Background: Hyposmia is one of the most common, as well as the first nonmotor condition in Parkinson disease (PD). The sniffin sticks test (SST) evaluates three different aspects of olfactory function: threshold (T), discrimination (D), and identification (I). The sum of the scores of these three subtests produce a global score of olfaction, the Threshold-Discrimination-Identification (TDI) score.
Objective: The aim of this study was to investigate if the TDI score or one of its subtests is better to discriminate PD patients from controls.
Methods: We recruited 27 PD patients and 17 healthy age-matched controls (HC) who were evaluated through a clinical interview, the Montreal Cognitive Assessment and Movement Disorders Society - Unified Parkinson Disease Rating Scale. The olfaction was assessed using the complete SST.
Results: The performance of PD patients on the olfactory test was significantly worse when compared with the HC (T: 3.0 vs. 6.5, p < 0.001; D: 8.1 vs. 11.2, p < 0.001; I: 7.3 vs. 11.7, p < 0.001; TDI: 18.8 vs. 29.9, p < 0.001). The prevalence of olfaction impairment in our study (PD: 100%, and HC: 56%) was greater than that found in the literature. Cognition influenced the performance on TDI. The olfactory subtests were impaired proportionally between patients and controls. Furthermore, D and I were correlated, but only in PD patients. The TDI showed a tendency to better discriminate PD patients from HC, when compared with its subtests.
Conclusions: Although the complete olfactory evaluation is time consuming, it seems to be a superior tool to identify olfaction impairment in PD patients, when compared with the isolated subtests.
Antecendentes: Hiposmia é um dos sintomas mais comuns da doença de Parkinson (DP), além de ser um de seus primeiros sintomas não-motores. O Sniffin Sticks Test avalia três diferentes aspectos da função olfatória: limiar (L), discriminação (D) e identificação (I). A soma dos escores desses três subtestes produz um escore global do olfato, o Threshold-Discrimination-Identification (TDI).
Objetivo: O objetivo deste estudo foi investigar se o TDI ou um de seus subtestes seria melhor em discriminar pacientes com DP de controles saudáveis. MéTODOS: Foram recrutados 27 pacientes com DP e 17 controles saudáveis de mesma faixa etária, que foram avaliados através de uma entrevista clínica, a Montreal Cognitive Assessment e Movement Disorders Society – Unified Parkinson Disease Rating Scale. O olfato foi examinado através da bateria completa do Sniffin Sticks Test (SST).
Resultados: Os pacientes com DP tiveram pior performance no teste olfatório quando comparados com os controles (L: 3,0 vs. 6,5; p < 0,001; D: 8,1 vs. 11,2; p < 0,001; I: 7,3 vs. 11,7; p < 0,001; TDI: 18,8 vs. 29,9; p < 0,001). A prevalência de comprometimento olfatório no nosso estudo (DP: 100%, e controles: 56%) foi maior do que a reportada na literatura. A cognição influenciou a performance no TDI. Os subtestes olfatórios foram afetados proporcionalmente entre pacientes e controles. Além disso, D e I se correlacionaram, mas apenas em pacientes de DP. O TDI mostrou uma tendência em melhor discriminar pacientes de DP dos controles, quando comparado com os seus subtestes. CONCLUSõES: Embora a avaliação olfatória completa consuma tempo, ela parece ser superior aos subtestes isolados para identificar comprometimento olfatório em pacientes com DP.
Academia Brasileira de Neurologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).