Altered Prefrontal Dynamic Functional Connectivity in Vascular Dementia During Olfactory Stimulation: An fNIRS Study.

Area of Science:

• Neuroscience
• Medical Imaging
• Neurology

Background:

• Vascular dementia (VD) is a progressive cognitive impairment.
• Understanding brain network alterations in VD is crucial for diagnosis and treatment.
• Olfactory dysfunction is often an early sign of neurodegenerative diseases.

Purpose of the Study:

• To investigate dynamic functional connectivity (dFC) changes in response to olfactory stimulation in patients with VD.
• To compare dFC responses between healthy controls and VD patients.
• To explore the potential of fNIRS as a non-invasive tool for assessing brain function in VD.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) was used to measure brain activity.
• Dynamic functional connectivity (dFC) was estimated using a sliding window correlation approach.
• Participants underwent cycles of rest and olfactory stimulation.

Main Results:

• The VD group exhibited more extensive fluctuations in oxy- and deoxyhemoglobin dFC compared to healthy controls.
• Significant differences in dFC were observed between groups during olfactory stimulation.
• These differences had moderate to large effect sizes.

Conclusions:

• Olfactory-evoked dFC alterations may indicate disrupted brain network dynamics in VD.
• fNIRS-based dFC analysis shows promise as a non-invasive and accessible tool for understanding VD.
• Further research is warranted to validate these findings and explore clinical applications.