Publications by authors named "Miguel Tabuas Pereira"

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  • Alzheimer's disease (AD) heritability is high at 70-80%, yet many contributing factors remain unexplained, prompting a study to explore inheritance patterns in Portuguese AD patients.
  • The research involved roughly 3,090 participants, examining family history, parental birthplace, and their relationships to AD risk, particularly focusing on gender differences in hereditary influences.
  • Results indicate that men with a maternal history of dementia face higher AD risk, and proximity of parents' birthplaces correlates with increased risk and earlier onset of dementia, suggesting evidence for X-linked inheritance and impacts of consanguinity.
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  • The study examined how cognitive specialists diagnose and manage functional cognitive disorder (FCD) compared to neurodegenerative diseases, using clinical vignettes for assessment.
  • Forty-five experts from 12 countries effectively distinguished between FCD and neurodegeneration, accurately diagnosing all neurodegenerative cases, but only 75%-88% of FCD cases were correctly classified due to varied terminology.
  • The findings highlight the need for improved agreement on FCD terminology and more research into validation and diagnostic tools, while suggesting that management strategies should include diagnostic communication and referrals for psychotherapy.
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  • Pathogenic heterozygous mutations in the GRN gene are a significant cause of frontotemporal dementia (FTD), leading to lower levels of the progranulin protein in biofluids, which has sparked therapeutic trials aimed at increasing these levels.
  • A systematic review of literature on biofluid PGRN concentrations included data from 7071 individuals, primarily focusing on plasma PGRN levels derived from a single assay type, which accounted for variations based on mutation type, age, sex, and clinical diagnosis.
  • Key findings established specific concentration cut-offs for plasma (74.8 ng/mL) and CSF (3.43 ng/mL) and indicated that plasma PGRN levels vary by mutation type,
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  • - Corticobasal syndrome is mainly sporadic but can have familial genetic cases linked to various gene variants, including GRN, MAPT, and c9orf72.
  • - A case study of a 57-year-old woman revealed symptoms like speech impairment, rigidity, and tremors, alongside MRI findings of left side brain atrophy and a SQSTM1 P392L genetic variant.
  • - This case adds new insights into the range of symptoms linked to SQSTM1 variants and highlights the potential role of the ubiquitin-proteasome system in corticobasal syndrome.
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In Portugal, heterozygous loss-of-function mutations in the progranulin () gene account for approximately half of the genetic mediated forms of frontotemporal dementia (FTD). mutations reported thus far cause FTD through a haploinsufficiency disease mechanism. Herein, we aim to unveil the mutation spectrum, investigated in 257 FTD patients and 19 family members from the central/north region of Portugal using sequencing methods.

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Background: Mild cognitive impairment (MCI) is considered a prodromal state of dementia. Abnormal values of cerebrospinal fluid Alzheimer's disease biomarkers (CSF-AD-b) have been associated with a higher risk of conversion to dementia (due to Alzheimer's disease), but studies evaluating the ability of Montreal Cognitive Assessment (MoCA) in this task are lacking.

Objective: This study aims to investigate the relationship between MoCA and CSF-AD-b, as well as the ability of those tools to predict conversion to dementia.

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Serum light-chain neurofilaments (sNfL) have been investigated as a potential minimally invasive biomarker that could help in the diagnosis of patients with cognitive symptoms. We assessed the correlation between sNfL and cerebrospinal fluid (CSF) biomarkers (sNfL versus CSF NfL, ρ= 0.70, p < 0.

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Background And Purpose: Blood-based biomarkers are promising tools for the diagnosis of Alzheimer disease (AD) at prodromal stages (mild cognitive impairment [MCI]) and are hoped to be implemented as screening tools for patients with cognitive complaints. In this work, we evaluated the potential of peripheral neurological biomarkers to predict progression to AD dementia and the relation between blood and cerebrospinal fluid (CSF) AD markers in MCI patients referred from a general neurological department.

Methods: A group of 106 MCI patients followed at the Neurology Department of Coimbra University Hospital was included.

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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 disease (AD) is the most prevalent neurodegenerative disease whose pathogenesis is still to be unveiled but has mostly been explored under the light of the amyloid-cascade hypothesis.

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Background: Frontal-variant of Alzheimer's disease (fvAD) was purposed for patients with AD pathology that, despite the typical amnestic presentation, show early and progressive deterioration of behavior and executive functions, closely resembling the behavioral-variant of frontotemporal dementia (bvFTD). This leads to a challenging differential diagnosis where neuropsychological evaluation and in vivo pathological evidence are essential.

Objective: To evaluate the contribution of a comprehensive neuropsychological assessment (NP) battery in distinguishing between fvAD-dementia and bvFTD supported by cerebrospinal fluid (CSF) biomarkers.

