Cerebrospinal fluid markers analysis in the differential diagnosis of dementia with Lewy bodies and Parkinson’s disease dementia

Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD) share a couple of clinical similarities that is often a source of diagnostic pitfalls. We evaluated the discriminatory potential of brain-derived CSF markers [tau, p-tau (181P), Aβ₁₋₄₂, NSE and S100B] across the spectrum of Lewy body disorders and assessed whether particular markers are associated with cognitive status in investigated patients. The tau CSF level, amyloid β₁₋₄₂ and p-tau/tau ratio were helpful in the distinction between DLB and PDD (p = 0.04, p = 0.002 and p = 0.02, respectively) as well as from PD patients (p < 0.001, p = 0.001 and p = 0.002, respectively). Furthermore, the p-tau/tau ratio enabled the differentiation of DLB with mild dementia from PDD patients (p = 0.02). The CSF tau and p-tau levels in DLB and CSF tau and p-tau/tau ratio in PDD patients reflected the severity of dementia. Rapid disease course was associated with the decrease of Aβ₁₋₄₂ in DLB but not in PDD. Elevation of S100B in DLB (p < 0.0001) as well as in PDD patients (p = 0.002) in comparison to controls was estimated. Hence, with the appropriate clinical context; the CSF marker profile could be helpful in distinguishing DLB from PDD patients even in early stages of dementia.