Decoding the neural basis of olfactory dysfunction: a multimodal MRI study in CRS-OD.

Area of Science:

• Neuroscience
• Radiology
• Otolaryngology

Background:

• Chronic rhinosinusitis with olfactory dysfunction (CRS-OD) impacts peripheral and central olfactory pathways.
• Persistent olfactory loss in CRS-OD may trigger neuroplastic brain changes.
• Hypothesis: CRS-OD is linked to gray matter atrophy and altered functional connectivity in olfactory regions.

Purpose of the Study:

• To investigate gray matter volume and functional connectivity alterations in CRS-OD patients.
• To correlate neuroimaging findings with olfactory dysfunction severity.

Main Methods:

• Prospective study of 23 CRS-OD patients and 23 healthy controls (HCs).
• MRI analysis including Voxel-Based Morphometry (VBM) for gray matter differences and seed-based functional connectivity (FC).
• Assessment of olfactory function using TDI, QOD, and OECS tests.

Main Results:

• CRS-OD patients showed significantly reduced olfactory bulb (OB) volumes compared to HCs.
• Gray matter atrophy was observed in the inferior frontal orbital gyrus, parahippocampal gyrus, hippocampus, thalamus, and putamen.
• Decreased FC in sensory-integration networks and increased FC in the superior occipital gyrus were noted, suggesting compensatory reorganization.

Conclusions:

• CRS-OD is associated with OB atrophy, gray matter loss, and disrupted FC, indicating peripheral and central neural alterations.
• Multimodal MRI offers insights into CRS-OD pathophysiology.
• Further longitudinal studies are warranted to understand the progression of these neural changes.