The aim of the NODAL clinical trial is to demonstrate the feasibility of new, low-cost, non-invasive biomarkers of neurodegenerative pathologies as early Alzheimer and Parkinson, based on the estimation of the multimodal connectome.
Alzheimer's (AD) and Parkinson's (PD) diseases are characterized by pre-clinical and asymptomatic phases, which can extend over decades, before progressing through different clinical stages where cognitive and/or motor symptoms appear. A major challenge for clinical neuroscience is the availability of reliable, non-invasive and inexpensive biomarkers to enable early diagnosis, be clinically relevant, and ideally contribute to prognosis and patient monitoring. Current criteria, which are essentially clinical, have a relatively low diagnostic accuracy, which is unfortunately responsible for a delay in diagnosis, whereas it has been established that early diagnosis makes it possible to postpone the loss of autonomy, open up opportunities for clinical trials for patients, and, epidemiologically speaking, ultimately reduce the prevalence of major neurocognitive disorders. Recent advances in neuroimaging techniques and connectome analysis have led to the identification of innovative biomarkers that reflect the disorganization of brain networks and are associated with clinical symptoms. After participant inclusion, the experimental visit will take place over half a day, for patients with early-stage Alzheimer's or Parkinson's disease and for healthy control volunteers. After clinical assessment, participants will undergo an MRI scan and then perform the CONFMEM experimental task. The aim of this paradigm is to identify the impact of cognitive conflict situations on recognition memory (the ability to judge whether or not a stimulus has been previously presented). The cerebral connectome will be assessed for each patient, with the aim of determining whether patterns can lead to pathology-specific markers.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
120
CHU Rennes
Rennes, France
RECRUITINGMultimodal connectivity graph metrics across diseases
Multi-layer graph combining the functional and structural connectivity will provide an ideal framework for identifying multimodal features. The first layer corresponds to the functional connectivity where links represent the similarity between the fMRI signal from different cerebral regions (i.e. the nodes), using the cross-correlation. The second layer represents the structural connectivity where the edges are the fiber density between the nodes. Topological metrics of graph: 1/ the nodal centrality which quantifies how important a node is within a network, 2/ the betweenness defined as the ratio of the number of the shortest paths comprising the node to the total number of shortest paths in the graph, measures the hub property of the node and 3/ local efficiency which quantify the ability of a network to transmit information at the global and local level, will be compared between patients at-risk for Alzheimer's Disease, patients with Parkinson's Disease and healthy controls.
Time frame: 2 hours and 30 minutes
Multimodal connectivity graph metrics across stages of disease
Multi-layer graph combining the functional and structural connectivity will provide an ideal framework for identifying multimodal features. The first layer corresponds to the functional connectivity where links represent the correlation between the fMRI signal. The second layer represents the structural connectivity where the edges are the fiber density between the nodes. Topological metrics of graph: 1/ the nodal centrality which quantifies how important a node is within a network, 2/ the betweenness defined as the ratio of the number of the shortest paths comprising the node to the total number and 3/ local efficiency which quantify the ability of a network to transmit information, will be compared between patients at-risk for Alzheimer's Disease at the Subjective Cognitive Decline stage and at the Mild Cognitive Impairment stage. Similarly, patients with Parkinson's Disease without cognitive impairment and with Parkinson's Disease with Mild Cognitive will be compared.
Time frame: 2 hours and 30 minutes
Correlation between multimodal connectivity graph metrics and cognitive scores
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Cognitive scores will include standard tasks (MOCA, Symbol Digit Modality Test - oral, Digit span, 16-items Free \& Cued Selective Reminding Test, 10/36 spatial recall test, Oral Letter-Number Sequencing test, D-KEFS Color-Word Interference Test, Benton Judgment of Line Orientation, CLOX clock-drawing test, Boston Naming Test, Animal fluency) and an experimental recognition memory task. As for the latter, the scores used will be the congruency effect during study (RT in milliseconds), global recognition accuracy, and the effect of congruency on subsequent memory (difference in recognition accuracy between congruent and incongruent trials at study).
Time frame: Up to 6 months (maximum delay between the study visit and the collection of standard tasks).