Brain AVMs for long had been enigmatic and 'touch me not' lesions, that is until some expert super confident vascular neurosurgeons started operating upon them, and some of them did pretty good job too. Also, radiosurgery ( gamma knife) has excellent results in a large number of these rather badly understood lesions. However, with the advent of smart endovascular neurointerventionists, they also started being treated by embolisation, initially as an adjunct to surgery of radiosurgery, and of late has been propagated as a single modality complete cure, especially with the advent and spread of ONYX.
However, the great interventional neuroradiologists advice a word of caution in following this approah.

Follow this link to see a good commentary by Jayaraman and Cloft.
http://www.ajnr.org/cgi/content/full/30/1/107

jayaraman.png on Aviary.

And here is an excellent reply to the above one from katsaridis
http://www.ajnr.org/cgi/content/full/30/5/e67
katsaridis.png on Aviary.

And here is an excellent comment in AJNR blog by the revered teacher Pearse Morris regarding the same point as Jayaraman.
This comment has incited a fantastic discussion on the above blog page among some of the biggest names in neurointervention.
http://www.ajnrblog.org/2009/02/02/embolization-of-brain-arteriovenous-malformations-for-cure/

pearse morris.png on Aviary.

And here is the link to the original article which started it all: the one by Panagiotopoulos et al
http://www.ajnr.org/cgi/content/short/ajnr.A1314v1
panagiotopoulos.png on Aviary.