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Emergency: requires immediate attention
Hydrocephalus in Adult
Other Resources UpToDate PubMed
Emergency: requires immediate attention

Hydrocephalus in Adult

Contributors: Carolyn Zyloney MD, Richard L. Barbano MD, PhD
Other Resources UpToDate PubMed


Hydrocephalus occurs when there is active distention of the ventricular system of the brain. It can result from abnormal cerebrospinal fluid (CSF) production, obstruction of CSF flow, or impaired CSF absorption. It can be congenital (eg, aqueductal stenosis) or acquired (eg, meningitis). There are communicating and noncommunicating forms of hydrocephalus.

Noncommunicating hydrocephalus is due to an obstruction of CSF flow within the ventricular system. Some cases are due to congenital malformations affecting the ventricular system, whereas other cases are due to mass lesions or tumors compressing part of the ventricular system.

Communicating hydrocephalus occurs when there is no obvious sign of obstruction within the ventricular system and is often due to impaired CSF absorption in the arachnoid villi surrounding the brain. Causes of communicating hydrocephalus include overproduction of CSF due to choroid plexus tumors, normal pressure hydrocephalus, and sequelae of meningitis or subarachnoid hemorrhages.

Increases in intracranial pressure (ICP) usually accompany the development of hydrocephalus. Signs and symptoms usually reflect increased ICP and may include headache, nausea / vomiting, and papilledema. Acute cases of hydrocephalus can lead to hemodynamic instability, coma, or death. Chronically, patients can develop intellectual impairment or memory changes, coordination and motor problems, urinary incontinence, and visual impairments.

Hydrocephalus due to an acute increase in ICP is a medical emergency and can potentially become fatal without neurosurgical intervention. Patients with more indolent hydrocephalus who lack symptoms of increased ICP can sometimes be monitored clinically and radiologically. Definitive treatment of hydrocephalus usually requires the placement of a ventriculoperitoneal shunt; however, there are several other treatment options available for select patient populations. Prognosis depends on the cause of hydrocephalus and timing of medical intervention.


G91.9 – Hydrocephalus, unspecified

230745008 – Hydrocephalus

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Differential Diagnosis & Pitfalls

Hydrocephalus is often caused by an underlying medical condition or brain injury, including:
  • Infections (eg, Bacterial meningitis, TORCH syndrome, Encephalitis, Bacterial sepsis)
  • Carcinomatous meningitis
  • Germinal matrix hemorrhage
  • Cerebral stroke
  • Subarachnoid hemorrhage
  • Cavernous sinus thrombosis
  • Traumatic brain injury
  • Brain tumor (eg, Glioblastoma multiforme, Ependymoma, Medulloblastoma, Oligodendroglioma)
  • Normal pressure hydrocephalus
  • Aqueductal stenosis or atresia of the foramen of Monroe
  • Ventricular colloid cysts
  • Choroid plexus papillomas or hyperplasia
  • Benign external hydrocephalus
  • Developmental malformations including Arnold-Chiari malformation, Meningomyelocele, or Dandy-Walker syndrome
  • Congenital hydrocephalus related to an underlying genetic disorder (eg, X-linked hydrocephalus)
Several other conditions can cause symptoms that may mimic the presenting symptoms of hydrocephalus but typically would not reveal significant ventricular enlargement on neuroimaging:
  • Migraine headache
  • Idiopathic intracranial hypertension
  • Cerebral edema
  • Bacterial sepsis
  • Gastroenteritis
  • Epilepsy (see Seizure)
  • Strabismus
  • Developmental delay

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Last Reviewed:01/17/2023
Last Updated:02/08/2023
Copyright © 2024 VisualDx®. All rights reserved.
Emergency: requires immediate attention
Hydrocephalus in Adult
A medical illustration showing key findings of Hydrocephalus (Toddlers & Older Children) : Blurred vision, Seizures, Headache, Nausea/vomiting, Diplopia, Gait disturbance, Papilledema, Urinary incontinence, Lethargy
Copyright © 2024 VisualDx®. All rights reserved.