Clinical neuroanatomy Relevance of subcortical visual pathways disruption to visual symptoms in dementia with Lewy bodies Stefano Delli Pizzi a,b,c , Valerio Maruotti b , John-Paul Taylor d , Raffaella Franciotti a,b,c , Massimo Caulo a,c , Armando Tartaro a,c , Astrid Thomas a,b , Marco Onofrj a,b and Laura Bonanni a,b,* a Department of Neuroscience and Imaging, “G. d'Annunzio” University, Chieti, Italy b Aging Research Centre, Ce.S.I.,“G. d'Annunzio” University Foundation, Chieti, Italy c Institute for Advanced Biomedical Technologies (ITAB), “G. d'Annunzio” University Foundation, Chieti, Italy d Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle Upon Tyne, UK article info Article history: Received 28 February 2014 Reviewed 26 March 2014 Revised 14 April 2014 Accepted 10 July 2014 Action editor Marco Catani Published online 22 July 2014 Keywords: Dementia with Lewy bodies Pulvinar Thalamus Visual hallucinations Visual dysfunction abstract Visual hallucinations represent a core diagnostic criterion for dementia with Lewy bodies (DLB). We hypothesized that thalamic regions, which are critically involved in the modulation of visual transmission, may be differentially disrupted in DLB as compared to Alzheimer's Disease (AD) and that these deficits could relate to visual dysfunction in DLB patients. Magnetic Resonance and Diffusion Tensor Imaging (DTI) were performed with a 3 T scanner on a sample population of 15 DLB patients, 15 AD patients and 13 healthy vol- unteers. Regional thalamic micro-structural changes were assessed by parcelling the thalamus based on its connectivity to cortex and to amygdala and by measuring the mean diffusivity (MD) in each connectivity-defined sub-region. Micro-structural grey matter damage associated to higher MD values was found bilat- erally in DLB compared to controls in the sub-regions projecting from thalamus to pre- frontal and parieto-occipital cortices. Right thalamic sub-region projecting to amygdala and left thalamic sub-region projecting to motor cortex were also affected in DLB compared to controls. Higher MD values were found bilaterally in AD compared to controls in the thalamic sub-regions projecting to temporal cortex. Specific comparison between the two forms of dementia found differences: the sub-regions which project from thalamus to parieto-occipital cortex and to amygdala showed higher MD values in DLB compared to AD patients. In DLB patients, correlation analysis showed a significant correlation between NPI hallucinations item scores and MD values in the right thalamic sub-regions projecting to parietal and occipital cortices. The present study demonstrates how thalamic connectivity alterations between higher and lower visual areas may be relevant in explaining visual hallucinations in DLB. © 2014 Elsevier Ltd. All rights reserved. * Corresponding author. Department of Neuroscience and Imaging, University G. d'Annunzio of Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy. E-mail address: l.bonanni@unich.it (L. Bonanni). Available online at www.sciencedirect.com ScienceDirect Journal homepage: www.elsevier.com/locate/cortex cortex 59 (2014) 12 e21 http://dx.doi.org/10.1016/j.cortex.2014.07.003 0010-9452/© 2014 Elsevier Ltd. All rights reserved.