Cerebrospinal fluid Aβ40 is similarly reduced in patients with Frontotemporal Lobar Degeneration and Alzheimer's Disease

Although CSF Aβ40 does not appear to have an additional value in the distinction between FTLD and AD, it increases the discrimination between subjects with dementia from controls. A CSF-AD biomarker profile can be seen in patients with a clinical phenotype of FTLD, reinforcing the need for autopsy confirmation.