Cultural determinants of food attitudes in anosmic patients.

The decrease in food enjoyment is a major factor why patients suffer from depression when having anosmia, or total loss of smell. While we have some knowledge about how food preferences and attitudes change with dysosmia, these findings are limited because other factors such as culture are not factored in. It is likely that the culture in which an anosmic patient identifies with will influence how their smell loss impacts their relationship with food. This study examined the current attitudes within the United States and Germany towards foods, focusing on the comparison between anosmic patients (N = 53) and those with a healthy sense of smell (N = 121). A survey was used to collect free responses for liking on a variety of foods (N = 15) that were also rated for their overall liking. Additionally, individuals rated and ranked their liking for sensory attributes in relation to their enjoyment of food. Free responses were classified into categories and subcategories, the frequency of those responses were then compared across groups. The patient population of each culture gave lower importance to aroma and flavor; however, the U.S.A. patient population showed a larger decrease from their healthy counterparts. Furthermore, anosmic patients from the U.S.A. showed less overall liking towards the food stimuli compared to their healthy counterparts, while no such effect observed among the German population. Reasons to enjoy a food were largely explained by the culture, and patients within a culture took on different compensation strategies which we use to explain their effectiveness.

Specific intranasal and central trigeminal electrophysiological responses in Parkinson's disease.

Olfactory dysfunction is a frequent early non-motor symptom of Parkinson's disease (PD). There is evidence that with regard to trigeminal perception, PD-related olfactory dysfunction is different from other olfactory disorders. More specifically, trigeminal sensitivity, when measured behaviorally, was unimpaired in PD patients as opposed to patients with non-Parkinsonian olfactory dysfunction (NPOD). We sought to investigate the trigeminal pathway by measuring electrophysiological recordings from the nasal epithelium and EEG-derived event-related potentials in response to a specific trigeminal stimulus in 21 PD patients and compare them to 23 patients with NPOD and 25 controls (C). The peripheral trigeminal response, as measured by the negative-mucosa potential, showed no difference between patients with PD and controls whereas PD patients showed faster responses than patients with NPOD, the latter having shown slower and larger responses than controls (18 PD, 14 NPOD, 20 C). The central trigeminal response, as measured by event-related potentials, revealed larger early component response in PD patients compared to patients with NPOD (15 PD, 21 NPOD, 23 C). As expected, psychophysical olfactory testing showed impaired olfactory function in both groups of patients as opposed to controls. Discriminant analysis revealed a model that could predict group membership for 80% of participants based on the negative-mucosa potential latency, olfactory threshold and discrimination tests. These results provide novel insights into the pattern of trigeminal activation in PD which will help to differentiate PD-related olfactory loss from NPOD, a crucial step towards establishing early screening batteries for PD including smell tests.