Background: Qualitative smell/taste disorders (such as phantosmia, parosmia, phantogeusia, and parageusia) have not yet been fully characterized in patients who had COVID-19, whereas quantitative disturbances (i.e., reduction/loss of smell/taste) have been widely investigated. Objective: To simultaneously assess the presence of both quantitative and qualitative smell/taste dysfunctions in patients who suffered from COVID-19. Methods: We enrolled 17 consecutive patients who suffered from COVID-19 over the last 6 months and 21 healthy controls, matched for sex and age. After a negative nasopharyngeal swab, the Sniffin’ Sticks Test and the Taste Strips were used to assess olfactory and taste function, respectively. At the same time, the presence of phantosmia, parosmia, phantogeusia, and parageusia was investigated with a standardized questionnaire. Results: Qualitative disturbances of smell and/or taste were found in 6/17 (35.3%) patients. Phantosmia was reported in 2/17 (11.8%) patients and parosmia in 4/17 (23.5%). There were no significant differences in smell test scores between patients who reported phantosmia and/or parosmia and patients who did not. Phantogeusia was described in 3/17 (17.6%) patients, and parageusia was identified in 4/17 (23.5%) patients. All tested patients were normogeusic. Conclusion: Around one-third of patients who recover from COVID-19 may have persistent qualitative dysfunction in smell/taste domains. Detection of phantogeusia in long-term COVID-19 patients represents a further novel finding. Further investigation is needed to better characterize the pathophysiology of phantosmia, parosmia, phantogeusia, and parageusia in patients who had COVID-19.

Background: Olfactory dysfunctions and hallucinations are considered common nonmotor symptoms in Parkinson’s disease (PD). Visual and auditory hallucinations are well-known; however, olfactory hallucinations (OHs) are not fully investigated. The aim of this study was to evaluate OHs in PD patients, and their correlation to motor impairment, cognitive abilities, visual and auditory hallucinations, and olfactory and gustatory function. Methods: A sample of 273 patients was enrolled: 141 PD patients (mean age ± SD: 70.1 ± 9.5 years) and 132 healthy controls (mean age ± SD: 69.4 ± 9.6 years). In all patients, the following parameters were evaluated: motor symptoms (UPDRS-III), olfactory function, cognitive abilities, and occurrence of OH, gustatory hallucinations (GHs), and visual/auditory hallucinations. Results: OHs were found only in PD patients with a percentage of 11.3%. Among PD patients with OHs, 2.8% also presented GHs. High significant frequencies of females, the presence of visual/auditory hallucinations, and a high mean UPDRS-III score were found in patients with OHs related to patients without them. Binary logistic regression evidenced the presence of visual/auditory hallucinations and sex as main variables predicting the presence of OHs. Conclusions: Our data indicated that OHs occur frequently in PD patients, especially in women, and often concomitant with visual and auditory hallucinations, without any association with olfactory impairment.

Introduction. Olfactory and cognitive disorders represent important non-motor symptoms in Parkinson’s disease (PD). No clear evidence was reported about association of specific cognitive domains and olfactory impairment. Objective. The aim of this study was to evaluate the association between olfactory dysfunction and specific cognitive domains in PD patients compared to controls. Methods. 178 PD patients and 98 controls were enrolled and evaluated for odor threshold (OT), discrimination (OD), identification (OI), and TDI score using the Sniffin’ Sticks test. Cognitive function was evaluated using the Montreal Cognitive Assessment scale with six sub-scores: Orientation (OIS), Attention (AIS), Language (LIS), Visuospatial (VIS), Memory (MIS), and Executive index scores (EIS). Results. Statistically significant correlations were observed between OT versus, LIS, and between TDI score versus EIS. Multivariate linear regression analysis, including age and sex which are well-known predictors of olfactory dysfunction, showed that, among specific cognitive domains, only LIS was significant predictor for OT, VIS was a significant predictor for OD, while both EIS and AIS were significant predictors for OI, and finally only EIS was significant predictor for TDI score. Conclusions. Olfactory disorders in PD patients appear commonly related to dysfunction of specific cognitive domains, with strict association between global olfactory impairment and executive function deficits.

