Hydrocephalus, also called "water on the brain", is a serious problem that results when excess cerebrospinal fluid (CSF) builds up around the brain. The increased pressure can cause brain damage. CSF is a liquid that circulates continuously around the brain and spinal cord. It provides nutrients, as well as cushioning, in order to protect these essential organs from damage. Ordinarily, CSF is produced and drained at a constant rate. However, in 80-90% of people with spina bifida, the flow of CSF is partially blocked, causing the CSF to build up in the brain, which can cause brain damage if left untreated.
When hydrocephalus occurs, a shunt tube must be placed to drain the extra CSF and relieve the brain from excess pressure. The shunt tube runs from the normal structures in the brain where the fluid has accumulated, through a valve, and into an area of the body that can safely absorb the excess fluid (generally the lining of the abdominal cavity). Shunting is not intended to stop the hydrocephalus completely, but rather to reduce it and prevent it from getting worse.
Shunt failure and revision
Once it is placed, a shunt can continue to work for quite some time, though it is not uncommon for a problem to develop with a shunt. If a shunt is placed in a small child, the neurosurgeon will include extra tubing on the abdominal end to allow for growth, but the tubing rarely stays intact for a lifetime.
Some people with mild hydrocephalus can outgrow the need for a shunt. For most people, however, the need for the shunt lasts longer than the shunt itself can remain working in place. If the tubing becomes clogged or disconnected, the person may again experience the effects of increasing pressure on the brain. This is a medical emergency. In such cases, the shunt must be replaced (known as a shunt revision), or else a second shunt is added.
It is important to be familiar with the most common signs and symptoms of hydrocephalus or shunt failure, which include:
change in mental status (confusion, drowsiness)
lethargy (fatigue, lack of energy)
increased irritability (in babies this might mean inconsolable crying)
decrease in function of motor skills (e.g., impaired coordination)
seizures or staring spells
sharp pain at the site of the lesion
bulging fontanel (the "soft spot") on the top of a baby's head
redness or swelling of the skin along the shunt tract
downward direction of the eyes (known as "sunset" appearance)
If you or your child experiences any of these symptoms that do not have another obvious cause, you should seek medical evaluation immediately. Be prepared to give a complete history for the examining health care provider. Do not assume that the health care professional knows that you or your child has a shunt.
Chiari II malformation
Chiari malformation is a condition in which a portion of the brain stem is displaced downward, out the back of the skull and into the neck. While there are different classes of Chiari malformation, nearly every person with spina bifida has "type II", or Chiari II malformation.
Many changes in the structure of the brain are associated with this abnormality, which may contribute to a number of medical and psychosocial issues for people with spina bifida, including learning disorders and early puberty.
Chiari (brainstem) compression
While nearly every person with spina bifida has Chiari malformation that can be seen on an MRI scan, only a small percentage are likely to experience symptoms of "Chiari compression" or "brainstem compression". The brainstem is the location of essential and complex activities needed for life, such as breathing and swallowing.
The symptoms of Chiari compression can be life- threatening. It is a fact that respiratory failure (stopping breathing) is the leading cause of death for infants with spina bifida. The most common signs and symptoms of Chiari compression include the following:
Difficulty swallowing food or liquid
- Coughing when drinking
- Nasal regurgitation (throwing up through the nose)
- Stridor (a high-pitched, harsh sound while breathing)
- Apnea (temporary stop in breathing)
Voice changes or loss of ability to speak (e.g., a weak cry in an infant)
Abnormal eye, face, tongue, or neck movements (arching of the neck, facial weakness)
Decrease in strength or mobility of upper limbs
- Stiffness or spasticity of arms or hands
- Loss of feeling in arms or hands
Decrease in visual or auditory sensation (impaired sight or hearing)
If these symptoms should occur suddenly or become worse over time, please seek medical evaluation immediately. If your child's breathing becomes abnormal or if he or she begins to regurgitate (throw up) through the nose, call 9-1-1. Report what you have observed and tell the doctor that you have been trained that these symptoms could be due to a Chiari compression. Emergency room doctors who are not intimately familiar with spina bifida may not think of this diagnosis.
Posterior fossa decompression
The treatment for Chiari compression is determined by the how severe the symptoms are. To treat it, occasionally a surgical procedure, known as "posterior fossa decompression", may be necessary. This procedure involves removing portions of the cervical vertebrae (bones in the neck area) and skull to relieve pressure on the brainstem.
