We evaluated the effect of memantine administration from baseline on Clinical Global Impression-Improvement scale , mini mental state examination ( MMSE ) , Clock Drawing Test ( CDT ) , Neuropsychiatric Inventory ( NPI ) , Japanese version of the Zarit Burden Interview ( J-ZBI ) and NIRS in two groups , donepezil administration memantine combination group ( combination group , n = @ ) donepezil administration memantine non-administration group ( control group , n = @ ) were assessed at weeks @ , @ , @ , and @ .