002), lipid-rich plaque morphology (OR 21.39; 95% CI 6.86–66.76; p < 0.001), and ulcerated plaque surface on CTA (OR 20.62; 95% CI 7.37–57.68; p < 0.001). Conclusions: Specific ultrasound and CT plaque characteristics were associated with ipsilateral silent brain lesions in patients with asymptomatic ≥70% carotid stenosis. A multiparametric imaging approach may improve risk stratification beyond stenosis severity alone. Full article

Background/Objectives: Magnetisation Transfer (MT) MRI is used for neuro-degenerative disorders, including Multiple Sclerosis (MS), providing an indirect measure of large biomolecular MR signal sources which cannot be observed directly because their typical T2 is usually much shorter than the echo time (TE) of conventional MR sequences. We investigated a 3D-radial Zero Time of Echo (ZTE) MT-weighted sequence with potentially enhanced sensitivity to short-T2 MR signals indirectly (via MT weighting) and directly (due to the short TE). Methods: The sequence runs on a human 7T MR scanner, producing whole-brain MT-weighted images with isotropic 0.8 mm resolution in 6.5 minutes. One RF pulse is used to suppress the fat signal and generate MT weighting, reducing RF power deposition to moderate levels. The small excitation pulses and the “quasi-adiabatic” MT pulse mitigate the negative effects of inhomogeneous transmit RF fields observed at 7T in the human head, facilitating the generation of uniform Magnetisation Transfer Ratio (MTR) maps. Results: Results from a biologic phantom, a healthy volunteer, and an MS patient illustrate important imaging features of the “SilentMT” sequence. When the MS patient images were compared with Fluid Attenuated Inversion Recovery (FLAIR) images taken on the same patient at 1.5T and 7T, SilentMT was able to detect all the MS lesions observed on the “reference truth” 1.5T FLAIR; 7T FLAIR, however, failed to detect some lesions in the temporal lobe and brain stem. SilentMT detected a lesion which was not immediately apparent on either FLAIR image. Increased MTR was observed in some regions of the brain of the MS patient, notably the left temporal lobe. Conclusions: This initial investigation of an MT-weighted ZTE sequence shows evidence that it may be more sensitive to pathology in a patient with MS. Full article

Silent Brain Infarction (SBI) is increasingly recognized in patients with cardiac conditions, particularly Atrial Fibrillation (AF) in elderly patients and those undergoing Transcatheter Aortic Valve Implantation (TAVI). While these infarcts often go unnoticed due to a lack of acute symptoms, they are associated with a threefold increase in stroke risk and are considered a precursor to ischemic stroke. Moreover, accumulating evidence suggests that SBI may contribute to the development of dementia, depression, and cognitive decline, particularly in the elderly population. The burden of SBI is substantial, with studies showing that up to 11 million Americans may experience a silent stroke annually. In AF patients, silent brain infarcts are common and can lead to progressive brain damage, even in those receiving anticoagulation therapy. The use of cerebral embolic protection devices (CEPDs) during TAVI has been explored to mitigate the risk of stroke; however, their efficacy remains under debate. Despite advancements in TAVI technology, cerebrovascular events, including silent brain lesions, continue to pose significant challenges, underscoring the need for improved preventive strategies and therapeutic approaches. We propose a device consisting of a strut structure placed at the base of the treated artery to model the potential risk of cerebral embolisms caused by atrial fibrillation, thromboembolism, or dislodged debris of varying potential TAVI patients. The study has been carried out in two stages. Both are based on computational fluid dynamics (CFD) coupled with the Lagrangian particle tracking method. The first stage of the work evaluates a variety of strut thicknesses and inter-strut spacings, contrasting with the device-free baseline geometry. The analysis is carried out by imposing flow rate waveforms characteristic of healthy and AF patients. Boundary conditions are calibrated to reproduce physiological flow rates and pressures in a patient’s aortic arch. In the second stage, the optimal geometric design from the first stage was employed, with the addition of lateral struts to prevent the filtration of particles and electronegatively charged strut surfaces, studying the effect of electrical forces on the clots if they are considered charged. Flowrate boundary conditions were used to emulate both healthy and AF conditions. Results from numerical simulations coming from the first stage indicate that the device blocks particles of sizes larger than the inter-strut spacing. It was found that lateral strut space had the highest impact on efficacy. Based on the results of the second stage, deploying the electronegatively charged device in all three aortic arch arteries, the number of particles entering these arteries was reduced on average by $62.6$% and $51.2$%, for the healthy and diseased models respectively, matching or surpassing current oral anticoagulant efficacy. In conclusion, the device demonstrated a two-fold mechanism for filtering emboli: (1) while the smallest particles are deflected by electrostatic repulsion, avoiding micro embolisms, which could lead to cognitive impairment, the largest ones are mechanically filtered since they cannot fit in between the struts, effectively blocking the full range of particle sizes analyzed in this study. The device presented in this manuscript offers an anticoagulant-free method to prevent stroke and SBIs, imperative given the growing population of AF and elderly patients. Full article

