Abstract

Background: Neurofilament (NF) proteins are major cytoskeletal constituents of neurons. Increased CSF NF levels may reflect neuronal degeneration.

Objective: To investigate the diagnostic value of CSF NF analysis to discriminate in relatively young dementia patients between frontotemporal lobe degeneration (FTLD) and early onset Alzheimer’s disease (EAD; onset ⩽65 years of age), and in elderly dementia patients between dementia with Lewy bodies (DLB) and late onset AD (LAD; onset >65 years of age).

Methods: In CSF of 28 FTLD, 37 EAD, 18 DLB and 33 LAD patients, and 26 control subjects, we analysed NF light chain (NFL), phosphorylated NF heavy chain (pNFH), amyloid β₄₂ protein (Aβ₄₂), total tau and tau phosphorylated at threonine 181 (p-tau₁₈₁).

Results: CSF NFL levels were higher in FTLD patients compared with EAD patients (p<0.001), and diagnostic accuracy of p-tau₁₈₁ and Aβ₄₂ analysis improved with addition of NFL analysis (sensitivity 86%, specificity 100%). CSF pNFH levels were elevated in DLB, LAD and FTLD compared with controls (p<0.05) but no significant differences were found between the dementia groups.

Conclusions: In the diagnostic workup of relatively young dementia patients, CSF NFL levels may play a role in the discrimination between FTLD and EAD, especially in combination with Aβ₄₂ and p-tau₁₈₁ analysis.