Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Impairment in different cognitive domains such as executive functions, language, memory, and visuospatial skills occurs frequently in Parkinson disease (PD) even in the early stages of the disease. Although frank dementia (Parkinson disease dementia, PDD) is less frequent, risk for developing dementia is two to six times greater than the prevalence rate in general population and it increases in relation to disease duration. Clinically, dementia in PD is characterized by uninsidious onset and slowly progressive cognitive decline, with a predominant dysexecutive syndrome accompanied frequently by a variety of behavioral symptoms such as hallucinations, depression, anxiety, and excessive daytime sleepiness. Although the exact pathophysiology and neurobiological basis of PDD is not known, dementia in PD probably develops as a result of progressive involvement of subcortical and cortical structures by Lewy-type pathology and associated Alzheimer-like histological changes. Dysfunction of different monoamine transmitter has also been implicated in the cognitive deterioration of PD but reduced cholinergic activity in the cortex is thought to account for the strongest mechanism in the development of dementia. Recent evidence suggests that cholinesterase inhibitors are effective in the treatment of dementia and accompanying behavioral symptoms in PD.
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PMID:Cognitive dysfunction and dementia in Parkinson disease. 1817 97

Dementia affects approximately one-third of all patients with Parkinson's disease. Currently there is no treatment to halt or reverse the disease progression. Symptomatic treatment approaches are based on substituting neurotransmitter deficits or ameliorating associated behavioral symptoms. The most prominent deficits are cholinergic, and treatment with cholinesterase inhibitors (ChE-I) has been shown to provide some benefits in cognitive and behavioral symptoms without undue worsening in motor symptoms. Based on a large, randomized, placebo controlled trial, the ChE-I rivastigmine has been approved for the treatment of dementia associated with PD.
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PMID:Treatment of dementia associated with Parkinson's disease. 1826 83

Parkinson's disease (PD) clinical features comprise both motor and nonmotor manifestations. Among the nonmotor complications, dementia is the most important. Approximately 40% of PD patients are affected by cognitive impairment. Remarkably, in addition to age, dementia is an independent predictor of mortality, whereas age at onset of PD and severity of neurological symptoms are not. In this review, I summarize the current knowledge of the pathogenesis of the PD cognitive impairment in relation to the therapies presently accessible and those that could become strategic in the near future. It is hypothesized that patients with PD show two components of cognitive dysfunction (CD): a generalized profile of subcortical dementia (PDsCD), and an overlapped pattern suggesting specific prefrontal damage with CD (PDpFCD). PDsCD is associated with structural neocortical/subcortical changes in the brain (in frontal, parietal, limbic, and temporal lobes, as well as in midbrain structures). In PDpFCD cognitive deficits comprise impairments in neuropsychological tests sensitive for frontal lobe function (discrete elements of episodic and working memory for instance), which are considered to be the consequence of dysfunction in neuronal loops connecting the prefrontal cortex and basal ganglia. Drugs reviewed for targeting PDsCD include: cholinesterase inhibitors, agents with mixed cholinergic and dopaminergic properties, antiglutamatergic drugs, mixed antiglutamatergic/dopaminergic agents; antioxidants and enhancers of mitochondrial functions, and anti-COX-2, as well as other anti-inflammatory mediators. Preliminary studies with vehicles that may target PDpFCD include piribedil, tolcapone, amantadine, and farampator. Additional agents (citicoline and neuroimmuniphilines, among others) will be outlined. A brief overview on neuroprotection and promising new biological advances in PD (deep brain stimulation, stem cells, gene therapy) also will be summarized.
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PMID:Current management of the cognitive dysfunction in Parkinson's disease: how far have we come? 1853 72

