Impaired functional differentiation for categories of objects in the ventral visual stream: A case of developmental visual impairment.
We report the case of a 14-year-old girl suffering from severe developmental visual impairment along with delayed language and cognitive development, and featuring a clear-cut dissociation between spared dorsal and impaired ventral visual pathways. Visual recognition of objects, including faces and printed words, was affected. In contrast, movement perception and visually guided motor control were preserved. Structural MRI was normal on inspection, but Voxel Based Morphometry (VBM) revealed reduced grey matter density in the mesial occipital and ventral occipito-temporal cortex. Functional MRI during the perception of line drawings uncovered impaired differentiation which is normally observed at even younger ages: no local category preferences could be identified within the occipito-temporal cortex for faces, houses, words or tools. In contrast, movement-related activations appeared to be normal. Finally, those abnormalities evolved on the background of chronic bilateral occipital epileptic activity, including continuous spike-wave discharges during sleep, which may be considered as the primary cause of non-specific intellectual disability and visual impairment.
Department of Neurology, Rouen University Hospital, France. Electronic address: olivier.martinaud@chu-rouen.fr.
Olivier
O
Martinaud
Department of Neurology, Rouen University Hospital, France.
Dorothée
D
Pouliquen
Department of Neurophysiology, Rouen University Hospital, France.
Dominique
D
Parain
Department of Genetics, Rouen University Hospital, France.
Alice
A
Goldenberg
Department of Neuroradiology, Rouen University Hospital, France.
Emmanuel
E
Gérardin
Department of Neurology, Rouen University Hospital, France; INSERM, U1079, IFRMP, Faculty of Medecine and Pharmacy, F-76031 Rouen, France.
Didier
D
Hannequin
Laboratoire de Sciences cognitives et Psycholinguistique, Département d'Etudes Cognitives, Ecole Normale Supérieure, EHESS, CNRS, PSL Research University, Paris, France.
Irène
I
Altarelli
Laboratoire de Sciences cognitives et Psycholinguistique, Département d'Etudes Cognitives, Ecole Normale Supérieure, EHESS, CNRS, PSL Research University, Paris, France.
Franck
F
Ramus
CEA, NeuroSpin Center, UNIACT, F-91191 Gif-sur-Yvette, France; INSERM, UMR 1129, Sorbonne Universités, UPMC Univ Paris Descartes, F-75015 Paris, France.
Lucie
L
Hertz-Pannier
CEA, NeuroSpin Center, UNICOG, F-91191 Gif-sur-Yvette, France; INSERM, U992, Cognitive Neuroimaging Unit, F-91191 Gif-sur-Yvette, France.
Ghislaine
G
Dehaene-Lambertz
INSERM, U1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013 Paris, France.
Laurent
L
Cohen
D000293:Adolescent; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D002648:Child; D002658:Developmental Disabilities / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D014786:Vision Disorders / Q000473:pathology / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology*
Agnosia; Developmental visual impairment; Dyslexia; Face recognition; Object recognition; Prosopagnosia