Objective: The aim of this study was to assess the association between the presence of a right-to-left shunt (RLS) and neurological decompression sickness (NDCS) and asymptomatic brain lesions among otherwise healthy divers. Background: Next to drowning, NDCS is the most severe phenotype of diving-related disease and may cause permanent damage to the brain and spinal cord. Several observational reports have described the presence of an RLS as a significant risk factor for neurological complications in divers, ranging from asymptomatic brain lesions to NDCS. Methods: We systematically reviewed the MEDLINE, Embase, and CENTRAL databases from inception until November 2021. A random-effects model was used to compute odds ratios. Results: Nine observational studies consisting of 1830 divers (neurological DCS: 954; healthy divers: 876) were included. RLS was significantly more prevalent in divers with NDCS compared to those without (62.6% vs. 27.3%; odds ratio (OR): 3.83; 95% CI: 2.79–5.27). Regarding RLS size, high-grade RLS was more prevalent in the NDCS group than the no NDCS group (57.8% versus 18.4%; OR: 4.98; 95% CI: 2.86–8.67). Further subgroup analysis revealed a stronger association with the inner ear (OR: 12.13; 95% CI: 8.10–18.17) compared to cerebral (OR: 4.96; 95% CI: 2.43–10.12) and spinal cord (OR: 2.47; 95% CI: 2.74–7.42) DCS. RLS was more prevalent in divers with asymptomatic ischemic brain lesions than those without any lesions (46.0% vs. 38.0%); however, this was not statistically significant (OR: 1.53; 95% CI: 0.80–2.91). Conclusions: RLS, particularly high-grade RLS, is associated with greater risk of NDCS. No statistically significant association between RLS and asymptomatic brain lesions was found. Full article

Cerebral cavernous malformations (CCM) are developmental venous dysplasias which present as abnormally dilated blood vessels occurring mainly in the brain. Alterations in vascular biology originate from somatic mutations in genes regulating angiogenesis and endothelial-to-mesenchymal transition. Vascular lesions may occur at any time and develop silently, remaining asymptomatic for years. However, symptomatic disease is often debilitating, and patients are prone to develop drug-resistant epilepsy and hemorrhages. There is no cure, and surgical treatment is recommended only for superficial lesions on cortical areas. The study of lesion biology led to the identification of different pathways related to disease onset and progression, of which RhoA/Rho-associated protein kinase (ROCK) shows activation in different subsets of patients. This work will explore the current knowledge about the involvement of ROCK in the many aspects of CCM disease, including isoform-specific actions, and delineate the recent development of ROCK inhibitors for CNS-targeted diseases. Full article

Head trauma is the most common cause of disability in young adults. Known as a silent epidemic, it can cause a mosaic of symptoms, whether neurological (sensory–motor deficits), psychiatric (depressive and anxiety symptoms), or somatic (vertigo, tinnitus, phosphenes). Furthermore, cranial trauma (CT) in children presents several particularities in terms of epidemiology, mechanism, and physiopathology—notably linked to the attack of an immature organ. As in adults, head trauma in children can have lifelong repercussions and can cause social and family isolation, difficulties at school, and, later, socio-professional adversity. Improving management of the pre-hospital and rehabilitation course of these patients reduces secondary morbidity and mortality, but often not without long-term disability. One hypothesized contributor to this process is chronic neuroinflammation, which could accompany primary lesions and facilitate their development into tertiary lesions. Neuroinflammation is a complex process involving different actors such as glial cells (astrocytes, microglia, oligodendrocytes), the permeability of the blood–brain barrier, excitotoxicity, production of oxygen derivatives, cytokine release, tissue damage, and neuronal death. Several studies have investigated the effect of various treatments on the neuroinflammatory response in traumatic brain injury in vitro and in animal and human models. The aim of this review is to examine the various anti-inflammatory therapies that have been implemented. Full article