Herbs and spices represent a possibility for the improvement of anosmia and ageusia. In this work we evaluated the role of Mediterranean aromatic herbs and spices in the salty taste perception of patients with hyposmia compared to healthy controls. To this goal, the salty taste perception in response to pure salt and different types of commercial flavored sea salt was assessed in patients with hyposmia, with or without a post-acute coronavirus syndrome, and healthy controls. Myrtle berries and leaves, a mixture of Mediterranean herbs and plants such as helichrysum, rosemary, liquorice, fennel seeds and myrtle leaves, oranges and saffron were used as salt flavoring ingredients. Differences in gustatory perception between 57 patients with hyposmia and 91 controls were evaluated considering the rate of the gustatory dimensions of pleasantness, intensity, and familiarity, using a 7-point hedonic Likert-type scale. At a dose of 0.04 g/mL, saline solutions of flavored salts, with an average 15% less NaCl, were perceived by patients with hyposmia as equally intense but less familiar than pure salt solution, with similar scores in the pleasantness dimension. Our study highlighted the central role of Mediterranean aromatic plants in the enhancement of salty perception in patients with hyposmia.

Background: Parkinson’s disease (PD) may present different motor subtypes depending on the predominant symptoms (tremor or rigidity/bradykinesia). Slower disease progression and cognitive decline were observed in tremor-dominant (TD) patients compared to those with the akinetic-rigid dominant (ARD) subtype. Although olfactory dysfunctions are well-known disturbances in PD patients, correlations among PD different subtypes and olfactory impairment were not clearly studied. Thus, we investigated the possible olfactory impairment in PD patients with TD and ARD subtypes as compared to healthy controls. Methods: A sample of 132 participants were enrolled: 62 PD patients divided into ARD (n = 42) and TD (n = 20) subgroups using tremor/rigidity ratio, and 70 healthy controls. Olfactory function was assessed with the Sniffin’ Sticks Test. Results: Odor threshold was significantly lower in the ARD than in the TD subtype, while odor identification, discrimination scores, and their sum (TDI score) were not significantly different. On multivariate linear regression analysis, the tremor/rigidity ratio was a significant predictor of odor threshold. Conclusions: Our pilot study showed a significant olfactory dysfunction in PD patients with the ARD subtype. This evidence confirms the biological relevance of clinical subgroups in PD patients, suggesting the existence of a different pathophysiological mechanism between the ARD and TD clinical subtypes.

We evaluated sex differences in the perception of bitter compounds and an aromatic bitter herbal liqueur (Mirtamaro) obtained by the infusion of myrtle leaves/berries together with a mixture of Mediterranean herbs/plants as flavoring/bittering ingredients. In a healthy population (n = 231 participants), using bivariate correlations and multivariate linear regression analyses, significant sex differences emerged in quinine bitterness perception, with women showing a higher bitter taste intensity rating than men. Among all participants, 40 subjects (subpopulation) were randomly selected for the evaluation of sex differences in Mirtamaro gustatory and olfactory perception using a hedonic Likert-type scale. Women showed higher ratings in Mirtamaro aroma (odor intensity) and bitterness (taste intensity) perception than men, with a superior capacity to perceive/describe its sensory attributes. 1,8-Cineole and methyl chavicol were the main contributors to the bitter liqueur aroma. A significant correlation (r = 0.564, p < 0.01) between Mirtamaro odor pleasantness/taste pleasantness was observed in women, indicating a positive contribution of aromatic herbs to bitter taste acceptability. Moreover, a higher bitter intensity rating of 6-n-propylthiouracil was evidenced in women than men. Our results highlighted sex differences in bitter taste acuity and the role of aromatic herbs/plants in modulating bitter taste acceptance, which is useful information in the field of precision nutrition and medicine.