Inhibition of α-synuclein Cell-cell Transmission by NMDAR Blocker, Memantine

Lewy Body Dementia (LBD), is the second most common form of dementia after Alzheimer's Disease. Dementia is defined as a serious loss in cognitive ability due to damages or disease in the brain beyond what is normal aging. With Lewy Body Dementia, protein deposits, or Lewy Bodies, accumulate in nerve cells throughout the brain, affecting motor control, memory and thinking. LBD can also form with the progression of Parkinson's disease (PD). PD is a degenerative nervous system disorder that affects movement ability. Using more sensitive MRI imaging techniques the investigators are attempting to see if disease progression can be monitored more closely. At the same time, the study medication Memantine will be compared to a placebo to determine if it can be used to slow the progression of PD. The purpose of this study is to assess if disease progression can be better monitored through brain imaging and if Memantine will help slow disease progression.