Hello! My husband had herpes encephalitis 30 years ago. There was quite a bit a damage to the hippocampus per MRI findings. He miraculously recovered 95%. But over the last 10 years the hippocampus has been aging faster than normal and he now has a diagnosis of probable Alzhiemer's type dementia. He is 77 years old. He has been on aricept for 3 years and was started on Namenda about a month ago. He has been sleeping at least 14 hours a day for a few years but now it is up to 20 hours. He feels like he is sick but is unable to express what is going on. Anyone else have experience with the excessive sleeping? Is it the Namenda? Thanks in advance for answering.