Affiliations: [a] Parkinson’s Disease & Movement Disorders Unit, Neurology Service, Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| [b] Rhinology Unit & Smell Clinic, ENT Department, Hospital Clínic de Barcelona, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Catalonia, Spain
| [c] Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Spain
| [d] Neurology Service, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain
| [e] Neurology Unit, Hospital General de Granollers, Universitat Internacional de Catalunya, Barcelona, Spain
| [f] ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clinic - Universitat de Barcelona, Barcelona, Spain
| [g] CIBER of Respiratory Diseases (CIBERES)
Correspondence to: Dolores Vilas, MD, Movement Disorders Unit, Hospital Germans Trias i Pujol, Badalona,
Barcelona, Spain. E-mail: [email protected].
Note:  These authors shared senior responsibilities.
Abstract: Background:Studies on olfaction in LRRK2-associated Parkinson’s disease (LRRK2-PD) have yielded variable results. The impact of smell dysfunction upon daily life activities have been rarely assessed in PD. Objective:To characterize the olfactory deficit in LRRK2-PD and its impact on daily life activities. Methods:Twenty-four LRRK2-PD, 40 idiopathic PD (IPD), and 49 age-sex-matched controls were interviewed about olfactory characteristics and the impact of smell on daily life activities. The Barcelona Smell Identification test (BAST-24) and the Spanish-version of the 40-item University of Pennsylvania smell test (UPSIT) were applied. Results:Nineteen (79.2%) LRRK2-PD patients reported subjective smell impairment with a low impact upon daily living activities. UPSIT score was higher in LRRK2-PD than in IPD (22.54±7.98 vs 18.84±6.03; p = 0.042). All IPD and 95.8% LRRK2-PD patients had hyposmia/anosmia, assessed by means of the UPSIT. No differences were found between LRRK2-PD and IPD regarding smell detection, memory or forced-choice identification. Conclusion:Most LRRK2-PD patients reported subjective smell impairment and presented hyposmia, according to validated smell tests, with a low impact of the smell dysfunction on daily life activities.