Publications by authors named "Xenia Kobeleva"

Introduction: Perivascular space (PVS) alterations are traditionally linked to cardiovascular risk factors and aging, but may also play a direct role in Alzheimer's disease (AD). To reduce confounding from age-related comorbidities, we examined PVSs in autosomal dominant AD (ADAD).

Methods: In this cross-sectional study of 96 non-demented individuals (62 mutation carriers), we quantified PVS count fraction and mean diameter in white matter and basal ganglia using automated magnetic resonance imaging analysis.

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White matter hyperintensities (WMH) are associated with cortical thinning in distant brain regions. However, it is currently unclear how WMH affect neurodegeneration in early Alzheimer's disease (AD). Here, we investigated associations between WMH and cortical thickness in temporal regions involved in early AD (AD cortical signature), while correcting for regional amyloid and tau accumulation assessed by PET.

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Article Synopsis
  • White matter damage, such as white matter hyperintensities (WMH), affects brain activity and can lead to cognitive symptoms, but the exact connection between this structural damage and brain function changes is still unclear.
  • Researchers used whole-brain modeling and a disconnectome approach along with data from 188 individuals to assess how WMH impacts both local and global brain dynamics, finding that while damage is generally local, it also decreases overall brain synchronization.
  • The study suggests that education may help mitigate the negative effects of WMH on brain connectivity, and the models developed can help evaluate how WMH specifically affects individuals' brain dynamics, providing insights for understanding brain function in diseases with similar disconnections
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  • * A 3-year study, TRANSLATE NAMSE, analyzed data from 1,577 patients, revealing that 32% received molecular diagnoses involving 370 distinct causes, primarily uncommon.
  • * The research showed that combining next-generation sequencing with advanced phenotyping methods improved diagnostic efficiency and helped identify new genotype-phenotype associations, particularly in neurodevelopmental disorders.
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Background: Hereditary spastic paraplegia (HSP) is characterized by progressive degeneration of distal axons in the long corticospinal tracts. Loss of retinal cells and microvascular networks has neither been suspected nor investigated. We concurrently examined the retinal microvasculature and retinal layer morphology in patients with HSP to assess whether retinal features may portray disease and its progression.

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Background: Alzheimer's disease is a neurodegenerative condition associated with the accumulation of two misfolded proteins, amyloid-beta (A[Formula: see text]) and tau. We study their effect on neuronal activity, with the aim of assessing their individual and combined impact.

Methods: We use a whole-brain dynamic model to find the optimal parameters that best describe the effects of A[Formula: see text] and tau on the excitation-inhibition balance of the local nodes.

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Previous studies have identified bilingualism as a protective factor against dementia. Here we aimed to test whether being bilingual at different life stages impacts cognition and brain structure in older adulthood. We included 746 participants from the DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE).

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Article Synopsis
  • Several lifestyle factors, particularly occupational cognitive requirements (OCR), may protect against Alzheimer's disease (AD) by potentially enhancing brain maintenance, brain reserve, or cognitive reserve throughout a person's life.
  • The study analyzed data from two population-based cohorts to understand how OCR interacts with genetic and biomarker factors related to cognitive decline and dementia onset.
  • Results indicated that higher OCR scores correlate with reduced cognitive decline risk, delayed onset of Alzheimer's, and relationships with brain structure and memory function, although OCR did not significantly affect Alzheimer's disease biomarkers over time.
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Functional magnetic resonance imaging (fMRI) captures information on brain function beyond the anatomical alterations that are traditionally visually examined by neuroradiologists. However, the fMRI signals are complex in addition to being noisy, so fMRI still faces limitations for clinical applications. Here we review methods that have been proposed as potential solutions so far, namely statistical, biophysical and decoding models, with their strengths and weaknesses.

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Background: Magnetic resonance-guided focused ultrasound of the ventral intermediate nucleus is a novel incisionless ablative treatment for essential tremor (ET).

Objective: The aim was to study the structural and functional network changes induced by unilateral sonication of the ventral intermediate nucleus in ET.

Methods: Fifteen essential tremor patients (66.

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Background: Variants in genes of the nucleotide excision repair (NER) pathway have been associated with heterogeneous clinical presentations ranging from xeroderma pigmentosum to Cockayne syndrome and trichothiodystrophy. NER deficiencies manifest with photosensitivity and skin cancer, but also developmental delay and early-onset neurological degeneration. Adult-onset neurological features have been reported in only a few xeroderma pigmentosum cases, all showing at least mild skin manifestations.

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Introduction: It is uncertain whether subjective cognitive decline (SCD) in individuals who seek medical help serves the identification of the initial symptomatic stage 2 of the Alzheimer's disease (AD) continuum.

