Special Issue: Mild Cognitive Impairment.

Mild Cognitive Impairment (MCI) is found in Alzheimer ’ s disease (ADMCI), Parkinson ’ s disease (PDMCI), Lewy body dementia, cerebrovascular disease (Brad fi eld 1 ), sleep apnea and insomnia (Gilley 2 ). Studies have shown that monoclonal antibody treatment removes amyloid plaques from the AD brain. However, this did not result in clinical improvement in moderate and severe AD. One explanation was that the brain cells were already too damaged. Subsequent studies of mild AD and ADMCI suggested some bene fi t by reducing amyloid before the brain was too damaged. In June 2021, this led to the FDA approval of the monoclonal antibody, aducanumab, for the treatment of mild AD and ADMCI. This MCI Special Issue is timely, because the FDA approval of aducanumab has led to increased interest in ADMCI.