2025 Proffered Presentations
S364: DISCREPANCY BETWEEN SUBJECTIVE AND OBJECTIVE OLFACTORY FUNCTION IN PATIENTS UNDERGOING ENDOSCOPIC ENDONASAL SKULL BASE SURGERY: IMPACT OF PRIOR SARS-COV-2 INFECTION
Bastien A Valencia-Sanchez, MD; Alaa Alhalabi, MD; Prishae Wilson, BS; Natasha Najmi, BS; Angela M Donaldson, MD; Department of Otolaryngology - Head and Neck Surgery, Mayo Clinic Florida
Background: The impact of prior SARS-CoV-2 infection on postoperative olfactory function following endoscopic endonasal skull base surgery (EESBS) remains unclear. Currently, there is no consensus on the relationship between subjective and objective olfactory function in these patients. While studies show that numerous patients with SARS-CoV-2 infection report olfactory dysfunction (OD) without demonstrating objective smell loss, less is known about patients who report normal olfaction but have impaired objective function. This study aims to investigate whether patients with a history of SARS-CoV-2 infection who subjectively report normal olfaction but demonstrate abnormal objective olfactory testing are at higher risk for postoperative OD following EESBS.
Methods: A retrospective review was conducted on patients who underwent EESBS for sellar/parasellar lesions between 2020 and 2024 at a tertiary referral center. Olfaction was assessed both subjectively, through patient-reported smell loss, and objectively using the University of Pennsylvania Smell Identification Test (UPSIT), both pre- and postoperatively. The UPSIT scores categorize patients as having normosmia, mild/moderate/severe microsmia, or anosmia. Patients with discordant olfactory function (i.e. normal subjective olfaction and non-normosmic UPSIT scores) were included in the study. Patients were divided into SARS-CoV-2 positive and negative cohorts based on positive PCR results or self-reported infection during their preoperative visit. Electronic medical records were reviewed for demographic characteristics, pre- and postoperative UPSIT scores, and post-operative OD. Mann-Whitney U, Wilcoxon signed-rank, and chi-squared tests were used to analyze continuous and categorical variables, respectively.
Results: 29 patients were included in the SARS-CoV-2 positive cohort and 141 in the SARS-CoV-2 negative cohort. The male-to-female ratio was 1:1.9 in the positive group and 1:1.27 in the negative group. Most patients were Caucasian (79.4% vs. 80.1%), with smaller proportions identifying as Hispanic (10.3% vs. 12.1%) or African American (10.3% vs. 7.8%). The mean age was comparable between groups (53.55 ±17.73 vs. 57.34 ±16.60, p=0.27). The majority of patients had mild microsmia (65.5% vs. 58.2%) and pituitary adenomas (82.8% vs. 92.2%).
Preoperative UPSIT scores were similar between the two groups (30.62 ± 2.69 vs. 29.63 ± 4.57, p=0.26). Postoperative UPSIT scores, available for 41.4% of the positive group and 34.8% of the negative group, showed no significant difference between groups (30.75 ± 4.49 vs. 30.14 ± 6.45, p=0.76). There was no statistically significant difference when comparing pre- and postoperative UPSIT scores within the positive or the negative group (p=0.57 and p=0.067, respectively). However, the risk of developing postoperative subjective OD was significantly higher in the SARS-CoV-2 positive group compared to the negative group (41.4% vs. 20.6%, p=0.02).
Conclusion: Patients with a history of pre-operative SARS-CoV-2 infection may be at greater risk of developing postoperative subjective OD following EESBS, despite no significant differences in objective olfactory function. These findings highlight the importance of addressing subjective olfactory concerns in this population and suggest that the increased risk of developing postoperative subjective OD in the SARS-CoV-2 positive population may be linked to a change in smell perception rather than objective OD. Further research is needed to investigate the mechanisms behind this discrepancy.