Childs Nerv Syst (2016) 32:593–598
DOI 10.1007/s00381-016-3033-2

CASE-BASED UPDATE

Spontaneous regression and complete disappearance of the vein
of Galen aneurysmal malformation
Ramin Mahmoodi 1 & Zohreh Habibi 2 & Vahid Heidari 2 & Farideh Nejat 2

Received: 5 January 2016 / Accepted: 1 February 2016 / Published online: 11 February 2016
# Springer-Verlag Berlin Heidelberg 2016

Introduction

Abstract
Introduction Thrombosis is frequently observed in Galen
malformation, but propagation of thrombosis resulting in the
disappearance of the aneurysmal malformation is a very rare
clinical condition.
Case report A rare case of spontaneous regression and disappearance of the vein of Galen aneurysmal malformation
(VoGAM) in a pediatric patient with repeated generalized seizure, increased head circumference, and congestive heart failure is recorded. The course of regression from infancy to
8 years of age has been depicted. Radiological studies initially
demonstrated VoGAM complicated by an intra-cerebral hemorrhage and hydrocephalus, which later underwent spontaneous regression. Long-term clinical and radiological follow-up
is presented.
Discussion Different conditions including hemodynamic alteration, compression of adjacent hematoma, and narrowing
of related vascular structures have been described to cause
thrombosis of VoGAM. The relevant literature to address possible mechanism is reviewed.

The vein of Galen aneurysmal malformations (VoGAMs) are
rare intracranial congenital vascular lesions. They are commonly diagnosed during neonatal period or early childhood,
when manifest as congestive heart failure and intracranial hypertension, respectively [1, 2]. The patients harboring VoGAM
may experience occlusion of the malformation following
thrombosis of the vascular lesion. Although thrombosis of
the Galen malformation is a common clinical condition and
has been frequently reported in the literatures [3–6], complete
regression resulting in disappearance of the aneurysmal malformation is a quite rare clinical condition, and to our knowledge, only four cases of spontaneous disappearance were reported previously [7–10]. Here, we present an infant harboring vein of Galen malformation, who experienced spontaneous total regression and disappearance of the vascular
pathology confirmed by long-term clinical and neuroradiological follow-up. Review of the relevant literature
has been performed to address the possible mechanisms.

Keywords Galen . Aneurysm . Regression

Historical background

* Farideh Nejat
nejat@sina.tums.ac.ir

1

Brain and Spinal Cord Injury Research Center, Neuroscience
Institute, Tehran University of Medical Science, Tehran, Iran

2

Department of Neurosurgery, Children’s Hospital Medical Center,
Tehran University of Medical Science, Tehran, Iran

It has been recognized that the vein of Galen malformation, as
an arteriovenous connection between primitive choroidal vessels
and the median prosencephalic vein of Markowski, develops
between the 6th and 11th weeks of gestation [11]. Different
classification schemes have been proposed for the vein of
Galen malformation. According to the Raybaud and
Lasjaunias classification, three types of aneurysmal malformation could be described: (a) choroidal, (b) mural, and (c) vein of
Galen dilatation following increased blood inflow due to an
arteriovenous malformation. The choroidal type is more severe
and usually causes multiple organs failure especially high output

594

heart failure in the neonates and characterized by multiple fistulas at the anterior and terminal segment of the median prosencephalic vein. The arterial feeders come from anterior and posterior choroidal arteries and some additional feeders from
quadrigeminal and thalamoperforating arteries. The mural type
is often slow flow and asymptomatic lesion with the fistula at the
lateral-inferior wall of the median prosencephalic vein. The arterial supply is usually from unilateral or bilateral quadrigeminal
and or posterior choroidal arteries. Galen aneurysmal dilatation
is a true vein of Galen that drains a dural arteriovenous fistula or
a brain arteriovenous malformation accompanied by venous
drainage of normal brain parenchyma. It is against to the persistent embryonic vein in the true VoGAM that does not drain the
normal brain and drains only the malformation [11–14].
In contrast to the superficial cerebral venous system and
venous sinuses, thrombosis of the deep venous system is a rare
clinical condition. In the territory of the deep venous drainage, a
relatively higher tendency of vein of Galen to thrombose formation has been mentioned [5]. Searching available current
literature to catch the first reported cases of thrombosed vein
of Galen malformation and excision of the thrombosed aneurysm results in finding two separate reports in 1950 by Davis
and 1968 by Weir, respectively [15, 16]. Although several cases
of spontaneous thrombosis or successful surgical treatment of
thrombosed aneurysm of Galen have been thereafter published,
spontaneous disappearance and regression of the malformation
is a rare clinical condition.

