Improvement of olfactory function after sinus surgery correlates with white matter properties measured by diffusion...

Area of Science:

• Neuroimaging
• Olfactory Neuroscience
• White Matter Research

Background:

• Olfactory impairment is linked to reduced volume in olfactory bulb and cortical gray matter.
• Restoration of olfaction can reverse gray matter volume loss.
• Cerebral white matter changes associated with olfaction restoration are understudied.

Purpose of the Study:

• To investigate cerebral white matter changes using magnetic resonance diffusion tensor imaging (DTI).
• To correlate white matter structural changes with olfactory function improvement after surgery.

Main Methods:

• Prospective study involving 31 patients with olfactory impairment (chronic rhinosinusitis) scheduled for functional endoscopic sinus surgery (FESS).
• Acquired pre- and postoperative MRI datasets using DTI.
• Assessed olfactory function using threshold, discrimination, and identification (TDI) scores pre- and post-surgery.

Main Results:

• Significant improvement in postoperative TDI scores observed.
• Patients with relevant olfactory gain (≥10 points) showed higher fractional anisotropy and apparent diffusion coefficient values in specific white matter regions.
• DTI parameters correlated significantly with TDI scores in the anterior cingulate cortex and amygdala.
• Tract-specific analysis revealed group differences in white matter tracts related to the cingulate cortex.

Conclusions:

• Postoperative restoration of olfaction is associated with structural changes in cerebral white matter.
• DTI can detect white matter alterations linked to olfactory function recovery.
• Findings suggest a neuroplastic response in white matter following olfactory restoration.