Memantine, in common with other adamantanes, is effective against numerous viral infections including the human coronavirus HCoV-OC43 and an ongoing thesis proposes that the Herpes Simplex Virus Type 1 [HSV-1] rather than p-tau is responsible for the inter-neuronal trans-synaptic pathological cascade proposed for the inter-cerebral propagation of AD (Ball et al., 2013). This evidence concerns the gene MAPT and Alzheimer disease.