Biomarkers: Parkinson disease with dementia and dementia with Lewy bodies.

[Guest guest]

Biomarkers: Parkinson disease with dementia and dementia with Lewy bodies.

Dementia is a common feature in Parkinson disease (PD), the time of onset

determining how patients are classified. Those patients where dementia develops

prior to parkinsonism or during the first year of disease are designated as

having dementia with Lewy bodies (DLB). In those where dementia develops over a

year after the onset of motor signs, the condition is known as Parkinson's

disease with dementia (PDD). While this seems at first sight to be a definitive

way to distinguish these conditions, reality is rather different. The overlap

between them is considerable, and there is much uncertainty associated with

patients who have both motor symptoms and early cognitive impairment. The

diagnosis is still based on medical history and clinical evaluation. It is not

even certain that they can be accurately distinguished at autopsy. For this

reason, the data concerning these entities have been reviewed, to examine

various markers employed or measured in clinical, neuropathological,

neuroimaging, and biochemical investigations. The concept of PDD and DLB being

separate conditions is comparatively new, and the most promising tools with

which to separate them at present are cerebrospinal fluid (CSF) markers and

positron emission tomography (PET) scanning that indicate increased amyloid-beta

burden in DLB compared to PDD. However as yet there are no markers that

unequivocally distinguish between PDD and DLB.

http://tinyurl.com/y8dt6rj