Olfactory dysfunction and cognitive impairment in patients with Parkinson’s disease

Abstract

Olfactory deficit has been described in some neurodegenerative diseases as well as in normal aging. There is pathological and biochemical evidence suggesting that hyposmia might be more severe in subjects with cognitive dysfunction. Objective: the association between olfactory dysfunction and cognitive impairment in mexican Parkinson’s disease (PD) patients is analyzed. Material and methods: a cross-sectional and analytic study with consecutive patients was carried out. The “sniffin’ sticks” (SS-16) testing and Montreal Cognitive Assessment (MoCA) were applied to all patients. Results: a total of 104 patients were included (64.4% male). An olfactory deficits was found in 82.9% of the sample. Additionally, 47.1% of the patients scored less than 26 points in Montreal Cognitive Assessment. No correlations was found between the total SS-16 score and the total MoCA score. When analyzing individual domains a weak correlation was found between lower scores in both tests (r=0.24, p=0.04). Conclusions: we did not found a relation between the presence of olfactory dysfunction and global cognitive function. A significant relation between olfactory deficit and visuospatial/executive dysfunction was noted.