Neuroimaging Findings in Patients with Hallucinations: Evidence from Neurodegenerative and Psychiatric Conditions

Pezzoli, Stefania; Venneri, Annalena

doi:10.1007/978-3-030-57231-0_17

Cited by 3 publications

(4 citation statements)

References 143 publications

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“…Contrasting findings may be due to methodological and clinical differences between studies, including those not distinguishing between hallucinations in different sensory modalities [14,24,25]. Occipital/occipito-temporal atrophy has been related to VH in previous studies of patients with AD and PD, and hypometabolism/hypoperfusion in these regions was found in hallucinating patients with PD and DLB [21,22,29,47,48]. In the present study, although the results of the independent comparisons of both AD sub-groups with CN participants seem to suggest a trend of divergent structural and metabolic alterations in VH and NVH patients (i.e., primarily occipital and temporal in VH and temporal in NVH), we detected no significant differences in the direct comparison between patients with and without VH contrary to our hypothesis.…”

Section: Discussionmentioning

confidence: 99%

“…For patients with data collected at two different time points, the earliest visit was chosen. Consistent with most studies investigating hallucinations in neurodegeneration, we explored trait-related features associated with VH, and differentiated hallucinating and non-hallucinating patients based on whether VH were among the reported clinical features [29]. The presence of VH was assessed with the NPI subsection for VH, namely by answering the question "Does [P] describe seeing things not seen by others or behave as if he/she is seeing things not seen by others (people, animals, lights, etc.)?"…”

Section: Study Participants and Clinical Assessmentmentioning

confidence: 99%

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A Multimodal Neuroimaging and Neuropsychological Study of Visual Hallucinations in Alzheimer’s Disease

Pezzoli

Manca

Cagnin

et al. 2022

JAD

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Background: Hallucinations in Alzheimer’s disease (AD) have been linked to more severe cognitive and functional decline. However, research on visual hallucinations (VH), the most common type of hallucinations in AD, is limited. Objective: To investigate the cognitive and cerebral macrostructural and metabolic features associated with VH in AD. Methods: Twenty-four AD patients with VH, 24 with no VH (NVH), and 24 cognitively normal (CN) matched controls were selected from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Differences in regional gray matter (GM) volumes and cognitive performance were investigated with whole brain voxel-based morphometry analyses of MRI structural brain scans, and analyses of neuropsychological tests. Glucose metabolic changes were explored in a subsample of patients who had FDG-PET scans available. Results: More severe visuoconstructive and attentional deficits were found in AD VH compared with NVH. GM atrophy and hypometabolism were detected in occipital and temporal areas in VH patients in comparison with CN. On the other hand, NVH patients had atrophy and hypometabolism mainly in temporal areas. No differences in GM volume and glucose metabolism were found in the direct comparison between AD VH and NVH. Conclusion: In addition to the pattern of brain abnormalities typical of AD, occipital alterations were observed in patients with VH compared with CN. More severe visuoconstructive and attentional deficits were found in AD VH when directly compared with NVH, and might contribute to the emergence of VH in AD.

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Section: Discussionmentioning

confidence: 99%

Section: Study Participants and Clinical Assessmentmentioning

confidence: 99%

A Multimodal Neuroimaging and Neuropsychological Study of Visual Hallucinations in Alzheimer’s Disease

Pezzoli

Manca

Cagnin

et al. 2022

JAD

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“…These regions are directly interconnected with each other, and indirectly through subcortical hubs in the striatum and the thalamus [ 34 ]. Reduced gray matter volume has been found in DLB patients with VH [ 9, 47 ], and altered frontal and parietal metabolism/perfusion has been reported [ 48 ]. Furthermore, high density of Lewy body pathology has been shown in frontal and anterior cingulate areas in patients with VH, and alterations of the cholinergic receptors within the anterior cingulate have been related to VH in DLB [ 49, 50 ].…”

Section: Discussionmentioning

confidence: 99%

“…Collerton et al [ 2 ] proposed an involvement of visual processing impairment, in addition to attention deficits. Occipital and occipito-temporal hypometabolism/perfusion has been repeatedly found in DLB and PD with VH, suggesting a contribution of ventral visual pathways [ 48 ]. In the present study, however, visual areas showed a pattern of both decreased and increased functional connectivity.…”

Section: Discussionmentioning

confidence: 99%

Functional Brain Connectivity Patterns Associated with Visual Hallucinations in Dementia with Lewy Bodies

Pezzoli

Marco

Zorzi

et al. 2021

ADR

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Background: The presence of recurrent, complex visual hallucinations (VH) is among the core clinical features of dementia with Lewy bodies (DLB). It has been proposed that VH arise from a disrupted organization of functional brain networks. However, studies are still limited, especially investigating the resting-state functional brain features underpinning VH in patients with dementia. Objective: The aim of the present pilot study was to investigate whether there were any alterations in functional connectivity associated with VH in DLB. Methods: Seed-based analyses and independent component analysis (ICA) of resting-state fMRI scans were carried out to explore differences in functional connectivity between DLB patients with and without VH. Results: Seed-based analyses reported decreased connectivity of the lateral geniculate nucleus, the superior parietal lobule and the putamen with the medial frontal gyrus in DLB patients with VH. Visual areas showed a pattern of both decreased and increased functional connectivity. ICA revealed between-group differences in the default mode network (DMN). Conclusion: Functional connectivity analyses suggest dysfunctional top-down and bottom-up processes and DMN-related alterations in DLB patients with VH. These impairments might foster the generation of false visual images that are misinterpreted, ultimately resulting in VH.

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Cognitive correlates and baseline predictors of future development of visual hallucinations in dementia with Lewy bodies

Pezzoli

Cagnin

Bussè

et al. 2021

Cortex

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Neuroimaging Findings in Patients with Hallucinations: Evidence from Neurodegenerative and Psychiatric Conditions

Cited by 3 publications

References 143 publications

A Multimodal Neuroimaging and Neuropsychological Study of Visual Hallucinations in Alzheimer’s Disease

A Multimodal Neuroimaging and Neuropsychological Study of Visual Hallucinations in Alzheimer’s Disease

Functional Brain Connectivity Patterns Associated with Visual Hallucinations in Dementia with Lewy Bodies

Cognitive correlates and baseline predictors of future development of visual hallucinations in dementia with Lewy bodies

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