Advancements in clinical management, pharmacological therapy and interventional procedures have strongly improved the survival rate for cardiovascular diseases (CVDs). Nevertheless, the patients affected by CVDs are more often elderly and present several comorbidities such as atrial fibrillation, valvular heart disease, heart failure, and chronic coronary syndrome. Standard treatments are frequently not available for “frail patients”, in particular due to high surgical risk or drug interaction. In the past decades, novel less-invasive procedures such as transcatheter aortic valve implantation (TAVI), MitraClip or left atrial appendage occlusion have been proposed to treat CVD patients who are not candidates for standard procedures. These procedures have been confirmed to be effective and safe compared to conventional surgery, and symptomatic thromboembolic stroke represents a rare complication. However, while the peri-procedural risk of symptomatic stroke is low, several studies highlight the presence of a high number of silent ischemic brain lesions occurring mainly in areas with a low clinical impact. The silent brain damage could cause neuropsychological deficits or worse, a preexisting dementia, suggesting the need to systematically evaluate the impact of these procedures on neurological function. Full article

According to the international societies’ recommendations, the 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) technique should not be used as the method of choice in brain tumour diagnosis. Therefore, the brain region can be omitted during standard [¹⁸F]FDG PET/CT scanning. We performed comprehensive literature research and analysed results from 14,222 brain and torso [¹⁸F]FDG PET/CT studies collected in 2010–2020. We found 131 clinically silent primary and metastatic brain tumours and 24 benign lesions. We concluded that the brain and torso [¹⁸F]FDG PET/CT study provides valuable data that may support therapeutic management by detecting clinically silent primary and metastatic brain tumours. Full article

From the beginning of SARS-CoV-2 virus pandemic, it was clear that respiratory symptoms are often accompanied with neurological symptoms. Neurological manifestations can occur even after mild forms of respiratory disease, and neurological symptoms are very often associated with worsening of the patient’s condition. The aim of this study was to show abnormal brain neuroimaging findings evaluated by MRI in patients after SARS-CoV-2 infection and neurological symptoms. Methods: Sixteen patients after mild forms of SARS-CoV-2 infection, twenty-three patients after moderate forms of SARS-CoV-2 infection as well as sixteen healthy participants in the control group underwent MRI 3T brain scan. All subjects in the SARS-CoV-2 group had small, punctuate, strategically located and newly formed hyperintense lesions on T2 and FLAIR sequences. New lesions were formed more often in the bilateral frontal subcortical and bilateral periventricular, correlated with the severity of the clinical picture. These changes indicate an example of silent cerebrovascular disease related to SARS-CoV-2 and once again emphasize the neurotropism of the virus. Full article

The aim of this paper is to correlate the extent of silent cerebral infarcts (SCIs) on magnetic resonance imaging (MRI) with the clinical severity of sickle cell disease (SCD) in adult patients. Twenty-four consecutive adult asymptomatic SCD patients (11 male and 13 female) with a mean age of 38.4 years (range 20–59) were submitted to brain MRI on a 1 Tesla Gyroscan Intera, Philips MR scanner with a dedicated head coil. The protocol consisted of TSE T2-weighted and FLAIR images on the axial and coronal planes. MRI readings were undertaken by two radiologists and consensus readings. Patients were compound heterozygotes (HbS/β-thal). The extent of SCIs was classified from 0–2 with 0 designating no lesions. Clinical severity was graded as 0–2 by the hematologist, according to the frequency and severity of vaso-occlusive crises. There was no statistically significant correlation between the severity of clinical disease and the extent of SCIs on MR imaging. The extent of SCI lesions did not differ statistically between younger and older patients. Patients receiving hydroxyurea had no statistically significant difference in the extent of SCI lesions. The extent of SCIs in heterozygous (HbS/β-thal) SCD patients is not age related and may be quite severe even in younger (<38.4 years) patients. However the extent of SCIs is not correlated with the severity of clinical disease. Full article

