Complex sentence: In late 1921 Lenin's health deteriorated, he was absent from Moscow for even longer periods, and eventually had three strokes between 26 May 1922 and 10 March 1923, which caused paralysis, loss of speech and finally death on 21 January 1924.
Split into simpler sentences: In late 1921 Lenin's health deteriorated, he was absent from Moscow for longer periods of time. He had three strokes between 26 May 1922 and 10 March 1923, which caused paralysis, loss of speech and finally death on 21 January 1924.