Metabolic Alterations in Patients With Parkinson Disease and Visual Hallucinations

Technische Universität München, München, Bavaria, Germany
JAMA Neurology (Impact Factor: 7.42). 08/2007; 64(7):984-8. DOI: 10.1001/archneur.64.7.984
Source: PubMed


Visual hallucinations (VHs) occur frequently in advanced stages of Parkinson disease (PD). Which brain regions are affected in PD with VH is not well understood.
To characterize the pattern of affected brain regions in PD with VH and to determine whether functional changes in PD with VH occur preferentially in visual association areas, as is suggested by the complex clinical symptomatology.
Positron emission tomography measurements using fluorodeoxyglucose F 18. Between-group statistical analysis, accounting for the variance related to disease stage.
University hospital. Patients Eight patients with PD and VH and 11 patients with PD without VH were analyzed. The presence of VH during the month before positron emission tomography was rated using the Neuropsychiatric Inventory subscale for VH (PD and VH, 4.63; PD without VH, 0.00; P < .002).
Parkinson disease with VH, compared with PD without VH, was characterized by reduction in the regional cerebral metabolic rate for glucose consumption (P < .05, corrected for false discovery rate) in occipitotemporoparietal regions, sparing the occipital pole. No significant increase in regional glucose metabolism was detected in patients with PD and VH.
The pattern of resting-state metabolic changes in regions of the dorsal and ventral visual streams, but not in primary visual cortex, in patients with PD and VH, is compatible with the functional roles of visual association areas in higher-order visual processing. These findings may help to further elucidate the functional mechanisms underlying VH in PD.

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    • "Since psychotic symptoms are associated with dementia , it is likely that genetic contributors to dementia in PD will also be contributory to psychotic symptoms. Positron emission tomography (PET) studies on PD patients with visual hallucinations have reported reduced metabolic activity in the occipital-parietaltemporal regions, consistent with alterations in visual association areas [50]. FMRI has revealed hypometabolism in response to visual stimulation in visual association cortex in PD patients who had visual hallucinations [51]. "
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    ABSTRACT: Psychotic symptoms are common in drug treated patients with Parkinson's disease (PD). Visual hallucinations occur in about 30% typically paranoid in nature, occur in about 5% particularly the delusions, cause great distress for patient and caregivers, and are among the most important precipitants for nursing home placement. Psychotic symptoms carry a poor prognosis. They often herald dementia, and are associated with increased mortality. These symptoms often abate with medication reductions, but this may not be tolerated due to worsened motor function. Only clozapine has level A evidence to support its use in PD patients with psychosis (PDP), whether demented or not. While quetiapine has been recommended by the American Academy of Neurology for "consideration," double blind placebo controlled trials have demonstrated safety but not efficacy. Other antipsychotic drugs have been reported to worsen motor function and data on the effectiveness of cholinesterase inhibitors is limited. PDP remains a serious problem with limited treatment options.
    Behavioural neurology 12/2012; 27(4). DOI:10.3233/BEN-129016 · 1.45 Impact Factor
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    • "In this situation, frontal dopamine levels are expected to increase in response to dopaminergic treatment (ON state), possibly explaining why visual hallucinations are associated with relative frontal hypermetabolism [88]. Nonetheless, visual hallucinations in PD are also linked to hypometabolism in occipitotemporoparietal regions [89]. "
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    ABSTRACT: Cognitive impairment and behavioural disorders are often encountered in subjects with Parkinson's disease (PD). A simple PD-related frontostriatal cognitive dysfunction (PDFCD) staging is proposed. Executive dysfunction and mental fatigue (stage I), depression/anxiety (stage IIa), apathy/pain (stage IIb), and dementia (stage III) reflect a sequential process of dopamine depletion occurring in different regions of the striatum (stages I and II) and the frontal cortex (stage III). In addition to these nonmotor manifestations present in the unmedicated (OFF) state, the PDFCD model also predicts a number of complications related to dopaminergic treatment (ON state), from impulse control disorders (stages I and IIa) to hallucinations (stage IIb) and psychosis (stage III). Although the model admittedly needs further refinements, it provides a framework for hypothesis testing and may help clinicians optimize therapeutic strategies.
    01/2012; 2012(14):561046. DOI:10.1155/2012/561046
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    • "Also using [123I] IMP SPECT scans, Matsui et al. found reduced perfusion in bilateral inferior parietal lobules, inferior temporal gyrus, precuneus gyrus, and occipital cortex in 31 PD patients with visual hallucinations, compared to 39 without hallucinations [38]. Decreased metabolism in temporal-occipital-parietal regions was found in 8 PD hallucinators compared to 11 nonhallucinators with [18F] FDG-PET [34]. Similar to some fMRI results which indicate disruptions in frontal and posterior activation patterns, Nagano-Saito et al. found greater regional cerebral glucose metabolic rates in frontal regions, especially the left superior frontal gyrus, in 8 nondemented, PD patients with visual hallucinations, compared to nonhallucinating PD and healthy controls, using [18F] FDG-PET [72]. "
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    ABSTRACT: Psychosis is a frequent nonmotor complication in Parkinson's disease (PD), characterized by a broad phenomenology and likely due to a variety of intrinsic (i.e., PD-related) and extrinsic factors. Safe and effective therapies are greatly needed as PD psychosis contributes significantly to morbidity, mortality, nursing home placement, and quality of life. Novel research strategies focused on understanding the pharmacology and pathophysiology of PD psychosis, utilizing translational research including animal models, genetics, and neuroimaging, and even looking beyond the dopamine system may further therapeutic advances. This review discusses new research strategies regarding the neurobiology and treatment of PD psychosis and several associated challenges.
    03/2011; 2011(4):675630. DOI:10.4061/2011/675630
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