Clinical Aspects of Olfactory and Gustatory Disorders

Olfaction and taste are two well known human senses. Everybody would agree that both senses are crucial in daily activities such as eating or drinking. Olfactory and gustatory information is important for our quality of life. How should we otherwise enjoy an excellent wine or taste our favorite dish? On the other hand, both senses represent an alarm system providing us with information about spoiled food or leaking gas. It is undeniable that olfactory information influences our behavior, but to what extent olfactory and taste stimuli influence our interaction with other humans and biological processes, is still a matter of debate within the field. Which importance an intact olfactory and gustatory function have, becomes often clear when theses senses are affected. The following thesis reflects the authors own clinical experience and publications as well as the thoughts, concepts, state of the art knowledge and research questions shared with national and international colleagues working in the same field of chemosensory disorders. The thesis draws a general overview of current concepts in human smell and taste disorders

Phantosmias and Parkinson disease

BACKGROUND: Impaired olfaction is a common, nonmotor manifestation of Parkinson disease (PD). However, to our knowledge, qualitative olfactory disturbances, such as odor distortions, have not been extensively reported in this condition. OBJECTIVE: To describe 2 patients who reported positive olfactory symptoms preceding typical PD, which were consistent with olfactory hallucinations (phantosmias) in the absence of major smell deficit. DESIGN: Case series. SETTING: University hospital. Patients We describe 2 patients, both seen in 2007, who reported pleasant olfactory hallucinations for several years. MAIN OUTCOME MEASURES: Iodine I 123-labeled ioflupane single-photon emission computed tomography and olfactometric testing results. RESULTS: The (123)I-labeled ioflupane single-photon emission computed tomography showed reduced radiotracer uptake in both striatum more marked in the putamen and on the left side in patient 1 and reduced radiotracer uptake in both putamen more marked on the right side in patient 2. Olfactometric testing showed mild hyposmia in patient 1 and normal function in patient 2. The disappearance of the phantosmias in both patients coincided with the development of typical PD. CONCLUSION: We propose phantosmia as a new premotor manifestation of PD and suggest that qualitative abnormalities of olfaction, rather than the typical smell loss demonstrated in this condition, should be more carefully examined in the prodromal phase of PD