Effective connectivity abnormalities in Lewy body disease with visual hallucinations

Giorgio Leodori; Andrea Fabbrini; Antonio Suppa; Marco Mancuso; Sankalp Tikoo; Daniele Belvisi; Antonella Conte; Giovanni Fabbrini; Alfredo Berardelli

doi:10.1016/j.clinph.2023.10.009

Effective connectivity abnormalities in Lewy body disease with visual hallucinations

Clin Neurophysiol. 2023 Dec:156:156-165. doi: 10.1016/j.clinph.2023.10.009. Epub 2023 Nov 3.

Authors

Giorgio Leodori¹, Andrea Fabbrini², Antonio Suppa¹, Marco Mancuso², Sankalp Tikoo³, Daniele Belvisi¹, Antonella Conte¹, Giovanni Fabbrini¹, Alfredo Berardelli⁴

Affiliations

¹ IRCCS Neuromed, Pozzilli, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.
² Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.
³ Biomedical Imaging Research Institute, Department of Biomedical Sciences, and Imaging, Cedars Sinai Medical Center, Los Angeles, CA, USA.
⁴ IRCCS Neuromed, Pozzilli, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy. Electronic address: alfredo.berardelli@uniroma1.it.

PMID: 37952445
DOI: 10.1016/j.clinph.2023.10.009

Abstract

Objective: To assess the changes in effective connectivity of important regions of the visual network (VIS) and dorsal attention network (DAN) underlying visual hallucinations (VHs) in Dementia with Lewy Bodies (DLB), Parkinson's Disease (PD) and Parkinson's Disease Dementia (PDD), as measured by a transcranial magnetic stimulation-electroencephalographic technique (TMS-EEG).

Methods: We stimulated the right visual cortex (V1/V2), the right intraparietal sulcus and the right frontal eye fields, two key regions of the DAN, and measured TMS-evoked cortical activation within the VIS and the DAN. We compared 11 patients with VHs and 15 patients without VHs.

Results: Patients with VHs showed lower TMS-evoked cortical activation within the DAN following intraparietal sulcus and frontal eye fields stimulation than patients without VHs. No difference was found between patients with and without cognitive impairment. Also, when considering only patients with cognitive impairment, VHs were associated with lower TMS-evoked cortical activation following intraparietal sulcus stimulation.

Conclusions: DLB, PD, and PDD patients with VHs had less effective connectivity of the right intraparietal sulcus within the DAN than patients without VHs.

Significance: We provided the first evidence that VHs are associated with specific intraparietal sulcus dysfunction within the DAN in patients with PDD, PD, and DLB.

Keywords: Dementia with Lewy Bodies; Dorsal Attentional Network; Effective Connectivity; Parkinson’s disease; TMS-EEG; Visual Hallucinations.

MeSH terms

Alzheimer Disease* / psychology
Dementia*
Hallucinations
Humans
Lewy Body Disease*
Parkinson Disease*