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Introduction: The CDR Dementia Staging Instrument PLUS National Alzheimer's Coordinating Center (CDR plus NACC FTLD) was developed by adding to the standard CDR two extra domains focused on the main features of frontotemporal lobar degeneration (FTLD): language and behavior/personality. We intended to perform the validation studies for the European-Portuguese population.

Methods: A total of 105 participants matched for age, education, and disease staging (35 bvFTD, 35 AD, and 35 controls) were included.

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Article Synopsis
  • The ATN scheme categorizes Alzheimer's disease biomarkers into three groups: Amyloidosis (A), Tauopathy (T), and Neurodegeneration (N), providing a framework that is relevant for both research and diagnosis.
  • In a study with 1,128 patients from various centers, the prevalence of ATN classifications showed that 47.8% fell into the Alzheimer's disease continuum, and ATN profiles were heavily influenced by factors like age and cognitive status.
  • While the ATN scheme effectively guides Alzheimer's diagnosis in real-world settings, it struggles with accuracy for other dementia types; adding markers for non-Alzheimer's conditions could improve differential diagnosis.
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  • Dementia with Lewy bodies is a neurodegenerative disease that has characteristics similar to both Parkinson's and Alzheimer's diseases.
  • A case study details a 60-year-old man who developed dementia with Lewy bodies and was found to have mutations in the PSEN1 and ATP7B genes.
  • This case emphasizes the importance of considering ATP7B mutations in patients with parkinsonism and supports the identification of the PSEN1 variant p.Ile408Thr as potentially pathogenic.
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Introduction: Frontotemporal dementia (FTD) is considered to be part of a continuum with amyotrophic lateral sclerosis (ALS). Many genes are associated with both ALS and FTD. Yet, many genes associated with ALS have not been shown to cause FTD.

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Background: Lewy bodies are a hallmark of Dementia with Lewy Bodies. They can also be found in the sinoatrial node and may be associated with heart disease.

Objectives: We aimed to investigate a possible association between Lewy Body dementia and atrial fibrillation.

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Background And Purpose: TP73 was recently reported to cause amyotrophic lateral sclerosis (ALS). ALS and frontotemporal dementia (FTD) are considered to form part of a continuum. We aimed to investigate whether TP73 variants may be associated with FTD.

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Background And Purpose: Neurofilament light chain (NfL) has recently been proposed as a promising biomarker in frontotemporal dementia (FTD). We investigated the correlation of both cerebrospinal fluid (CSF) and serum NfL with detailed neuropsychological data and cognitive decline in a cohort of sporadic and familial FTD.

Methods: CSF and serum NfL, as well as conventional CSF Alzheimer's disease (AD) biomarkers (Aβ42, t-Tau, p-Tau181), were determined in 63 FTD patients (30 sporadic-FTD, 20 with progranulin (GRN) mutations [FTD-GRN], 13 with chromosome 9 open reading frame 72 [C9orf72] expansions [C9orf72-FTD]), 37 AD patients, and 31 neurologic controls.

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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.

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The Toulouse-Piéron Cancelation Test (TP) is a classic psychometric tool for the assessment of selective/sustained attention, processing speed and visuo-perceptual abilities. It is commonly used in neurological disorders such as epilepsy, multiple sclerosis or Alzheimer's disease. It encompasses two main indexes: Work-Efficiency (WE) and Dispersion-Index (DI).

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Lewy body dementia is a common cause of dementia leading to the progressive deterioration of cognitive function and motor skills, behavioral changes, and loss of autonomy, impairing the quality of life of patients and their families. Even though it is the second leading cause of neurodegenerative dementia, diagnosis is still challenging, due to its heterogenous clinical presentation, especially in the early stages of the disease. Accordingly, Lewy body dementia is often misdiagnosed and clinically mismanaged.

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Background And Purpose: The COVID-19 (SARS-CoV-2) outbreak has disrupted residency programmes due to university and hospitals' priorities to face this emergency at all cost. Most research projects and clinical trials were temporarily stopped or postponed. The Resident and Research Fellow Section (RRFS) of the European Academy of Neurology (EAN) has decided to assess the impact of the COVID-19 pandemic on neurology training.

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The distinction between sporadic and genetic behavioural-variant frontotemporal dementia (bvFTD) regarding some neuropsychological (NP) features remains challenging. Specifically, progranulin (GRN)-associated bvFTD frequently presents with early episodic memory impairment and some degree of parietal dysfunction which are supporters of Alzheimer's disease (AD) diagnosis. In this context, we aimed to characterize the NP profile of GRN-bvFTD as compared to sporadic-bvFTD and AD in patients with mild dementia (Mini-Mental State Examination score ≥ 17 and Clinical Dementia Rating Scale score ≤ 1.

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The spatial coordinate system in which a stimulus representation is embedded is known as its reference frame. Every visual representation has a reference frame [1], and the visual system uses a variety of reference frames to efficiently code visual information [e.g.

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