Search results for "Neuroimaging"
showing 10 items of 281 documents
Reference standard space hippocampus labels according to the European Alzheimer's Disease Consortium–Alzheimer's Disease Neuroimaging Initiative harm…
2017
Abstract Introduction A harmonized protocol (HarP) for manual hippocampal segmentation on magnetic resonance imaging (MRI) has recently been developed by an international European Alzheimer's Disease Consortium–Alzheimer's Disease Neuroimaging Initiative project. We aimed at providing consensual certified HarP hippocampal labels in Montreal Neurological Institute (MNI) standard space to serve as reference in automated image analyses. Methods Manual HarP tracings on the high-resolution MNI152 standard space template of four expert certified HarP tracers were combined to obtain consensual bilateral hippocampus labels. Utility and validity of these reference labels is demonstrated in a simple …
Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography.
2016
The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group su…
Comparison of Different Hypotheses Regarding the Spread of Alzheimer’s Disease Using Markov Random Fields and Multimodal Imaging
2018
Alzheimer’s disease (AD) is characterized by a cascade of pathological processes that can be assessed in vivo using different neuroimaging methods. Recent research suggests a systematic sequence of pathogenic events on a global biomarker level, but little is known about the associations and dependencies of distinct lesion patterns on a regional level. Markov random fields are a probabilistic graphical modeling approach that represent the interaction between individual random variables by an undirected graph. We propose the novel application of this approach to study the interregional associations and dependencies between multimodal imaging markers of AD pathology and to compare different hy…
Impact of Resilience on the Association Between Amyloid-β and Longitudinal Cognitive Decline in Cognitively Healthy Older Adults
2019
The present study aims at investigating if the association between amyloid-β and longitudinal cognitive decline in cognitively healthy elderly is modulated by resilience capacity. Resilience capacity was quantified by education, which is a common proxy of resilience and has been shown to be related to a wide range of behaviors promoting resilience. Analyses were conducted with longitudinal cognitive data from the Alzheimer's Disease Neuroimaging Initiative (ADNI). 276 cognitively healthy older individuals (≥56 years) were included in the study. Baseline amyloid pathology was quantified using CSF amyloid-β 1-42 measurements. Longitudinal cognitive decline was assessed using ADAS13, Clinical …
Association of Common Polymorphisms in the Nicotinic Acetylcholine Receptor Alpha4 Subunit Gene with an Electrophysiological Endophenotype in a Large…
2016
PLoS one 11(4), e0152984 (2016). doi:10.1371/journal.pone.0152984
Molecular properties underlying regional vulnerability to Alzheimer’s disease pathology
2018
Amyloid deposition and neurofibrillary degeneration in Alzheimer's disease specifically affect discrete neuronal systems, but the underlying mechanisms that render some brain regions more vulnerable to Alzheimer's disease pathology than others remain largely unknown. Here we studied molecular properties underlying these distinct regional vulnerabilities by analysing Alzheimer's disease-typical neuroimaging patterns of amyloid deposition and neurodegeneration in relation to regional gene expression profiles of the human brain. Graded patterns of brain-wide vulnerability to amyloid deposition and neurodegeneration in Alzheimer's disease were estimated by contrasting multimodal amyloid-sensiti…
Expanding the β-III Spectrin-Associated Phenotypes toward Non-Progressive Congenital Ataxias with Neurodegeneration
2021
(1) Background: A non-progressive congenital ataxia (NPCA) phenotype caused by b-III spectrin (SPTBN2) mutations has emerged, mimicking spinocerebellar ataxia, autosomal recessive type 14 (SCAR14). The pattern of inheritance, however, resembles that of autosomal dominant classical spinocerebellar ataxia type 5 (SCA5). (2) Methods: In-depth phenotyping of two boys studied by a customized gene panel. Candidate variants were sought by structural modeling and protein expression. An extensive review of the literature was conducted in order to better characterize the SPTBN2-associated NPCA. (3) Results: Patients exhibited an NPCA with hypotonia, developmental delay, cerebellar syndrome, and cogni…
Children show right-lateralized effects of spoken word-form learning
2017
It is commonly thought that phonological learning is different in young children compared to adults, possibly due to the speech processing system not yet having reached full native-language specialization. However, the neurocognitive mechanisms of phonological learning in children are poorly understood. We employed magnetoencephalography (MEG) to track cortical correlates of incidental learning of meaningless word forms over two days as 6±8-year-olds overtly repeated them. Native (Finnish) pseudowords were compared with words of foreign sound structure (Korean) to investigate whether the cortical learning effects would be more dependent on previous proficiency in the language rather than ma…
Hirayama disease: Nosological classification and neuroimaging clues for diagnosis
2022
Hirayama disease (HD) is a rare, benign, and nonprogressive motor neuron disease (MND) affecting the upper limbs. It usually presents with weakness and amyotrophy in a single upper extremity with an insidious onset between adolescence and the third decade of life. Since its description in 1959, HD has been known under several names and eponyms in Europe and in Asian countries probably due to its heterogeneous clinical features. Thus, the unclear nosological classification makes challenging the differential diagnosis between HD and other neuromuscular conditions, such as MNDs. However, apart from the nosological difficulties and the lack of evidence-based guideline for diagnosis, the neuroim…
Association of Structural Global Brain Network Properties with Intelligence in Normal Aging
2013
Higher general intelligence attenuates age-associated cognitive decline and the risk of dementia. Thus, intelligence has been associated with cognitive reserve or resilience in normal aging. Neurophysiologically, intelligence is considered as a complex capacity that is dependent on a global cognitive network rather than isolated brain areas. An association of structural as well as functional brain network characteristics with intelligence has already been reported in young adults. We investigated the relationship between global structural brain network properties, general intelligence and age in a group of 43 cognitively healthy elderly, age 60–85 years. Individuals were assessed cross-sect…