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In vivo positron emission tomographic evidence for compensatory changes in presynaptic dopaminergic nerve terminals in Parkinson's disease
Clinical symptoms of Parkinson's disease (PD) do not manifest until dopamine (DA) neuronal loss reaches a symptomatic threshold. To explore the mechanisms of functional compensation that occur inExpand
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Expectation and Dopamine Release: Mechanism of the Placebo Effect in Parkinson's Disease
The power of placebos has long been recognized for improving numerous medical conditions such as Parkinson's disease (PD). Little is known, however, about the mechanism underlying the placebo effect.Expand
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Age‐dependent decline of dopamine D1 receptors in human brain: A PET study
Radioligand binding studies in animals have demonstrated age‐related loss of dopamine receptors in the caudate and putamen. In humans, while age‐related declines in dopamine D2 receptors have beenExpand
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PET in LRRK2 mutations: comparison to sporadic Parkinson's disease and evidence for presymptomatic compensation.
Parkinson's disease may arise from multiple aetiologies, including genetic mutations that are for the most part uncommon. We describe here the positron emission tomography (PET) findings inExpand
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Longitudinal progression of sporadic Parkinson's disease: a multi-tracer positron emission tomography study.
Parkinson's disease is a heterogeneous disorder with multiple factors contributing to disease initiation and progression. Using serial, multi-tracer positron emission tomography imaging, we studied aExpand
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Effects of expectation on placebo-induced dopamine release in Parkinson disease.
CONTEXT Expectations play a central role in the mechanism of the placebo effect. In Parkinson disease (PD), the placebo effect is associated with release of endogenous dopamine in both nigrostriatalExpand
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Increase in Dopamine Turnover Occurs Early in Parkinson's Disease: Evidence from a New Modeling Approach to PET 18F-Fluorodopa Data
An increase in dopamine turnover has been hypothesized to occur early in Parkinson's disease (PD) as a compensatory mechanism for dopaminergic neuronal loss. A new approach to the determination ofExpand
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Evaluation of Dopaminergic Presynaptic Integrity: 6-[18F]Fluoro-L-Dopa Versus 6-[18F]Fluoro-L-m-Tyrosine
The effectiveness of 6-[18F]fluoro-L-m-tyrosine (6FMT) to evaluate dopamine presynaptic integrity was compared to that of 6-[18F]fluoro-L-dopa (6FDOPA) in vivo by positron emission tomography (PET).Expand
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Biochemical variations in the synaptic level of dopamine precede motor fluctuations in Parkinson's disease: PET evidence of increased dopamine turnover.
Motor fluctuations are a major disabling complication in the treatment of Parkinson's disease. To investigate whether such oscillations in mobility can be attributed to changes in the synaptic levelsExpand
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Levodopa-induced changes in synaptic dopamine levels increase with progression of Parkinson's disease: implications for dyskinesias.
Peak-dose dyskinesias are abnormal movements that usually occur 1 h after oral administration of levodopa, and often complicate chronic treatment of Parkinson's disease. We investigated by PET withExpand
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