3011
Twenty common migraine patients received a one sided frontotemporal application of nitroglycerin ( 10 patients ) or placebo ointment ( 10 patients ) in a double blind study .
 migraine, nitroglycerin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 migraine, nitroglycerin