Visual hallucinations are a typical feature of Lewy body parkinsonism and occur in some 40% of patients with Parkinson's disease. Age and cognitive decline are the most important intrinsic risk factors, but hallucinosis is often triggered by comorbid conditions such as infection and dehydration. The single most important trigger, however, is exposure to CNS drugs, in particular antiparkinsonian agents. While hallucinosis and psychosis can be triggered by amantadine and anticholinergics, they are more commonly experienced after changes in dopaminergic medication. Dopamine agonists have greater potential to induce hallucinosis compared with L-dopa. Attempting to reduce antiparkinsonian drugs is an important part in the management of these patients, but atypical neuroleptics like clozapine or quetiapine are frequently necessary. Visual hallucinations in Parkinson's disease patients with dementia can also be improved by treatment with the cholinesterase inhibitor rivastigmine.
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PMID:When a Parkinson's disease patient starts to hallucinate. 1864 10

It has been reported that the cholinesterase inhibitor, donepezil, improves cognitive decline in patients with Parkinson's disease dementia (PDD). However, this improvement was dominant for frontal lobe dysfunction, and the increase in the Mini-Mental State Examination (MMSE) score was minimal. We report a PDD patient with a decline of regional cerebral blood flow (rCBF) in the posterior cingulate cortex, precunei, and bilateral parietotemporal association cortex, as determined by single-photon emission computed tomography (SPECT) using the easy Z-scores imaging system (e-ZIS). Upon administration of donepezil, both the rCBF and MMSE score increased. The effectiveness of donepezil may vary based on the rCBF pattern in PDD.
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PMID:The effect of donepezil on increased regional cerebral blood flow in the posterior cingulate cortex of a patient with Parkinson's disease dementia. 1864 36

Dementia associated with Parkinson's disease (PD) ultimately develops in approximately 70% of patients with PD older than 80 years of age. The neuropathology of PD dementia (PDD) is likely multifactorial and affects several neuronal populations. There is evidence that PDD is associated with a cholinergic deficit, supporting the therapeutic role of cholinesterase inhibitors, which are already first-line agents in the treatment of Alzheimer's disease. Open-label and small controlled studies suggested a clinical efficacy of cholinesterase inhibitors in PDD. One large randomized placebo-controlled trial of 541 patients demonstrated that oral rivastigmine improved cognition, attention and executive functions, activities of daily living and behavioral symptoms after 6 months of treatment. Rivastigmine is a dual cholinesterase inhibitor, being effective on both acetylcholinesterase and butyrylcholinesterase. This paper reviews the pharmacokinetic and pharmacodynamic properties of rivastigmine (oral and transdermal administration). It also reviews evidence on clinical efficacy, safety and tolerability of the oral administration in PDD patients at doses of 3-12 mg/day.
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PMID:Rivastigmine in Parkinson's disease dementia. 1867 61

Parkinson's disease (PD) is characterized by its motor impairment. However, non-motor symptoms such as psychiatric disorders, autonomic disturbances and sleep disorders frequently complicate the course of the disease. In particular, psychiatric disturbances including cognitive impairment, depression and psychosis impact these patients considerably. Approximately 31 % of PD patients suffer from cognitive impairment and dementia. Currently, two different clinical presentations are distinguished in PD patients, who present with dementia: Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB), which are two different presentations of a single underlying disease process leading to the deposition of alpha-synuclein. Clinically, PDD is distinguished from DLB alone by the different temporal manifestations of extrapyramidal motor symptoms. Dementia is characterized by a subtle onset and progressive cognitive decline with a predominant dysexecutive syndrome, which can be accompanied by different behavioral symptoms such as hallucinations, depression, anxiety and sleep disorders. Dysregulation of different neurotransmitters has been associated with cognitive decline, but reduced cholinergic transmission is currently thought to be the pivotal mechanism in the development of cognitive dysfunction. Therefore, cholinesterase inhibitors are used in the treatment of dementia and accompanying behavioral symptoms in PDD and DLB. The occurrence of dementia impacts not only the patients themselves but also their care-givers and family.This article focuses on the clinical issues related to both disorders and is based on a meeting of experts which took place in April 2008 in Dresden.
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PMID:Lewy body dementia and Parkinson's disease with dementia. 1878 81