Methods: Cross-sectional and longitudinal data from the multicenter, memory clinic-based DELCODE study.

Results: The SCD group showed slightly worse cognition as well as more subtle functional and behavioral symptoms than the control group (CO).

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The brain rapidly processes and adapts to new information by dynamically transitioning between whole-brain functional networks. In this whole-brain modeling study we investigate the relevance of spatiotemporal scale in whole-brain functional networks. This is achieved through estimating brain parcellations at different spatial scales (100-900 regions) and time series at different temporal scales (from milliseconds to seconds) generated by a whole-brain model fitted to fMRI data.

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As the global health crisis unfolded, many academic conferences moved online in 2020. This move has been hailed as a positive step towards inclusivity in its attenuation of economic, physical, and legal barriers and effectively enabled many individuals from groups that have traditionally been underrepresented to join and participate. A number of studies have outlined how moving online made it possible to gather a more global community and has increased opportunities for individuals with various constraints, e.

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Background And Purpose: Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that causes progressive degeneration of neurons in motor and non-motor brain regions, affecting multiple cognitive domains such as memory. A functional magnetic resonance imaging (fMRI) study was performed to explore working memory function in ALS.

Methods: To contribute to the growing research field that employs structural and functional neuroimaging to investigate the effect of ALS on different working memory components, the localization and intensity of alterations in neural activity was explored using fMRI.

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Brainhack is an innovative meeting format that promotes scientific collaboration and education in an open, inclusive environment. This NeuroView describes the myriad benefits for participants and the research community and how Brainhacks complement conventional formats to augment scientific progress.

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(1) Purpose: Quantitative magnetic resonance imaging (qMRI) measurements can be used to sensitively estimate brain morphological alterations and may support clinical diagnosis of neurodegenerative diseases (ND). We aimed to establish a normative reference database for a clinical applicable quantitative MR morphologic measurement on neurodegenerative changes in patients; (2) Methods: Healthy subjects (HCs, = 120) with an evenly distribution between 21 to 70 years and amyotrophic lateral sclerosis (ALS) patients ( = 11, mean age = 52.45 ± 6.

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Background: Early identification of individuals at risk of dementia is mandatory to implement prevention strategies and design clinical trials that target early disease stages. Subjective cognitive decline (SCD) and neuropsychiatric symptoms (NPS) have been proposed as potential markers for early manifestation of Alzheimer's disease (AD). We aimed to investigate the frequency of NPS in SCD, in other at-risk groups, in healthy controls (CO), and in AD patients, and to test the association of NPS with AD biomarkers, with a particular focus on cognitively unimpaired participants with or without SCD-related worries.

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We report bi-allelic pathogenic HPDL variants as a cause of a progressive, pediatric-onset spastic movement disorder with variable clinical presentation. The single-exon gene HPDL encodes a protein of unknown function with sequence similarity to 4-hydroxyphenylpyruvate dioxygenase. Exome sequencing studies in 13 families revealed bi-allelic HPDL variants in each of the 17 individuals affected with this clinically heterogeneous autosomal-recessive neurological disorder.

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The diagnostic gap for rare neurodegenerative diseases is still considerable, despite continuous advances in gene identification. Many novel Mendelian genes have only been identified in a few families worldwide. Here we report the identification of an autosomal-dominant gene for hereditary spastic paraplegia (HSP) in 10 families that are of diverse geographic origin and whose affected members all carry unique truncating changes in a circumscript region of UBAP1 (ubiquitin-associated protein 1).

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Background: Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive, fatal motor neuron disease with a variable natural history. There are no accurate models that predict the disease course and outcomes, which complicates risk assessment and counselling for individual patients, stratification of patients for trials, and timing of interventions. We therefore aimed to develop and validate a model for predicting a composite survival endpoint for individual patients with ALS.

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Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) require differential management despite presenting with symptomatic overlap. Currently, there is a need of inexpensive DLB biomarkers which can be fulfilled by electroencephalography (EEG). In this regard, an established electrophysiological difference in DLB is a decrease of dominant frequency (DF)-the frequency with the highest signal power between 4 and 15 Hz.

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Attention and executive dysfunction are features of Lewy body dementia (LBD) but their neuroanatomical basis is poorly understood. To investigate underlying dysfunctional attention-executive network (EXEC) interactions, we examined functional connectivity (FC) in 30 patients with LBD, 20 patients with Alzheimer's disease (AD), and 21 healthy controls during an event-related functional magnetic resonance imaging (fMRI) experiment. Participants performed a modified Attention Network Test (ANT), where they were instructed to press a button in response to the majority direction of arrows, which were either all pointing in the same direction or with one pointing in the opposite direction.

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