Clinical application of a card-type odor identification test to olfactory assessment in Parkinson's disease

Current studies have provided valuable evidence that Parkinson's disease (PD) is closely associated with olfactory loss and that the use of olfactory testing is regarded as one of the potential screening tools for early diagnosis of PD.

Twenty-six patients with PD, age- and sex-matched 14 patients with other neurological diseases and 10 healthy controls were evaluated the sense of smell by the Open Essence (OE).

The motor performance of the patients with PD was assessed using the Hoehn and Yahr scale. The OE scores for patients with PD were significantly lower than those with both the patients with other neurological diseases and controls. There was no significant difference of the OE scores between patients with other neurological diseases and controls. In the PD group, the OE score was not correlated with gender, smoking habit, disease duration, age at examination, or cognitive status. However, the OE scores were significantly correlated with Hoehn and Yahr stages.

OE was found to be practically self-administered, time-saving, reliable, and inexpensive method for correct diagnosis of olfactory dysfunction associated with PD.