Clinical presentation
Most symptoms of the VoGAMs are related to the magnitude of
the intracranial shunt and differ considerably in neonate from
those seen in older ages [17]. In neonates, cardiac decompensation often develops due to high flow systemic shunt. Increased
head circumference secondary to venous hypertension and subsequent hydrocephalus is commonly observed in infancy.
Obvious signs of intracranial hypertension, intra-cerebral hemorrhage, seizure, and infarcts related to the retrograde venous
engorgement or diversion of the blood flow may occur [13, 18].
Since thrombosis of the Galen malformation is an uncommon occurrence, its clinical presentation and symptoms have not
been discussed in detailed. Generally, spontaneous thrombosis
of the VoGAM has variable clinical course and symptoms from
asymptomatic to death [9]. It may be accompanied by seizure,
alteration of consciousness, and intracranial hemorrhage [19].

Diagnosis
The diagnosis of the VoGAM is usually obtained in infancy or
early childhood, comprising 30 % of the pediatric intracranial
vascular lesions [20]. Angiography provides useful detailed

Childs Nerv Syst (2016) 32:593–598

information about the pathology and has become the gold
standard diagnostic method. Prenatal detection of the
VoGAMs has been facilitated by pulsed and color Doppler
ultrasonography in the 2nd or 3rd trimester of pregnancy.
The malformation appears in prenatal ultrasound study as a
midline posterior third ventricle echogenic mass, associating
with dilated cerebral venous sinuses, dilated neck vessels, and
cardiomegaly [18, 21, 22]. Regarding the age of developing
thrombosis, the detection of a thrombosed VoGAM in prenatal
sonography and MRI, later confirmed by autopsy, has been
reported as early as 21st weeks of gestation [18].
In case of thrombosed VoGAM, angiography fails to reveal
the lesion and demonstrates the absence of flow. The lesion
appears in CT scan as a hyperdense lesion with occasionally
calcified capsule, and MRI contributes the characteristics of
extracellular methemoglobin in the central part and hemosiderin in the peripheral part of lesion [23]. Considering the anatomical location of the lesion and presence of thrombosis or
calcification, VoGAMs can mimic radiologic and clinical features of pineal tumors, arachnoid cyst, cavum vergae, or
porencephalic cyst in neuroimaging studies [24, 25].

Management
Although the diagnosis of the VoGAM is feasible as early as
the prenatal period by utilizing various modalities, optimal
management strategy of the patients is still controversial and
complex. Since the initial management in less symptomatic
patients and low flow variants is a conservative approach
through medical management and treating hydrocephalus,
several reports exist on spontaneous thrombosis of the vascular pathology in the course of observation. The reported cases
of spontaneous thrombosis were usually without significant
morbidities, demanding only conservative management.
Although surgical treatment of VoGAM has generally poor
outcome, limited reports exist on successful operative intervention to manage the thrombosed VoGAM with satisfactory
outcome [16, 26–29].

Prognosis and outcome
Although the mechanisms involved in spontaneous thrombosis are not well defined, it is believed that thrombosis occurs as
a result of low flow shunt and insufficient venous drainage
[29]. Since the shunt is low flow, the spontaneous occlusion of
the vascular lesion does not lead to unfavorable clinical conditions, and the thrombosis of VoGAM usually has been described with an excellent or good prognosis in the published
articles [30, 31].

Childs Nerv Syst (2016) 32:593–598

595

Fig. 1 First brain computed tomography scan shows three ventricular hydrocephalus and severely dilated vein of Galen and torcula herophili

Case description
The patient was a 4-month-old boy admitted to the hospital because of a suddenly decreased level of consciousness and repeated generalized seizures. The child was a product of an uneventful
pregnancy and delivery from non-consanguineous parents. The
last prenatal ultrasound exam was performed at 20th week of
gestational age which confirmed no obvious fetal abnormality.
The head circumference at admission was 4 cm larger than
expected value for the age. Anterior fontanel was wide and
tense accompanied by right side eye deviation. Clinical evaluations confirmed congestive heart failure with respiratory

distress during feeding. Laboratory tests confirmed normal coagulation status, normal platelet count, and no bleeding
diathesis.
The first brain computed tomography (CT) scan revealed right
occipital intra-cerebral hemorrhage, brain atrophy, threeventricular hydrocephalus, and two round isodense midline
masses, 3.5 and 5.5 cm in diameter compatible with severely
dilated vein of Galen and torcula herophili, respectively
(Fig. 1). Brain magnetic resonance imaging (MRI) and magnetic
resonance angiography (MRA) confirmed vein of Galen aneurysmal malformation accompanied by thrombosis formation and
dilated torcula (Fig. 2). CT angiography confirmed a mural type

Fig. 2 Brain magnetic resonance imaging (a) and magnetic resonance angiography (b) confirms vein of Galen aneurysmal malformation accompanied
by thrombosis formation and dilated torcula

596

Childs Nerv Syst (2016) 32:593–598

Fig. 3 CT angiography shows Galen aneurysm with severely dilated torcula, straight sinus, which the straight sinus contains a short narrowing segment
distal to the Galen

VoGAM with severely dilated torcula, straight and transverse
sinus, with the straight sinus being associated with a short
narrowing segment distal to Galen (Fig. 3).
Congestive heart failure was managed with diuretics and
digoxin. The neurological problems gradually improved over
1 week. The patient was scheduled for digital subtraction angiography, but the parents refused to perform the test and
discharged the child with their permission.
The seizure was successfully managed with phenobarbital,
but congestive heart failure improved during the next few
months without any medication. As the child was stable from
neurological and cardiorespiratory aspects, the parents did not
seek medical care until he experienced a new seizure attack
3 years later. New brain CT scan revealed a porencephalic cyst
at the place of previous intra-cerebral hemorrhage with

calcified thrombosis inside the torcula and Galen which was
corresponded to the previous severely dilated torcula and aneurysmal malformation of Galen. Later in follow-up at the age
of seven, new brain CT with CT angiography was performed
that confirmed complete regression and disappearance of the
aneurysmal dilatation of Galen (Fig. 4).
Currently, this healthy 8-year-old child manifests no
neurological signs or symptoms except for slight school
performance problem. His ventriculomegaly is not associated with headache or papilledema and has been considered as arrested hydrocephalus which was left untreated because of being asymptomatic. Digital subtraction
angiography confirms the regression of the aneurysmal
lesion and fails to reveal any other vascular abnormalities (Fig. 5).

Fig. 4 a Bain CT scan after 3 years confirms calcified thrombosis inside the torcula and Galen which corresponds to the previous severely dilated torcula
and aneurysmal malformation of Galen. b CT angiography reveals complete regression and disappearance of the aneurysmal dilatation of Galen

Childs Nerv Syst (2016) 32:593–598

597

After all the abovementioned hypotheses, the exact mechanism of complete regression and disappearance of the lesion
is still unknown. To describe the exact mechanism of such
intralesional thrombosis, a bioengineered modeling of hemodynamic changes inside the VoGAM and associated sinuses,
and venous system can be of help.

References
1.

2.
3.
4.
Fig. 5 Digital angiography of right carotid shows normal anteroposterior
view of angiogram without any abnormality

5.

