Fronto-striatal alterations correlate with apathy severity in behavioral variant frontotemporal dementia

Area of Science:

• Neuroimaging
• Neurology
• Cognitive Neuroscience

Background:

• Behavioral variant frontotemporal dementia (bvFTD) is associated with structural and functional brain alterations.
• A multimodal neuroimaging approach can offer deeper insights into the neural correlates of bvFTD's neuropsychiatric symptoms.

Purpose of the Study:

• To investigate structural abnormalities (cortical thickness and subcortical volumes) and functional connectivity (FC) in bvFTD patients.
• To explore the relationship between these neuroimaging findings and clinical/neuropsychological outcomes, specifically apathy.

Main Methods:

• Multicenter study comparing 37 bvFTD patients with 37 healthy controls using structural MRI (cortical thickness, subcortical volumes).
• Whole-brain FC analysis using resting-state fMRI in a sub-cohort (22 bvFTD, 22 controls) seeded from regions with structural changes.
• Correlations between imaging data and apathy scores from the Neuropsychiatry Inventory Questionnaire.

Main Results:

• bvFTD patients exhibited decreased cortical thickness in frontal and temporal regions and reduced subcortical volumes (basal ganglia, thalamus, hippocampus, amygdala).
• Decreased FC was observed between the dorsal striatum and left caudal middle frontal gyrus, putamen and fronto-parietal regions, and pallidum and cerebellum.
• Increased FC was found between the left middle temporal gyrus and paracingulate gyrus, caudate nucleus and insula, and amygdala and parahippocampal gyrus.
• Cortical thickness in frontal regions and caudate nucleus volume negatively correlated with apathy severity.

Conclusions:

• Multimodal structural and functional neuroimaging reveals significant alterations in fronto-striatal networks in bvFTD.
• These fronto-striatal structural and functional deviations are linked to the severity of apathy in bvFTD patients.