Maillet, Audrey, Thobois, Stéphane, Fraix, Valérie, Redoute, Jerome, Le Bars, Didier, Lavenne, Franck, Derost, Philippe, Durif, Franck, Bloem, Bastiaan, Krack, Paul, Pollak, Pierre, Debû, Bettina, Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Hospices Civils de Lyon (HCL), ANTE-INSERM U836, équipe 10, Dynamique des réseaux neuronaux du mouvement, UM des troubles du mouvement, Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble-Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble, Centre d'Etude et de Recherche Multimodal Et Pluridisciplinaire en imagerie du vivant (CERMEP - imagerie du vivant), Centre Hospitalier Universitaire de Saint-Etienne [CHU Saint-Etienne] (CHU ST-E)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-CHU Grenoble-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Neuro-Psycho Pharmacologie des Systèmes Dopimanégiques sous-corticaux (NPsy-Sydo), CHU Clermont-Ferrand-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Department of Clinical Genetics, Département de neurologie, Université Joseph Fourier - Grenoble 1 (UJF)-CHU Grenoble, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-CHU Grenoble-Hospices Civils de Lyon (HCL)-CHU Saint-Etienne-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Douhairie, Marie-Laurence, and Université de Lyon-Université de Lyon-CHU Grenoble-Hospices Civils de Lyon (HCL)-CHU Saint-Etienne-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)
Contains fulltext : 153489.pdf (Publisher’s version ) (Closed access) Gait disturbances, including freezing of gait, are frequent and disabling symptoms of Parkinson's disease. They often respond poorly to dopaminergic treatments. Although recent studies have shed some light on their neural correlates, their modulation by dopaminergic treatment remains quite unknown. Specifically, the influence of levodopa on the networks involved in motor imagery (MI) of parkinsonian gait has not been directly studied, comparing the off and on medication states in the same patients. We therefore conducted an [H2 (15) 0] Positron emission tomography study in eight advanced parkinsonian patients (mean disease duration: 12.3 +/- 3.8 years) presenting with levodopa-responsive gait disorders and FoG, and eight age-matched healthy subjects. All participants performed three tasks (MI of gait, visual imagery and a control task). Patients were tested off, after an overnight withdrawal of all antiparkinsonian treatment, and on medication, during consecutive mornings. The order of conditions was counterbalanced between subjects and sessions. Results showed that imagined gait elicited activations within motor and frontal associative areas, thalamus, basal ganglia and cerebellum in controls. Off medication, patients mainly activated premotor-parietal and pontomesencephalic regions. Levodopa increased activation in motor regions, putamen, thalamus, and cerebellum, and reduced premotor-parietal and brainstem involvement. Areas activated when patients are off medication may represent compensatory mechanisms. The recruitment of these accessory circuits has also been reported for upper-limb movements in Parkinson's disease, suggesting a partly overlapping pathophysiology between imagined levodopa-responsive gait disorders and appendicular signs. Our results also highlight a possible cerebellar contribution in the pathophysiology of parkinsonian gait disorders through kinesthetic imagery.