cheer (up) vs convulse

cheer (up)

convulse

verb
  • To suffer violent involuntary contraction of the muscles, producing contortions of the body or limbs. 

  • To create great laughter. 

  • To violently shake or agitate. 

How often have the words cheer (up) and convulse occurred in a corpus of books? (source: Google Ngram Viewer )