Sinonasal surgery alters brain structure and function: Neuroanatomical correlates of olfactory dysfunction

Area of Science:

• Neuroscience
• Neuroimaging
• Olfactory research

Background:

• Olfactory dysfunction (OD) is prevalent, impacting quality of life and serving as an early biomarker for neurodegenerative diseases.
• Previous cross-sectional studies suggest gray matter (GM) reductions in olfactory regions correlate with OD, but lack causal evidence.
• Longitudinal studies on olfactory structural plasticity, especially with functional imaging, are scarce.

Purpose of the Study:

• To investigate longitudinal structural and functional brain plasticity in central olfactory networks.
• To explore the neuroanatomical correlates of olfactory function and dysfunction.
• To assess changes following surgical treatment for chronic rhinosinusitis.

Main Methods:

• A longitudinal multimodal neuroimaging study.
• Compared 24 patients undergoing chronic rhinosinusitis surgery with 17 healthy controls.
• Utilized structural and functional imaging techniques (including BOLD signal).

Main Results:

• Demonstrated functionally significant structural plasticity in orbitofrontal, anterior cingulate, insular cortices, and temporal poles 3 months post-surgery.
• Observed decreased GM volume in these regions.
• Correlated structural changes with improved psychophysical olfactory scores and increased BOLD signal.

Conclusions:

• This is the first study to show both structural and functional plasticity in central olfactory networks.
• Confirms these brain regions as key neuroanatomical correlates of olfactory function and dysfunction.
• Highlights the dynamic nature of olfactory brain regions in response to interventions.