Atilla Uslu1, Mehmet Ergen2, Hasan Demirci3, Ebba Lohmann4, Hasmet Hanagasi5, Tamer Demiralp6. 1. Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, 34093 Capa, Istanbul, Turkey. Electronic address: auslu@istanbul.edu.tr. 2. Department of Physiology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Atasehir 34752, Istanbul, Turkey. 3. Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, 34093 Capa, Istanbul, Turkey. 4. Department of Neurology, Behavioral Neurology and Movement Disorders Unit, Istanbul Faculty of Medicine, Istanbul University, 34093 Capa, Istanbul, Turkey; Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, 72076 Tübingen, Germany; German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany. 5. Department of Neurology, Behavioral Neurology and Movement Disorders Unit, Istanbul Faculty of Medicine, Istanbul University, 34093 Capa, Istanbul, Turkey. 6. Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, 34093 Capa, Istanbul, Turkey; Hulusi Behcet Life Sciences Research Laboratory - Neuroimaging Unit, Istanbul University, 34093 Capa-Istanbul, Turkey.
Abstract
OBJECTIVE: To investigate cognitive functions in non-demented patients with early-onset Parkinson's disease (PD), and to compare PARK2 gene mutation carriers and non-carriers by means of event-related brain potentials (ERPs). METHODS: The participants comprised patients with early-onset PD (EOPD) and healthy controls (HC). Patients with EOPD were divided into two groups as carriers of known pathogenic variants of PARK2 gene (EOPD-PC) and non-carriers of genes involved in familial PD (EOPD-NC). ERP data were collected during auditory oddball and visual continuous performance test (CPT). RESULTS: Both EOPD groups (EOPD-PC and EOPD-NC) displayed reduced and delayed P3 in response to oddball target and CPT NoGo. CPT Go P3 was reduced in EOPD-NC but not in EOPD-PC. Oddball target N1 was reduced and P2 was enhanced in both EOPD-PC and EOPD-NC. In both cognitive tasks, RTs were prolonged and accuracy was lower in EOPD-PC and EOPD-NC. CONCLUSIONS: We found several EOPD-related neurophysiologic changes, implying impairments in cognitive functions. Pairwise comparisons between EOPD-PC and EOPD-NC revealed no significant ERP marker. SIGNIFICANCE: In this study, the confounding effect of normative aging was somewhat excluded compared with many previous studies. In contrast with the many oddball studies in non-demented PD, we clearly observed reduced and prolonged P3 in early-onset PD. Our NoGo P3 findings also contribute to the limited ERP research concerning response inhibition.
OBJECTIVE: To investigate cognitive functions in non-demented patients with early-onset Parkinson's disease (PD), and to compare PARK2 gene mutation carriers and non-carriers by means of event-related brain potentials (ERPs). METHODS: The participants comprised patients with early-onset PD (EOPD) and healthy controls (HC). Patients with EOPD were divided into two groups as carriers of known pathogenic variants of PARK2 gene (EOPD-PC) and non-carriers of genes involved in familial PD (EOPD-NC). ERP data were collected during auditory oddball and visual continuous performance test (CPT). RESULTS: Both EOPD groups (EOPD-PC and EOPD-NC) displayed reduced and delayed P3 in response to oddball target and CPT NoGo. CPT Go P3 was reduced in EOPD-NC but not in EOPD-PC. Oddball target N1 was reduced and P2 was enhanced in both EOPD-PC and EOPD-NC. In both cognitive tasks, RTs were prolonged and accuracy was lower in EOPD-PC and EOPD-NC. CONCLUSIONS: We found several EOPD-related neurophysiologic changes, implying impairments in cognitive functions. Pairwise comparisons between EOPD-PC and EOPD-NC revealed no significant ERP marker. SIGNIFICANCE: In this study, the confounding effect of normative aging was somewhat excluded compared with many previous studies. In contrast with the many oddball studies in non-demented PD, we clearly observed reduced and prolonged P3 in early-onset PD. Our NoGo P3 findings also contribute to the limited ERP research concerning response inhibition.