Effects of olfactory training on resting‑state effective connectivity in patients with posttraumatic olfactory...

Area of Science:

• Neuroscience
• Olfactory Research
• Brain Connectivity

Background:

• Post-traumatic olfactory dysfunction impacts quality of life.
• Understanding the neural mechanisms of olfactory recovery is crucial.
• Resting-state effective connectivity offers insights into brain network function.

Purpose of the Study:

• To investigate the impact of a smell training scheme on resting-state effective connectivity.
• To identify changes in brain networks associated with olfactory function improvement.
• To explore connectivity alterations in olfactory-related regions.

Main Methods:

• Recruited 16 patients with post-traumatic olfactory dysfunction.
• Assessed olfactory performance using the Sniffin' Sticks test.
• Utilized resting-state functional magnetic resonance imaging (fMRI) and spectral dynamic causal modeling.

Main Results:

• Smell training group showed improved odor discrimination and overall olfactory function compared to controls.
• Treatment group exhibited increased self-inhibitory orbitofrontal cortex (OFC) connectivity.
• Enhanced excitatory connectivity from the cingulate cortex to the insula was observed post-training.

Conclusions:

• Smell training can induce measurable changes in resting-state effective connectivity.
• Altered connectivity in the OFC, cingulate cortex, and insula correlates with olfactory performance improvements.
• This study provides evidence for the neural plasticity underlying olfactory training efficacy.