Objective: Decrease of olfactory function in Parkinson's disease (PD) is a well-investigated fact. Studies indicate that pharmacological treatment of PD fails to restore olfactory function in PD patients. The aim of this investigation was whether patients with PD would benefit from “training” with odors in terms of an improvement of their general olfactory function. It has been hypothesized that olfactory training should produce both an improved sensitivity towards the odors used in the training process and an overall increase of olfactory function. Methods: We recruited 70 subjects with PD and olfactory loss into this single-center, prospective, controlled non-blinded study. Thirty-five patients were assigned to the olfactory training group and 35 subjects to the control group (no training). Olfactory training was performed over a period of 12 weeks while patients exposed themselves twice daily to four odors (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon, and eugenol: cloves). Olfactory testing was performed before and after training using the “Sniffin' Sticks” (thresholds for phenyl ethyl alcohol, tests for odor discrimination, and odor identification) in addition to threshold tests for the odors used in the training process. Results: Compared to baseline, trained PD patients experienced a significant increase in their olfactory function, which was observed for the Sniffin' Sticks test score and for thresholds for the odors used in the training process. Olfactory function was unchanged in PD patients who did not perform olfactory training. Conclusion: The present results indicate that olfactory training may increase olfactory sensitivity in PD patients.

L’agrément d’un vin dépend du jugement de ses qualités organoleptiques par un jury de professionnels. Les performances olfactives et gustatives nécessaires des dégustateurs y jouent un rôle déterminant. Pourtant jusqu’ici, ces aptitudes sensorielles fondamentales n'étaient pas directement prises en compte par les professionnels. Même si l’on peut donner une définition de l'expert, en préciser les capacités nécessaires, de multiples études ont mis en relief l’hétérogénéité des appréciations individuelles de dégustation et le manque de consensus forts. La littérature illustre les différences d’expertises entre professionnels et novices, mais aucune étude ne s’intéresse à l’amplitude des différences sensorielles interindividuelles chez les experts.Nos recherches nous ont conduit à caractériser les capacités olfactives de la population des professionnels du vin et à mesurer leur influence sur l’appréciation d’un vin. Nos mesures ont montré la variété interindividuelle des capacités perceptives, des appréciations hédoniques et des capacités cognitives recrutées par le traitement de l’information olfactive chez les professionnels du vin. Nos expériences ont suggéré que ces différences interindividuelles, relatives notamment à la sensibilité et l’appréciation hédonique, influencent la perception et le jugement d’un même vin par les experts. Cependant les résultats confirment aussi la possible influence de la dimension cognitive liée au vécu du sujet sur la perception olfactive plus ou moins complexe et l’apprentissage olfactif. Finalement, ce travail permet de déterminer des besoins en formation. Nous proposons en conséquence des outils pratiques d’évaluation des capacités sensorielles et des pédagogies d’entraînement adaptées. C'est l'occasion de souligner la pertinence de certains facteurs cognitifs dans l’amélioration des performances olfactives, tels que ceux impliquant l’attention ou l'imagerie mentale olfactives. / The quality of a wine is measured primarily by experts who evaluate its organoleptic features. Their olfactory and gustatory capacities are decisive, but these experts do not appreciate their own sensory abilities. Moreover, although we can give a clear definition of the expertise, several studies have shown that professionals are often confronted with disparities in their wine assessment. Several studies have also shown the differences between experts and novices, but no attention was paid to the diversity of the chemosensory abilities of the experts.At the Oenology Faculty in Bordeaux, with voluntary participation of the professionals, we characterized the olfactory performances of wine professionals and measured their impact on the wine assessment.The results showed significant inter-individual variation in olfactory sensitivities, hedonic ratings and cognitive abilities among the wine professionals. Further, our experiments have suggested that these inter-individual differences, especially concerning the sensitivity and the hedonic appreciation, influence perceptions and judgments of a same wine by the experts. However, the results confirm the possible influence of the cognitive dimensions related to the experience of the subject on their perception and their olfactory training. Finally, this work identifies training needs. We therefore propose and test practical tools for assessment of sensory performances and appropriate sensorial training. This has been an opportunity to highlight the potential role of attention or olfactory mental imagery in the improvement of the olfactory performance.

