The enlarged skull of a person with hydrocephalus, which is a symptom of the excess CSF in the ventricular system. This may be caused by<unk> , and in some cases, it is thought that hydrocephalus will cause<unk> . Many of the signs and symptoms of<unk>  are similar to those of hydrocephalus. These typical symptoms include: headache, nausea and vomiting, cognitive difficulty, sleepiness, seizures, balance and gait disturbances, visual abnormalities, and incontinence. *Headache may be a result of the raised intracranial pressure from the disrupted flow of CSF, and sometimes this symptom may come on suddenly as a “thunderclap headache”. *In children, cognitive difficulty and developmental delay have been seen in a range of severities. Mild developmental delay is characterized by motor and neurological development that is no greater than 2 standard deviations below average for the age of the child, and moderate delay is characterized by greater than 2 standard deviations below. A child with severe delay may be unable to use spoken language or control movement or interact with others, and can behave abusively towards themselves. *A patient's level of consciousness may also deteriorate with time, and this can lead to coma or death. *The visual abnormalities previously mentioned include “upward gaze palsy”, where a person has difficulty looking up. *Tremors have also been reported as a symptom, but are not as common as these previously mentioned. Signs of<unk>  other than those mentioned in “Causes of<unk> ” include detection of an enlarged lateral and third ventricle in conjunction with a smaller fourth ventricle. This variation in ventricle size is indicative of a blockage in the aqueduct because it lies between the third and fourth ventricles. Another sign of<unk>  is deformation of the midbrain, which can be severe. This is caused by the pressure gradient formed from a blockage in the aqueduct.
Aqueductal stenosis
Chiari malformation
Dandy–Walker malformation
Cranio-lenticulo-sutural dysplasia
Acrocallosal syndrome
Septo-optic dysplasia
Basilar invagination
Periventricular leukomalacia