Olfactory function and Parkinson's disease in Southern Brazil

The idiopathic Parkinson disease (IPD) is traditionally diagnosed by motor signs, but non-motor symptoms and signs are frequent and may help in the clinical diagnosis. Purpose: To evaluate the olfactory function in Brazilian healthy subjects, patients with early-onset PD (EOPD) and late-onset PD (LOPD) using the Sniffin' Sticks odor-identification test (SST). Method: We studied 70 patients with IPD (19 EOPD and 51 LOPD) and 70 controls matched for gender, age and years of schooling. Subjects with dementia and loss of smell for other reasons were excluded. Results: The SST showed a significant difference (p<0.001) between groups: control groups (12.0 +/- 0.3), EOPD (8.3 +/- 0.7), and LOPD (6.7 +/- 0.4) when the groups were adjusted for gender, age, disease duration, and years of schooling. Conclusion: Both groups of IPD patients presented olfactory impairments, but those whose symptoms started before 45 years-old (EOPD) had better sense of smell than the LOPD patients.