Q. Do you have to honour and stand up for an elderly Talmid Hacham that is senile or blind and is not aware of the honour you are giving him?

A. Ginas Verodim (Y.D. 4: 2),Birkey Yosef (Y,D, 244: 2), Rabi Akiva Eiger ztl (Y.D. 240: 7), Ben Ish Chai (Ki Tetze 15) et. al. rule regarding the blind, that one has to honour them even if they are unaware of the respect given. Poskim maintain that it is similar to embarrassing the blind which is prohibited (Bava Kama 86b). Derech Sicha (P. 374) asserts that the same applies to the elderly or ill, who are oblivious to the treatment given to them.
Horav Shlomo Millers Shlita opinion is similar.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a