João Sargento-Freitas

• MD
• Hospitais da Universidade de Coimbra

Background Hemorrhagic transformation after thrombectomy is associated with poor outcomes. This study aimed to assess post-thrombectomy angiographic signs and increased blood flow on transcranial Doppler as potential predictive factors for parenchymal hemorrhage after successful endovascular stroke treatment. Methods This cohort study included con...

BACKGROUND Patients presenting with cervical artery dissection (CAD) are at risk for subsequent ischemic events. We aimed to identify characteristics that are associated with increased risk of ischemic stroke after initial presentation of CAD and to evaluate the differential impact of anticoagulant versus antiplatelet therapy in these high-risk ind...

Hemispheric functional asymmetries are a key aspect of human brain organization. Revealing how causal manipulations of hemispheric (im)balances dynamically change pre and postsynaptic GABA regulation, in terms of mean and variance changes, is essential to understand plasticity of brain asymmetries in health and disease. This has direct implications...

Introduction Evidence regarding the benefit of endovascular therapy (EVT) in patients with acute ischemic stroke (AIS) due to isolated cervical internal carotid artery occlusion (c-ICA-O) is lacking. We assessed the outcomes and safety of EVT in patients with isolated c-ICA-O. Methods Retrospective multicenter cohort study of patients with an AIS...

Background: The optimal endovascular management of cervical carotid dissection causing tandem occlusion remains uncertain. We investigated the impact of emergent carotid stenting during endovascular treatment (EVT) for acute ischemic stroke (AIS) in patients with tandem occlusion secondary to cervical carotid artery dissection. Methods: This was a...

Objectives: Cervical artery dissection (CeAD) accounts for 25% of ischemic strokes in young adults. This study evaluated the benefits and harms of intravenous thrombolysis (IVT) in patients presenting with spontaneous CeAD and acute ischemic stroke symptoms. Methods: This analysis used data from the retrospective STOP-CAD study and included pati...

https://authors.elsevier.com/a/1jmNx7skofHLFj

Introduction: Although scarce, regional telestroke networks have been developed worlwide in the last few decades. The COVID-19 pandemic put the healthcare system under exceptional pressure. We aimed to assess the impact of the first year of the COVID-19 pandemic on the telestroke network performance in the central region of mainland Portugal. Metho...

Objective Patients with cervical artery dissection (CAD) are at increased ischemic stroke risk. We aimed to identify characteristics that are associated with increased risk of ischemic stroke following initial presentation of CAD and to evaluate the differential impact of anticoagulant versus antiplatelet therapy in these high-risk individuals. Me...

Introduction After several uncontrolled studies and one randomized clinical trial, there is still uncertainty regarding the role of endovascular treatment (EVT) in cerebral venous thrombosis (CVT). This study aims to describe and assess different acute management strategies in the treatment of CVT. Methods We performed a retrospective analysis of...

Introduction: Stroke is considered one of the greatest public health challenges worldwide, with the ischemic subtype being the most prevalent. Various acute stroke clinical guidelines recommend early rehabilitation interventions, including very early mobilization. However, despite the studies conducted in recent years regarding when to initiate mob...

Purpose To provide an overview on education, training, practice requirements, and fields of application of neurosonology in Europe and beyond. Materials and Methods National representatives and experts in neurosonology were surveyed regarding neurosonology requirements and practice in their countries. Descriptive statistics were used to report the...

BACKGROUND Small, randomized trials of patients with cervical artery dissection showed conflicting results regarding optimal stroke prevention strategies. We aimed to compare outcomes in patients with cervical artery dissection treated with antiplatelets versus anticoagulation. METHODS This is a multicenter observational retrospective internationa...

BACKGROUND The association of COVID-19 with higher bleeding risk and worse outcomes in acute ischemic stroke (AIS) undergoing revascularization may be related to the presence of infection symptoms. We aimed to assess the safety and outcomes of revascularization treatments in patients with AIS with asymptomatic COVID-19 (AS-COVID) or symptomatic COV...

Background: The optimal imaging method for detecting distal medium vessel occlusions (DMVOs) remains undefined. Purpose: The objective of this study is to compare the diagnostic performance of CTA with CTP in detecting DMVOs. Data sources: We searched PubMed, EMBASE, Web of Science Core Collection, and Cochrane Central Register of Controlled T...

Herein, we investigate the bioactivity of small extracellular vesicles (sEVs), focusing on their local effect in the brain.

Purpose Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) are often complicated by vasospasm and ischemia. Monitoring with transcranial color-coded Doppler (TCCD) could be useful, but its role is not established. We studied the incidence of ultrasonographic vasospasm (uVSP) in PRES/RCVS and...

