Assessment of retronasal olfactory function in patients with smell loss and subjectively normal flavor perception

Background:

The human sense of smell constitutes the main part of flavor perception. Patients with loss of olfactory function complain in most cases of diminished perception during eating and drinking. However, some patients with smell loss still report normal flavor perception. The aim of the present study was to investigate orthonasal and retronasal olfactory function in patients with smell loss and subjectively normal flavour perception.

Material and methods:

10 patients (5 female, 5 male, mean age/range 56.9/13 – 82 years) with self-reported olfactory impairment but subjective normal to excellent flavor perception were included. Olfactory performance was assessed using the Sniffin' Sticks (TDI) for orthonasal and the Candy Smell Test (CST) for retronasal function. Visual analogue scales were used for the self-assessment of odor perception (SOP), taste perception (STP) and flavor perception (SFP).

Results:

Mean/SD orthonasal TDI score of all patients was 14.9/5.7 (range 7 – 25.25). Mean/SD retronasal CST score was 8.4/2.7 (range 3 – 11). No correlation was found between SFP and the CST (p = 0.95)

Conclusion:

The present results show that normal subjective flavor perception in patients with smell loss is not confirmed by retronasal smell test results. In most of the investigated patients orthonasal and retronasal smell test results yielded scores within the range of anosmia. The reasons for unchanged flavor perception in some patients with smell loss might result from unconscious memory recall but have to be investigated in further studies.

Publication History

Publication Date:
23 April 2019 (online)