Conclusion
Spontaneous thrombosis of an intracranial vascular lesion is a
known phenomenon and has been frequently described in
arteriovenous malformations, arteriovenous fistula, and aneurysms. The formation and regression of the Bflow-related^
aneurysm, which is well documented, highlights the role of
alteration of hemodynamic in thrombosis and regression of
vascular lesions. Although the exact mechanism and clinical conditions resulting in thrombosis of the VoGAM are
not clearly understood, it could be postulated that like
other vascular lesions, alteration in hemodynamic status
may play an important role in developing thrombosis. The
possible mechanism which could alter the hemodynamic
condition in the VoGAM could be assumed as compression or mass effect caused by the adjacent hematoma or
intraaneurysmal clot, posthemorrhagic edema, regressive
arteriosclerosis changes in the feeding vessel walls, vascular spasm, and gliosis by fragmentary micro-bleeding
[2, 32].
In addition to the abovementioned mechanisms as the possible causes of the thrombosis, the unique shape of straight
sinus of our patient could result in thrombosis of the lesion.
The narrowing of straight sinus distal to Galen aneurysm may
facilitate the thrombosis formation inside the dilated Galen,
and thrombosis could propagate distal to narrow part of the
sinus. Progressive blood flow stagnation distal to the
narrowed part of the sinus caused thrombosis discrete the lesion and induced size decrement of venous sinus system.
Thrombosis and aneurysm resorption led to recovery of cardiac problems too.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

Jones BV, Ball WS, Tomsick TA, Millard J, Crone KR (2002) Vein
of Galen aneurysmal malformation: diagnosis and treatment of 13
children with extended clinical follow-up. AJNR American Journal
of Neuroradiology 23:1717–1724
Hoang S, Choudhri O, Edwards M, Guzman R (2009) Vein of
Galen malformation. Neurosurg Focus 27:E8
Olin MS, Eltomey AA, Dunsmore RH, Roberts MP (1982)
Thrombosed vein of Galen aneurysm. Neurosurgery 10:258–262
Whitaker JB, Latack JT, Venes JL (1987) Spontaneous thrombosis
of a vein of Galen aneurysm. AJNR American Journal of
Neuroradiology 8:1134–1136
Beltramello A, Perini S, Mazza C (1991) Spontaneously healed
vein of Galen aneurysms. Clinical radiological features. Child’s
Nervous System: ChNS: Official Journal of the International
Society For Pediatric Neurosurgery 7:129–134
Shah QA, Qureshi AI (2011) Spontaneous thrombosis of a large
vein of galen malformation. Journal of Neuroimaging: Official
Journal of the American Society Of Neuroimaging 21:87–88
Kuroki K, Uozumi T, Arita K, Takechi A, Matsuura R, Fujidaka M
(1995) Spontaneous disappearance of an aneurysmal malformation
of the vein of Galen. Neuroradiology 37:244–246
Tawk RG, Mohasseb G, Charbel FT, Debrun GM (2002)
Spontaneous disappearance of vein of galen malformation and posterior fossa venous pouch. Acta Neurochir 144:1225–1231
Moftakhar P, Danielpour M, Maya M, Alexander MJ (2009)
Spontaneous thrombosis of neonatal vein of Galen malformation.
Neurosurg Focus 27:E12
Kumar A, Krishna G, Singh PK, Garg A, Sharma BS (2015)
Spontaneously disappearing pineal region mass: a rare manifestation of vein of galen malformation. Indian J Pediatr 82:201–202
Raybaud CA, Strother CM, Hald JK (1989) Aneurysms of the vein
of Galen: embryonic considerations and anatomical features relating to the pathogenesis of the malformation. Neuroradiology 31:
109–128
Litvak J, Yahr MD, Ransohoff J (1960) Aneurysms of the great vein
of Galen and midline cerebral arteriovenous anomalies. J
Neurosurg 17:945–954
Lasjaunias P, Ter Brugge K, Lopez Ibor L, Chiu M, Flodmark O,
Chuang S, Goasguen J (1987) The role of dural anomalies in vein of
Galen aneurysms: report of six cases and review of the literature.
AJNR American Journal of Neuroradiology 8:185–192
Lasjaunias P, Garcia-Monaco R, Rodesch G, Ter Brugge K, Zerah
M, Tardieu M, de Victor D (1991) Vein of Galen malformation.
Endovascular management of 43 cases. Childs Nerv Syst 7(7):
360–367
Davis PB (1950) Thrombosis of the internal cerebral veins of
Galen; report of two cases involving adults. The Journal of the
American Osteopathic Association 50:21–22
Weir BK, Allen PB, Miller JD (1968) Excision of thrombosed vein
of Galen aneurysm in an infant. Case Report Journal of
Neurosurgery 29:619–622

