Dementia with Lewy body (DLB) is the second most common form of dementia after Alzheimer's disease (AD), accounting for 15% to 20% of neuropathologically defined cases. Two-thirds of the patients affected are not or misdiagnosed. In this review, we evaluate the discriminatory power of cerebrospinal fluid (CSF) alpha-synuclein by focusing more specifically on differential diagnosis between DLB and AD. Alpha-synuclein assay in the CSF has an interest in the discrimination between DLB and AD but not in segregation between DLB and healthy elderly subjects. The development of biomarkers such as phospho-alpha-synuclein and oligomeric alpha-synuclein should help to reinforce this discrimination power.
Keywords: Alzheimer's disease; Lewy body disease; alpha-synuclein; cerebrospinal fluid; differential diagnosis.