Differential cognitive correlates of tau and neurofilament light chain in cerebrospinal fluid of frontotemporal lobar degeneration patients with and without Alzheimer’s markers

Abstract Background Frontotemporal lobar degeneration (FTLD) phenotypes can be associated with Alzheimer’s disease (AD). It is unknown whether differences exist in relationship between markers of such as tau and neurofilament light chain (NFL) cognition FTLD without AD. Method 40 patients were included this study: (A) 31 AD [5 behavioral variant FTD, 11 corticobasal syndrome (CBS), 1 non‐fluent primary progressive aphasia (nfvPPA), 12 supranuclear palsy (PSP), 2 semantic PPA (svPPA); age (67.74±10.28); sex (20M:11F)]; (B) 9 positive for [6 CBS‐AD, nfvPPA‐AD, PSP‐AD, svPPA‐AD; (66±8.46); (5M:4F)]. CSF levels Aβ42, phosphorylated (p‐tau) & total (t‐tau) measured using sandwich ELISA pathology was deemed present if p‐tau > 68 pg/mL Aβ42 to t‐tau index < 0.8. NFL SIMOA. Full neuropsychological battery completed, controlled age/education. Result In the cohort, significant relationships observed CDR sum boxes (r=0.599, p=.001) MOCA (r=‐0.530, p=.004). group, digit span backwards (DSB) significantly (r=‐0.492, p=.009) (r=‐0.427, p=.02); while verbal fluency, Trail Making Test part A forward (DSF) only related (r=‐0.410, p=.03; r=0.463, p=.02; r=‐0.374, p=.05, respectively). FTLD‐AD (r=‐1.00, p<.0001) (r=‐0.887, memory executive function tests including California learning test 30s recall, DSB DSF (r=‐0.788, p=.04; r=‐0.836, r=‐0.760, p=.07, respectively); fluency category (r=‐0.841, r=‐1.00, p<.0001), (r=‐0.981, p<.001; (r=‐0.984, r=‐0.977, Conclusion both AD, overall severity but it t‐tau. The presence alters NFL, which may indicative extent degeneration.