Pressure from a Chiari compression can also be relieved by shunting the fourth ventricle in the brain or a syrinx (see below), if one is present. The neurosurgeon will order further testing as needed, and will discuss the risks and benefits of any procedure with you.
Tethering of the spinal cord (also known as tethered cord syndrome) is a condition in which the spinal cord is not free to move in the spinal canal. In most cases, the cord is anchored (tethered) by scarring between the cord itself and the protective membrane that covers the spinal cord. (This is the same membrane that is surgically closed when a spina bifida lesion is originally repaired).
In other cases, the cord may be anchored by a fatty tumor, called a lipoma. An MRI of the spine of a person with spina bifida often reveals a tethered cord. However, as with Chiari malformation, a tethered cord only requires treatment if and when it is causing problems.
The most common signs and symptoms of tethered cord syndrome include the following:
Dull pain or ache at the site of the lesion
Decreased motor function in the legs
- New or increasing difficulty in walking (e.g. change in gait)
- Leg weakness or pain
- Decreasing muscle size or strength
- New or increasing muscle spasms
- New or increasing loss of sensation (feeling)
Progressive skeletal abnormalities
- Increasing spine curvature (e.g. scoliosis)
- Increasing foot deformities
Recurring ulcerations (sores) on feet
Bowel and bladder changes
- Loss of continence or increasing wetness between catheterizations
- Recurrent urinary tract infections (UTIs)
- Change in perineal sensation
- New or increasing bladder spasms
- Need to increase dosages of urinary continence medications for same results
- New or more frequent bowel accidents
- Worsening constipation
Tethered cord release
Surgery to release the tethered cord may stop or reverse the symptoms. Early diagnosis and treatment are important to minimize permanent loss of function. Some people with spina bifida will never experience tethered cord syndrome. Others may experience it more than once.
Another structural abnormality in the brain or spinal cord that can occur in individuals with spina bifida is called a syrinx, also known as a "hydromyelia" or "syringomyelia". A syrinx is an abnormal fluid space within the spinal cord that may trap CSF and prevent it from circulating properly. A syrinx may also exert pressure on the spinal cord and nerve roots (area where the spinal nerves leave the spinal cord).
A syrinx may develop in the spinal cord due to tethering or Chiari compression. A syrinx can also be present in the brainstem. In this case it is called "syringobulbia". Symptoms of syringomyelia are similar to those for Chiari compression.
A seizure can be a symptom of hydrocephalus, but seizures can occur for other reasons too. About 1 in every 500 children in the United States has a seizure disorder. Among children with spina bifida, the incidence increases to one in four. The risk is higher for children who have had several shunt failures or who have had a brain infection. Most seizure disorders can be treated effectively with medications.
Migraine headaches are characterized as severe recurring headaches, usually affecting only one side of the head, and often accompanied by nausea, vomiting, and/or visual disturbances. Migraines are more common than usual among people with shunted hydrocephalus, and more common among adolescents and young adults with spina bifida. It is not uncommon to experience headaches, but because a headache can be an early warning sign of hydrocephalus, persistent or recurring headaches should be brought to the attention of your primary provider or the clinic staff.
Some research studies have shown increased incidence of depression in people with spina bifida. Currently, the most well accepted theory is that depression is caused by lower level or poor functioning of certain chemicals in the brain that are called "neurotransmitters". Neurotransmitters send signals or instructions from cell to cell. Depression is linked to risk factors like stress, isolation, limited social support, low self-esteem, and learned helplessness.
Depression is also more common in people who:
Have a close family member who has been diagnosed with depression
Are female (probably due to hormonal influences)
Have experienced a significant loss in life
Everyone has experienced sadness and anxiety, but clinical depression and anxiety are more severe. Clinical depression can include:
Feelings of sadness that last longer and do not go away on their own
Inability to do the things that one previously enjoyed
Changes in eating habits such as a reduced appetite, or overeating
Changes in sleeping habits such as difficulty sleeping or oversleeping
If the people you are close to ask you whether you are depressed, take the question seriously—they have noticed a change in you.
Depression is treatable. Treatments may include:
Exercising can have a profound effect, especially if physical activity is combined with social contact.
Counseling can make a crucial difference, especially if a person has low self-esteem.
Medications can also make a tremendous difference, because they work at the neurotransmitter level. Anti-depressant medications are generally recommended for two to six months, in combination with counseling.
If you or someone you know seems to be depressed, talk to a health care provider about it. Kaiser members may self-refer for Behavioral Medicine services. You may contact your local Behavioral Medicine Department by visiting the KP Member website.