Malte Bertram1, Claire V Warren2, Florian Lange3, Caroline Seer4, Alexander Steinke1, Florian Wegner1, Christoph Schrader1, Dirk Dressler1, Reinhard Dengler1, Bruno Kopp1. 1. Department of Neurology, Hannover Medical School, Hannover, Germany. 2. Department of Neurology, Hannover Medical School, Hannover, Germany. Electronic address: warren.claire@mh-hannover.de. 3. Department of Neurology, Hannover Medical School, Hannover, Germany; Behavioural Engineering Research Group, KU Leuven, Leuven, Belgium. 4. Department of Neurology, Hannover Medical School, Hannover, Germany; Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium; LBI - KU Leuven Brain Institute, KU Leuven, Belgium.
Abstract
OBJECTIVE: Parkinson's Disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons. Cognitive impairments have been reported using the event-related potential (ERP) technique. Patients show reduced novelty P3 (nP3) amplitudes in oddball experiments, a response to infrequent, surprising stimuli, linked to the orienting response of the brain. The nP3 is thought to depend on dopaminergic neuronal pathways though the effect of dopaminergic medication in PD has not yet been investigated. METHODS: Twenty-two patients with PD were examined "on" and "off" their regular dopaminergic medication in a novelty 3-stimulus-oddball task. Thirty-four healthy controls were also examined over two sessions, but received no medication. P3 amplitudes were compared throughout experimental conditions. RESULTS: All participants showed sizeable novelty difference ERP effects, i.e. ndP3 amplitudes, during both testing sessions. An interaction of diagnosis, medication and testing order was also found, indicating that dopaminergic medication modulated ndP3 in patients with PD across the two testing sessions: We observed enhanced ndP3 amplitudes from PD patients who were off medication on the second testing session. CONCLUSION: Patients with PD 'off' medication showed ERP evidence for repetition-related enhancement of novelty responses. Dopamine depletion in neuronal pathways that are affected by mid-stage PD possibly accounts for this modulation of novelty processing. SIGNIFICANCE: The data in this study potentially suggest that repetition effects on novelty processing in patients with PD are enhanced by dopaminergic depletion.
OBJECTIVE:Parkinson's Disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons. Cognitive impairments have been reported using the event-related potential (ERP) technique. Patients show reduced novelty P3 (nP3) amplitudes in oddball experiments, a response to infrequent, surprising stimuli, linked to the orienting response of the brain. The nP3 is thought to depend on dopaminergic neuronal pathways though the effect of dopaminergic medication in PD has not yet been investigated. METHODS: Twenty-two patients with PD were examined "on" and "off" their regular dopaminergic medication in a novelty 3-stimulus-oddball task. Thirty-four healthy controls were also examined over two sessions, but received no medication. P3 amplitudes were compared throughout experimental conditions. RESULTS: All participants showed sizeable novelty difference ERP effects, i.e. ndP3 amplitudes, during both testing sessions. An interaction of diagnosis, medication and testing order was also found, indicating that dopaminergic medication modulated ndP3 in patients with PD across the two testing sessions: We observed enhanced ndP3 amplitudes from PDpatients who were off medication on the second testing session. CONCLUSION:Patients with PD 'off' medication showed ERP evidence for repetition-related enhancement of novelty responses. Dopamine depletion in neuronal pathways that are affected by mid-stage PD possibly accounts for this modulation of novelty processing. SIGNIFICANCE: The data in this study potentially suggest that repetition effects on novelty processing in patients with PD are enhanced by dopaminergic depletion.
Authors: Evelien De Groote; Annelies Bockstael; Dick Botteldooren; Patrick Santens; Miet De Letter Journal: J Neural Transm (Vienna) Date: 2021-04-24 Impact factor: 3.575
Authors: Jan Willem de Gee; Camile M C Correa; Matthew Weaver; Tobias H Donner; Simon van Gaal Journal: Cereb Cortex Date: 2021-06-10 Impact factor: 5.357