What is a Chiari malformation?
Chiari (pronounced “Key-ari”) malformation, also known as Arnold Chiari malformation, is a condition where a small portion of brain tissue from the lower back of the skull extends into the spinal canal. This occurs when the skull is smaller than expected, leaving limited space for the brain. As a result, part of the brain called the cerebellum pushes downward through the opening at the base of the skull, known as the foramen magnum.
Chiari malformation is most often congenital, which means it is present at birth. While Chiari malformation is rare, advancements in imaging technology have led to more frequent diagnoses during a woman’s pregnancy.
Types of Chiari malformation
Chiari malformations are most often present at birth. However, in rare cases, the condition can develop later in life due to injury, disease or conditions that cause excess fluid buildup in the skull. These are known as secondary or acquired Chiari malformations.
No matter when a Chiari malformation develops, doctors classify it into one of four types based on which parts of the brain extend into the spinal canal and the severity of the condition. This classification helps guide treatment decisions.
Chiari Malformation Type I
The most common form, Type I, happens when the lower part of the cerebellum (the part of the brain that controls balance and coordination) pushes into the opening between the skull and the spinal cord, known as the foramen magnum. Most people don’t have symptoms at first, and it’s often found incidentally during imaging tests for other conditions.
Chiari Malformation Type II
In Type II Chiari malformation, both the cerebellum and brainstem push downward into the spinal canal, where they normally do not belong. This type is almost always linked to a condition called myelomeningocele, a serious form of spina bifida that happens when the spinal cord and backbone don’t close properly before birth. Myelomeningocele often leads to weakness or paralysis below the affected area of the spine. Type II is also the type most often associated with hydrocephalus, which means a buildup of excess fluid in the brain.
Chiari Malformation Type III
Type III is a very rare and severe form that occurs when the cerebellum and parts of the brainstem extend through an opening in the back of the skull, forming a sac (called an encephalocele). This rare condition can cause significant neurological symptoms, such as seizures, developmental delays and physical disabilities.
Chiari Malformation Type IV
The rarest and most severe form, Type IV happens when the cerebellum doesn’t fully develop. Parts of the cerebellum may be missing or underdeveloped, which can lead to serious problems with brain function.
Chiari malformation symptoms
Not everyone with a Chiari malformation has symptoms. Some people may not notice side effects until later in life. Symptoms depend on several factors, including the type of Chiari malformation, how much the brain presses on the bottom of the lower skull, and whether it restricts the fluid that surrounds the brain and spinal cord, known as cerebrospinal fluid.
When Chiari malformation symptoms occur, they may include:
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Head and balance problems
- Headaches, often triggered by coughing, sneezing or straining
- Dizziness or loss of balance
- Ringing in the ears (tinnitus)
- Vision changes, such as blurred or double vision
- Hearing loss
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Muscle and movement issues
- Weakness in the arms or legs
- Problems with coordination
- Scoliosis (curvature of the spine)
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Breathing, eating and speaking difficulties
- Trouble swallowing, gagging, or frequent choking
- Problems with breathing or sleep apnea
- Speech difficulties
- Drooling or frequent vomiting (more common in infants and children)
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Other possible symptoms
- Sleep problems, such as insomnia
- Depression
- Difficulty gaining weight in infants
- Heart palpitations
When to see a doctor
See your primary care doctor if you or your child experience any unusual symptoms. Your doctor can rule out other conditions and help determine whether a Chiari malformation could be the cause. If your doctor suspects this defect, they may refer you to a neurologist for a more detailed evaluation and specialized treatment.
Chiari malformation causes
A Chiari malformation happens when the lower part of the brain pushes down into the spinal canal, the space where your brain and spinal cord meet. This is caused by a structural issue in the brain and spinal cord, where the area that holds your cerebellum (the part of the brain that controls movement) is smaller than usual. This extra pressure causes the cerebellum to move to an unusual spot. This typically happens while babies are still developing in the womb.
The condition is often linked to a genetic change (mutation) inherited from your family, or it can happen randomly after conception. In very rare cases, a Chiari malformation can develop later in life, even if you weren't born with it. This can happen if there’s a change in the shape of your skull or spinal cord caused by:
- A brain tumor
- A cyst
- Blood buildup (hematoma)
- Fluid buildup in the brain (hydrocephalus)
- Increased pressure in the brain (intracranial hypertension or pseudotumor cerebri)
Sometimes, a Chiari malformation can also be seen alongside other health conditions like:
- Goldenhar syndrome
- Achondroplasia (a form of dwarfism)
- Connective tissue disorders like Ehlers-Danlos syndrome
- Spina bifida
Chiari malformation risk factors
Scientists are still learning what can increase the risk of a Chiari malformation. A Chiari malformation can affect anyone, but you're more likely to develop it if someone in your biological family has the condition.
