Research Roundup - May 2025
Penn FTD Center- 2 days ago
- 2 min read
Read the below Research Roundup from Penn FTD Center Postdoctoral Fellow Melanie Matyi PhD.
Terms to Know:
bvFTD: behavioral variant frontotemporal dementia. As the most common presentation of frontotemporal dementia (FTD), bvFTD affects a person’s higher cognitive functioning, typically presenting with symptoms such as apathy, disinhibition, and compulsive behaviors.
Magnetic resonance imaging: a non-invasive technique used to create detailed images of the brain and body. MRI uses a strong magnet and radio waves to create detailed images of organs and tissues in the body.
Diffusion-weighted MRI: MRI can be applied in different ways to visualize specific aspects of tissue. Diffusion MRI uses MRI to detect the extent to which the movement of water molecules is restricted in tissue, including in the white matter connections in the brain. This allows us to study the connectivity of brain regions.
Executive function: higher-order cognitive skills that involve things like planning, attention, problem-solving.
Salience network: The salience network is one common large-scale brain network that is critical for detecting stimuli that are important for behavior and directing attention towards these stimuli.
Network segregation: The extent to which brain networks are distinct from one another as measured by greater within-network connectivity relative to between-network connectivity.
What we knew:
We know that the brain is organized into networks, where groups of brain regions are highly connected within networks with fewer connections between networks. In healthy brains, greater differentiation of brain networks supports cognition. There is also evidence in healthy aging and in Alzheimer’s disease that this network structure breaks down which, in turn, is related to worse cognition. bvFTD is associated with executive dysfunction and breakdown of the salience network.
What we didn’t know:
In this study, we first wanted to evaluate if structural network integrity, measured by network segregation, in bvFTD is lower than that of cognitively normal controls, indicating network breakdown. Then, we tested whether structural network desegregation in bvFTD is associated with worse executive function.
What this research/study shows:
We found that patients with bvFTD, compared to cognitively normal controls, exhibited lower segregation of the salience network. Additionally, the extent to which the salience network was less segregated was associated with worse executive function. Importantly, lower network segregation was related to executive dysfunction above and beyond the volume/thickness of the cortex, a common measure of disease burden.
What to do with this information:
These findings indicate that brain lower network segregation, which reflects a reduced capacity for the brain to support specialized processing, may contribute to the emergence of executive dysfunction. These findings motivate longitudinal studies to evaluate network segregation as a mechanism of executive dysfunction. That is, does breakdown of the salience network lead to worsening in executive function? Additionally, identifying the processes underlying lower network segregation, like neurotransmitter systems and gene expression, could inform efforts to manage executive dysfunction in bvFTD.
More Information: