====== Cerebellar hemorrhage from Cerebellar Arteriovenous Malformation ======

Patients with [[cerebellar arteriovenous malformation]]s are significantly more likely to present with [[cerebellar hemorrhage]]  than patients with [[cerebral arteriovenous malformation]] (three quarters vs. one half). Hemorrhagic presentation results in more neurological deficits both preoperatively and at late follow-up
((da Costa L, Thines L, Dehdashti AR, Wallace MC, Willinsky RA, Tymianski M, Schwartz ML, ter Brugge KG. Management and clinical outcome of [[posterior fossa arteriovenous malformation]]s: report on a single-center 15-year experience. J Neurol Neurosurg Psychiatry. 2009 Apr;80(4):376-9. doi: 10.1136/jnnp.2008.152710. Epub 2008 Nov 21. PMID: 19028763.))
((de Oliveira E, Tedeschi H, Raso J. [[Comprehensive]] [[management]] of [[arteriovenous malformation]]s. Neurol Res. 1998 Dec;20(8):673-83. doi: 10.1080/01616412.1998.11740583. PMID: 9864730.))
((Lawton MT, Du R, Tran MN, Achrol AS, McCulloch CE, Johnston SC, Quinnine NJ, Young WL. Effect of presenting hemorrhage on outcome after microsurgical resection of brain arteriovenous malformations. Neurosurgery. 2005 Mar;56(3):485-93; discussion 485-93. doi: 10.1227/01.neu.0000153924.67360.ea. PMID: 15730573.))
((Muñoz F, Clavel P, Molet J, Castaño C, de Teresa S, Solivera J, de Quintana C, Tresserras P, Rodríguez R, Bartumeus F. Manejo actual de las malformaciones arteriovenosas. Estudio retrospectivo de 31 casos y revisión de la literatura [Current management of arteriovenous malformations. Retrospective study of 31 cases and literature review]. Neurocirugia (Astur). 2007 Oct;18(5):394-404; discussion 404-5. Spanish. PMID: 18008013.)).

The explanation for increased bleeding from cerebellar AVMs is unclear
((Fleetwood IG, Steinberg GK. Arteriovenous malformations. Lancet. 2002 Mar 9;359(9309):863-73. doi: 10.1016/S0140-6736(02)07946-1. PMID: 11897302.))
((Stapf C, Mast H, Sciacca RR, Choi JH, Khaw AV, Connolly ES, Pile-Spellman J, Mohr JP. Predictors of hemorrhage in patients with untreated brain arteriovenous malformation. Neurology. 2006 May 9;66(9):1350-5. doi: 10.1212/01.wnl.0000210524.68507.87. PMID: 16682666.)).

Younger age, single [[feeding artery]], and exclusively [[deep venous drainage]] were independent risk factors for hemorrhagic presentation. [[Eloquent]] location, associated [[aneurysm]], and presence of [[intraventricular hemorrhage]] may predict severe immediate post hemorrhage outcome
((Tong X, Wu J, Lin F, Cao Y, Zhao Y, Wang S, Zhao J. Cerebellar Arteriovenous Malformations: Clinical Feature, Risk of Hemorrhage and Predictors of Posthemorrhage Outcome. World Neurosurg. 2016 Aug;92:206-217. doi: 10.1016/j.wneu.2016.05.006. Epub 2016 May 10. PMID: 27178234.))

===== Case reports =====

11-year-old patient being previously asymptomatic at school, he began a [[sudden]] onset severe [[headache]] with subsequent Environmental Disconnection and falling to the ground with self-limited movements of one leg. Upon the arrival of the ambulance, they find the patient with a poor response (response to painful stimuli) and an altered [[level of consciousness]]. Presents later, several vomiting.

