44805
Another of his departure from Galen and the medical theories of the time is his description of stroke as produced by the brain and caused by an obstruction of the arteries from the heart to the brain .
 Galen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Galen