Developmental Neurosurgery
Developmental neurosurgery includes a wide range of disorders that include hydrocephalus, spina bifida, chiari malformation and syringomyelia and which may overlap.
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Developmental Neurosurgery
The Developmental Neurosurgery Web page provides indexes for hydrocephalus, spina bifida, chiari malformation and syringomyelia, as well as other conditions, and links to related topics.
Hydrocephalus Association
The Hydrocephalus Association homepage gives basic information on the conditions, as well as support, education materials and advocacy for families and professionals.
Spina Bifida Association of America
This is the homepage of the Spina Bifida Association of America, which provides publications, conferences, education, scholarships and other services for members and professionals, including links to other Web sites.
American Syringomyelia Alliance Project Inc.
The American Syringomyelia Alliance Project Inc. (ASAP) offers educational materials, a newsletter and annual conference, networking and other efforts for families and professionals of patients with syringomyelia, chiari malformations and related disorders. The ASAP also supports research to find the causes, develop and improve treatments and help improve the lives of people with the disorder.
National Institute of Neurological Disorders and Stroke
The National Institute of Neurological Disorders and Stroke offers a patient guide to disorders that are listed on this Web page alphabetically under the heading of publications. Information on hydrocephalus, spina bifida, chiari malformation and syringomyelia is available in the alphabetical directory. This Web site also has information for professionals. |
Hydrocephalus
Definition
While hydrocephalus may be commonly called ‘water on the brain,’ it is actually the abnormal accumulation of cerebrospinal fluid inside the four spaces or ventricles inside the brain.
This accumulation causes the ventricles to swell and compress the surrounding tissue, which can harm the brain and have an impact on both physical and cognitive development.
Cerebrospinal fluid is extremely important to the function of the brain and therefore the entire body. It normally flows in pathways from one ventricle to the next and outside the brain, down the spinal cord and into the bloodstream.
The fluid acts as protection for the brain and spinal cord, delivers nutrients, removes waste and compensates for changes in blood volume within the brain.
Congenital hydrocephalus occurs in about one or two per 1000 births. The cause often cannot be determined, possibly environmental factors during development or genetic predisposition. Premature babies can be at risk for hydrocephalus because their brains are still developing.
Acquired hydrocephalus develops at birth or later and can be caused by head trauma, tumors, cysts, meningitis or intraventricular hemorrhage.
About 90 percent of children born with spina bifida have hydrocephalus.
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Symptoms
The symptoms vary greatly with the age of the patient, the progression of the disease and the ability to tolerate the pressure from the cerebrospinal fluid.
Babies and infants with hydrocephalus may have enlarged heads or a rapid increase in head circumference. They may be able to tolerate the pressure better because their skulls are not fully developed. Their other symptoms may include vomiting, sleepiness, irritability, downward deviation of the eyes and seizures.
Older children or adults will have the pressure, but not the enlarged heads, because their skulls are already developed and closed. Their symptoms may include headache, vomiting, nausea, blurred or double vision, downward deviation of the eyes, problems with balance and coordination, a slowing of development, lethargy, drowsiness, changes in personality or cognition.
Diagnosis
After physical and neurological evaluations, the patient may undergo scanning such as ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) and pressure monitoring techniques.
Because of advances in diagnostic imaging, congenital hydrocephalus can be diagnosed prenatally.
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Treatment
The most frequent treatment is the insertion of a shunt system that diverts the flow of the fluid to a region of the body where it can be absorbed. The system includes a flexible tube, a catheter and a valve.
Shunt systems must be carefully monitored because of the potential for problems and the need for revisions.
Another method is to make a hole in the third ventricle to allow the fluid to bypass an obstruction and flow around the brain.
In addition, rehabilitation therapies, as well as educational interventions, may be needed because of any problems with physical or cognitive development.
Spina Bifida
Definition
Spina bifida is a neural tube defect that occurs when the vertebrae and/or the spinal cord of the fetus do not develop properly, causing damage to the spinal cord and nervous system.
The damage can vary from an open spinal cord to a missing or misformed vertebrae. Other damage to the central nervous system can also occur, including hydrocephalus, chiari malformations and syringomyelia. The defect occurs as the vertebrae and spinal cord are developing in the fetus during the first month.
It occurs in about one of every 1,000 children born in the United States. No single cause has been found, but genetics and environment as well as a folate deficiency may be factors.
In 1992, the U.S. Public Health Service published a recommendation that "all women of childbearing age in the United States should consume 0.4 mg of folic acid daily to reduce the risk of having a pregnancy affected by a neural tube defect."
This means taking folic acid before conception and during the first few weeks of pregnancy.
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Symptoms
The symptoms vary as to the level of the condition. In some cases, the spinal cord may protrude through the back and be covered by skin or a thin membrane.