Background Distal medium vessel occlusions (DMVOs) represent 25–40% of all acute ischemic strokes (AIS). DMVO clinical syndromes are heterogenous, but as eloquent brain regions are frequently involved, they are often disabling. Since current intravenous fibrinolytic therapies may fail to recanalize up to two-thirds of DMVOs, endovascular treatment...

Background: Blood-brain barrier permeability (BBBp) is key process involved in ischemic stroke pathophysiology. However, there is a lack of consensus on how BBBp evolves after the ischaemic injury, and its clinical relevance at different time points post stroke. Aims: To assess BBBp evolution through stroke phases, and its implications on patien...

The existence of a selective blood-brain barrier (BBB) and neurovascular coupling are two unique central nervous system vasculature features that result in an intimate relationship between neurons, glia, and blood vessels. This leads to a significant pathophysiological overlap between neurodegenerative and cerebrovascular diseases. Alzheimer’s dise...

Background and Objectives COVID-19-related inflammation, endothelial dysfunction, and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with acute ischemic stroke (AIS). We aimed to evaluate the safety and outcomes of revascularization treatments in patients with AIS and COVID-19.

Objetives Time is relative in large-vessel occlusion acute ischemic stroke (LVO-AIS). We aimed to evaluate the rate of inter-hospital ASPECTS decay in patients transferred from a primary (PSC) to a comprehensive stroke center (CSC); and to identify patients that should repeat computed tomography (CT) before thrombectomy. Materials and methods This...

Background and objectives COVID-19 related inflammation, endothelial dysfunction and coagulopathy may increase the bleeding risk and lower efficacy of revascularization treatments in patients with acute ischemic stroke. We aimed to evaluate the safety and outcomes of revascularization treatments in patients with acute ischemic stroke and COVID-19....

BACKGROUND Twitter is a social media platform popularly used by health practitioners, a trend that has been followed by medical journals. The impact of Twitter in bibliometrics of stroke-related literature is yet to be determined. AIMS We aimed to qualitatively assess the usage of Twitter by stroke journals and study the relationship between Twitte...

Ischemic stroke is becoming one of the most common causes of death and disability in developed countries. Since current therapeutic options are quite limited, focused on acute reperfusion therapies that are hampered by a very narrow therapeutic time window, it is essential to discover novel treatments that not only stop the progression of the ische...

Introduction Oculopalatal tremor (OPT) is a late manifestation of a Guillain-Mollaret triangle lesion. Memantine has been shown to improve nystagmus in OPT, but its long-term efficacy and putative distinct effects on each plane of nystagmus and on associated phenomena (e.g., gravity perception) are largely unknown. Methods We conducted a 6-month o...

Background and objectives Intravenous thrombolysis (IV–rtPA) has been suggested as a potential cause of myocardial infarction (MI) after acute ischemic stroke (AIS), with randomized clinical trials showing a higher number of cardiac events within the thrombolysis group. We assessed the prevalence and MI mechanisms after IV–rtPA for AIS. Methods Re...

Introduction: To design more effective interventions, such as neurostimulation, for stroke rehabilitation, there is a need to understand early physiological changes that take place that may be relevant for clinical monitoring. We aimed to study changes in neurophysiology following recent ischemic stroke, both at rest and with motor planning and ex...

Acute ischemic stroke is essentially a hemodynamic event: It is triggered by a vascular occlusion and the current mainstay of treatment is reopening the culprit vessel using endovascular procedures and/or thrombolysis. Despite this oversimplistic view, concealing overwhelming cellular, intercellular, inflammatory, and hypoxic mechanisms, it is wide...

Stroke is a leading cause of death worldwide and poses significant societal and healthcare challenges due to functional impairment of the brain. In order to fully restore brain function, innovative approaches have aimed to regenerate the injured tissue and to restore neuronal circuitry. In the last 5 years, stem cells have been consistently explore...

Introduction: Since the publication of endovascular treatment trials and European Stroke Guidelines, Portugal has re-organized stroke healthcare. The nine centers performing endovascular treatment are not equally distributed within the country, which may lead to differential access to endovascular treatment. Our main aim was to perform a descripti...

Objectives To determine the predictive value of early transcranial color-coded sonography (TCCS) for intracranial hemorrhage (ICH) in patients with large artery occlusion (LAO) stroke of carotid circulation, who were submitted to endovascular therapy (EVT) with successful reperfusion. Materials and Methods Retrospective study evaluating a cohort o...