Cerebral vasculitis is a rare disease. Vasculitis of autoimmune origin is most common, either as cerebral vasculitis in the course of a systemic autoimmune disease or as cerebral vasculitis with exclusive manifestation within the central nervous system (primary angiitis of the CNS). Primary angiitis of the CNS is very rare, but may be a diagnostic challenge. Systemic vasculitis syndromes affect the CNS with different frequency,sometimes first as the only manifestation of a systemic autoimmune disease. Some systemic vasculitis syndromes affect the peripheral nervous system more frequently than the CNS (e.g. polyarteritis nodosa). In particular with systemic vasculitis syndromes, interdisciplinary approaches are warranted that take into account the affected organ systems and adapt therapeutic regimens. Specific diagnosis relies on the pattern and extent of organ involvement, neuroimaging and autoantibodies in blood and cerebrospinal fluid (CSF) analyses. CSF findings are non-specific and similar to those seen in multiple sclerosis.They may be even normal. Also neuroimaging findings are non-specific. Although there may be certain patterns of findings that are typical for vasculitis and more frequent in vasculitis than in other diseases, specificity remains low. Therefore, diagnosis should – if possible – always be based on histopathological analyses.This should be performed before the initiation of immunosuppressive treatment apart from very severe cases, which do not allow delay of therapy. If there is no peripheral organ affected outside the central nervous system, which may be biopsied less invasively, a combined biopsy of leptomeninges and cerebral parenchyma is warranted. If possible, biopsy has to be gained from a gadolinium-enhancing lesion within a clinically silent area of the brain. Treatment of cerebral vasculitis of autoimmune origin first aims at clinical and paraclinical remission. This is normally achieved by prednisolone, which in acute cases is given at a high dose intravenously for several days. In very severe cases, particularly in Wegener’s granulomatosis, Churg-Strauss vasculitis and systemic lupus erythematosus, prednisolone is combined with cyclophosphamide right from the beginning. Cyclophosphamide is either administered orally on a daily basis or intravenously as pulse therapy every 1–3 month. Oral cyclophosphamide long-run therapy may be more effective than intravenous pulse therapy, but has more side effects. During maintenance therapy, oral immunosuppressants like azathioprine or methotrexate are administered in order to reduce the dosage of prednisolone below the Cushing threshold. Full article

The frontal lobe is the largest lobe of the brain and it is thus commonly involved in stroke. Moreover, almost one in five strokes is limited to the prerolandic areas.This high frequency of anatomical involvement is in sharp contrast with the apparent rarity of clinical frontal dysfunction in stroke. It is remarkable that frontal behavioural syndromes have rather uncommonly been reported in patients with stroke as compared to patients with other diseases, such as brain tumour. This fact is paradoxical, because an acute process (stroke) is expected to yield more clinical dysfunction than a more chronic disease (tumour). A volume effect may be the main factor leading to this phenomenon. Another interesting aspect of frontal strokes is the contribution of so-called “silent”strokes, the recurrence of which may nevertheless lead to intellectual decline and compromise recovery from another stroke with more specific neurologic dysfunction. The contribution of stroke to understanding of frontal lobe dysfunction is important, because of the focal nature of this disease, and a great opportunity for clinical-topographic classification correlations. One of the first modern attempts to develop a clinical-topographic classification of frontal lobe lesions came from the school of Luria, who tried to delineate three main types of frontal lobe syndromes (premotor syndrome, prefrontal syndrome, medial-frontal syndrome). Recent anatomic correlates using MRI make it possible to improve this classification.We suggest considering six main clinical-anatomic frontal stroke syndromes: (1) prefrontal, (2) premotor, (3) superior medial, (4) orbital-medial, (5) basal forebrain, (6) white matter. Finally, another fascinating topic relates to frontal lobe symptomatology due to stroke sparing the frontal cortex or white matter. This occurs mainly in three instances: lenticulo-capsular stroke, caudate stroke and thalamic stroke. Studies using blood-flow or metabolism measurements suggest that diaschisis (frontal lobe dysfunction from a remote lesion) may play a role. We believe that this is more likely to be related to dynamic interruption of complex circuitry than to static frontal lobe deactivation. Full article