Abnormal Olfaction in Parkinson’s Disease Is Related to Faster Disease Progression

• Main Authors: Sara Cavaco, Alexandra Gonçalves, Alexandre Mendes, Nuno Vila-Chã, Inês Moreira, Joana Fernandes, Joana Damásio, Armando Teixeira-Pinto, António Bastos Lima
• Format: Article
• Language: English
• Published: Hindawi Limited 2015-01-01
• Series: Behavioural Neurology
• Online Access: http://dx.doi.org/10.1155/2015/976589

Introduction. A possible association between olfactory dysfunction and Parkinson’s disease (PD) severity has been a topic of contention for the past 40 years. Conflicting reports may be partially explained by procedural differences in olfactory assessment and motor symptom evaluation. Methods. One hundred and sixty-six nondemented PD patients performed the Brief-Smell Identification Test and test scores below the estimated 20th percentile as a function of sex, age, and education (i.e., 80% specificity) were considered demographically abnormal. Patients underwent motor examination after 12 h without antiparkinsonian medication. Results. Eighty-two percent of PD patients had abnormal olfaction. Abnormal performance on the Brief-Smell Identification Test was associated with higher disease severity (i.e., Hoehn and Yahr, Unified Parkinson’s Disease Rating Scale-III, Freezing of Gait questionnaire, and levodopa equivalent dose), even when disease duration was taken into account. Conclusions. Abnormal olfaction in PD is associated with increased severity and faster disease progression.