Atrial fibrillation (AF), the most common arrhythmia in the adult population worldwide, represents a significant burden in terms of cardiovascular mortality and morbidity and has repercussions on health economics. Oral anticoagulation (OAC) is key to stroke prevention in AF and, in recent years, results from landmark clinical trials of non-vitamin...

Background In patients transferred from a primary stroke center (PSC) to a comprehensive stroke center (CSC) with a large vessel occlusion (LVO-AIS) it is unclear who should undergo CT scan before mechanical thrombectomy (MT). We aimed to identify which patients benefited from such reevaluation. Methods We conducted a retrospective study, includin...

Background APOE ε4 is independently associated with lobar intracranial hemorrhages (ICH). Although the ε4 allele enhances amyloid deposition in blood vessels, the ε2 allele predisposes to vasculopathic changes leading to rupture of amyloid laden vessels. Thus, ε4 and ε2 carriers might have increased susceptibility to ICH. We aimed to study the impa...

Stroke represents the second leading cause of mortality and morbidity worldwide. Ischemic strokes are the most prevalent type of stroke, and they are characterized by a series of pathological events prompted by an arterial occlusion that leads to a heterogeneous pathophysiological response through different hemodynamic phases, namely the hyperacute...

BACKGROUND AND PURPOSE: Stroke is reported as a consequence of severe acute respiratory syndrome coronavirus-2 (SARSCoV- 2) infection in several reports. However, data are sparse regarding the details of these patients in a multinational and large scale. METHODS: We conducted a multinational observational study on features of consecutive acute isch...

Introduction: This study aimed to evaluate the performance of non-vitamin K antagonist oral anticoagulation (NOAC) in patients with previous stroke and non-valvular atrial fibrillation (AF) compared with left atrial appendage occlusion (LAAO) in primary and secondary stroke prevention settings. Methods: This was a prospective, single-center, non...

Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2), which is involved in the inflammatory atherosclerotic process, has emerged as an independent risk factor for atheromatous vascular events. Its impact on coronary disease has already been demonstrated, however, its influence in cerebrovascular etiology is still unknown. We aimed to obse...

The objective of this study is to assess the impact of recanalization (spontaneous and therapeutic) on upper limb functioning and general patient functioning after stroke. This is a prospective, observational study of patients hospitalized due to acute ischemic stroke in the territory of the middle cerebral artery (n = 98). Patients completed a com...

The blood–brain barrier (BBB) is a dynamic interface responsible for maintaining the central nervous system homeostasis. Its unique characteristics allow protecting the brain from unwanted compounds, but its impairment is involved in a vast number of pathological conditions. Disruption of the BBB and increase in its permeability are key in the deve...

Atrial fibrillation (AF), the most common arrhythmia in the adult population worldwide, represents a significant burden in terms of cardiovascular mortality and morbidity and has repercussions on health economics. Oral anticoagulation (OAC) is key to stroke prevention in AF and, in recent years, results from landmark clinical trials of non-vitamin...

Introduction Ischaemic stroke is the most prevalent type of stroke and is characterised by a myriad of pathological events triggered by a vascular arterial occlusion. Disruption of the blood-brain barrier (BBB) is a key pathological event that may lead to fatal outcomes. However, it seems to follow a multiphasic pattern that has been associated wit...

Background: Stroke is reported as a consequence of SARS-CoV-2 infection. However, there is a lack of regarding comprehensive stroke phenotype and characteristics Methods: We conducted a multinational observational study on features of consecutive acute ischemic stroke (AIS), intracranial hemorrhage (ICH), and cerebral venous or sinus thrombosis (CV...

Purpose Prescription patterns of non–vitamin K antagonist oral anticoagulants (NOACs) are unknown among primary care physicians, where most patients with nonvalvular atrial fibrillation (NVAF) are diagnosed and followed up. The goal of this study was to evaluate overdosing and underdosing of NOACs in patients with NVAF followed up in primary care a...

Background and Purpose: Bypassing the emergency department (ED) and the CT suite by directly transporting to the neuroangiography suite for imaging assessment and treatment may shorten reperfusion times while maintaining proper patient selection. Methods: Patients from prospectively collected databases of 4 international comprehensive stroke center...

Purpose: Better understanding of clinical predictors of aphasia outcome is of the utmost importance, in patients' rehabilitation planning, expectation management, and further physiopathology understanding. We aimed to identify clinical predictors of long-term poststroke aphasia's outcome. Methods: We conducted a prospective longitudinal observat...

Background and aims: Statin pretreatment (SP) is associated with improved outcomes in acute ischemic stroke (AIS) patients. Collateral circulation status and final infarct volume (FIV) are independent predictors of functional outcome in AIS. Methods: We sought to evaluate the association of SP with collateral circulation and FIV in AIS patients....

