Posterior cortical atrophy (PCA) is rare neurodegenerative dementia, clinically characterized by a progressive decline in higher-visual object and space processing. After a brief review of the literature on the neuroimaging in PCA, here we present a study of the brain structural connectivity in a patient with PCA and progressive isolated visual and visuo-motor signs. Clinical and cognitive data were acquired in a 58-years-old patient (woman, right-handed, disease duration 18 months). Brain structural and diffusion tensor (DT) Magnetic Resonance Imaging (MRI) were obtained. A voxel-based morphometry (VBM) study was performed to explore the pattern of gray matter (GM) atrophy, and a fully automatic segmentation was assessed to obtain the hippocampal volumes. DT MRI-based tractography was used to assess the integrity of long-range white matter (WM) pathways in the patient and in six sex- and age-matched healthy subjects. This PCA patient had a clinical syndrome characterized by left visual neglect, optic ataxia, and left limb apraxia, as well as mild visuo-spatial episodic memory impairment. VBM study showed bilateral posterior GM atrophy with right predominance; DT MRI tractography demonstrated WM damage to the right hemisphere only, including the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus, as compared to age-matched controls. The homologous left-hemisphere tracts were spared. No difference was found between left and right hippocampal volumes. These data suggest that selective visuo-spatial deficits typical of PCA might not result from cortical damage alone, but by a right-lateralized network-level dysfunction including WM damage along the major visual pathways.
|Titolo:||Brain networks in posterior cortical atrophy: a single case tractography study and literature review.|
|Autori:||R., Migliaccio; F., Agosta; M. N., Toba; D., Samri; F., Corlier; L. C., de Souza; M., Chupin; M., Sharman; Gorno Tempini, Maria Luisa; B., Dubois; M., Filippi; P., Bartolomeo|
|Titolo del periodico:||CORTEX|
|Anno di pubblicazione:||2011|
|Numero e parte del fascicolo:||10|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.cortex.2011.10.002|
|Appare nelle tipologie:||03.1 Articolo su rivista (Journal article)|