Lorenzo Kiferle1, Roberto Ceravolo2, Martina Giuntini1, Giuseppe Linsalata1, Giulia Puccini3, Duccio Volterrani3, Ubaldo Bonuccelli1. 1. Section of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy. 2. Section of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy. Electronic address: r.ceravolo@med.unipi.it. 3. Regional Center of Nuclear Medicine, University of Pisa, Italy.
Abstract
OBJECTIVE: The pathogenesis of visual hallucinations (VHs) in Parkinson's disease (PD) has been considered multifactorial. In the pathophysiology of VHs a combination of impaired visual processing and attention has been reported. Imaging studies evidenced a role of the primary visual system and visual association areas as well as a dysfunctional activation of frontal areas in the occurrence of VHs. Due to the functional connections between basal ganglia and frontal areas, a role of basal ganglia and of the fronto-striatal circuits in the pathogenesis of VHs may be postulated. Aim of this study is to unveil whether a presynaptic dopamine deficiency at baseline may predict the development of VHs. METHODS: A group of 18 non demented PD patients with VHs was matched with 18 non demented PD patients without VHs as regards age of onset of disease, disease duration and severity and levodopa equivalent dose. We retrospectively analyzed the (123)I-FP CIT SPECT performed on the two groups at the onset of their disease. The striatal uptake values in the two groups were examined, in order to evaluate nigrostriatal differences between the groups with different behavioral phenotype. RESULTS: The group of patients with VHs had a significant reduction (p < 0.05) in right caudate uptake values at baseline when compared with patients without VHs. No significant differences were found between the groups regarding left caudate and putaminal uptake values. CONCLUSIONS: The frontal impairment reported in PD patients with VHs may be due to a right caudate dysfunction, as it is connected to the frontal brain areas via neuronal loops.
OBJECTIVE: The pathogenesis of visual hallucinations (VHs) in Parkinson's disease (PD) has been considered multifactorial. In the pathophysiology of VHs a combination of impaired visual processing and attention has been reported. Imaging studies evidenced a role of the primary visual system and visual association areas as well as a dysfunctional activation of frontal areas in the occurrence of VHs. Due to the functional connections between basal ganglia and frontal areas, a role of basal ganglia and of the fronto-striatal circuits in the pathogenesis of VHs may be postulated. Aim of this study is to unveil whether a presynaptic dopamine deficiency at baseline may predict the development of VHs. METHODS: A group of 18 non demented PDpatients with VHs was matched with 18 non demented PDpatients without VHs as regards age of onset of disease, disease duration and severity and levodopa equivalent dose. We retrospectively analyzed the (123)I-FP CIT SPECT performed on the two groups at the onset of their disease. The striatal uptake values in the two groups were examined, in order to evaluate nigrostriatal differences between the groups with different behavioral phenotype. RESULTS: The group of patients with VHs had a significant reduction (p < 0.05) in right caudate uptake values at baseline when compared with patients without VHs. No significant differences were found between the groups regarding left caudate and putaminal uptake values. CONCLUSIONS: The frontal impairment reported in PDpatients with VHs may be due to a right caudate dysfunction, as it is connected to the frontal brain areas via neuronal loops.
Authors: Mei Yuan; Laura Sperry; Norika Malhado-Chang; Alexandra Duffy; Vicki Wheelock; Sarah Farias; Kevin O'Connor; John Olichney; Kiarash Shahlaie; Lin Zhang Journal: Brain Behav Date: 2017-04-14 Impact factor: 2.708
Authors: John O'Brien; John Paul Taylor; Clive Ballard; Roger A Barker; Clare Bradley; Alistair Burns; Daniel Collerton; Sonali Dave; Rob Dudley; Paul Francis; Andrea Gibbons; Kate Harris; Vanessa Lawrence; Iracema Leroi; Ian McKeith; Michel Michaelides; Chaitali Naik; Claire O'Callaghan; Kirsty Olsen; Marco Onofrj; Rebecca Pinto; Gregor Russell; Peter Swann; Alan Thomas; Prabitha Urwyler; Rimona Sharon Weil; Dominic Ffytche Journal: J Neurol Neurosurg Psychiatry Date: 2020-03-25 Impact factor: 10.154