Identifying a Common Functional Framework for Apathy Large-Scale Brain Network.

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Apathy, characterized by reduced motivation and interest, is common in neurodegenerative diseases like frontotemporal dementia (FTD) and Parkinson's disease (PD).
• Understanding the neural basis of apathy is crucial for developing targeted interventions in these patient populations.

Purpose of the Study:

• To investigate large-scale brain network differences associated with apathy in patients with FTD and PD compared to healthy controls (HC).
• To identify specific brain regions and functional connectivity alterations underlying apathy in neurodegenerative disorders.

Main Methods:

• Utilized 3T brain MRI (structural and resting-state fMRI) on 60 participants (20 apathetic FTD/PD, 20 non-apathetic FTD/PD, 20 HC).
• Assessed functional connectivity (FC) using a whole-brain, seed-to-seed approach comparing apathetic and non-apathetic patient groups.
• Employed disease-specific apathy scales for patient assessment.

Main Results:

• Significant hypoconnectivity was found between the left planum polare and the right pre- or post-central gyrus in apathetic patients (FTD and PD) compared to HC.
• Replication analysis on non-apathetic patient subgroups (PD and FTD) did not reveal significant functional differences, suggesting apathy-specific alterations.
• These findings point to specific neural pathway involvement in reduced information processing and motor outcomes in apathy.

Conclusions:

• Apathy in FTD and PD is associated with distinct patterns of brain functional connectivity, particularly involving the left planum polare and motor/premotor cortices.
• The observed hypoconnectivity is likely linked to the apathy syndrome itself, rather than being solely a consequence of the underlying neurodegenerative pathology.
• These neural alterations may underlie the characteristic motivational and motor deficits observed in apathetic patients.