Dementia with Lewy body (DLB)
General description
Dementia with Lewy body (DLB) is the second most common form of degenerative dementia after Alzheimer's disease and is caused by the accumulation of Lewy bodies in the brain, which consist of an abnormal protein called α-synuclein.
Diagnostic criteria
For the diagnosis of dementia with Lewy bodies (DLB), the presence of dementia is a mandatory criterion.
There are three core features:
- Fluctuating cognition with pronounced variations in attention and alertness
- Recurrent visual hallucinations that are typically well-formed and detailed
- Spontaneous features of Parkinsonism
The diagnostic criteria for probable DLB require the presence of at least two out of these three core features, while possible DLB is diagnosed if only one core feature is present.
Additionally, there are three suggestive features:
- REM sleep behavior disorder
- Severe neuroleptic sensitivity
- Low dopamine transporter uptake in the basal ganglia demonstrated by SPECT or PET imaging
The diagnosis of probable DLB can also be made if one core feature and one or more suggestive features are present.
Other clinical test
In dementia with Lewy bodies (DLB), cardiac scintigraphy with 123I-metaiodobenzylguanidine (MIBG) frequently demonstrates decreased uptake in the myocardium.
CBF SPECT
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CerebrumOccipital lobe
Cerebral blood flow single-photon emission computed tomography (CBF SPECT) is characterized by a generalized reduction in perfusion, involving multiple brain regions, including the occipital lobes.
DAT scan
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Caudate nucleus
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Putamen
In corticobasal syndrome, dopamine transporter (DAT) imaging typically demonstrates bilateral striatal uptake abnormalities. However, it is important to note that in some cases, DAT scan findings may remain normal throughout the clinical course of the disease.