{{::cerebellar_hemorrhage_from_cerebellar_arteriovenous_malformation.png?200|}}

[[Cerebellar hemorrhage]] centered in the midline and slightly lateralized to the left of approximately 38x56x16 mm (diameters AP x T x CC). It presents an opening to the [[ventricular system]] identifying hematic content in the [[fourth ventricle]], [[Cerebral aqueduct]], [[third ventricle]], [[lateral ventricle]]s and [[cisterna magna]]. It causes displacement of the adjacent cerebellar parenchyma with the collapse of the cerebellar sulci.
He presents with peripheral [[vasogenic edema]] without being able to clearly identify underlying space-occupying lesions.
Mild dilatation of the [[temporal horn]]s, suggesting early signs of acute hydrocephalus.

{{::q10182angiography.png?400|}}

Compact [[nidus]] [[pia]]l [[posterior fossa arteriovenous malformation]] at midline level, approximately 2.5 cm x 1.5 cm. Arterial supplies originate from both [[posterior inferior cerebellar artery]] and venous drainage through two collectors to the right and left [[transverse sinus]].

[[Supine position]] with the [[head]] in a neutral [[position]]. Right precoronal frontal [[incision]] and [[trephine]]. [[Durotomy]]. Insertion of a Codman [[Bactiseal]]-type [[ventricular catheter]] up to approximately 5-6cm with low-pressure hematic CSF outflow. Tunneling and fixation of the drainage with [[silk suture]], checking its permeability. Incision closure by planes (subcutaneous with absorbable and skin with [[absorbable monofilament]])

Second stage: SUBOCCIPITAL CRANIECTOMY-POSTERIOR FOSAL DECOMPRESSION: Prone position on U-shaped padding with the head fixed with Mayfield. Linear medial incision from inion to spinosa C1. Subperiosteal dissection of the cervical musculature to expose the occipital scale and arch of C1. Suboccipital craniectomy with extension to the limit with the transverse sinus. Durotomy in "Y" with exposure of the cerebellar hemispheres, without objectifying active bleeding or hematoma outcropping to the cortex, except for a slight subarachnoid hemorrhage adjacent to the right cerebellar [[fissure]]. Enlargement of the bilateral star-shaped durotomy. Apposition of subdural and epidural [[spongostan]], without closure of the dura mater. Closure of the incision by planes (fascia and subcutaneous with absorbable and skin with absorbable monofilament)

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A case of infant fistula-type AVM that developed into a nidus-type AVM 15 years later. This is the first report to document morphologic changes of AVM over time in 1 case.

The present case suggests the possibility that AVM morphology may change with age and is important when considering the history of AVM
((Yamada E, Ito Y, Nakai Y, Uemura K, Ishikawa E, Matsumura A. Infant Fistula-Type Arteriovenous Malformation with Cerebellar Hemorrhage Developed into Nidus-Type in Adolescence. World Neurosurg. 2020 Apr;136:205-207. doi: 10.1016/j.wneu.2020.01.086. Epub 2020 Jan 17. PMID: 31958586.)).
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The first documented case of delayed hemorrhage associated with a cerebellar AVM 5 years after linear accelerator-based radiation in a man with 31 years despite apparent angiographic obliteration.

Intracranial hemorrhage after radiosurgery in digital subtraction angiography-confirmed obliterated AVMs is rare, with limited understanding of risk factors, appropriate preventative management, and mechanisms of occurrence. This case serves to demonstrate the need for greater awareness of this rare complication, as well as the need for appropriate surveillance and management strategies
((Chagoya G, Hardigan AA, Fox BM, Laskay N, Salehani AA, Rotman LE, Elsayed GA, Bernstock JD, Omar NB, Tabibian BE, Ilyas A, Hackney J, Fisher WS 3rd. Cerebellar Arteriovenous Malformation Rupture Despite Apparent Angiographic Obliteration. World Neurosurg. 2020 Feb;134:25-32. doi: 10.1016/j.wneu.2019.10.067. Epub 2019 Oct 17. PMID: 31629928.)).