Hemispheric Network Expression in Parkinson’s Disease: Relationship to Dopaminergic Asymmetries

Journal of Parkinson s Disease, vol. 10, pp. 1737–1749

Abstract

BACKGROUND: Parkinson's disease (PD) is characterized by brain metabolic networks, specifically associated with motor and cognitive manifestations. Few studies have investigated network changes in cerebral hemispheres ipsilateral and contralateral to the clinically more affected body side. OBJECTIVE: We examined hemispheric network abnormalities and their relationship to striatal dopaminergic deficits in PD patients at different stages. METHODS: 45 PD patients underwent dual-tracer positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) and 18F-fluorodopa (FDOPA) in a high-resolution PET scanner. In all patients, we computed expression levels for the PD-related motor/cognition metabolic patterns (PDRP/PDCP) as well as putamen/caudate FDOPA uptake values in both hemispheres. Resulting hemispheric measures in the PD group were compared with corresponding healthy control values and assessed across disease stages. RESULTS: Hemispheric PDRP and PDCP expression was significantly elevated contralateral and ipsilateral to the more affected body side in patients with unilateral symptoms (H&Y 1: p < 0.01) and in patients with bilateral limb involvement (H&Y 2-3: p < 0.001; H&Y 4: p < 0.003). Elevations in pattern expression were symmetrical at all disease stages. By contrast, FDOPA uptake in the caudate and putamen was reduced bilaterally (p < 0.002), with lower values on both sides at more advanced disease stages. Hemispheric uptake was asymmetrical in both striatal regions, with lower contralateral values at all disease stages. The magnitude of hemispheric uptake asymmetry was smaller with more advanced disease, reflecting greater change ipsilaterally. CONCLUSION: Symmetrical network expression in PD represents bilateral functional effects unrelated to nigrostriatal dopaminergic asymmetries.

Authors 9

1. Chris C. Tang

   Feinstein Institute for Medical Research

   Affiliation as printed

   Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY, USA

2. Florian Holtbernd Aachen JARA Brain Institute Molecular Neuroscience and Neuroimaging (INM-11) Department of Neurology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   Institute of Neuroscience and Medicine 4 (INM-4), Juelich Research Centre, Juelich, Germany

   JARA-BRAIN Institute Molecular Neuroscience and Neuroimaging, Juelich Research Centre and RWTH Aachen University, Aachen, Germany

   RWTH Aachen University, Department of Neurology, Aachen, Germany

3. Yilong Ma

   Feinstein Institute for Medical Research

   Affiliation as printed

   Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY, USA

4. Phoebe G. Spetsieris

   Feinstein Institute for Medical Research

   Affiliation as printed

   Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY, USA

5. Alice Oh

   Feinstein Institute for Medical Research

   Affiliation as printed

   Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY, USA

6. Gereon R. Fink

   Forschungszentrum Jülich · University of Cologne

   Affiliation as printed

   Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Jülich Research Centre, Jülich, Germany

   Department of Neurology, University of Cologne, Cologne, Germany

7. Lars Timmermann

   Forschungszentrum Jülich · Universitätsklinikum Gießen und Marburg

   Affiliation as printed

   Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Jülich Research Centre, Jülich, Germany

   Department of Neurology, University Hospital of Giessen and Marburg, Marburg, Germany

8. Carsten Eggers

   Universitätsklinikum Gießen und Marburg

   Affiliation as printed

   Center for Mind, Brain and Behavior, Universities Marburg and Giessen, Marburg, Germany

   Department of Neurology, University Hospital of Giessen and Marburg, Marburg, Germany

9. David Eidelberg corresponding

   Feinstein Institute for Medical Research

   Affiliation as printed

   Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY, USA