Remote Cortical Network for Frontal Cognitive Symptoms Derived from Tau Accumulation in Progressive Supranuclear...

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Progressive Supranuclear Palsy (PSP) presents with motor and frontal cognitive impairments.
• Subcortical tau deposits are linked to motor symptoms, but frontal cognitive dysfunction mechanisms are unclear due to limited and heterogeneous frontal tau accumulation.
• Understanding the network basis of PSP's cognitive symptoms is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the network mechanisms underlying frontal cognitive deficits in PSP.
• To differentiate the roles of direct tau deposition versus network effects in PSP symptoms.
• To identify specific brain networks affected by tau pathology in PSP.

Main Methods:

• Utilized tau-positron emission tomography (PET) with a novel high-contrast probe.
• Combined tau-PET imaging with normative connectome data.
• Analyzed the relationship between tau deposition sites, cortical networks, and patient symptoms (motor and cognitive).

Main Results:

• Identified a common cortical network connected to subcortical tau deposition sites, distinct from networks identified by structural MRI atrophy.
• This network significantly overlapped with action-mode and frontoparietal networks crucial for goal-directed behavior.
• Subcortical tau correlated with motor symptoms, but connectivity from tau sites to the identified network specifically explained frontal cognitive deficits, independent of atrophy.

Conclusions:

• Frontal cognitive impairments in PSP are likely caused by remote effects of subcortical tau pathology on specific cortical networks.
• This mechanism operates independently of direct frontal tau accumulation and brain atrophy.
• Findings suggest a novel understanding of PSP pathophysiology, emphasizing network connectivity in cognitive decline.