About Chiari Malformations
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Chiari malformations are structural defects that affect tissue in the brainstem, cerebellum (the area of the brain at the back of the skull), and spinal cord. They can cause symptoms ranging from headaches and neck pain to issues with sleep and swallowing.
Types of Chiari Malformations
Chiari malformations can be categorized into different types, with Chiari malformation type I being the most common.
Type I symptoms can develop during childhood, adolescence, or even into adulthood. With Chiari malformation type I, the brain bulges through an opening at the base of the skull, putting pressure on the brain and spinal cord. This can block the normal flow of cerebrospinal fluid (CSF), causing hydrocephalus (a buildup of fluid in the brain) or a syrinx (a fluid-filled cyst within the spinal cord). A syrinx can lead to numbness, tingling, weakness, back or extremity pain, scoliosis, or changes in bowel or bladder function.
Type II typically affects children born with spina bifida, specifically infants with a myelomeningocele -- spinal cord tissue that protrudes through an opening in the spine.
Type III is a rare and very serious form of Chiari malformation. Some parts of the brain may stick out, or herniate, through an abnormal opening in the back of the skull.
Type IV is very rare. In this type, part of the brain is underdeveloped or missing.
Diagnosing Chiari Malformations
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Duke neurosurgeons combine clinical evaluation with advanced testing to diagnose and better understand your or your child’s condition. We take time to listen and understand your medical history, symptoms, prior treatments, and their impact on your quality of life.
Physical and Neurological Exam
Your doctor will conduct a thorough physical and neurological examination to identify signs and symptoms.
Imaging
Your doctor may recommend imaging tests, such as MRI or CT scans, to confirm a diagnosis or evaluate changes over time. Other images, such as X-rays, can be beneficial if you have associated medical conditions, such as scoliosis.
Treatments for Chiari Malformations
Treatments Overview
Our neurosurgeons collaborate with neurologists, sleep medicine specialists, therapists (physical, occupational, and speech), neuro-ophthalmologists, neuro-radiologists, pain medicine specialists, and others to provide you or your child with the best care.
Monitoring
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For people with less severe symptoms, we may recommend monitoring the Chiari malformation over time. In adults, this usually means tracking symptoms and updating our team if concerns come up. In children, this can mean periodic repeat imaging as they grow. In younger children, a Chiari malformation may improve on its own without surgery.
Headache Medication
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Medications can help manage headache pain.
Shunt Surgery
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Often, symptoms of a type II Chiari malformation can be relieved by surgically placing a shunt -- a device that helps divert excess fluid away from the brain due to hydrocephalus. A shunt consists of two long, flexible tubes (catheters) and a valve joining them to control the flow of fluid. One end of the shunt is placed into the part of the brain where there is too much fluid. The other end drains the fluid to another area of the body where the excess fluid can be absorbed. A shunt that is no longer working may make Chiari malformation symptoms worse. In this case, repairing the shunt may be all that is needed.
Decompression Surgery
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When symptoms become severe and affect function, decompression surgery may be the best option. During this procedure, a small area of bone at the back of the skull is removed to create more space around the lower brain and upper spine. This relieves pressure on the brainstem and spinal cord. Depending on the condition and circumstances, your neurosurgeon may consider also opening the dura (a membrane that surrounds the brain and spinal cord), opening the arachnoid membrane to restore CSF flow, and inserting a patch to further expand the space. The goal of decompression surgery is to restore the normal flow of CSF, reduce the size of the syrinx (if present), and improve quality of life.
Syringomyelia (Syrinx) Surgery
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If you have a syrinx (this condition is called syringomyelia), depending on its size and your symptoms, decompression surgery may be indicated. Rarely, surgery may not resolve the syrinx and other interventions may be required.
