207131
Classically , it has been associated with three major groups : However , any other compression , ischemia or damage to this region can produce these phenomena : obstructive hydrocephalus , midbrain hemorrhage , cerebral arteriovenous malformation , trauma and brainstem toxoplasmosis infection .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None