Most cases of hydrocephalus in children are caused by excess CSF accumulating in the cerebral ventricles due to disturbances of CSF circulation (known as obstructive or non-communicating hydrocephalus). Less often, the CSF accumulates because of impaired absorption (known as communicating hydrocephalus) or because of excessive CSF production. (See 'Pathogenesis' above.)
●Untreated hydrocephalus that begins in infancy before fusion of the cranial sutures typically results in marked enlargement of the head and in less destruction of brain tissue compared with hydrocephalus that develops acutely. This is because the skull expands, partially relieving the intracranial pressure. As hydrocephalus progresses, edema and ischemia develop in the periventricular brain tissue, leading to atrophy of the white matter. (See 'Pathophysiology' above.)
●Common causes of congenital hydrocephalus include intraventricular hemorrhage and neural tube defects including myelomeningocele. Other causes include infection, genetic defects (X-linked hydrocephalus), trauma, tumors, and teratogens. These disorders can be grouped according to the primary pathogenic mechanism (obstructive versus absorptive) (table 1).
●The signs and symptoms of hydrocephalus result from increased intracranial pressure (ICP) and dilatation of the ventricles. The time of presentation depends upon the acuity of the process. Symptoms of hydrocephalus are nonspecific and independent of the etiology. Headache is a prominent symptom; it tends to occur in the early morning and may be associated with nausea and vomiting. Affected patients often have changes in their personality and behavior. (See 'Clinical features' above.)
●Hydrocephalus should be suspected in an infant whose head circumference is enlarged at birth or in whom serial measurements cross percentiles in standard growth curves, indicating excessive head growth. The diagnosis is confirmed by head ultrasonography in infants and by computerized tomography (CT) or magnetic resonance imaging (MRI) in older infants or children. Brain imaging can help to distinguish obstructive (non-communicating) from absorptive (communicating) hydrocephalus, and this information informs treatment decisions. (See 'Imaging' above.)
●Most cases of hydrocephalus are progressive, meaning that neurological deterioration will occur if the hydrocephalus is not effectively and continuously treated, using shunting or endoscopic third ventriculostomy (ETV). In general, ETV is the procedure of choice for pure obstructive hydrocephalus. Shunting is used for patients with communicating hydrocephalus or for those in whom ETV is not successful. However, many forms of hydrocephalus have both obstructive and absorptive components, so the outcome of ETV cannot be consistently predicted. (See 'Management' above.)
●Most complications of treated hydrocephalus are due to malfunction of the shunt. If the shunt malfunctions and if the mechanism causing the hydrocephalus is still active, symptoms of hydrocephalus recur, and a shunt revision or other drainage procedure is required. Shunt malfunction may be caused by infection or by mechanical failure. Approximately 40 percent of standard shunts malfunction within the first year after placement. (See'Complications' above.)
Subarachnoid spaces and cisterns as seen in a median section of the brain
The superior cistern (located dorsal to the midbrain) together with the subarachnoid space at the sides of the midbrain are referred to clinically as the cisterna ambiens. The superior cistern is important because it contains internal cerebral veins which join caudally to form the great cerebral vein (of Galen). It also contains the posterior cerebral and superior cerebellar arteries. The choroid plexuxes in the roof of the third and fourth ventricles are shown in red.
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Common causes of hydrocephalus in the infant and newborn: Classification of obstructive versus absorptive hydrocephalus
| Communicating hydrocephalus |
| Permanent impaired absorption: |
| Primary congenital hydrocephalus |
| Malformed brain |
| Developmental/genetic association |
| Secondary prenatal hydrocephalus |
| Posthemorrhagic |
| Postinfectious |
| Secondary postnatal hydrocephalus |
| Prematurity-related |
| Posthemorrhagic |
| Postinfectious |
| Venous congestion: craniosynostosis, achondroplasia |
| Venous thrombosis: superior vena cava obstruction after cardiac surgery |
| Increased secretion: Choroid plexus papilloma/carcinoma |
| Communicating hydrocephalus, with an obstructive component |
| Tumors |
| Intraventricular hemorrhage resulting in a clot at aqueduct or fibrosis of aqueduct (acute phase)* |
| Intraventricular hemorrhage resulting in intracranial cysts (acute phase)* |
| Infection resulting in intracranial cysts |
| Meningitis/encephalitis resulting in secondary obstruction* |
| Chiari 2 malformation |
| Dandy Walker malformation |
| Holoprosencephaly: lobar, semilobar, alobar |
| Encephalocele |
| Lissencephaly |
| Hydranencephaly |
| Obstructive hydrocephalus, with a transient minor communicating component |
| Same as group 2, subacute or late phase (at least several months from primary insult: infection, bleed)* |
| Large arachnoid cysts |
| Chromosomal abnormalities, syndromic, genetic: |
| X-linked hydrocephalus (mostly aqueductal stenosis) |
| Osteogenesis imperfecta |
| Craniofacial syndromic disorders |
| Part of metabolic inherited disease: |
| Hurler's disease (MPS T1) |
| Achondroplasia |
| Obstructive hydrocephalus (pure) |
| Intracranial cysts with no evidence of bleed at diagnosis |
| Triventricular hydrocephalus due to radiologically apparent aqueductal stenosis |
| Membranous obstruction of aqueduct |
| Asymmetrical hydrocephalus, due to atresia of the foramen of Monro |
| Obstruction of fourth ventricle outlets |
* In these disorders, the communicating component is initially prominent, but tends to decrease over time, so that the obstructive component predominates in the later phases.
