Motor Features in Parkinson’s Disease With Normal Olfactory Function Malco Rossi, MD, 1 Alex Medina Escobar, MD, 1 Andrea Bril, MD, 1 Patricio Millar Vernetti, MD, 1 Juan Ignacio De Palo, MD, 1 Daniel Cerquetti, Eng, 1 and Marcelo Merello, MD, PhD 1,2 * 1 Movement Disorders Section, Neuroscience Department, Raul Carrea Institute for Neurological Research (FLENI), Ciudad Aut onoma de Buenos Aires, Argentina 2 Argentine National Scientific and Technological Research Council (CONICET), Buenos Aires, Argentina ABSTRACT Background: Normosmic Parkinson’s disease (PD) might be a unique clinical phenotype with a more benign course when compared with hyposmic PD. Objective: The objective of this study was to evaluate motor features and the acute levodopa response according to olfactory function. Methods: A total of 169 de novo PD patients that underwent olfactory testing and acute levodopa chal- lenge for clinical prediction of sustained long-term dopaminergic response were evaluated. Results: The overall frequency of normosmia was 33%. Normosmic PD patients scored nonsignificantly different to hyposmic/anosmic patients on motor scale and on degree of improvement with levodopa. Motor scores at follow-up were comparable among groups. Conclusions: Normal olfactory function is common in early PD and was not associated with a different motor phenotype when compared with PD patients with olfac- tory dysfunction. V C 2016 International Parkinson and Movement Disorder Society Key Words: olfaction; normosmia; motor features; levodopa response; Parkinson’s disease Olfactory dysfunction in Parkinson’s disease (PD) patients is highly prevalent during all stages of the dis- ease, with frequencies ranging from 45% to 98%. 1-7 It usually develops prior to motor features onset, and the degree of impairment appears to be independent of disease duration or severity. 1 Disturbances in olfaction in PD patients involve mostly the identifica- tion, but odor threshold and discrimination are also affected. Several studies evaluated the relationship between olfactory impairment, motor phenotypes, and nonmotor symptoms such as depression, apathy, and cognitive dysfunction. 8-10 However, controversy exists regarding motor function and spared olfaction. 4,5 A recently published study found that normosmic PD patients had better motor function than hyposmic PD patients, which suggests that the former group may have a unique clinical phenotype with a more benign course. 5,11 To disclose whether a relationship between olfactory function and motor status on PD patients exists, we evaluated motor features in the OFF and ON states and the acute levodopa response in a large cohort of early PD patients according to their olfactory function. Material and Methods The protocol conformed to Helsinki Declaration principles and was approved by the local institutional review board. All participants gave written informed consent prior to the study. Study Sample A retrospective review of medical records from de novo PD patients with 2 years of follow-up and sus- tained responses to dopaminergic therapy who under- went both olfactory function assessment and acute levodopa challenge within the first year of motor symp- toms onset was conducted. The evaluation of de novo PD patients within the first year with olfactory testing and acute levodopa challenge is a typical practice in our clinic and is indicated in 100% of our patients. Baseline and 2-year follow-up data from evaluated patients between March 1, 2011, through September 31, 2015, were obtained. Patients were submitted to acute levo- dopa challenge for the clinical prediction of sustained or continuous long-term dopaminergic response to support a possible diagnosis of PD, 12 which was finally made according to the UK Parkinson’s Disease Society Brain Bank criteria at 2 years follow-up. Patients who were diagnosed as atypical parkinsonism or essential tremor at follow-up were excluded. None of the included patients received dopamine replacement therapy prior ------------------------------------------------------------ *Correspondence to: Dr. Marcelo Merello, Movement Disorders Section, and Neuroscience Department, Raul Carrea Institute for Neurological Research (FLENI), Monta~ neses 2325, Ciudad Aut onoma de Buenos Aires (1428), Argentina; mmerello@fleni.org.ar Relevant conflicts of interests/financial disclosures: Nothing to report. Received: 25 February 2016; Revised: 4 May 2016; Accepted: 8 May 2016 Published online 00 Month 2016 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/mds.26687 BRIEF REPORT Movement Disorders, Vol. 00, No. 00, 2016 1