It is definitely NOT needed. I am completing my last month of residency on Neuro as we speak. I don't know why a fellowship exist for it. Yes, doing an aneurysm is different from an AVM. But, it doesn't take a whole fellowship to figure it out. A lot of old attendings do not like neuro because a great portion of the case is spent positioning, prepping, etc. before incision happens. This can become a way of missing out on other cases with higher anesthesia unit per hour (such as a short ENT procedure). Being willing to do neuro may help you get a job, but the fellowship is WAY over-kill.