Abstract
ObjectiveTo investigate whether baseline olfactory dysfunction in Parkinson’s disease (PD) patients is associated with baseline and longitudinal motor and cognitive function.MethodsWe recruited 228 drug-naïve PD patients who were followed for a mean of 6 years. Patients underwent the Cross-Cultural Smell Identification Test (CCSIT), a neuropsychological test, and N-(3-[18F]fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane positron emission tomography within 6 months of the baseline evaluation. Olfactory dysfunction was categorized as normosmia (CCSIT score ≥ 9), hyposmia (CCSIT score 5–8), and anosmia (CCSIT score ≤ 4). During the follow-up period, we investigated changes in the levodopa-equivalent dose (LED) and the occurrence of wearing-off, levodopa-induced dyskinesia, and dementia.ResultsAmong the PD patients, 80.7% were hyposmic at the time of diagnosis, and 26.1% were anosmic. Baseline olfactory dysfunction was not associated with either initial parkinsonian motor symptoms or with the longitudinal LED increment and motor complications. Meanwhile, the anosmic group had lower baseline scores on the Korea version of the Boston Naming Test and Stroop color reading test than the normosmic and hyposmic groups. The anosmic group exhibited a higher rate of conversion to dementia than the normosmic [adjusted hazard ratio (HR) 3.99, 95% confidence interval (CI) 1.08–14.72] and hyposmic (adjusted HR 2.48, 95% CI 1.15–5.32) PD groups, regardless of baseline motor deficits and cognitive status.ConclusionBaseline olfactory dysfunction was not associated with motor deficits and complications, but it was associated with cognitive dysfunction and prognosis, suggesting that severe olfactory impairment may reflect early cortical involvement, probably in the frontotemporal region, and rapid spreading of Lewy body pathology.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.