Cerebrospinal fluid cytokine levels affect electroencephalographic activity in Alzheimer's disease

To investigate the role of neuroinflammation as mediator of amyloid-β-induced cortical activity changes in Alzheimer's disease (AD), we examined the relationship between cerebrospinal fluid (CSF) inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, TNF-α, IFN-γ, GM-CSF, G-CSF, MIP-1α, MCP-1) and electroencephalographic (EEG) abnormalities in a cohort of biologically defined AD patients (n = 55, M:F = 19:36, median age 73, Mini-Mental State Examination ≥ 22). We retrieved a positive association between IL-4 CSF levels and EEG background activity frequency; IL-7, IL-8, and IL-12 CSF levels were positively associated with the presence of interictal epileptiform discharges. Neuroinflammation accompanying AD pathology may enhance the amyloid's epileptogenic potential while also counteracting neurodegenerative damage.