Excessive production of CSF, or failure of CSF reabsorption due to obstruction of the passageways out of the fourth ventricle, leads to an accumulation of fluid in the brain ventricles. This can cause raised intracranial pressure (ICP). Hydrocephalus is present in approximately 90 per cent of people affected by DWS. And can result in the failure of parts of the cerebellum to develop correctly. A large cyst is then visible on scans of the back of the brain.
Symptoms caused by ICP can include:
In early infancy:
- slow motor development
- progressive enlargement of the skull.
In older children:
- signs of cerebellar dysfunction, such as unsteadiness, lack of muscle coordination or jerky movements of the eyes
- increased head circumference
- bulging at the back of the skull
- problems with the nerves that control the eyes, face and neck
- abnormal breathing