Objectives: To test the prevalence and evolution of acute olfactory and gustatory functional impairment and of their morphologic correlates in COVID-19 patients who require hospitalization due to COVID-19-related respiratory conditions. Key-words: COVID-19, taste, olfaction, electrogustometry, contact endoscopy Design: Electrogustometric (EGM) - thresholds at the tongue area supplied by the chorda tympani, at the soft palate and at the vallate papillae area were recorded bilaterally. Olfaction was examined by Sniffin’ sticks. The patients’ nasal and oral mucosa (fungiform papillae, fpap) were examined by contact endoscopy. Setting: Tertiary referral medical centre. Patients: 53 consecutive hospitalized patients (23 males, 30 females, age 42,54 ± 10, 95 yrs) with RT-PCR-confirmed COVID-19 diagnosis were included. Patients have been examined twice: just after hospital discharge and 4-6 weeks later. Main outcome measures: EGM-thresholds and taste strips, Schniffin-Sticks, Contact-Endoscopyesults: EGM-thresholds in patients were significantly higher at both instances than those of healthy subjects. EGM-thresholds at the second measurement were significantly lower than those at the first measurement. Accordingly, patient-reported gustatory outcomes were improved at the second measurement. The same pattern has been found using Sniffin’ sticks. Significant alterations in form and vascularization of fPap have been detected in patients, especially at the first instance. Conclusions: COVID-19 affects both gustatory and olfactory functions. It also affects in parallel the structure and vascularization of both nasal and oral mucosa, although the nasal mucosa to a much less, non-significant, extent. Our findings suggest that COVID-19 may cause a mild to profound neuropathy of multiple cranial nerves.

Introduction: Aim is to investigate in parallel changes in electrogustometric thresholds and in morphology of the fungiform papillae as well as in shape and density of the vessels of the tip of the tongue in patients with head and neck malignancy before and after treated with radiochemotherapy. We have also studied whether the observed changes in function and morphology may be reversible. Materials and Methods: Eighteen patients with tonsil-cancer treated with radiochemotherapy were prospectively studied. Measurements took place before starting treatment and at the end of each cycle of chemotherapy. Additional measurements were conducted two and four months after the end of the therapy. Results: All patients showed alterations in form and vascularization of fungiform Papillae (fPap). After the end of therapy an improvement in the EGM-thresholds without immediate improvement in the shape and vascularization of fungiform papillae was found. Two months after the end of the therapy a minimally significant difference in the EGM-thresholds measured on the tip of the tongue was shown. By the second measurement we have noticed a little improvement of the EGM-threshold, accompanied only by an improvement in the vascularization of fPap. Conclusions: The improvement in taste acquity was not directly accompanied by changes in vascularization of papillae and shape. The last parameters seem to recover late in time.

Objectives: The primary goal was to evaluate the effect of stimulus-duration on Electrogustometry (EGM) Thrasholds, to evaluate any gender-related influences and compare the above results to those after application of Taste-Strips. Design: Electrogustometry (EGM) thresholds of various stimulus duration (0.5, 1.0, 1.5, and 2.0 s) were measured in 212 non-smokers (age range: 10 – 80 years, divided into 8 age groups) without self-reported gustatory impairment. Furthermore, taste strips chemogustometry measurements in 132 participants were performed. Setting: Tertiary referral medical centre. Participants: 212 non-smokers, divided in 8 age-groups participated in the study. Main outcome measures: EGM-Thresholds and taste-strips, duration of stimuli Results: EGM-thresholds increased progressively with age and with increase in stimulus duration from 0.5 sec up to 2 sec. This pattern was consistent at all 6 anatomic areas, irrespective from gender. In contrast, in chemogustometry no differences related either to age or to gender were found. Conclusions: Age-related electrophysiological and functional gustatory decline can be better documented by EGM than using chemogustometry. This superiority of EGM was not influenced by stimulus duration; nonetheless, stimulus duration should be clearly documented in future quantitative EGM-threshold recordings, given that it may significantly influence EGM amplitude threshold measurements.