Objective: Presumed microvascular ischemia is the most frequent cause of ocular motor palsy (OMP). Ischemic stroke incidence after an episode of microvascular OMP (mOMP) is not established, contrasting with other common vascular conditions, such as lacunar ischemic stroke (LS). We sought to compare the incidence of subsequent ischemic stroke betwe...

Resumo Introdução Os anticoagulantes orais demonstraram ser altamente eficazes na prevenção do acidente vascular cerebral (AVC) associado a fibrilhação auricular (FA). A ocorrência de AVC apesar da hipocoagulação oral não é expectável, existindo escassa informação sobre os mecanismos responsáveis pela sua ocorrência. O objetivo deste estudo foi av...

INTRODUCTION Oral anticoagulants have proved to be highly effective in preventing atrial fibrillation (AF)-related strokes. The occurrence of stroke despite oral anticoagulation is unexpected and little is known about the mechanisms responsible. The aim of this study was to assess possible mechanisms for stroke occurrence, such as poor treatment ad...

Introduction: Observational study data suggest that statin pretreatment (SP) could be associated with better outcomes in acute ischemic stroke (AIS) by improving collateral circulation. In turn, adequacy of collateral circulation is known to improve neurological outcome through the reduction of final infarct volume (FIV) after an AIS. We sought to...

Herpes simplex virus 1 is a prevalent neurotropic pathogen that infects and establishes latency in peripheral sensory neurons. It can migrate into the central nervous system and cause encephalitis. The association between herpes simplex virus encephalitis and cerebral venous thrombosis is rare, with a very limited number of case reports described i...

Objective Whether intracerebral haemorrhage (ICH) associated with non‐vitamin K antagonist oral anticoagulants (NOAC‐ICH) has a better outcome compared to ICH associated with vitamin‐K antagonists (VKA‐ICH) is uncertain. Methods We performed a systematic review and individual patient data meta‐analysis of cohort studies comparing clinical and radi...

OBJECTIVE: Whether intracerebral haemorrhage (ICH) associated with non-vitamin K antagonist oral anticoagulants (NOAC-ICH) has a better outcome compared to ICH associated with vitamin-K antagonists (VKA-ICH) is uncertain. METHODS: We performed a systematic review and individual patient data meta-analysis of cohort studies comparing clinical and rad...

We performed a retrospective study with the aim of investigating the association between blood pressure (BP) variability in the first 24 h after ischemic stroke and functional outcome, regarding arterial recanalization status. A total of 674 patients diagnosed with acute stroke and treated with revascularization therapies were enrolled. Systolic an...

Objective: To evaluate the potential of neuroimaging, serum biomarkers, stroke etiology, and clinical characteristics as predictors of upper limb functioning 12 weeks after stroke. Methods: This was a prospective, observational study of patients (18–85 years-old) hospitalized due to acute ischemic stroke in the territory of the middle cerebral arte...

Introduction: Classical aphasia evaluation scales are too long to use in the context of acute stroke or as a monitoring tool. The Aphasia Rapid Test is a 26-point scale developed as a bedside assessment to rate aphasia severity in acute stroke patients in less than 3 minutes. We aimed to adapt and validate this scale for European Portuguese. Materi...

Introduction: Classical aphasia evaluation scales are too long to use in the context of acute stroke or as a monitoring tool. The Aphasia Rapid Test is a 26-point scale developed as a bedside assessment to rate aphasia severity in acute stroke patients in less than 3 minutes. We aimed to adapt and validate this scale for European Portuguese. Materi...

Background: Stroke is a major cause of short-term functional impairment, but the recovery timeframes are not well-established. Aim: This study aims to evaluate the progression of functional recovery during the first 24 weeks after acute ischaemic stroke, to determine the timeframes for (a) motor, (b) cognitive, and (c) overall recovery. Design:...

Rationale/aim Despite the increasing efficacy of recanalization therapies for acute ischemic stroke, a large number of patients are left with long-term functional impairment, devoid of efficacious treatments. CD34+ cells comprise a subset of bone marrow-derived mononuclear cells with the capacity to promote angiogenesis in ischemic lesions and have...

Background Cerebral edema is frequent in patients with acute ischemic stroke (AIS) who undergo reperfusion therapy and is associated with high mortality. The impact of collateral pial circulation (CPC) status on the development of edema has not yet been determined. Methods We studied consecutive patients with AIS and documented M1–middle cerebral...

Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contras...

Background: Stroke is one of the leading causes of disability worldwide. Early prediction of poststroke disability using clinical models is of great interest, especially in the rehabilitation field. Although some biomarkers and neuroimaging techniques have shown potential predictive value, there are still insufficient data to support their clinica...

