Brain structural analysis in patients with post-traumatic anosmia: Voxel-based and surface-based morphometry.

Area of Science:

• Neuroimaging
• Neuroanatomy
• Olfactory Neuroscience

Background:

• Post-traumatic anosmia (PTA) is a common consequence of head injuries.
• Understanding the neuroanatomical basis of PTA is crucial for developing effective treatments.

Purpose of the Study:

• To investigate gray matter (GM) neuroanatomical changes in patients with PTA using voxel-based morphometry (VBM) and surface-based morphometry (SBM).
• To explore the functional correlates of these GM changes with olfactory test performance.

Main Methods:

• MRI scans and olfactory test results (Sniffin' Sticks) from 39 PTA patients and 39 controls were analyzed.
• GM structure was assessed using CAT12 and FreeSurfer.
• Olfactory bulb (OB) volume and olfactory sulcus (OS) depth were quantified using 3D-Slicer.

Main Results:

• PTA patients exhibited reduced OB volume, OS depth, and olfactory test scores compared to controls.
• VBM and SBM identified overlapping GM alterations in orbitofrontal cortex, frontal and temporal gyri, cingulate cortex, and insular cortex.
• Decreased cortical thickness was observed in the parietal regions; orbitofrontal cortex and middle frontal gyrus showed correlations with odor threshold and smell loss duration, respectively.

Conclusions:

• Morphological alterations in the OB, OS, and central olfactory pathways are implicated in the pathophysiology of olfactory dysfunction following head trauma.
• Neuroimaging techniques like VBM and SBM are valuable tools for characterizing brain changes associated with PTA.