Trotsky knew the truth. “Who killed Lenin?” he said, smirking, “Just axe me.”
http://www.telegraph.co.uk/news/6406447/Vladimir-Lenin-died-from-syphilis-new-research-claims.html
In the first report I saw of this explanation, many years ago, it was stated Lenin was moved to a private facility and all the dogs in the neighborhood had to be shot because their howling in concert with his constant mad howling would create too much of a din.
The only group of nurses who would care for him in this final period of his evil life were some Orthodox nuns who did so out of Christian compassion. For their kindness the nuns were all killed after Lenin died to insure their silence.
That report, as I recall, appeared in a Swiss publication some years ago and despite a search, cursory at best, I could not find it.