Cognitive Dysfunction and Olfactory Function in Patients with...

Cognitive Dysfunction and Olfactory Function in Patients with Parkinsonism

Abstract ID: a13242

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Abstract:
Moon Ho Park, PhD, MD, Korea University, Ansan, Korea, Republic of (South) and Do Young Kwon, MD, PhD, Korea University Ansan Hospital, Ansan, Korea, Republic of (South)

Background: The evaluation of olfactory function is a valuable marker for the detection of parkinsonism prior to motor symptoms and for the early diagnosis of various degenerative dementias. Parkinson’s disease (PD) patients have an increased risk of associated dementia and one-third of patients with PD have mild cognitive impairment (MCI) at the time of diagnosis. However, the characteristics of olfactory dysfunction in PD-MCI patients have not been well investigated. Methods: A total of 106 drug-naïve PD patients were enrolled in the study. We performed a neuropsychiatric battery to assess cognitive status and sub-classified the types of cognitive impairment into four categories. Olfactory dysfunction was examined by the Korean version of the Sniffin’ stick test II (KVSS II). Results: Olfactory dysfunction was more prevalent in the PD-MCI group than in the PD-normal cognition group. Olfactory threshold and odor discrimination was more impaired in the PD-MCI group as compared with the PD-normal cognition group. Among PD-MCI subgroups, patients with multiple domains of cognitive impairment were more associated with olfactory dysfunction than patients with a single domain of cognitive impairment. Conclusions: In our study, we concluded that PD-MCI patients were more likely to be associated with olfactory dysfunction compared to PD-normal cognition patients. We hypothesized that there may be more extensive neurodegenerative processes affecting olfaction in PD-MCI patients. With further investigation and validation using neuropathological data, an objective olfactory function test could be used as a tool to evaluate disease progression. Further studies investigating the prognostic value of olfactory dysfunction in PD-MCI patients are essential. Elucidating the characteristics of olfactory dysfunction in patients with PD-MCI will expand our knowledge of the pathophysiology of PD and help us better predict the development of PDD.