Comparison of Parkinson?s disease olfactory identification patterns among patients from different countries

PATRICIO MILLAR VERNETTI; MALCO ROSSI; DANIEL CERQUETTI; SANTIAGO PEREZ LLORET; MARCELO MERELLO

Estocolmo

Congreso; 18th International Congress of Parkinson?s Disease and Movement Disorders; 2014

Objectives: To compare the olfactory function of Parkinson?s disease (PD) patients of our population with those previously reported in other countries and thus consider the necessity/ need/ importance to select/ of selecting a subset of items in each cultural setting in particular.Background: Olfactory function assessment is one of the best tools in differentiating PD patients from healthy controls and patients with other parkinsonism or non-degenerative entities. It has been suggested that PD patients have distinctive patterns of ?restrictive? or ?selective? hyposmia, nonetheless, several authors in different countries have reported various sets of odors that best discriminate between these groups. Furthermore, it has been recently shown that both patients with PD and individuals who are hyposmic for other causes share the same patterns of hyposmia, indicating that these different patterns might be due not to specific pathological feature of their disease, but to cultural aspects.Methods: Chi-square analysis was conducted to compare our population?s results against previously reported data from Brazil, the Netherlands, Germany, China and Sri Lanka, comparing the performance of PD patients on the Sniffin? Sticks identification task across countries and across each odor in particular in order to see which countries and showed less differences overall with our population and which odors showed less differences across countries.We performed a hierarchical cluster analysis on previously reported data from Brazil, the Netherlands, Germany, China and Sri Lanka and our own population of 112 PD patients to find out which countries showed the most similarity and which odors behaved more similarly across countries. Results: The percentages of correct guesses for each odor in our population were as follows:We found no statistically significant differences in 12 out of 16 items in the Brazilian population; 11/16 in the German; 8/16 in the Chinese; 7/16 in the Sri Lankan and 4/16 in the Dutch. Regarding each item: 4 out of the other 5 populations showed no significant different with our population for cinnamon; 3/5 for pineapple; 2/5 for orange, leather and garlic; 1/5 for lemon, liquorice, coffee, apple and aniseed; and 0/5 for mint, banana, turpentine, clove, roses and fish.The hierarchical cluster analysis showed that [the most similar populations identification-wise, were those from Argentina and Brazil; further similar clusters were acknowledged by the subsequent single addition of Holland, China, Sri-Lanka and, finally, Germany.Conclusions: based on our findings we have concluded that even though there is a degree of similarity between the overall different cultural patterns of identification, it would still be necessary / recommendable / advisable to perform a selection of particular items specific to the population to which the test is applied in order to obtain a reduced cultural-specific set of odors when applying the SST identification task to PD patients.