Development of a new olfactory function scale for Parkinson's Disease patients.

DANIEL CERQUETTI; MALCO ROSSI; SANTIAGO PEREZ-LLORET

Paris, Francia

Congreso; Congreso Internacional de Movimientos Anormales; 2009

Objective: To develop and validate a self-administered scale for the evaluation ofolfactory dysfunction in PD patients.Background: Olfactory dysfunction is common in Parkinson s Disease (PD) and hasbeen shown to precede the motor symptoms of the disease.Methods: A consecutive serie of PD patients recruited from a tertiary out-patientmovement disorder clinic were polled about their perceptions regarding their olfactoryfunction (normal or abnormal).Then a 20 Likert-type items self administeredquestionnaire was presented to them. Fifteen items were related to the frequency atwhich the patient perceived different odors (1-not at all, to 4- always spontaneously)and five items to patient's ability to discriminate between smells (1-not at all, to4-clearly). Perception f common smells such as coffe, baked-bread, flowers, cigarette,grass, butane-gas, burning-goods, ambient fresheners, garbage, combustion ofgasoline, perfume, bleach, transpiration, food and paint were evaluated. Total score wasexpressed as the percentage of the maximal score possible. Another group of 16Parkinson's disease patients and 11 healthy controls were recruited for the evaluation ofthe scale's clarity, response range, internal consistency (by Chronbach's alfa) and itsability to differentiate healthy controls from PD patients complaining about olfactoryproblems or not.Results: All items were easily understood by controls and patients. One patient failed torespond one item. Two patients (12%) displayed ceiling effect. Chronbach's alfa was >0.90. Six patients complained about olfactory dysfunction (37%). Olfactory scores incontrols, non-complaining or complaining PD patients were 95.2 1.1%, 94.5 1.7% and57.3 9.7% respectively (p=0.006, Brown-Forsythe ANOVA). In the latter, the totalscore ranged from 31-90%.Conclusions: The scale was easy to understand and complete, with little ceiling effect.It showed adequate internal consistency and good ability to differentiate controls andnon-complaining PD patients from those complaining from olfactory problems. Futurestudies should evaluate the scale reproducibility and validity.