OBJECTIVE: To investigate whether baseline olfactory dysfunction in Parkinson's disease (PD) patients is associated with baseline and longitudinal motor and cognitive function. METHODS: We 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. RESULTS: Among 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. CONCLUSION: Baseline 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.
OBJECTIVE: To investigate whether baseline olfactory dysfunction in Parkinson's disease (PD) patients is associated with baseline and longitudinal motor and cognitive function. METHODS: We recruited 228 drug-naïve PDpatients 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. RESULTS: Among the PDpatients, 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. CONCLUSION: Baseline 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.
Authors: Gabriel A de Erausquin; Heather Snyder; Traolach S Brugha; Sudha Seshadri; Maria Carrillo; Rajesh Sagar; Yueqin Huang; Charles Newton; Carmela Tartaglia; Charlotte Teunissen; Krister Håkanson; Rufus Akinyemi; Kameshwar Prasad; Giovanni D'Avossa; Gabriela Gonzalez-Aleman; Akram Hosseini; George D Vavougios; Perminder Sachdev; John Bankart; Niels Peter Ole Mors; Richard Lipton; Mindy Katz; Peter T Fox; Mohammad Zia Katshu; M Sriram Iyengar; Galit Weinstein; Hamid R Sohrabi; Rachel Jenkins; Dan J Stein; Jacques Hugon; Venetsanos Mavreas; John Blangero; Carlos Cruchaga; Murali Krishna; Ovais Wadoo; Rodrigo Becerra; Igor Zwir; William T Longstreth; Golo Kroenenberg; Paul Edison; Elizabeta Mukaetova-Ladinska; Ekkehart Staufenberg; Mariana Figueredo-Aguiar; Agustín Yécora; Fabiana Vaca; Hernan P Zamponi; Vincenzina Lo Re; Abdul Majid; Jonas Sundarakumar; Hector M Gonzalez; Mirjam I Geerlings; Ingmar Skoog; Alberto Salmoiraghi; Filippo Martinelli Boneschi; Vibuthi N Patel; Juan M Santos; Guillermo Rivera Arroyo; Antonio Caballero Moreno; Pascal Felix; Carla Gallo; Hidenori Arai; Masahito Yamada; Takeshi Iwatsubo; Malveeka Sharma; Nandini Chakraborty; Catterina Ferreccio; Dickens Akena; Carol Brayne; Gladys Maestre; Sarah Williams Blangero; Luis I Brusco; Prabha Siddarth; Timothy M Hughes; Alfredo Ramírez Zuñiga; Joseph Kambeitz; Agustin Ruiz Laza; Norrina Allen; Stella Panos; David Merrill; Agustín Ibáñez; Debby Tsuang; Nino Valishvili; Srishti Shrestha; Sophia Wang; Vasantha Padma; Kaarin J Anstey; Vijayalakshmi Ravindrdanath; Kaj Blennow; Paul Mullins; Emilia Łojek; Anand Pria; Thomas H Mosley; Penny Gowland; Timothy D Girard; Richard Bowtell; Farhaan S Vahidy Journal: Alzheimers Dement (N Y) Date: 2022-09-22