Children with spina bifida may also have hydrocephalus, syringomyelia and chiari malformations. They may suffer physical problems, muscle paralysis, bowel and bladder complications, respiratory difficulties and swallowing problems. They can have secondary conditions such as learning problems, latex allergies, tendinitis, obesity, skin breakdown, gastrointestinal disorders, depression and social issues.
Diagnosis
Before birth, diagnosis can be made on the basis of elevated maternal alpha fetal protein levels or by using ultrasound.
Spina bifida may be recognized after birth. Further examinations and testing may be done to determine the intensity of the condition or any additional problems.
Treatment
Often spina bifida is treated medically and surgically. Infants may require immediate surgery to close the back and spinal cord. Hydrocephalus may need to be treated immediately with a shunt system.
They may need multiple surgeries to help with spinal, foot or leg problems, techniques to control bladder and bowel functions and braces and other equipment to help with movement.
Because many different parts of the body and central nervous system are involved, many physicians, therapists and others may be part of the treatment.
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Chiari Malformation
Definition
Chiari malformation, also known as Arnold-Chiari, is a condition in which the cerebellum protrudes down into the spinal canal.
The malformation may be associated with other conditions such as spina bifida, hydrocephalus and syringomyelia.
The effect of this protrusion is that it can lead to physical, as well as mental problems, including paralysis and neurological impairment.
Chiari malformation may be congenital. It may begin in infancy or may be delayed until adolescence or adulthood. The cause is unknown.
Symptoms
Many patients can be without symptoms or have vague symptoms. The most common are headache and neck pain. Other symptoms can include paralysis in the arms and/or legs, difficulty swallowing, vomiting, mental impairment and muscle weakness in the head and face.
Straining can make the symptoms worse.
Adults and adolescents may develop involuntary, rapid downward eye movements, double vision, deafness, lack of coordination and episodes of pain around the eyes.
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Diagnosis
Physical and neurological evaluations of the patient may lead to further testing to determine the depth of the problem. Malformations may be difficult to see on a computerized tomography (CT) scan or X-ray and may require magnetic resonance imaging (MRI).
Treatment
Untreated, Chiari malformations can lead to very serious problems, including paralysis and the development of other injuries to the child’s function.
Basically the treatment for these malformations is surgery, aimed at uncrowding the area at the base of the cerebellum by removing a small portion of bone at the base of the skull.
The operation may be altered if hydrocephalus or syringomyelia are present. The surgery typically improves the symptoms.
Syringomyelia
Definition
Syringomyelia (or syringohydromyelia) is a disorder that involves the abnormal collection of cerebral fluid in the spine that is often referred to as a syrinx or a cyst.
In most cases, it may be a congenital abnormality related to Chiari malformation. Some people may also have hydrocephalus. Symptoms may not appear until ages 25 to 40. About 21,000 Americans have syringomyelia.
Another form of syringomyelia comes about as the result of trauma, meningitis, hemorrhage or tumor. Symptoms may not appear until months or years after the initial problem.
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Symptoms
The symptoms may be vague because they are related to damage caused by the impact of the cyst on the central nervous system. They can be dormant and not show up for years.
The symptoms also are similar to other conditions, making diagnosis difficult. Coughing and straining can cause sudden onset. Patients may also have other conditions, such as hydrocephalus.
Symptoms include pain, weakness and stiffness in the back, shoulders, arms or legs. Other symptoms are headaches and the loss of temperature sensitivity, particularly in the hands. Untreated, syringomyelia can lead to severe, chronic pain, weakness in the arms and legs and loss of hand sensation.
If the syringomyelia is the result of an injury, the symptoms may begin as pain, weakness of lack of feeling at the site of the injury and then spread upward.
Diagnosis
Patients with these symptoms would first have physical and neurological examinations before having more detailed testing, such as magnetic resonance imaging (MRI) to identify not only the syringomyelia, but any associated abnormalities.
Additional testing could include electromyography (EMG) to measure muscle weakness, lumbar puncture to measure cerebrospinal fluid and computed tomography (CT) scans for the presence of tumors and other abnormalities.
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Treatment
Treatment for causes such as hydrocephalus or chiari malformation may help the syringomyelia resolve on its own.
Surgery is done to make more space for the cerebellum at the base of the skull and upper neck. Recurrence could require additional surgery. If a tumor is present, it will be removed and may eliminate the syrinx.
Treatment also could involve a drain or shunt to divert fluid to other locations. Shunts require close follow-up and the potential of revisions.
Research
Studies on disorders like hydrocephalus, spina bifida, chiari malformation and syringomyelia begin with the development of the fetus.
Research is aimed at treatment (like taking folic acid) to prevent disorders like spina bifida. In addition, researchers are trying to understand the impact of these neurological conditions on cognitive development, academic achievement and behavior in children with the condition.
Research is also underway to improve the shunt system to allow fewer revisions and complications. Diagnostic techniques in which conditions can be seen even before symptoms appear are another area of research.
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