Publications by authors named "Ana Quiroga Varela"

Background And Objectives: The role of the complement system in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is not completely understood, and studies exploring its potential utility for diagnosis and prognosis are lacking. We aimed to investigate the value of complement factors (CFs) as diagnostic and prognostic biomarkers in patients with MOGAD.

Methods: Multicentric retrospective cohort study including patients with MOGAD, multiple sclerosis (MS) and aquaporin-4 seropositive neuromyelitis optica spectrum disorder (AQP4-NMOSD) with available paired serum and CSF samples.

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Immunohistochemical studies have identified complement component C1q in MS lesions. We aimed to compare serum (sC1q) and CSF (csfC1q) levels in a large cohort of MS patients (pwMS) (n = 222) with those of healthy controls (HC, n = 52), individuals with other immune (IND, n = 14), and non-immune neurological disorders (nIND, n = 15), and to analyze their correlation with other biomarkers. pwMS were divided into three series based on their origin.

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Article Synopsis
  • - The study explored how serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) levels could predict worsening disability in multiple sclerosis (MS), enrolling 725 patients across 13 European hospitals from 1994 to 2023.
  • - Higher levels of sNfL were significantly associated with increased risks of relapse-associated worsening (RAW), progression independent of relapse activity (PIRA), and reaching an Expanded Disability Status Scale (EDSS) score of 3, while elevated sGFAP levels were linked to a higher risk of reaching the EDSS score.
  • - Combining both sNfL and sGFAP levels indicated that low values represented low risk for worsening
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Background: Our objective was to explore various biomarkers for predicting suboptimal responses to disease-modifying treatments (DMTs) in patients with MS (pwMS).

Methods: We conducted a longitudinal, bicentric study with pwMS stratified based on their DMTs responses. Treatment failure (TF) was defined as the onset of a second relapse, presence of two or more T2 new lesions, or disability progression independent of relapse during the follow-up period.

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Background: Calcitriol, the active form of vitamin D (also known as 1,25-dihydroxycholecalciferol), improves the phenotype and increases frataxin levels in cell models of Friedreich ataxia (FRDA).

Objectives: Based on these results, we aimed measuring the effects of a calcitriol dose of 0.25 mcg/24h in the neurological function and frataxin levels when administered to FRDA patients for a year.

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Background: Cognitive impairment is present in 40-65% of patients with multiple sclerosis (pwMS). Objectively measured cognitive performance often does not match patients' subjective perception of their own performance.

Objective: We aimed to compare cognitive performance and subjective perception of cognitive deficits between pwMS and healthy controls (HCs), as well as the accuracy of subjective perception.

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Introduction: Progressive multifocal leukoencephalopathy is a rare but often fatal complication of some multiple sclerosis treatments. Although it has mainly been associated with natalizumab treatment, its appearance with other immunosuppressive therapies has also been reported.

Aims: The aim of this case report is to describe the development of progressive multifocal encephalopathy in a patient with relapsing-remitting multiple sclerosis treated with ocrelizumab without previous use of natalizumab.

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Learning and memory mainly rely on correct synaptic function in the hippocampus and other brain regions. In Parkinson's disease, subtle cognitive deficits may even precede motor signs early in the disease. Hence, we set out to unravel the earliest hippocampal synaptic alterations associated with human α-synuclein overexpression prior to and soon after the appearance of cognitive deficits in a parkinsonism model.

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Importance: The value of serum neurofilament light chain (sNfL) levels for predicting long-term disability in patients with multiple sclerosis (MS) remains controversial.

Objective: To assess whether high sNfL values are associated with disability worsening in patients who underwent their first demyelinating MS event.

Design, Setting, And Participants: This multicenter cohort study included patients who underwent their first demyelinating event suggestive of MS at Hospital Universitario Ramón y Cajal (development cohort; June 1, 1994, to September 31, 2021, with follow-up until August 31, 2022) and 8 Spanish hospitals (validation cohort; October 1, 1995, to August 4, 2020, with follow-up until August 16, 2022).

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Background And Objectives: Primary progressive multiple sclerosis (PPMS) displays a highly variable disease progression with a characteristic accumulation of disability, what makes difficult its diagnosis and efficient treatment. The identification of microRNAs (miRNAs)-based signature for the early detection in biological fluids could reveal promising biomarkers to provide new insights into defining MS clinical subtypes and potential therapeutic strategies. The objective of this cross-sectional study was to describe PPMS miRNA profiles in CSF and serum samples compared with other neurologic disease individuals (OND) and relapsing-remitting MS (RRMS).

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Background: The presence of lipid-specific oligoclonal IgM bands (LS-OCMB) in cerebrospinal fluid is associated with a more severe clinical multiple sclerosis (MS) course.

Objective: To investigate LS-OCMB as a prognostic biomarker of cognitive long-term outcomes in MS.

Methods: Ninety-nine patients underwent neuropsychological assessment.