Parkinson's disease (PD) has long been considered predominantly a motor disorder. However, its frequent association with dementia, which contributes significantly to the morbidity and mortality of the condition, is gaining increasing recognition. PD dementia (PDD) has a unique clinical profile and neuropathology, distinct from Alzheimer's disease (AD). Cholinergic deficits, a feature of both AD and PDD, underlie the rationale for cholinesterase inhibitor therapy in both conditions. In clinical practice, it is important that PDD should be recognised and appropriately treated. This review aims to outline the recently proposed clinical diagnostic criteria for PDD and to summarise the guidelines/recommendations published since 2006 on the use of cholinesterase inhibitors in the management of PDD. Although the cholinesterase inhibitor rivastigmine has recently been approved for the management of PDD, there remains a need for the development of novel therapies that can affect key mechanisms of the disease or prevent/delay patients with PD and mild cognitive impairment from progressing to PDD.
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PMID:Diagnosis and management of Parkinson's disease dementia. 1882 28

Dementia with Lewy bodies (DLB), the second most frequent cause of dementia after Alzheimer disease (AD), is characterized by the widespread distribution of Lewy bodies in virtually every brain area. Clinically, DLB is distinguished from AD by fluctuating cognition, prominent visual hallucinations and parkinsonism, and from Parkinson disease, by the appearance of parkinsonism within one year of cognitive or behavioral decline. The main component of Lewy bodies is alpha-synuclein. Accumulating evidence suggests that its aggregation constitutes one of the first steps preceding Lewy body formation, so that antiaggregation strategies would be very useful to prevent alpha-synuclein fibril formation. Main therapies nevertheless applied up to the present remain symptomatological. In this context, cholinesterase inhibitors such as rivastigmine, galantamine and donepezil, are used for the treatment of delusions and other psychotic symptoms. This review focuses on the recent discovery of possible alpha-synuclein anti-aggregation factors, where four main classes can be defined. First, beta-synuclein as well as alpha-synuclein derived peptides in addition to antibodies present a group of proteins and peptides that directly interact with alpha-synuclein and so inhibit its aggregation. Second, small molecules interfere with alpha-synuclein aggregation by their covalent binding, although not all of them are suitable for an appropriate inhibition of alpha-synuclein aggregation. Third, to inhibit the expression of alpha-synuclein and its isoforms at the RNA level, the use of interference RNA represents a future challenge. The fourth strategy is based on the enhancement of inclusion body formation to accelerate the elimination of soluble alpha-synuclein oligomers. Each chapter section includes the discussion of possible strategies for the development of drugs and therapies.
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PMID:The therapeutical potential of alpha-synuclein antiaggregatory agents for dementia with Lewy bodies. 1899 34

Apolipoprotein E (APOE) epsilon4 and butyrylcholinesterase-K (BuChE-K) are associated with an increased risk for Alzheimer's disease. The primary objective was to evaluate frequencies of these alleles in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). A secondary objective was to evaluate influences on rate of cognitive decline. This analysis used data from participants consenting to pharmacogenetic testing in placebo-controlled rivastigmine studies. Allele frequencies in DLB and PDD were compared using logistic regression. Within the PDD placebo sample, associations with cognitive decline were evaluated (the DLB sample was too small for these evaluations). Fifty-seven DLB and 323 PDD subjects provided APOE and BuChE data. Allelic frequencies were higher in DLB, relative to PDD subjects, for BuChE-K (P = 0.06), APOE epsilon4 (P < 0.001), or both alleles together (P < 0.001). More rapid cognitive decline was seen in PDD patients carrying both alleles, compared with other genotypes. Subjects with hyperhomocysteinemia were associated with more rapid decline in the presence of BuChE-K, with or without APOE epsilon4. These results suggest that genetic and biochemical risk factors for AD and PDD pathology may be important in dementia onset and progression in these Lewy body disorders.
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PMID:BuChE-K and APOE epsilon4 allele frequencies in Lewy body dementias, and influence of genotype and hyperhomocysteinemia on cognitive decline. 1900 90


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