Alan Tucholka

Alan Tucholka
Pixyl Medical · R&D

PhD

About

70
Publications
8,366
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1,356
Citations

Publications

Publications (70)
Preprint
Full-text available
Deep neural networks have become the gold-standard approach for the automated segmentation of 3D medical images. Their full acceptance by clinicians remains however hampered by the lack of intelligible uncertainty assessment of the provided results. Most approaches to quantify their uncertainty, such as the popular Monte Carlo dropout, restrict to...
Article
Full-text available
Objectives Determining the volume of brain lesions after trauma is challenging. Manual delineation is observer-dependent and time-consuming and cannot therefore be used in routine practice. The study aimed to evaluate the feasibility of an automated atlas-based quantification procedure (AQP) based on the detection of abnormal mean diffusivity (MD)...
Preprint
Full-text available
Objectives. The determination of the volume of brain lesions after trauma is challenging. Manual delineation is observer-dependent and time-consuming which inhibits the practice in clinical routine. We propose and evaluate an automated atlas-based quantification procedure (AQP) based on the detection of abnormal mean diffusivity (MD) values compute...
Article
Childhood adversity and anxiety have been associated with increased risk for internalizing disorders later in life and with a range of brain structural abnormalities. However, few studies have examined the link between harsh parenting practices and brain anatomy, outside of severe maltreatment or psychopathology. Moreover, to our knowledge, there h...
Preprint
Full-text available
Automatic segmentation of brain abnormalities is challenging, as they vary considerably from one pathology to another. Current methods are supervised and require numerous annotated images for each pathology, a strenuous task. To tackle anatomical variability, Unsupervised Anomaly Detection (UAD) methods are proposed, detecting anomalies as outliers...
Article
Recent studies identified chronic leptomeningeal enhancement (LME) in late-acquired FLAIR sequences in secondary progressive (SP) multiple sclerosis (MS). These LMEs correlate with focal cortical inflammation and demyelination observed by pathology, which are supposed to drive long-term cortical atrophy. We report a spontaneously remitting meningea...
Article
Purpose The purpose of this study was to create an algorithm that combines multiple machine-learning techniques to predict the expanded disability status scale (EDSS) score of patients with multiple sclerosis at two years solely based on age, sex and fluid attenuated inversion recovery (FLAIR) MRI data. Materials and methods Our algorithm combined...
Article
Full-text available
Background: Mechanisms of functional compensation throughout the progression of Alzheimer's disease (AD) remain largely underspecified. By investigating functional connectomics in relation to cerebrospinal fluid (CSF) biomarkers across the pathophysiological continuum of AD, we identify disease-stage-specific patterns of functional degradation and...
Article
The identification of healthy individuals harboring amyloid pathology constitutes one important challenge for secondary prevention clinical trials in Alzheimer's disease (AD). Consequently, noninvasive and cost-efficient techniques to detect preclinical AD constitute an unmet need of critical importance. In this manuscript, we apply machine learnin...
Preprint
Full-text available
Background: Mechanisms of functional compensation throughout the progression of Alzheimer's disease (AD) remain largely underspecified. By investigating functional connectomics in relation to cerebrospinal fluid (CSF) biomarkers across the pathophysiological continuum of AD, we identify disease-stage-specific patterns of functional degradation and...
Article
Full-text available
Hidden beneath the Sylvian fissure and sometimes considered as the fifth lobe of the brain, the insula plays a multi-modal role from its strategic location. Previous structural studies have reported cortico-cortical connections with the frontal, temporal, parietal and occipital lobes, but only a few have looked at its connections with subcortical s...
Article
Full-text available
Background In temporal lobe epilepsy (TLE), advanced neuroimaging techniques reveal anomalies extending beyond the temporal lobe such as thinning of fronto-central cortices. Operculo-insular epilepsy (OIE) is an under-recognized and poorly characterized condition with the potential of mimicking TLE. In this work, we investigated insular and extra-i...
Article
Full-text available
Alzheimer's disease (AD) is characterized by an accumulation of β-amyloid (Aβ42) accompanied by brain atrophy and cognitive decline. Several recent studies have shown that Aβ42 accumulation is associated with gray matter (GM) changes prior to the development of cognitive impairment, in the so-called preclinical stage of the AD (pre-AD). It also has...
Article
Full-text available
Background: Gray matter changes associated with the progression of Alzheimer's disease (AD) have been thoroughly studied. However, alterations in white matter tracts have received less attention, particularly during early or preclinical stages of the disease. Objective: To identify the structural connectivity changes across the AD continuum. Me...
