ArticleNeuropsychologia2018
Dopamine-related dissociation of cortical and subcortical brain activations in cognitively unimpaired Parkinson's disease patients OFF and ON medications.
Article in Neuropsychologia, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 1 of them a synthesis that pooled it.
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Who cites it
8 citing papers in PubMed, 1 synthesis or guideline pooled it, 18 citations in OpenAlex.
- Brain Motor Network Changes in Parkinson's Disease: Evidence from Meta-Analytic Modeling.Movement disorders : official journal of the Movement Disorder Society · 2021Pooled it
- Is levodopa induced freezing of gait a paradox or an expected phenomenon?: a clinico-pathophysiological hypothesis.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026Review
- Article
- Automatic and controlled attentional orienting toward emotional faces in patients with Parkinson's disease.Cognitive, affective & behavioral neuroscience · 2023Article
- Imaging the Limbic System in Parkinson's Disease-A Review of Limbic Pathology and Clinical Symptoms.Brain sciences · 2022Review
- Dopamine-Related Reduction of Semantic Spreading Activation in Patients With Parkinson's Disease.Frontiers in human neuroscience · 2022Article
- Dopaminergic therapy and prefrontal activation during walking in individuals with Parkinson's disease: does the levodopa overdose hypothesis extend to gait?Journal of neurology · 2021Article
- Mnemonic Similarity Task to study episodic memory in Parkinson's disease.Clinical parkinsonism & related disorders · 2020Article
Corrections and comments
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Authors and funding
8 authors at 3 institutions in 1 country.
Funding
Abstract
backgroundDespite dopaminergic depletion that is severe enough to cause the motor symptoms of Parkinson's disease (PD), many patients remain cognitively unimpaired. Little is known about brain mechanisms underlying such preserved cognitive abilities and their alteration by dopaminergic medications.
objectivesWe investigated brain activations underlying dopamine-related differences in cognitive function using a unique experimental design with PD patients off and on dopaminergic medications. We tested the dopamine overdose hypothesis, which posits that the excess of exogenous dopamine in the frontal cortical regions can impair cognition.
methodsWe used a two-choice forced response Choice Reaction Time (CRT) task to probe cognitive processes underlying response selection and execution. Functional magnetic resonance imaging data were acquired from 16 cognitively unimpaired (Level-II) PD participants and 15 well-matched healthy controls (HC). We compared task performance (i.e. reaction time and accuracy) and brain activation of PD participants off dopaminergic medications (PD_OFF) in comparison with HC, and PD_OFF participants with those on dopaminergic medications (PD_ON).
resultsPD_OFF and PD_ON groups did not differ from each other, or from the HC group, in reaction time or accuracy. Compared to HC, PD_OFF activated the bilateral putamen less, and this was compensated by higher activation of the anterior insula. No such differences were observed in the PD_ON group, compared to HC. Compared to both HC and PD_OFF, PD_ON participants showed dopamine-related hyperactivation in the frontal cortical regions and hypoactivation in the amygdala.
conclusionOur data provide further evidence that PD_OFF and PD_ON participants engage different cortical and subcortical systems to achieve similar levels of cognitive performance as HC. Crucially, our findings demonstrate dopamine-related dissociation in brain activation between cortical and subcortical regions, and provide novel support for the dopamine overdose hypothesis.
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