Psychosis in Parkinson’s disease (PD) is common and associated with a range of negative outcomes. Dementia and psychosis are highly correlated in PD, but the frequency and correlates of psychosis in patients without cognitive impairment are not well understood. One hundred and ninety-one non-demented PD patients at two movement disorders centers participated in a study…
Research Article
Minor hallucinations occur in drug-naive Parkinson’s disease patients, even from the premotor phase
Objectives The description of minor hallucinatory phenomena (presence, passage hallucinations) has widened the spectrum of psychosis in Parkinson’s disease (PD). Minor hallucinatory phenomena seem to antedate the development of more severe hallucinations. Early detection of minor hallucinations may be useful for screening patients with more severe endophenotypes. Motivated by the observation of “de novo,” drug-naive…
Validation of the Psychosis and Hallucinations Questionnaire in Non-demented Patients with Parkinson’s Disease
People diagnosed with Parkinson’s disease (PD) frequently experience visual and non-visual hallucinations often with comorbid psychosis, however, there is currently no gold standard tool for accurately assessing these symptoms. To address this problem, we designed a novel questionnaire to evaluate the presence of hallucinatory and psychotic symptoms in PD, as well as related symptoms, such…
Retinal nerve fiber layer thickness and visual hallucinations in Parkinson’s Disease
Defective visual information processing from both central and peripheral pathways is one of the suggested mechanisms of visual hallucination in Parkinson’s disease (PD). To investigate the role of retinal thinning for visual hallucination in PD, we conducted a case-control study using spectral domain optical coherence tomography. We examined a representative sample of 61 patients with…
Visual hallucinations in Parkinson’s disease: Theoretical models
One of the most challenging tasks in neuroscience is to be able to meaningfully connect information across the different levels of investigation, from molecular or structural biology to the resulting behavior and cognition. Visual hallucinations are a frequent occurrence in Parkinson’s disease and significantly contribute to the burden of the disease. Because of the widespread…
Risk factors for hallucinations in Parkinson’s disease: Results from a large prospective cohort study
The aim of this study was to identify risk factors for the development of hallucinations in patients with Parkinson’s disease (PD). A broad range of motor and nonmotor features was assessed at baseline and during the following 5 years in 386 PD patients. Cross-sectional analyses of baseline data and longitudinal analyses of follow-up data were…
Increased levels of 5-HT1A receptor binding in ventral visual pathways in Parkinson’s disease
Visual hallucinations are common in advanced Parkinson’s disease (PD). The pathophysiology of visual hallucinations may involve enhanced serotonergic neurotransmission. The atypical antipsychotics clozapine and quetiapine, which have affinity for 5-HT(2A) and 5-HT(1A) receptors, are effective against visual hallucinations in PD. 5-HT(2A) receptors are increased in ventral visual pathways in PD patients with visual hallucinations, and…
Scales to assess psychosis in Parkinson’s disease: Critique and recommendations
Psychotic symptoms are a frequent occurrence in Parkinson’s disease (PD), affecting up to 50% of patients. The Movement Disorder Society established a Task Force on Rating Scales in PD, and this critique applies to published, peer-reviewed rating psychosis scales used in PD psychosis studies. Twelve psychosis scales/questionnaires were reviewed. None of the reviewed scales adequately…
REM behavior disorder, hallucinations and cognitive impairment in Parkinson’s disease: A two-year follow up
In Parkinson’s disease (PD) the presence of REM parasonnias as REM Behaviour Disorder (RBD) or vivid dreams/nightmares, is recognized as largely associated with hallucinations, even if the risk of the development of hallucinations seem not to depend on how long the REM parasomnias had been occurring. The aim of this study was to establish if…
A neuropsychological longitudinal study in Parkinson’s patients with and without hallucinations
The aim of this work was to determine the progression of cognitive impairment in Parkinson’s disease (PD) patients with or without hallucinations. Two years after the first assessment, 36 PD patients were re-evaluated on standardized neuropsychological tests, including the Frontal Assessment Battery (FAB), and on rating scales for overall cognitive functioning, functional autonomy, behavioral disorders.…
Increased 5-HT2A receptors in the temporal cortex of parkinsonian patients with visual hallucinations
Well-formed visual hallucinations (VH) are common in patients with Parkinson’s disease (PD). The pathophysiology of VH in PD is unknown but may involve structures mediating visual processing such as the inferior temporal cortex. Serotonergic type 2A (5-HT2A) receptors have been linked to many psychiatric disorders, including psychosis. We hypothesized that enhanced 5-HT2A receptor levels may…
Severity of neuropsychiatric symptoms and dopamine transporter levels in dementia with Lewy bodies: A 123I-FP-CIT SPECT study
Neuropsychiatric symptoms are frequent in dementia with Lewy bodies (DLB). Dopamine transporter (DAT) imaging with 123I-labeled ligand N-δ-(fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)tropene (123I-FP-CIT), which reliably measures midbrain dopaminergic dysfunction, has provided important evidence on the neurobiological substrate of some of these symptoms including apathy and depression. However, little is known on DAT levels and other distressing symptoms such as…
Visual plus nonvisual hallucinations in Parkinson’s disease: Development and evolution over 10 years
The objective of the study was to assess the development and evolution of visual and nonvisual hallucinations in patients with Parkinson’s disease over 10 years. Hallucinations increase over time, but minimal attention has been placed on nonvisual domains. We studied 60 patients with Parkinson’s disease who had never hallucinated at baseline and followed them over…
Disease-related and genetic correlates of psychotic symptoms in Parkinson’s disease
Our aim was to examine disease-related and genetic correlates of the development of psychotic symptoms in a large population of patients with Parkinson’s disease. We studied 500 patients with Parkinson’s disease from the NeuroGenetics Research Consortium using logistic regression models. Predictors were demographic, clinical (motor/nonmotor features), and genetic, measured as continuous or dichotomous variables. Continuous…
Visual hallucinations and altered visual information processing in Parkinson disease and dementia with Lewy bodies
Visual hallucinations (VHs) are common in dementia with Lewy bodies (DLB) and Parkinson’s disease with dementia (PDD), while auditory hallucinations are rare. To neurophysiologically investigate the pathophysiology of VHs in these disorders, we studied event-related potentials (ERPs) of DLB, PDD, and Alzheimer’s disease (AD) patients. We compared visual and auditory ERP latencies among PDD patients…
