M J Mentis1, V Dhawan, T Nakamura, M F Ghilardi, A Feigin, C Edwards, C Ghez, D Eidelberg. 1. Functional Brain Imaging Laboratory, Center for Neurosciences, North Shore-Long Island Jewish Research Institute, North Shore University Hospital and New York University School of Medicine, Manhasset, NY 11030, USA. marcjm@optonline.net
Abstract
BACKGROUND: Although the pathophysiology remains unknown, most nondemented patients with PD have difficulty with frontal tasks, including trial-and-error sequence learning. If given time, they can perform cognitive tasks of moderate difficulty as well as controls. However, it is not known how brain function is altered during this time period to preserve higher cortical function in the face of PD pathology. METHOD: To evaluate this phenomenon, the authors matched sequence learning between PD and control subjects for the last 30 seconds of a PET scan. Learning during the initial 50 seconds of PET was unconstrained. RESULTS: Learning indices were equivalent between groups during the last 30 seconds of the scan, whereas rates of acquisition, correct movements, and forgetting differed in the first 30 seconds. In normal controls sequence learning was associated with activations in the right prefrontal, premotor, parietal, rostral supplementary motor area, and precuneus regions. To achieve equal performance, the PD group activated greater volume within these same regions, and also their left sided cortical homologs and the lateral cerebellum bilaterally. CONCLUSIONS: Mildly affected patients with PD demonstrated only modest impairment of learning during the first 30 seconds of the task and performed equivalently with controls thereafter. However, the mechanism by which they achieved equiperformance involved considerable changes in brain function. The PD group had to activate four times as much neural tissue as the controls, including recruiting brain from homologous cortical regions and bilateral lateral cerebellum.
BACKGROUND: Although the pathophysiology remains unknown, most nondemented patients with PD have difficulty with frontal tasks, including trial-and-error sequence learning. If given time, they can perform cognitive tasks of moderate difficulty as well as controls. However, it is not known how brain function is altered during this time period to preserve higher cortical function in the face of PD pathology. METHOD: To evaluate this phenomenon, the authors matched sequence learning between PD and control subjects for the last 30 seconds of a PET scan. Learning during the initial 50 seconds of PET was unconstrained. RESULTS: Learning indices were equivalent between groups during the last 30 seconds of the scan, whereas rates of acquisition, correct movements, and forgetting differed in the first 30 seconds. In normal controls sequence learning was associated with activations in the right prefrontal, premotor, parietal, rostral supplementary motor area, and precuneus regions. To achieve equal performance, the PD group activated greater volume within these same regions, and also their left sided cortical homologs and the lateral cerebellum bilaterally. CONCLUSIONS: Mildly affected patients with PD demonstrated only modest impairment of learning during the first 30 seconds of the task and performed equivalently with controls thereafter. However, the mechanism by which they achieved equiperformance involved considerable changes in brain function. The PD group had to activate four times as much neural tissue as the controls, including recruiting brain from homologous cortical regions and bilateral lateral cerebellum.
Authors: Laura Bonzano; Andrea Tacchino; Luca Roccatagliata; Giovanni Luigi Mancardi; Giovanni Abbruzzese; Marco Bove Journal: Hum Brain Mapp Date: 2011-02 Impact factor: 5.038
Authors: Meggan Mackay; Mathew P Bussa; Cynthia Aranow; Aziz M Uluğ; Bruce T Volpe; Patricio T Huerta; Miklos Argyelan; Arthur Mandel; Joy Hirsch; Betty Diamond; David Eidelberg Journal: Mol Med Date: 2011-09-21 Impact factor: 6.354
Authors: Lucio Marinelli; Angelo Quartarone; Mark Hallett; Giuseppe Frazzitta; Maria Felice Ghilardi Journal: Clin Neurophysiol Date: 2017-04-09 Impact factor: 3.708