598
17.

Bhattacharya JJ, Thammaroj J (2003) Vein of galen malformations.
Journal of neurology, neurosurgery, and psychiatry 74 Suppl 1: i42–
44
18. Vijayaraghavan SB, Vijay S, Kala MR, Neha D (2006) Prenatal
diagnosis of thrombosed aneurysm of vein of Galen. Ultrasound
in Obstetrics & Gynecology: the Official Journal of the
International Society Of Ultrasound in Obstetrics and Gynecology
27:81–83
19. Marques RM, Lobao CA, Sassaki VS, Aguiar LR (2006) Vein of
Galen aneurysm in an adult: case report. Arq Neuropsiquiatr 64:
862–864
20. Recinos PF, Rahmathulla G, Pearl M, Recinos VR, Jallo GI, Gailloud
P, Ahn ES (2012) Vein of Galen malformations: epidemiology, clinical presentations, management. Neurosurg Clin N Am 23:165–177
21. Paternoster DM, Manganelli F, Moroder W, Nicolini U (2003)
Prenatal diagnosis of vein of Galen aneurysmal malformations.
Fetal Diagn Ther 18:408–411
22. Busing K, Kilian K, Schaible T, Neff W (2008) Prenatal magnetic
resonance imaging of vein of Galen aneurysm associated with congestive heart failure. Pediatrics International: Official Journal of the
Japan Pediatric Society 50:818–821
23. Abrao GP, Barbosa LA, Sa AT Jr, Caldas JG (2010) Spontaneous
thrombosis of a malformation of the vein of Galen. Arq
Neuropsiquiatr 68:648–650
24. Ahmad M, Mir S, Wahab S, Rizvi I (2012) Vein of Galen malformation. BMJ Case Reports 2012. doi:10.1136/bcr-2012-006822

Childs Nerv Syst (2016) 32:593–598
25.

26.
27.

28.
29.

30.

31.

32.

Gokhale S, Laskowitz DT (2013) Teaching neuroimages: vein of
Galen aneurysm mimicking pineal mass in a young adult.
Neurology 80:e240
Lazar ML (1974) Vein of Galen aneurysm: successful excision of a
completely thrombosed aneurysm in an infant. Surg Neurol 2:22–24
Di Rocco C, Iannelli A, Puca A, Cj C (1983) Spontaneous thrombosis of an aneurysm of the great vein of Galen. Eur Neurol 22:
293–299
Di Rocco C (1991) Comment on spontaneous healed vein of Galen
aneurysm. Child’s Nerv Syst 7:359
Konovalov AN, Pitskhelauri DI, Arutiounov NV (2002) Surgical
treatment of the thrombosed vein of galen aneurysm. Acta
Neurochir 144:909–915 discussion 915
Nikas DC, Proctor MR, Scott RM (1999) Spontaneous thrombosis
of vein of Galen aneurysmal malformation. Pediatr Neurosurg 31:
33–39
Hurst RW, Kagetsu NJ, Berenstein A (1992) Angiographic
findings in two cases of aneurysmal malformation of vein of
Galen prior to spontaneous thrombosis: therapeutic implications. AJNR American Journal of Neuroradiology 13:1446–
1450
Yoshimoto T, Kashiwaba T, Houkin K, Abe H (1996) Spontaneous
disappearance of arteriovenous malformation during staged treatment of multiple cerebral arteriovenous malformations—case report. Neurol Med Chir 36:812–814