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Video

Rhinology/Allergy

(A1135) Structural Brain Changes in Congenital Anosmia Patients: MRI-Based Analysis of Grey and White Matter Volumes

Monday, October 13, 2025
12:00 PM - 1:00 PM EDT
Location: OTO EXPO, Posters

    Presenting Author(s)

  • SL

    Shun-Hung Lin, MD

    Resident
    Taichung Veterans General Hospital
    Taichung, Taichung, Taiwan (Republic of China)

    • Senior Author(s)

  • Rong-San Jiang, MD, PhD

    Vice-President Good morning! Your poster portal tasks for the 2025 AAO-HNSF Annual Meeting & OTO EXPO are due this Monday, July 7! Please log in below. {Login Now} Your #OTOMTG25 Poster Portal Tasks URL: https://www.conferenceharvester.com/harvester2/login.asp?EventKey=GSGJLWVQ Username: rsjtaiwan@yahoo.com.tw Password (Access Key): HNLWFUUP Vice President
    Tungs' Taichung MetroHarbor Hospital
    Taichung City, Taiwan (Republic of China)

Disclosure(s):
Shun-Hung Lin, MD: No relevant relationships to disclose.
Rong-San Jiang, MD, PhD: No relevant relationships to disclose.


Introduction: This study investigates brain structural alterations in congenital anosmia patients using MRI, focusing on gray and white matter changes to understand the condition’s impact on brain development.

Methods: We retrospectively reviewed all cases of CA from January 1, 2001, to August 30, 2024, at a single medical center. A total of 58 individual cases met the inclusion criteria. We excluded 30 patients based on the exclusion criteria or missing data. Additionally, healthy individuals with no history of anosmia, age- and gender-matched, were randomly selected from our image database to serve as the control group. In total, 56 participants were included in the study: 28 CA patients and 28 healthy controls.

Results: Patients with CA exhibited significantly smaller gray matter (GM) volumes compared to healthy controls (560.6 ± 114.7 cm³ vs. 693.7 ± 96.3 cm³, p < 0.001) but larger white matter (WM) volumes (554.2 ± 75.4 cm³ vs. 491.1 ± 79.7 cm³, p = 0.015). After dividing the brain into 11 regions, we observed that patients with congenital anosmia had significantly smaller grey matter volumes in the frontal(131.9 ± 33.7 cc vs. 173.7 ± 27.0 cc, P-value: < .001), temporal (81.1 ± 18.4 cc vs. 96.5 ± 14.1 cc, P-value: .001), parietal (52.4 ± 15.2 cc vs. 77.2 ± 12.4 cc, P-value: < .001), sub-lobar (57.8 ± 9.7 cc vs. 68.2 ± 10.2 cc, P-value: .001), occipital (39.1 ± 13.0 cc vs. 57.8 ± 8.9 cc, P-value: < .001), and midbrain (2.0 ± 0.5 cc vs. 2.3 ± 0.4 cc, P-value: .006) regions. Conversely, these patients exhibited significantly larger white matter volumes in the frontal (152 ± 19.9 cc vs. 139.2 ± 24 cc, p = .027), temporal (71.5 ± 11.5 cc vs. 60.8 ± 9.5 cc, p < .001), parietal (75.8 ± 12.4 cc vs. 61.9 ± 11.5 cc, p < .001), and occipital (58.7 ± 10.3 cc vs. 41.9 ± 7.9 cc, p < .001) regions compared to controls.

Conclusions: This study demonstrates significant structural brain differences in individuals with CA compared to healthy controls, including reduced GM volumes and increased WM volumes. These changes were widespread across cortical and sub-lobar regions, suggesting that congenital olfactory deprivation impacts brain development beyond the olfactory pathways.