The featured image above shows a CT scan of the brain of a patient with hydrocephalus (left) versus that of a normal brain (right). Hydrocephalus is a condition associated with a buildup of excess cerebrospinal fluid (CSF) in the brain, causing an increase in pressure on the brain tissue. Normally, the cerebrospinal fluid surrounds the brain and spinal cord, transporting nutrients, removing wastes, and cushioning against injuries. If too much CSF is produced, or if the flow or absorption of CSF is blocked, the fluid can build up in the cranial cavity and cause hydrocephalus. The buildup of fluid puts pressure on the brain, pushing the brain up against the skull and damaging or destroying brain tissues.
Hydrocephalus can start while a baby is growing in the womb; this is known as congenital hydrocephalus. Congenital hydrocephalus is often seen in conjunction with myelomeningocele, a birth defect in which the backbone and spinal canal don’t close before birth.
Genetic defects and infections that occur during pregnancy can also cause hydrocephalus. In older children and adults, hydrocephalus may be associated with infections that affect the central nervous system (like meningitis), bleeding in the brain during delivery (especially in preemies), injury before, during, or after birth, tumors of the central nervous system, injury, or trauma.
The symptoms depend on the cause of the blockage, the person’s age, and how much brain tissue has been damaged by the swelling. In infants with hydrocephalus, CSF builds up in the central nervous system, causing the fontanelle (soft spot) to bulge and the head to be larger than expected. Early symptoms may also include eyes that appear to gaze downward, irritability, seizures, sleepiness, and vomiting.
Image Source: Pascal Deloche
In older children, symptoms include
- brief, shrill, high-pitched cry
- changes in personality, memory, or the ability to reason or think
- changes in facial appearance and eye spacing
- crossed eyes or uncontrolled eye movements
- difficulty feeding
- excessive sleepiness
- poor temper control
- loss of bladder control (urinary incontinence)
- loss of coordination and trouble walking
- muscle spasms
- slow growth (especially in children 0-5 years)
One way to test for hydrocephalus is to tap the skull and listen for abnormal sounds that indicate thinning and separation of skull bones. Scalp veins may also appear stretched or enlarged. Part of or the entire head may be larger than normal, but enlargement is most commonly seen in the front part of the head. Head circumference measurements, repeated over time, may show that the head continues to grow. Reflexes may be abnormal. The best way to diagnose hydrocephalus, however, is a CT scan of the head.
Sadly, there is a 50-60% death rate for untreated hydrocephalus. In addition, survivors will have intellectual, physical, and neurological disabilities. Patients with hydrocephalus caused by tumors usually do very poorly when tested in these areas. Most children with hydrocephalus who survive their first year will have a fairly normal life span. About 33% of these children will have normal intellectual function, but neurological difficulties may continue.
The main goal of treatment for hydrocephalus is to reduce or prevent brain damage by improving the flow of CSF. If possible, blockages are surgically removed. If not, a shunt (flexible tube) is placed in the brain to help CSF flow around the blocked area. The other end of the shunt is placed in another part of the body where the extra CSF can be absorbed into the blood stream. The removal or burning away (cauterizing) of the parts of the brain that produce CSF can also reduce CSF production. Follow-up examinations generally continue throughout the child’s life.
Featured Image Source: Cry, Baby, Cry by Anton Bielousov