Thesis title: Investigating cortical network dynamics in Parkinson’s disease and Dementia with Lewy Bodies using TMS-EEG
Motor impairment in Parkinson’s disease (PD) reflects changes in the basal ganglia-thalamocortical circuit converging on the primary motor cortex (M1) and supplementary motor area (SMA). Visual hallucinations (VHs) are a core feature of Dementia with Lewy Bodies (DLB), Parkinson’s disease with (PDD) and without dementia (PD) and emerge due to dysfunction of specific cortical attentional networks. The aim of the thesis was to unveil motor cortical network changes in PD and attentional network dysfunction in PD and DLB patients with VH using transcranial magnetic stimulation techniques coupled with electroencephalographic recordings (TMS-EEG). Patients with PD showed reduced M1 and increased pre-SMA excitability, as measured with transcranial evoked potentials (TEPs). On the other hand, PD and DLB patients with VH showed decreased TMS-evoked cortical activation within the dorsal attentional network (DAN) compared to patients without hallucinations. These studies further strengthen the concept that TMS-EEG techniques can provide important insights on the pathophysiology of motor impairment and visual hallucinations in patients with PD and DLB.