Article
Purpose Rolandic epilepsy (RE), also called benign epilepsy with centrotemporal spikes (BECTS) is the most common childhood epilepsy syndrome. RE is associated with cognitive difficulties, which can affect children's quality of life. The underlying causes of these cognitive impairments are unclear. The objective of this prospective study is to inve...
Article
Full-text available
Alzheimer's disease (AD) is the most common dementia with dramatic consequences. The research in structural and functional neuroimaging showed altered brain connectivity in AD. In this study, we investigated the whole-brain resting state functional connectivity (FC) of the subjects with preclinical Alzheimer's disease (PAD), mild cognitive impairme...
Article
Cerebral white matter hyperintensities are believed the consequence of small vessel disease and are associated with risk and progression of Alzheimer's disease. The ɛ4 allele of the APOE gene is the major factor accountable for Alzheimer's disease heritability. However, the relationship between white matter hyperintensities and APOE genotype in hea...
Article
Full-text available
The insula is a complex structure involved in a wide range of functions. Tracing studies on nonhuman primates reveal a wide array of cortical connections in the frontal (orbitofrontal and prefrontal cortices, cingulate areas and supplementary motor area), parietal (primary and secondary somatosensory cortices) and temporal (temporal pole, auditory,...
Article
Background: Chronic substance use can disrupt the reward function of the anterior cingulate cortex (ACC), biasing the ACC to favor goal-directed behaviors that converge on drug use. Here we used multimodal neuroimaging methods to ask whether modulating reward-related signaling in the ACC can reverse the atypical valuation of nondrug and drug rewar...
Article
Full-text available
Introduction Among other metabolic functions, the apolipoprotein E (APOE) plays a crucial role in neuroinflammation. We aimed at assessing whether APOE ε4 modulates levels of glial cerebrospinal fluid (CSF) biomarkers and their structural cerebral correlates along the continuum of Alzheimer's disease (AD). Methods Brain magnetic resonance imaging...
Preprint
Full-text available
Understanding the mechanisms behind Alzheimer’s disease (AD) is one of the most challenging problems in neuroscience. Recent efforts provided valuable insights on the genetic, biochemical and neuronal correlates of AD. The advances in structural and functional neuroimaging provided massive evidence for the AD related alterations in brain connectivi...
Article
Introduction: TREM2 is involved in the regulation of inflammatory response and phagocytosis. A soluble fragment (sTREM2) is often found abnormally increased in cerebrospinal fluid (CSF) in Alzheimer's disease (AD). Methods: Of the total, 114 participants (45 control, 19 preclinical, 27 mild cognitive impairment [MCI], and 23 AD) underwent CSF sT...
Article
Background: Manganese (Mn) can have neurotoxic effects upon overexposure. We previously reported poorer cognitive and motor development in children exposed to Mn through drinking water, suggesting possible neurotoxic effects from Mn in water. Hyperintensity in the globus pallidus (GP) on T1-weighted magnetic resonance imaging (MRI) indicates exces...
Article
Individuals with post-traumatic stress disorder (PTSD) exhibit exaggerated emotional reactions to threatening stimuli, which may represent deregulated fear-conditioning, associated with long-term adaptations in the sympathetic nervous system. Within a repeated measures design, functional magnetic resonance imaging (fMRI) was employed to investigate...
Article
Introduction: Children with benign epilepsy with centro-temporal spikes (BECTS) often have language problems. Abnormal epileptic activity is found in central and temporal brain regions, which are involved in reading and semantic and syntactic comprehension. Using functional magnetic resonance imaging (fMRI), we examined reading networks in BECTS c...
Article
Diffusion-weighted magnetic resonance imaging (dMRI) is a unique tool, which allows non-invasive in-vivo assessment of the white matter integrity and characterization of the brain maturation process in normal and abnormal subjects. In this review, we briefly present dMRI techniques and methodologies for non-experts and we describe recent studies in...
Poster
Full-text available
The structural connectivity profile of the human insula with subcortical regions such as the thalamus, hippocampus, caudate nucleus, putamen, amygdala, nuclei accumbens and the globus pallidus.
Article
PurposeVenous oxygenation (Yv) is an important index of brain physiology and may be indicative of brain diseases. A T2-relaxation-under-spin-tagging (TRUST) MRI technique was recently developed to measure Yv. A multisite evaluation of this technique would be an important step toward broader availability and potential clinical utilizations of Yv mea...
Article
Full-text available
Gilles de la Tourette syndrome is a childhood-onset syndrome characterized by the presence and persistence of motor and vocal tics. A dysfunction of cortico-striato-pallido-thalamo-cortical networks in this syndrome has been supported by convergent data from neuro-pathological, electrophysiological as well as structural and functional neuroimaging...