Reproduced from: Beni-Adani L, Biani N, Ben-Sirah L, Constantini S. The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices. Childs Nerv Syst 2006; 22:1543; with kind permission from Springer Science + Business Media B.V.
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Aqueductal stenosis due to a tectal lesion
Sagittal T1 weighted magnetic resonance imaging (MRI) showing aqueductal stenosis. The hydrocephalus was treated with a third ventriculostomy.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Hydrocephalus due to a Chiari II malformation
Sagittal T1 weighted magnetic resonance imaging (MRI) showing acquired hydrocephalus due to a Chiari II malformation in a child with spina bifida. Note the shallow posterior fossa and descent of cerebellar tonsils past the foramen magnum. Other findings include large massa intermedia, low lying torcula, and partial agenesis of the corpus callosum.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Intracranial MRI findings of a child with a Chiari II malformation
A sagittal T1-weighted MRI in a pediatric patient shows several characteristic intracranial findings of the Chiari II malformation, including downward displacement of cerebellar tissue through the foramen magnum (arrow), a small fourth ventricle (arrowhead), and tectal beaking (dashed arrow).
MRI: magnetic resonance imaging.
Courtesy of Eric D Schwartz, MD.
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Hydrocephalus associated with Dandy Walker malformation
Four-month-old child with a Dandy Walker malformation, showing agenesis of the cerebellar vermis and a large posterior fossa cyst.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Hydrocephalus due to a vein of Galen malformation
Vein of Galen malformation, causing hydrocephalus.
(Panels A-D) Axial T2 weighted magnetic resonance imaging (MRI).
(Panels E, F) Cerebral angiogram.
(Panels A-D) Axial T2 weighted magnetic resonance imaging (MRI).
(Panels E, F) Cerebral angiogram.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Hydrocephalus due to a choroid plexus papilloma
Magnetic resonance imaging in a 10-month-old male infant, showing a papilloma of the choroid plexus in the right lateral ventricle. There is associated hydrocephalus, caused by overproduction of cerebrospinal fluid (CSF).
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Hydrocephalus due to germinal matrix intraventricular hemorrhage (IVH) of prematurity
Ultrasound in an infant with grade IV intraventricular hemorrhage.
(Panel A) Coronal view.
(Panel B) Sagittal view.
(Panel A) Coronal view.
(Panel B) Sagittal view.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Post hemorrhagic hydrocephalus sequelae
Coronal T2 weighted magnetic resonance imaging (MRI) in a child with communicating hydrocephalus.
Courtesy of Drs. Abilash Haridas and Tadanori Tomita.
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Parinaud syndrome (dorsal midbrain syndrome)
The patient has (A) bilateral lid retraction, pupillary dilatation; (B) the inability to look upward. The pupils do not react to light but do constrict to near effort.
Reproduced with permission from: Tasman W, Jaeger E. The Wills Eye Hospital Atlas of Clinical Ophthalmology, 2nd ed, Lippincott Williams & Wilkins, 2001. Copyright © 2001 Lippincott Williams & Wilkins.
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Ophthalmic findings in the Parinaud syndrome
| Vertical gaze abnormalities, especially upgaze |
| Downward gaze preference or tonic downward deviation of the eyes ("setting-sun sign") |
| Primary position upbeat or downbeat nystagmus |
| Impaired convergence and divergence |
| Excessive convergence tone |
| Convergence-retraction nystagmus |
| Skew deviation, often with the higher eye on the side of the lesion |
| Alternating adduction hypertropia or alternating adduction hypotropia |
| Bilateral upper eyelid retraction (Collier "tucked-lid" sign) |
| Bilateral ptosis |
| Pupillary abnormalities (large with light-near dissociation) |
Modified with permission from: Lee AG, Brazis PW. Clinical Pathways in Neuro-ophthalmology: An Evidence-based Approach, Thieme, New York 1998.
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The cutaneous syndrome in occult spinal dysraphism
| Patch of hyperkeratosis |
| Patch of hypertrichosis |
| Patch of hyperpigmentation |
| Patch of epidermal atrophy (may be tender) |
| Subcutaneous mass (lipoma or neurofibroma) |
| Capillary hemangioma or cutaneous angioma |
| Dorsal dermal sinus |
| Sacrococcygeal pit |
| Sacrococcygeal dimple |
| Caudal cutaneous appendage (true tail or pseudotail) |
| Isolated deviation of the intergluteal fold |
Courtesy of Chaouki Khoury, MD, MS.
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