Are Parkinson’s Disease with dementia and Dementia with lewy Bodies the Same Entity?

Abstract

Dementias associated with cortical Lewy bodies are traditionally classified as dementia with Lewy bodies (DLB), characterized by parkinsonism, visual hallucinations and cognitive fluctuations, 1 or Parkinson's disease with dementia (PDD). Overall, DLB accounts for about 20% of late-onset dementia cases, 1 and dementia develops in the majority of cases with a diagnosis of PD. 2 As outlined below, there are clinical and neurobiological similarities between DLB and PDD patients. The distinction between the conditions as operationally defined within the standardized clinical criteria depends entirely on the duration of parkinsonism prior to dementia. The consensus criteria for a clinical diagnosis of DLB state that a diagnosis cannot be made if parkinsonian symptoms developed more than 1 year before the onset of dementia (although proposed recent changes to the criteria may alter this to making the diagnosis according to whether parkinsonism or cognitive impairment arises first). This raises several key conceptual questions; for example, are these conditions distinct or part of the same spectrum? If they are distinct conditions, is an arbitrary cutoff (either 1 year or which symptom presents first) a meaningful distinction between clinical entities with different clinical presentations? Addressing these issues is critical to taking forward our understanding of this spectrum of conditions, establishing biological markers, determining prognostic indicators, and, most important, designing appropriate intervention studies and developing treatment paradigms across the dementias associated with cortical Lewy bodies. In the current article, key issues pertaining to DLB and PDD are reviewed, and the similarities and differences in the clinical profile (cognitive deficits, neuropsychiatric symptoms, and parkinsonism), imaging, genetic predisposition, neurochemistry, and neuropathology are discussed to enable some conclusions about the relationship of the 2 conditions and to offer some suggestions for critical future research. Direct comparative studies of patients with PDD and DLB are necessary to explore the relationship between these 2 syndromes. We searched the MEDLINE using Parkinson* disease and dementia Are Parkinson's Disease With Dementia and Dementia With Lewy Bodies the Same Entity?Dag Aarsland, MD, PhD, C. G. Ballard, MD, MRCPsych, and Glenda Halliday, PhD ABSTRACTThe diagnosis of Parkinson's disease with dementia (PDD) or dementia with Lewy bodies (DLB) is based on an arbitary distinction between the time of onset of motor and cognitive symptoms. These syndromes share many neurobiological similarities, but there are also differences. Deposition of beta-amyloid protein is more marked and more closely related to cognitive impairment in DLB than PDD, possibly contributing to dementia at onset. The relatively more severe executive impairment in DLB than PDD may relate to the loss of frontohippocampal projections in DLB. Visual hallucinations and delusions associate with more abundant Lewy body pathology in temporal c...

A comparison of cerebral glucose metabolism in Parkinson's disease, Parkinson's disease dementia and dementia with Lewy bodies

“…Additionally, this metabolic difference between DLB and PDD may partly explain why executive dysfunction is more pronounced in DLB than in PDD patients [2], although the overall cognitive profiles are similar in these two disorders.…”

“…However, DLB and PDD share many clinical and neurobiological similarities, including similar motor effects, neuropsychological profiles, and neurochemical and neuropathological findings [2].…”

Demência na doença de Parkinson

“…Na mesma linha de raciocínio, mas do ponto de vista neuropatológico, a deposição da proteína beta amilóide é mais marcante e mais diretamente relacionada ao prejuízo cognitivo na DCL que na demência da DPI; parece haver maior comprometimento das projeções fronto-hipocampais na DCB, como atestado pela maior disfunção executiva nesta entidade; a maior abundância de corpos de Lewy nas regiões corticais temporais na DCL parece se associar com maior freqüência de alucinações visuais e delírios; o comprometimento patológico diferencial do estriado entre as duas entidades pode explicar particularidades no tipo de parkinsonismo exibido em cada uma delas. 29 As diretrizes atuais sugerem que para que o diagnóstico de DCL seja estabelecido é necessário que o início dos sintomas de demência preceda ou ocorra simultaneamente com os sinais de parkinsonismo. 26 Quando o período entre o início dos sintomas parkinsonianos e o posterior surgimento da síndrome demencial for à DPI: é a chamada "regra de um ano".…”

Rivastigmine for the treatment of dementia associated with Parkinson’s disease

“…Neuropathologically PDD overlaps with DLB and AD in numerous studies (Mahler and Cummings 1990;Perl et al 1998;Aarsland et al 2004;Galvin et al 2006). Dementia with Lewy Bodies (DLB) and PDD are typically categorized as two separate disease states with distinct pathologies, but debate continues as to whether DLB and PDD are, in fact, along the same disease spectrum (Levy et al 2006;Galvin et al 2006;Padovani et al 2006).…”