Objective: Decrease of olfactory function in Parkinson's disease (PD) is a well-investigated fact. Studies indicate that pharmacological treatment of PD fails to restore olfactory function in PD patients. The aim of this investigation was whether patients with PD would benefit from “training” with odors in terms of an improvement of their general olfactory function. It has been hypothesized that olfactory training should produce both an improved sensitivity towards the odors used in the training process and an overall increase of olfactory function. Methods: We recruited 70 subjects with PD and olfactory loss into this single-center, prospective, controlled non-blinded study. Thirty-five patients were assigned to the olfactory training group and 35 subjects to the control group (no training). Olfactory training was performed over a period of 12 weeks while patients exposed themselves twice daily to four odors (phenyl ethyl alcohol: rose, eucalyptol: eucalyptus, citronellal: lemon, and eugenol: cloves). Olfactory testing was performed before and after training using the “Sniffin' Sticks” (thresholds for phenyl ethyl alcohol, tests for odor discrimination, and odor identification) in addition to threshold tests for the odors used in the training process. Results: Compared to baseline, trained PD patients experienced a significant increase in their olfactory function, which was observed for the Sniffin' Sticks test score and for thresholds for the odors used in the training process. Olfactory function was unchanged in PD patients who did not perform olfactory training. Conclusion: The present results indicate that olfactory training may increase olfactory sensitivity in PD patients.

L’infection virale des voies respiratoires supérieures est la cause la plus fréquente des troubles de l’odorat. L’entraînement olfactif permet un rétablissement des fonctions olfactives chez une bonne proportion des patients avec une perte olfactive post-virale. Aussi, les fonctions olfactives sont corrélées avec différentes mesures neuroanatomiques du cortex olfactif. L’objectif de ce mémoire est donc de reproduire les résultats bénéfiques de l’entraînement olfactif chez des patients avec un trouble de l’odorat post-viral et d’observer si le rétablissement des performances olfactives modifie l’épaisseur corticale des régions olfactives. Trente-neuf patients ayant un trouble de l’odorat post-viral ont complété un entraînement olfactif d’une durée de 12 semaines. L’entraînement olfactif consistait à sentir des contenants avec une odeur de rose, de citron, d’eucalyptus et de clou de girofle, deux fois par jour. Les capacités olfactives ont été mesurées avec les tests Sniffin’Sticks au début et à la fin de l’étude. L’entraînement olfactif a permis l’amélioration clinique (≥6 points SDI) des fonctions olfactives chez 59% des patients. Ces patients avaient une épaisseur corticale plus importante au niveau du cortex orbitofrontal latéral gauche à p<0,0001 non corrigé. Les patients avec une amélioration du score SDI (≥0,25 points) ont une augmentation de l’épaisseur du cortex orbitofrontal médial gauche, du cortex entorhinal droit et du cortex cingulaire postérieur gauche (p<0,0001, non corrigé). Ces résultats démontrent l’efficacité de l’entraînement olfactif chez les patients avec un trouble de l’odorat post-viral et que la rémission des fonctions olfactives semble modifier l’épaisseur corticale de certaines régions du cortex olfactif. / Viral infection of the upper respiratory tract is the most common cause of disturbances in smell. Olfactory training allows a reestablishment of olfactory functions in a good proportion of patients with post-viral olfactory loss. Also, olfactory functions are correlated with different neuroanatomic measures of the olfactory cortex. The objective of this dissertation is therefore to reproduce the beneficial results of olfactory training in patients with post-viral olfactory dysfunction and to observe whether the restoration of olfactory performances changes the cortical thickness of the olfactory cortex. Thirty-nine patients with post-viral olfactory dysfunction completed a twelve-week olfactory training. The olfactory training consisted of smelling containers with the scent of roses, lemon, eucalyptus and cloves, twice a day. Olfactory functions were measured with the Sniffin'Sticks tests at the start and end of the study. Olfactory training resulted in clinical improvement (≥6 SDI points) of olfactory functions in 59% of patients. These patients had greater cortical thickness in the left lateral orbitofrontal cortex at p <0,0001 uncorrected. Patients with improved SDI score (≥0,25 points) had an increase in the thickness of the left medial orbitofrontal cortex, right entorhinal cortex and left posterior cingulate cortex (p <0,0001, uncorrected). These results demonstrate the effectiveness of olfactory training in patients with post-viral olfactory loss and that remission of olfactory functions appears to alter the cortical thickness of certain regions of the olfactory cortex.

This study aimed to elucidate the role of smell diaries in Olfactory training (OT) and probe gender differences in intensity ratings and measured olfactory function throughout the OT course. Fifty olfactory loss patients (36 women and 14 men) undergoing OT rated odor intensities on a daily basis for at least 12 weeks. They exhibited significant improvement in measured olfactory function after OT; gender had no significant effect. As for the diaries, women rated odors with higher intensities than men, and ratings from women increased with time while men rated odors at the same level. Across all patients, there was a weak positive correlation between ratings and psychophysical test scores (r = 0.30, p = .04). Throughout the OT course, the increase in odor intensity ratings was more pronounced in women than it was in men (F[1, 44] = 7.9, p = .007). However, this gender-related difference was not found for measured olfactory function, suggesting pronounced gender-differentiated behaviors in terms of self-ratings of olfactory function.