Primary Progressive Aphasia (Logopenic Variant) vs Alzheimer's Disease: Aβ42 (CSF)
Meta-analysis did not show a diffrence in the levels of Aβ42 in the cerebrospinal fluid of people with logopenic variant primary progressive aphasia and people with Alzheimer's disease. However, a paucity of data limited the meta-analysis, with only two eligible studies and a small number of individuals with lvPPA. For comparison, the level of Aβ42 in the CSF of control subjects is nearly double that of people with Alzheimer's disease. The decrease in Aβ42 in the CSF of AD patients is thought to reflect the deposition of the peptide into amyloid plaques in the brain; notably, lvPPA has also been associated with amyloid deposition (Mesulam et al., 2008; Rabinovici et al., 2008).