Also known as: Porencephalic Cyst


This is a condition whereby there are isolated cavities within the cerebral hemisphere. They may or may not be single and there may be communication with ventricles and other subarachnoid space.


Medical text written February 2003 by Mr N Buxton. Last Updated July 2008 by Mr N Buxton, Consultant Paediatric Neurosurgeon, Alder Hey Children’s Hospital, Liverpool, UK.

What are the causes?

The aetiology, in children, is thought to be that there is a localised destruction of brain tissue due to a number of causes but potentially including toxaemia, maternal injuries, infection, hypoxic injury or even intra-uterine intra-cerebral haemorrhage. It has been seen after multiple taps of the ventricles (fluid cavities inside the brain), to relieve raised intracranial pressure. Its overall incidence is unknown, aetiology must be multi-factorial and some series suggest that there is a risk that a patient with porencephaly has a two to four per cent chance of having a child with a neural-tube defect.

People with mature brains can get similar cysts developing due to loss of brain tissue after brain haemorrhages, strokes and head injuries. These cysts, like porencephalic cysts, are what is left behind by the normal process of the brain clearing away dead tissue as part of the normal healing processes of the body.

How is it treated?

There is no specific treatment other than for conditions that may have caused it. There may be seizures but most of the time these present as incidental findings.

Inheritance patterns and prenatal diagnosis

Inheritance patterns

Prenatal diagnosis
None is available at present. Cysts can sometimes be detected by ultrasound scanning.

Is there support?

There is no support group for porencephaly in the UK. Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.

Back to A-Z Conditions