Distinct grey and white matter changes are associated with the phenomenology of visual hallucinations in Lewy Body Disease

Bibliographic Details
Title: Distinct grey and white matter changes are associated with the phenomenology of visual hallucinations in Lewy Body Disease
Authors: Fabrizia D’Antonio, Alice Teghil, Maddalena Boccia, Giulia Bechi Gabrielli, Giovanni Giulietti, Desirée Conti, Antonio Suppa, Andrea Fabbrini, Marco Fiorelli, Francesca Caramia, Giuseppe Bruno, Cecilia Guariglia, Dag Aarsland, Dominic Ffytche
Source: Scientific Reports, Vol 14, Iss 1, Pp 1-11 (2024)
Publisher Information: Nature Portfolio, 2024.
Publication Year: 2024
Collection: LCC:Medicine
LCC:Science
Subject Terms: Medicine, Science
More Details: Abstract Visual hallucinations in Lewy body disease (LBD) can be differentiated based on phenomenology into minor phenomena (MVH) and complex hallucinations (CVH). MVH include a variety of phenomena, such as illusions, presence and passage hallucinations occurring at early stages of LBD. The neural mechanisms of visual hallucinations are largely unknown. The hodotopic model posits that the hallucination state is due to abnormal activity in specialized visual areas, that occurs in the context of wider network connectivity alterations and that phenomenology of VH, including content and temporal characteristics, may help identify brain regions underpinning these phenomena. Here we investigated both the topological and hodological neural basis of visual hallucinations integrating grey and white matter imaging analyses. We studied LBD patients with VH and age matched healthy controls (HC). VH were assessed using a North-East-Visual-Hallucinations-Interview that captures phenomenological detail. Then we applied voxel-based morphometry and tract based spatial statistics approaches to identify grey and white matter changes. First, we compared LBD patients and HC. We found a reduced grey matter volume and a widespread damage of white tracts in LBD compared to HC. Then we tested the association between CVH and MVH and grey and white matter indices. We found that CVH duration was associated with decreased grey matter volume in the fusiform gyrus suggesting that LBD neurodegeneration-related abnormal activity in this area is responsible for CVH. An unexpected finding was that MVH severity was associated with a greater integrity of white matter tracts, specifically those connecting dorsal, ventral attention networks and visual areas. Our results suggest that networks underlying MVH need to be partly intact and functional for MVH experiences to occur, while CVH occur when cortical areas are damaged. The findings support the hodotopic view and the hypothesis that MVH and CVH relate to different neural mechanisms, with wider implications for the treatment of these symptoms in a clinical context.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2045-2322
Relation: https://doaj.org/toc/2045-2322
DOI: 10.1038/s41598-024-65536-w
Access URL: https://doaj.org/article/0493a1b7bbe343168f2a6dcff6dd44dd
Accession Number: edsdoj.0493a1b7bbe343168f2a6dcff6dd44dd
Database: Directory of Open Access Journals
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More Details
ISSN:20452322
DOI:10.1038/s41598-024-65536-w
Published in:Scientific Reports
Language:English