The Effectiveness and Difference of Memantine and Donepezil - Relating to Changes in Cerebral Blood Flow and Clinical Efficacy

The effects of memantine on AD were examined from the perspective of cerebral blood flow using SPECT. Significant increases in blood flow were observed bilaterally from the orbital gyrus to the anterior cingulate gyrus, in the hippocampus and Para hippocampal gyrus, and from the posterior cingulate gyrus to the precuneus following single administration of memantine at 20 mg/day in comparison with prior to administration. In concomitant administration with donepezil, significant increases in blood flow were observed over a wide range from the orbital gyrus to the anterior cingulate gyrus and from the right angular gyrus to the superior, middle and inferior temporal gyrus in comparison with prior to additional administration of memantine. A correlation was suggested between these results and improvement of clinical BPSD symptoms such as increased conversation, improvement of irritation and agitation, and elimination of wandering