Vein of Galen Malformation


Vein of Galen malformation (VGM) is a rare arteriovenous malformation (AVM – an abnormal direct connection between arteries and veins) in the brain. High pressure blood flows directly from arteries into veins without slowing down and without releasing its load of oxygen and nutrients – a process called arteriovenous shunting.


Last updated May 2014 by Dr V Ganesan, Senior Lecturer and Honorary Consultant Paediatric Neurologist, UCL Institute of Child Health, London, UK.

What are the symptoms?

Blood is diverted away from other organs into the VGM; this results in failure of these organs, such as the heart. It is also difficult for the veins to do their job of soaking up and circulating water from the brain and so fluid may collect within the brain (see entry hydrocephalus). There is also a risk of bleeding from the abnormal vessels, although this is relatively low.

The symptoms of VGM will vary between individuals, although some patterns are recognised:

  • neonatal (after birth) presentation: some babies present with heart failure in the early days of life (see above)
  • infants may have difficulties in reaching developmental milestones, or may have a large head size (due to increased water in the brain)
  • older children may have seizures, developmental difficulties or a large head size.

What are the causes?

This is not currently known.

How is it diagnosed?

Brain scans will show the VGM and any associated effects on the brain. A cerebral angiogram (where pictures of brain blood vessels are taken after injection of dye) is usually carried out to confirm the diagnosis.

How is it treated?

Treatment of children with VGM consists of closing the abnormal communications between arteries and veins, as well as treatment of secondary complications, such as heart failure. Closure of the abnormal communications is undertaken in a procedure known as embolization. This involves injection of fast-setting glue directly into the point of abnormal artery-vein communication(s). Secondary effects are dealt with using medication and by dealing with the underlying VGM.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
In general, VGM is not a condition that runs in families and its causes are not clearly known. There are a very small number of cases described with changes in a gene called RASA1; these people also have red flat birthmarks on the skin. It is unlikely that changes in RASA1 account for the majority of cases with VGM but you may wish to discuss the relevance of this with your child’s doctor.

Prenatal diagnosis
It is possible that, in some cases, VGM can be identified on an ultrasound scan. If this is the case, other assessments may include more detailed scanning of the mother and baby. Usually these assessments will be undertaken by a specialist in fetal medicine.

Is there support?

Vein of Galen Support Group

Tel: 01963 34393

The Group is a parent support group, established in 1999. It offers support and information and links families where possible. The Group works to increase awareness of this rare condition within the medical profession. It offers an online forum via its website and is in contact with parents worldwide.

Group details last updated November 2014.

Back to A-Z Conditions