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Article Synopsis
  • The study investigates how disease-modifying therapies, specifically anti-CD20 treatments and sphingosine 1-phosphate receptor modulators (S1PRM), affect immune responses to SARS-CoV-2 vaccines in patients with multiple sclerosis (MS) and other autoimmune diseases.
  • Researchers enrolled 457 patients and measured both humoral (antibody) and cellular (T-cell) immune responses before and after vaccination, finding that responses varied based on treatment type and duration.
  • Results indicate that while anti-CD20 and S1PRM treatments can reduce antibody responses, anti-CD20 patients may still generate T-cell responses even without detectable antibodies, highlighting the complexities of vaccine response in these populations.
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Synaptic impairment might precede neuronal degeneration in Parkinson's disease. However, the intimate mechanisms altering synaptic function by the accumulation of presynaptic α-synuclein in striatal dopaminergic terminals before dopaminergic death occurs, have not been elucidated. Our aim is to unravel the sequence of synaptic functional and structural changes preceding symptomatic dopaminergic cell death.

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In the original version of this article, the Figure 3 was published in an incorrect format, even though the data and the related information in the text are correct.

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Rationale: Impulse control disorders (ICD) and other impulsive-compulsive behaviours are frequently found in Parkinson's disease (PD) patients treated with dopaminergic agonists. To date, there are no available animal models to investigate their pathophysiology and determine whether they can be elicited by varying doses of dopaminergic drugs. In addition, there is some controversy regarding the predispositional pattern of striatal dopaminergic depletion.

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Purpose: To study the feasibility of the in vivo [F]-DPA-714 TSPO positron emission tomography (PET) to detect glial activation in a rat model of progressive parkinsonism induced by viral-mediated overexpression of A53T mutated human α-synuclein (hα-syn) in the substantia nigra pars compacta (SNpc).

Methods: We conducted a cross-sectional study in a model of progressive parkinsonism. Bilateral intranigral injections with 2/9 adeno-associated viral vectors encoding either hα-syn (AAV-hα-syn) or green fluorescent protein (AAV-GFP) were performed in rats (n = 60).

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Background: Dynamic functional network analysis may add relevant information about the temporal nature of the neurocognitive alterations in PD patients with impulse control disorders (PD-ICD). Our aim was to investigate changes in dynamic functional network connectivity (dFNC) in PD-ICD patients, and topological properties of such networks.

Methods: Resting state fMRI was performed on 16 PD PD-ICD patients, 20 PD patients without ICD and 17 healthy controls, whose demographic, clinical and behavioral scores were assessed.

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Parkinson's disease is a progressive neurodegenerative disorder characterized by altered striatal dopaminergic signalling that leads to motor and cognitive deficits. Parkinson's disease is also characterized by abnormal presence of soluble toxic forms of α-synuclein that, when clustered into Lewy bodies, represents one of the pathological hallmarks of the disease. However, α-synuclein oligomers might also directly affect synaptic transmission and plasticity in Parkinson's disease models.

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Objective: Spreading depolarization (SD) is a transient self-propagating wave of neuronal and glial depolarization coupled with large membrane ionic changes and a subsequent depression of neuronal activity. Spreading depolarization in the cortex is implicated in migraine, stroke, and epilepsy. Conversely, spreading depolarization in the striatum, a brain structure deeply involved in motor control and in Parkinson's disease (PD) pathophysiology, has been poorly investigated.

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When James Parkinson described the classical symptoms of the disease he could hardly foresee the evolution of our understanding over the next two hundred years. Nowadays, Parkinson's disease is considered a complex multifactorial disease in which genetic factors, either causative or susceptibility variants, unknown environmental cues, and the potential interaction of both could ultimately trigger the pathology. Noteworthy advances have been made in different fields from the clinical phenotype to the decoding of some potential neuropathological features, among which are the fields of genetics, drug discovery or biomaterials for drug delivery, which, though recent in origin, have evolved swiftly to become the basis of research into the disease today.

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Treatment with dopaminergic agonists such as pramipexole (PPX) contributes to the development of impulse control disorders (ICDs) in patients with Parkinson's disease (PD). As such, animal models of abnormal impulse control in PD are needed to better study the pathophysiology of these behaviors. Thus, we investigated impulsivity and related behaviors using the 5-choice serial reaction time task, as well as FosB/ΔFosB expression, in rats with mild parkinsonism induced by viral-mediated substantia nigra overexpression of human A53T mutated α-synuclein, and following chronic PPX treatment (0.

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Background: There is a need for biomarkers of dementia in PD.

Objectives: To determine if the levels of the main CSF proteins and their ratios are associated with deterioration in cognition and progression to dementia in the short to mid term.

Methods: The Parkinson's Progression Markers Initiative database was used as an exploratory cohort, and a center-based cohort was used as a replication cohort.

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Cognitive impairment is common in multiple sclerosis (MS). Unfortunately, the synaptic and molecular mechanisms underlying MS-associated cognitive dysfunction are largely unknown. We explored the presence and the underlying mechanism of cognitive and synaptic hippocampal dysfunction during the remission phase of experimental MS.

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Background: Advanced Parkinson's disease (PD) is characterized by massive degeneration of nigral dopaminergic neurons, dramatic motor and cognitive alterations, and presence of nigral Lewy bodies, whose main constituent is α-synuclein (α-syn). However, the synaptic mechanisms underlying behavioral and motor effects induced by early selective overexpression of nigral α-syn are still a matter of debate.

Methods: We performed behavioral, molecular, and immunohistochemical analyses in two transgenic models of PD, mice transgenic for truncated human α-synuclein 1-120 and rats injected with the adeno-associated viral vector carrying wild-type human α-synuclein.

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