Introduction: Clinical trials and subsequent meta-analyses showed advantages of non-vitamin K antagonists oral anticoagulants (NOACs) over vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation. The impact of preadmission anticoagulation in acute ischaemic stroke (AIS) has not been established. Objective: To compare funct...

Background Endothelial Progenitor Cells (EPCs) are a circulating stem cell population with in vivo capacity of promoting angiogenesis after ischemic events. Despite the promising preclinical data, their potential integration with reperfusion therapies and hemodynamic evolution of stroke patients is still unknown. Our aim was to determine the associ...

Objective: To study the association among endothelial progenitor cells (EPCs), subacute blood-brain barrier (BBB) permeability, and clinical outcome after ischemic stroke, determining the micro RNAs of EPCs responsible for good clinical outcome. Methods: We included consecutive patients with nonlacunar acute ischemic strokes in the territory of...

Background: Calcifications are an important element of atherosclerotic plaques and have been used as a marker of atherosclerosis and clinical outcome predictor in different vascular territories. CT-scan, performed in the acute ischemic stroke setting, can reliably detect intracranial arterial calcifications. Objectives: To investigate the associ...

Introduction: Pathophysiology of cervical artery dissection is complex and poorly understood. In addition to well-known causative and predisposing factors, including major trauma and monogenic connective tissue disorders, morphological characteristics of the styloid process have been recently recognized as a possible risk factor for cervical intern...

Objectives: The clinical approach to acute vestibular syndromes is often complex for the physician. Neurosonology offers a noninvasive method to study the cervicocephalic circulation when a vascular etiology is suspected. We aim to evaluate the diagnostic accuracy of a vascular neurosonological exam in isolated acute vestibular syndrome. Methods:...

Background: Cardioembolism has tendency to recur and cause lesions in distinct cerebrovascular territories. Using the imaging characteristics of cerebral lesions to determine dissemination in time and space (DTS) is a concept already used in other neurologic conditions; however, it has never been applied as a diagnostic tool in ischemic stroke eti...

Background: There is a lower reported incidence of intracranial hemorrhage with non-vitamin K antagonist oral anticoagulants compared with vitamin K antagonist. However, the functional outcome and mortality of intracranial hemorrhage patients were not assessed. Aims: To compare the outcome of vitamin K antagonists- and non-vitamin K antagonist oral...

Introdução: O acidente vascular cerebral é uma das principais causas de mortalidade e morbilidade em todo o mundo, associando-se a considerável incapacidade funcional. Atualmente sabe-se que tanto técnicas de neuroimagem como determinados biomarcadores fornecem informações úteis acerca da etiologia, decisão terapêutica, follow-up e prognóstico em d...

Introduction: Stroke remains one of the leading causes of morbidity and mortality around the world and it is associated with an important long-term functional disability. Some neuroimaging resources and certain peripheral blood or cerebrospinal fluid proteins can give important information about etiology, therapeutic approach, follow-up and functi...

Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients, bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contra...

Background: The diagnosis of Parkinson's disease (PD) can sometimes be a challenge in the early stages of the disease. Both transcranial sonography (TCS) and DaTSCAN are recommended as auxiliary examinations for the differential diagnosis of PD; however, only few data exist regarding their diagnostic accuracy in the early stage of PD and essential...

BACKGROUND AND PURPOSE: Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features. METHODS: Consecutive patients hospitalized for ischemic...

Background and purpose: Historical stroke cohorts reported a U- or J-shaped relationship between blood pressure (BP) and clinical outcome. However, these studies predated current revascularization strategies, disregarding the recanalization state of the affected arterial territory. We aimed to investigate the relationship between BP in the first 2...

Stroke is one of the leading causes of death and disability worldwide. However, current therapies only reach a small percentage of patients and may cause serious side effects. We propose the therapeutic use of retinoic acid-loaded nanoparticles (RA-NP) to safely and efficiently repair the ischaemic brain by creating a favourable pro-angiogenic envi...

Introduction: The evaluation of hyperechogenicity of the substantia nigra (SN) by transcranial sonography (TCS) is validated for the diagnosis of Parkinson's disease (PD). However, its correlation with the severity of motor involvement is still uncertain. Methods: We included patients with clinical diagnosis of idiopathic PD in a cross-sectional...

We aim to assess the impact of early nocturnal blood pressure (BP) variation in the functional outcome of patients after an acute ischemic stroke. We included consecutive stroke patients treated with intravenous thrombolysis (IVrtPA) in a tertiary stroke center. BP measurements were performed at regular intervals throughout day and night during the...