Hydrocephalus refers to the accumulation of excessive cerebrospinal fluid (CSF)in the brain due to either obstruction in CSF flow pathways or poor absorption of CSF. In most of the cases it is present at birth or may be acquired after birth. The presence of this at birth is not necessarily a hereditary birth defect. It increases the intracranial pressure which in most of the cases can be severely life threatening if not immediately treated. Surgical treatment via placement of a shunt is the treatment of choice though medical measures are available to decrease the intracranial pressure. Babies with this condition may have increased head size and fullness of the fontanelles. Such babies can present with complaints of excessive crying, urinary incontinence, headache, vomiting and alteration in behavior .
This condition can occur at any age but in most cases it is seen in infancy or early childhood. The gender of the baby does not relate to the incidence of it except for a few exceptions. Almost one in every 1000 babies is born with it. The exact data is available about incidence of congenital hydrocephalus while the actual incidence of it due to acquired causes is not known. The incidence of it is due to congenital causes in U.S is considered to be almost 200 cases per 100,000 live births; and almost 6,000 children annually develop acquired this medical condition during the first 2 years of life. Almost 60% of the total cases are congenital or acquired during infancy and in early childhood .
Causes and risk factors
Normally a delicate balance is present between the synthesis, circulation, and absorption levels of cerebrospinal fluid in the brain’s ventricles. It occurs as a result of an imbalance of the distribution of cerebrospinal fluid. The risk factors for hydrocephalus in babies may include the following factors :
- History of recent head injury
- Premature infants
- Low birth weight babies
- Presence of neural tube defects
Congenital causes are:
- Congenital infections like rubella, cytomegalovirus, etc
- Dandy-Walker syndrome- It is characterized by an enlarged fourth ventricle and poorly formed cerebellum.
- Aqueductal abnormalities- The abnormality in the development of the aqueduct of Sylvius or the presence of a tumor in the fourth ventricle can cause development of an non-communicating type of hydrocephalous in infants and children. Aqueductal stenosis is characterized by the narrowing of the aqueduct of Sylvius.
- Chiari malformation (types I and II): Chiari malformation type II is an important cause of progressive hydrocephalus and myelomeningocele in babies.
- Neural tube defects
- Intracranial bleeding
- Arteriovenous malformation .
Acquired causes in babies are:
- Infections like meningitis and cerebral abscess
- CNS tumors
- Cysts in the brain
- Increased venous sinus pressure
- Intraventricular hemorrhage
- Subarachnoid hemorrhage
- Leukemic metastasis of CNS
- Bickers-Adams syndrome
- Choroid plexus papilloma is a very rare [3,6].
There are many ways to classify hydrocephalus in babies. Various types include :
- Congenital hydrocephalus is one of the most common birth defects. The various causes of this are neural tube defects, stenosis of the aqueduct of Sylvius, Dandy-Walker syndrome, Chiarii malformations and CNS (Central Nervous System) tumor.
- Acquired hydrocephalus occurs after birth due to some reason, such as, CNS infection and intracranial bleeding.
- A communicating hydrocephalus occurs when a communication between the ventricles and subarachnoid space exists. Its causes include poor absorption of CSF, venous drainage insufficiency, and excessive production of CSF.
- Non-communicating hydrocephalous occurs when there is lack of communication between the ventricles and the subarachnoid space.
- Benign external hydrocephalus results from poor absorption of CSF. It is characterized by raised ICP and enlargement of the subarachnoid spaces. This condition generally resolves within 1 year .
Signs and Symptoms
Signs and symptoms of hydrocephalus in infants may include :
- Nausea and Vomiting
- Poor feeding ability
- Irritable behavior
- Constant downward gaze of the eyes-sunset sign
- Occasional seizures
- Fullness of fontanelles
Signs and symptoms in older children are:
- Moderate to severe headache
- Nausea and vomiting
- Visual defects
- Poor coordination-ataxia
- Personality changes
- Lack of concentration
- Altered behavior
- Urinary incontinence .
Tests that can help in diagnosing it include:
- CT-scan of the head
- MRI-brain .
Treatment Options :
Shunt placement is the most common treatment. A shunt is a tube which is placed surgically between the brain and some other body part to bypass extra CSF from the head to another place where the body can remove it naturally [6,7].
Endoscopic Third Ventriculostomy
An endoscopic third ventriculostomy (ETV) is a surgical technique that aims at relieving the buildup of cerebrospinal fluid pressure in the third ventricle of the brain [6,7].
It is aimed at decreasing the intracranial pressure by the use of various drugs like mannitol and acetazolmide .
Hydrocephalus in babies is one of the most common congenital birth defects. It exacerbates the intracranial pressure that can lead to life threatening complications and even death in some cases. Placement of a shunt is the treatment of choice. The outcome of it depends upon the cause and timely treatment.
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