formication vs spasm

formication

noun
  • An abnormal skin sensation similar to that of insects crawling over or within the skin; a tactile hallucination involving such a sensation. A common side-effect of substance abuse, it can also be experienced with high fever, menopause, skin cancer, diabetic neuropathy, or herpes zoster. 

spasm

noun
  • A violent, excruciating seizure of pain. 

  • A sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ. 

  • A sudden and temporary burst of energy, activity, or emotion. 

verb
  • To produce and undergo a spasm or series of spasms. 

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