Hydrocephalus and Birth Injury

Sometimes, babies with birth injuries develop a condition called hydrocephalus, which is characterized by excessive fluid in the brain. Hydrocephalus gets its name from the Greek words “hydro” (water) and “cephalus” (brain) and is sometimes called “water on the brain,” although it actually involves an accumulation of cerebrospinal fluid (CSF) (1). CSF is a clear substance that protects the brain, provides nourishment, and removes waste (2). Hydrocephalus occurs when there is too much CSF within the cerebral ventricles and/or subarachnoid spaces of the brain. The signs and symptoms of hydrocephalus depend on variables such as the underlying cause and the affected individual’s age. In newborns, this condition may result in noticeable swelling of the head. It is very important that physicians promptly diagnose and treat infants with hydrocephalus in order to avoid permanent brain damage and other long-term complications (3).

Hydrocephalus in newborns may be congenital or acquired. Congenital hydrocephalus can be caused by genetic abnormalities or complications during fetal development. Acquired hydrocephalus is caused by something that goes wrong during the birthing process or shortly after. Examples include (1, 4):

• Birth trauma: If a baby is harmed due to excessive mechanical force during labor and delivery, this is called birth trauma or a traumatic birth injury.
  • Birth trauma often causes intracranial hemorrhages (brain bleeds), especially in premature infants. Intracranial hemorrhages, in turn, often cause hydrocephalus. For more information on particular types of intracranial hemorrhages that can result in hydrocephalus, please click on the following links:
    • Intraventricular hemorrhage
    • Subarachnoid hemorrhage
• Central nervous system tumors

Because intracranial hemorrhages underlie many cases of acquired hydrocephalus, it is important to know the causes and risk factors for brain bleeds. These include the following (5, 6, 7, 8, 9):

• Prematurity: Premature babies often have a low birth weight and underdeveloped blood vessels, which can easily rupture due to injury. Therefore, preemies are more susceptible to intracranial hemorrhages. Indeed, prematurity is a major risk factor for many types of birth injury, so it is crucial that medical professionals do all they can to prevent premature birth.
• Lack of indicated antenatal steroids: These drugs can help babies likely to be born early mature faster, minimizing their risk of intracranial hemorrhage and other birth injuries.
• Hypoxic ischemic encephalopathy (HIE): This is a type of brain damage caused by a lack of oxygenated blood flow to the baby’s brain.
• Infections: Examples include meningitis and herpes encephalitis.
• Untreated respiratory distress syndrome (RDS): This is a neonatal breathing complication that is common in premature babies.
• Delivery involving forceps or vacuum extractors: The use of these tools is especially risky in births involving complications such as macrosomia, cephalopelvic disproportion (CPD), or an abnormal fetal presentation.
• Pitocin: Pitocin is a synthetic version of the hormone oxytocin. It is sometimes used to induce labor or enhance contractions. This drug, especially when used incorrectly, can increase the risk of uterine tachysystole/hyperstimulation, intracranial hemorrhage, and other complications.

A baby with hydrocephalus may not show any obvious signs (10). However, many will have an increasing head circumference due to the excess fluid. An infant’s skull is able to expand to accommodate the fluid build up because their sutures have not fully fused together (1).

Besides head swelling, signs of hydrocephalus in infants include the following (1, 4):

• Vomiting
• Sleepiness
• Irritability/fussing
• Seizures
• Eyes fixed downward (“sun-setting”)
• Bulging fontanel
• Feeding problems
• Low muscle tone (hypotonia)

It is important to note that older children and adults with hydrocephalus exhibit different signs and symptoms.

Hydrocephalus should be suspected in babies who have a head circumference that is larger than normal at birth or whose head measurements after birth indicate excessive head growth.  Babies who had a traumatic birth or who were born prematurely should have frequent head measurements. In addition, babies who have an increased intracranial pressure should be suspected of having hydrocephalus.

Diagnosis of hydrocephalus is confirmed by head imaging. Depending on the circumstances, this may involve ultrasound, CT scans, or MRIs. Hydrocephalus is characterized by enlarged ventricles (ventriculomegaly) and increased intracranial pressure.

Brain imaging can help distinguish between obstructive hydrocephalus and communicating hydrocephalus (10). In obstructive hydrocephalus, the flow of CSF between ventricles is blocked. In communicating hydrocephalus, the ventricles stay open, and CSF can still flow between them (1). This distinction is important because it will influence treatment decisions (10).

Hydrocephalus is often manageable if diagnosed in a timely manner. The most common treatment involves surgical placement of a shunt system, made up of a tube and a valve. This helps CSF flow at a normal rate and in the correct direction. The shunt allows CSF to drain from the brain into the chest or abdominal cavity, where it is more easily absorbed. Shunts are generally permanent and require careful monitoring.

Some babies with hydrocephalus are able to have an endoscopic third ventriculostomy (ETV) instead of a shunt. This is a procedure that involves creating a hole in the bottom of a ventricle, which allows CSF to drain out of the brain. The hole can fail or become blocked, so it is important to watch the child for signs of increasing intracranial pressure (11).

The prognosis for an individual baby with hydrocephalus depends on the extent to which they are affected, how promptly they are diagnosed, and what the cause of their hydrocephalus is, among other variables. Some children with hydrocephalus go on to live normal, healthy lives. However, hydrocephalus can also cause permanent brain damage and impact both cognitive and physical development when not timely diagnosed and treated. Many children with hydrocephalus benefit from rehabilitative therapies (e.g. physical therapy, occupational therapy) and educational interventions (1).