Editing Cerebral arteriovenous malformation (section)

==Treatment==
Treatment depends on the location and size of the AVM and whether there is bleeding or not.<ref name="Mayo-Treatment">{{Cite web|url=http://www.mayoclinic.com/health/brain-avm/DS01126/DSECTION=treatments-and-drugs |title=Brain AVM (arteriovenous malformation)-Treatments and drugs |author=Mayo Clinic staff |date=February 2009|publisher=Mayo Clinic |access-date=2010-05-18}}</ref>

The treatment in the case of sudden bleeding is focused on restoration of [[vital function]].<ref>{{Cite web |title=Arteriovenous Malformation - Conditions - For Patients - UR Neurosurgery |url=https://www.urmc.rochester.edu/neurosurgery/services/conditions/arteriovenous.aspx |access-date=2022-04-22 |website=[[University of Rochester Medical Center]]}}</ref>

===Medical===

Anticonvulsant medications such as [[phenytoin]] are often used to control seizure; medications or procedures may be employed to relieve intracranial pressure.  Eventually, curative treatment may be required to prevent recurrent hemorrhage. However, any type of intervention may also carry a risk of creating a neurological deficit.<ref>{{Cite web|url=http://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Arteriovenous-Malformations|title=AANS {{!}} Arteriovenous Malformations|website=www.aans.org|language=en|access-date=2018-02-03}}</ref>

=== Surgical ===
Surgical elimination of the blood vessels involved is the preferred curative treatment for many types of AVM.<ref name="Mayo-Treatment" /> Surgery is performed by a [[neurosurgeon]] who temporarily removes part of the skull ([[craniotomy]]), separates the AVM from surrounding brain tissue, and resects the abnormal vessels.<ref name="Mayo-Treatment" /> While surgery can result in an immediate, complete removal of the AVM, risks exist depending on the size and the location of the malformation. The AVM must be resected en bloc, for partial resection will likely cause severe hemorrhage.<ref name=":0" /> The preferred treatment of Spetzler-Martin grade 1 and 2 AVMs in young, healthy patients is surgical resection due to the relatively small risk of neurological damage compared to the high lifetime risk of hemorrhage. Grade 3 AVMs may or may not be amenable to surgery. Grade 4 and 5 AVMs are not usually surgically treated.<ref>{{cite journal|last=Starke|first=RM|journal=Br J Neurosurg|year=2009|volume=23|pages=376–86|pmid=19637008|doi=10.1080/02688690902977662|title=Treatment guidelines for cerebral arteriovenous malformation microsurgery|issue=4|s2cid=26286536|display-authors=etal}}</ref>

===Radiosurgical===

[[Radiosurgery]] has been widely used on small AVMs with considerable success.  The [[Gamma Knife]] is an apparatus used to precisely apply a controlled radiation dosage to the volume of the brain occupied by the AVM. While this treatment does not require an incision and craniotomy (with their own inherent risks), three or more years may pass before the complete effects are known, during which time patients are at risk of bleeding.<ref name="Mayo-Treatment" /> Complete obliteration of the AVM may or may not occur after several years, and repeat treatment may be needed. Radiosurgery is itself not without risk. In one large study, nine percent of patients had transient neurological symptoms, including headache, after radiosurgery for AVM. However, most symptoms resolved, and the long-term rate of neurological symptoms was 3.8%.<ref>{{cite journal|last=Flickinger|first=JC|journal=Int J Radiat Oncol Biol Phys|year=1998|volume=40|pages=273–278|pmid=9457809|doi=10.1016/S0360-3016(97)00718-9|title=Analysis of neurological sequelae from radiosurgery of arteriovenous malformations: How location affects outcome|issue=2|display-authors=etal}}</ref>

===Neuroendovascular therapy===

[[Embolization]] is performed by [[interventional neuroradiologists]] and the occlusion of blood vessels most commonly is obtained with [[ethylene vinyl alcohol]] copolymer ([[Onyx (interventional radiology)|Onyx]]) or [[n-butyl cyanoacrylate]]. These substances are introduced by a [[radiographically]] guided catheter, and block vessels responsible for blood flow into the AVM.<ref>{{Cite journal|last1=Ellis|first1=Jason A.|last2=Lavine|first2=Sean D.|date=2014-01-01|title=Role of Embolization for Cerebral Arteriovenous Malformations|journal=Methodist DeBakey Cardiovascular Journal|volume=10|issue=4|pages=234–239|doi=10.14797/mdcj-10-4-234|issn=1947-6094|pmc=4300062|pmid=25624978}}</ref> Embolization is frequently used as an adjunct to either surgery or radiation treatment.<ref name="Mayo-Treatment"/> Embolization reduces the size of the AVM and during surgery it reduces the risk of bleeding.<ref name="Mayo-Treatment"/> However, embolization alone may completely obliterate some AVMs. In high flow intranidal fistulas balloons can also be used to reduce the flow so that embolization can be done safely.<ref>Huded V. Endovascular balloon-assisted glue embolization of intranidal high flow fistula in brain AVM. J Neurosci Rural Pract 2013;4, Suppl S1:148-9</ref>

=== Risks ===
A first-of-its-kind controlled [[clinical trial]] by the [[National Institutes of Health]] and [[National Institute of Neurological Disorders and Stroke]] focuses on the risk of stroke or death in patients with an AVM who either did or did not undergo interventional eradication.<ref>{{Cite journal |last=Mohr |first=Jay Preston |date=June 4, 2015 |others=[[Columbia University]] |title=A Randomized Trial of Unruptured Brain Arteriovenous Malformations |url=https://clinicaltrials.gov/ct2/show/NCT00389181 |journal=[[ClinicalTrials.gov]] |access-date=2023-03-06}}</ref> Early results suggest that the invasive treatment of unruptured AVMs tends to yield worse results than the therapeutic (medical) management of symptoms.<ref name="aruba02">{{cite web |date=January 29, 2014 |title=A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) |url=http://www.ninds.nih.gov/news_and_events/news_articles/ARUBA_trial_results.htm |archive-url=https://web.archive.org/web/20160704222521/http://www.ninds.nih.gov/news_and_events/news_articles/ARUBA_trial_results.htm |archive-date=2016-07-04 |access-date=2023-03-06 |website=[[National Institute of Neurological Disorders and Stroke]]}}</ref>{{efn|According to established medical research, however, the chance of eventual hemorrhage increases over time.<ref name=":1" />}} Because of the higher-than-expected [[experimental event rate]] (e.g. stroke or death), patient enrollment was halted by May 2013, while the study intended to follow participants (over a planned 5 to 10 years) to determine which approach seems to produce better long-term results.<ref name="aruba02" />