MARCKS Phosphorylation at Ser46 reflects neurite degeneration and is a candidate marker for presymptomatic and preaggretaion pathology of Alzheimer’s disease. Here, we demonstrate the similar change in Parkinson’s disease and Dementia with Lewy body prior to alpha-synuclein aggregation, and suggest an ultra-early stage pathology shared by different groups of neurodegenerative diseases.