Visual Hallucinations in PD and Lewy Body Dementias: Old and New Hypotheses

Onofrj, Marco; Taylor, John‐Paul; Monaco, Daniela; Franciotti, Raffaella; Anzellotti, Francesca; Bonanni, Laura; Onofrj, Valeria; Thomas, Astrid

doi:10.1155/2013/703924

Cited by 80 publications

(85 citation statements)

References 131 publications

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“…These functional attributes of the memory perception network and the enhancement of its activity may be involved in the generation of visual hallucination in DLB. Contrary to our results, many previous DLB studies reported visual hallucination patients in association with worse visuospatial and cognitive function compared with patients without visual hallucination [94, 95]. However, while we used drug-free early-stage DLB patients, in these studies, visual hallucination patients tended to have more advanced stage of the disease than patients without visual hallucination and were treated with drugs such as AchEI, levodopa, and antipsychotics, which affect DLB symptoms and brain functions.…”

Section: Discussioncontrasting

confidence: 99%

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

et al. 2019

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Background: Dementia with Lewy bodies (DLB) is characterized by progressive cognitive decline, fluctuating cognition, visual hallucinations, rapid eye movement sleep behavior disorder, and parkinsonism. DLB is the second most common type of degenerative dementia of all dementia cases. However, DLB, particularly in the early stage, is underdiagnosed and sometimes misdiagnosed with other types of dementia. Thus, it is of great interest investigating neurophysiological markers of DLB. Method: We introduced exact low-resolution brain electromagnetic tomography (eLORETA)-independent component analysis (ICA) to assess activities of 5 electroencephalography (EEG) resting-state networks (RSNs) in 41 drug-free DLB patients. Results: Compared to 80 healthy controls, DLB patients had significantly decreased activities in occipital visual and sensorimotor networks, where DLB patients and healthy controls showed no age dependences in all EEG-RSN activities. Also, we found correlations between all EEG-RSN activities and DLB symptoms. Specifically, decreased occipital α activity showed correlations with worse brain functions related to attention/concentration, visuospatial discrimination, and global cognition. Enhanced visual perception network activity correlated with milder levels of depression and anxiety. Enhanced self-referential network activity correlated with milder levels of depression. Enhanced memory perception network activity correlated with better semantic memory, visuospatial discrimination function, and global cognitive function as well as with severer visual hallucination. In addition, decreased sensorimotor network activity correlated with a better semantic memory. Conclusion: These results indicate that eLORETA-ICA can detect EEG-RSN activity alterations in DLB related to symptoms. Therefore, eLORETA-ICA with EEG data can be a useful noninvasive tool for sensitive detection of EEG-RSN activity changes characteristic of DLB and for understanding the neurophysiological mechanisms underlying this disease.

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Section: Discussioncontrasting

confidence: 99%

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

et al. 2019

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“…14 These deficits of visual perception and attentional control are thought to cause visual hallucinations and illusions through an imbalance of top-down expectations and bottom-up visual processing (see ref. 15 for a review). Consistent with the neuropsychological findings, visual hallucinations are associated with reduced grey matter volume in the visual system, hippocampus, frontal regions ( particularly lateral frontal cortex) and cerebellum.…”

Section: Introductionmentioning

confidence: 99%

Risk factors for early psychosis in PD: insights from the Parkinson's Progression Markers Initiative

ffytche

Pereira

Ballard

et al. 2017

J Neurol Neurosurg Psychiatry

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Parkinson's Disease (PD) psychosis refers to the spectrum of illusions, formed hallucinations and delusions that occur in PD. Visual hallucinations and illusions are thought to be caused by specific cognitive and higher visual function deficits and patients who develop such symptoms early in the disease course have greater rates of cognitive decline and progression to dementia. To date, no studies have investigated whether such deficits are found prior to the onset of PD psychosis. Here we compare baseline cognitive, biomarker (structural imaging and cerebrospinal fluid) and other PD psychosis risk factor data in patients who go on to develop illusions or hallucinations within 3-4 years of follow-up in the Parkinson's Progression Markers Initiative cohort of newly diagnosed PD. Of n=423 patients with PD, n=115 (27%) reported predominantly illusions with median onset at 19.5 months follow-up. At study entry these patients had reduced CSF amyloid Aß1-42, lower olfaction scores, higher depression scores and increased REM sleep behaviour disorder symptoms compared to patients without early onset PD psychosis but no differences in cognitive, higher visual or structural imaging measures. A subset of patients with early onset formed hallucinations (n=21) had reduced higher visual function at baseline, cortical thinning in parietal, occipital and frontal cortex and reduced hippocampal volume. The findings suggest early onset illusions and formed hallucinations are linked to amyloid pathology in PD and point to a difference in the underlying pathophysiological mechanism of illusions and formed hallucinations, with implications for their respective links to future cognitive decline.

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“…39 As in Alzheimer's and Parkinson's, hallucinations are common in Lewy body dementia and are most frequently visual in nature. 40 Visual hallucinations early in the course of the disease, in fact, are considered to be a core feature of Lewy body dementia. 41 A recent study found that 63% of patients experienced visual hallucinations, 17 and another found that 78% of patients had hallucinations, 56% had misidentifications, and 25% had delusions.…”

Section: Alzheimer's Disease and Other Dementiasmentioning

confidence: 99%

Psychosis in Later Life

Colijn

Nitta²,

Grossberg³

2015

Harvard Review of Psychiatry

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Psychosis is relatively common in later life and can present in a wide variety of contexts, including early-onset and late-onset schizophrenia, delusional disorder, mood disorders, and various dementias. It can also occur as the result of numerous medical and neurological diseases and from the use of certain medications. Although identifying the cause of psychosis in older patients can be challenging, the unique clinical features associated with the different disorders can help in making the diagnosis. Accurate diagnosis of psychosis in older populations is essential, as its treatment varies depending on the context in which it appears. Despite the safety concerns regarding the use of antipsychotics in older patients, certain pharmacological treatments appear to be both efficacious and reasonably safe in treating psychosis in older populations. Additionally, although research is limited, numerous psychosocial therapies appear promising. This review summarizes the literature on the epidemiology, clinical characteristics, neuroimaging, and treatment of psychosis in later life, and serves as an update to past reviews on this topic.

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Visual Hallucinations in PD and Lewy Body Dementias: Old and New Hypotheses

Cited by 80 publications

References 131 publications

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

EEG Resting-State Networks in Dementia with Lewy Bodies Associated with Clinical Symptoms

Risk factors for early psychosis in PD: insights from the Parkinson's Progression Markers Initiative

Psychosis in Later Life

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