Single-Case Neuropsychological Assessment of a Patient with a Posterior Parietal Lesion Using Behavioral Testing and Resting-State fMRI
Authors:   Trajectory team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France, Martín-Arévalo Elisa ,   University UCBL Lyon 1, University of Lyon, Lyon, France,   Department of Experimental Psychology and Brain, Mind, and Behavior Research Center (CIMCYC), University of Granada, Spain, Guedj Carole ,   University UCBL Lyon 1, University of Lyon, Lyon, France,   Impact team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France, Cotton François ,   Trajectory team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France,   University UCBL Lyon 1, University of Lyon, Lyon, France,   MRI center, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, Pierre Bénite, France; Observatoire Français de la Sclérose en Plaques, Lyon, France; CREATIS-LRMN, CNRS/UMR/5220-INSERM U630, Villeurbanne, France, Rode Gilles ,   Trajectory team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France,   University UCBL Lyon 1, University of Lyon, Lyon, France,   Service de Rééducation Neurologique, Hôpital Henry Gabrielle, Hospices Civils de Lyon, France, Reilly Karen T. ,   Trajectory team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France,   University UCBL Lyon 1, University of Lyon, Lyon, France, Hadj-Bouziane Fadila ,   University UCBL Lyon 1, University of Lyon, Lyon, France,   Impact team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France, Pisella Laure ,   Trajectory team, INSERM U1028, CRNS-UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France,   University UCBL Lyon 1, University of Lyon, Lyon, France
Published: August 2021

This study integrated functional connectivity measures using resting-state fMRI and behavioral data from a single-case observation of patient (PER) one year after right-hemispheric hemorrhage in the intraparietal sulcus and superior parietal lobule (IPS/SPL). PER showed no sign of clinical neglect. Her behavioral performance in the visuo-manual pointing task and in the letter discrimination task under conditions of endogenous and exogenous attentional cueing was compared between the left (affected) and right (unaffected/control) peripheral visual fields. The resting-state fMRI demonstrated an imbalance between the right and left hemispheric frontoparietal functional connectivity within the dorsal attentional and motor networks. Although the frontal and occipital cortices were not structurally damaged, specific fronto-occipital functional connectivity was imbalanced, which was strongly associated with the behavioral changes. First, the activity in the right frontal eye field showed weaker correlations with the activity in the right inferior occipital area compared to the correlation with the activity in the left inferior occipital area. This imbalanced fronto-occipital functional connectivity was accompanied by a specific impairment in endogenous covert attention in the left visual field. Second, the activity within M1 in both hemispheres showed weaker correlations with the activity of the right cuneus compared to the correlation with the activity in the left cuneus. The imbalanced fronto-occipital functional connectivity was associated with the impairment of the reaching movement of the left and right hands towards the left visual field (optic ataxia). Altogether, our results showed that a lesion to the posterior parietal cortex affects the relationship between distal regions underlying the sensorimotor and attentional abilities