Poster
Full-text available
Located in the depth of the Sylvian fissure, the insula is divided by the central insular sulcus into an anterior portion comprising 3 short gyri, and a posterior portion composed of 2 long gyri. It is divided into three architectonic zones based on its organization, shape, number and type of neurons: agranular zone, granular zone, dysgranular zone...
Chapter
Most of the brain's cognitive functions are based on the coordinated interactions of large numbers of neurons that are distributed across different specialized brain areas. These brain areas are said to be organized like a 'small-world' network with abundant local connections to minimize wiring and energy cost but also relatively sparse long-range...
Chapter
The first reports of spontaneous insular seizure recordings and descriptions of associated clinical features date from the early 21st century. The growing body of observations since then has revealed an astonishing variety of ictal symptoms resulting from insular seizure discharge. Failure to recognize or correctly interpret such symptoms may be re...
Article
Full-text available
The main objective of this structural magnetic resonance imaging (MRI) study was to investigate, using diffusion tensor imaging, whether a neurofeedback training (NFT) protocol designed to improve sustained attention might induce structural changes in white matter (WM) pathways, purportedly implicated in this cognitive ability. Another goal was to...
Article
Full-text available
Huntington disease (HD) is associated with early and severe damage to the basal ganglia and particularly the striatum. We investigated cortico-striatal connectivity modifications occurring in HD patients using a novel approach which focuses on the projection of the connectivity profile of the basal ganglia onto the cortex. This approach consists in...
Article
Being able to detect reliably functional activity in a population of subjects is crucial in human brain mapping, both for the understanding of cognitive functions in normal subjects and for the analysis of patient data. The usual approach proceeds by normalizing brain volumes to a common three-dimensional template. However, a large part of the data...
Conference Paper
Full-text available
The deep brain nuclei play an important role in many brain functions and particularly motor control. Damage to these structures result in movement disorders such as in Parkinson's disease or Huntington's disease, or behavioural disorders such as Tourette syndrome. In this paper, we propose to study the connectivity profile of the deep nuclei to the...
Conference Paper
Full-text available
This paper presents a connectivity-based parcellation of the human post-central gyrus, at the level of the group of subjects. The dimension of the clustering problem is reduced using a set of cortical regions of interest determined at the inter-subject level using a surface-based coordinate system, and representing the regions with a strong connect...
Article
Full-text available
Activation detection in functional Magnetic Resonance Imaging (fMRI) datasets is usually performed by thresholding activation maps in the brain volume or, better, on the cortical surface. However, basing the analysis on a site-by-site statistical decision may be detrimental both to the interpretation of the results and to the sensitivity of the ana...
Conference Paper
Full-text available
Brain imaging provides a wealth of information that computers can explore at a massive scale. Categorizing the patterns of the human cortex has been a challenging issue for neuroscience. In this paper, we propose a data mining approach leading to the construction of the first computerized dictionary of cortical folding patterns, from a database of...
Conference Paper
In this paper, we study the recognition of about 60 sulcal structures over a new T1 MRI database of 62 subjects. It continues our previous work [7] and more specifically extends the localization model of sulci (SPAM). This model is sensitive to the chosen common space during the group study. Thus, we focus the current work on refining this space us...
Article
Full-text available
An important challenge in neuroimaging multi-subject studies is to take into account that different brains cannot be aligned perfectly. To this end, we extend the classical mass univariate model for group analysis to incorporate uncer-tainty on localization by introducing, for each subject, a spatial "jitter" variable to be marginalized out. We der...
Conference Paper
Full-text available
Defining precisely the position of active regions obtained from functional neuroimaging studies is challenging due to the functional and anatomical variability across subjects. Traditional volumetric normalization techniques ignore the geometry of the cortex and use a relatively imprecise three-dimensional coordinate system. In this study we propos...
Conference Paper
Full-text available
Understanding brain structure and function entails the inclusion of anatomical and functional information in a common space, in order to study how these different informations relate to each other in a population of subjects. In this paper, we revisit the parcellation model and explicitly combine anatomical features, i.e. a segmentation of the cort...