Complications
In some people, a Chiari malformation may not cause any symptoms, and they may not need treatment. However, in others, the condition can worsen over time and lead to serious complications. These complications may include:
- Hydrocephalus: This occurs when too much fluid builds up in the brain, which can affect thinking and cause other issues. People with hydrocephalus may need a shunt, a flexible tube that helps drain the extra fluid to another part of the body.
- Spina bifida: This is a condition where the spinal cord or its protective covering doesn't fully develop. Part of the spinal cord may be exposed, leading to serious problems like paralysis. People with Chiari malformation Type II often have a type of spina bifida called myelomeningocele.
- Syringomyelia: Some people with Chiari malformation also develop syringomyelia, where a cyst or cavity (called a syrinx) forms in the spinal cord. As it grows, the syrinx can put pressure on the nerves, causing pain, weakness, and stiffness.
- Tethered cord syndrome: In this condition, the spinal cord becomes attached to the spine, causing it to stretch. This can lead to nerve and muscle damage, especially in the lower body.
How is Chiari malformation diagnosed?
To diagnose a Chiari malformation, your doctor will do a physical exam and check things like your memory, balance, coordination, reflexes and movement. They may also order imaging tests to confirm the diagnosis or to look for other conditions, such as fluid buildup in the brain (hydrocephalus) or bone abnormalities.
Medical history and exam
Your doctor will ask about any health conditions you have and how you’re treating them. They’ll also want to know about any conditions or disorders that run in your family and as much information as possible about your symptoms, including when they began, how often they occur, what they feel like and how they affect your ability to function. Your doctor will conduct a thorough exam of your physical health and may also want to test important indicators of neurological health, such as your reflexes, balance and motor skills. Problems with balance and other neurological functions may be signs of a Chiari malformation.
Imaging tests
Several imaging tests can provide valuable information about the condition of your brain and spinal cord and help your doctor make a diagnosis, including:
- Magnetic resonance imaging (MRI) scan: This type of imaging, which creates pictures using radio waves and magnets, is often the first imaging test providers order for diagnosing a Chiari malformation. An MRI can show how much of the cerebellum, if any, has entered the spinal canal.
- Computed tomography (CT) scan: Your provider may also order a CT scan to help rule out other potential causes of your symptoms, such as a brain tumor. A type of X-ray test, a CT scan can also show abnormalities in the skull and spine.
- X-ray: Your doctor may want you to have X-rays to look for problems with the bones at the bottom of your skull.
Chiari malformation treatment
Your doctor will develop a personalized treatment plan tailored to your specific needs, considering factors like the severity of your symptoms, how they affect your daily life and your personal goals. Not everyone with Chiari malformation needs treatment. If you don't have any symptoms, your doctor may recommend monitoring the condition with regular imaging tests. You and your doctor can always adjust your plan and start treatment if symptoms appear.
If your Chiari malformation causes symptoms, your doctor might suggest lifestyle changes, therapy or medications to help manage things like headaches. For more severe symptoms, surgery to create more space for the cerebellum or address related problems, like hydrocephalus, may be the most effective solution.
Lifestyle changes
Not everyone with Chiari malformation requires surgery, especially for mild symptoms. You might be able to manage your symptoms and improve your quality of life by adjusting your daily activities.
Some lifestyle changes for Chiari malformation include:
- Reducing symptom triggers: Avoiding heavy lifting, straining or intense physical activity can prevent increased pressure on the brain and spinal cord, which can lead to headaches and other symptoms.
- Using assistive devices: A cane can offer more stability when walking. Glasses can help with blurry vision, and hearing aids may improve symptoms like hearing loss.
Medication
Medications can’t treat a Chiari malformation, but they can help you manage pain and other symptoms. Your doctor may recommend prescription or over-the-counter medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), to help with pain relief.
Therapy
In addition to medications, therapy may help improve your quality of life. These treatments can reduce symptoms and help you manage daily activities more comfortably.
- Physical therapy: A physical therapist can teach you exercises to improve balance and reduce dizziness. They can also use techniques like manual therapy to help relieve joint pain.
- Massage therapy: This type of therapy can help relax muscles, reduce tension and improve circulation, which may ease pain or discomfort related to Chiari malformation.
Surgery
For some people, nonsurgical treatments aren't enough. If symptoms are severe, surgery may offer the best chance of reducing symptoms and improving your overall quality of life. Your surgical options may include:
- Posterior fossa decompression: This is the most common procedure to treat Chiari malformation. It involves removing a piece of bone at the base of the skull to create more space for the cerebellum and relieve pressure on the brain.
- Laminectomy: During this procedure, your surgeon will remove the lamina, a type of bone covering the spinal canal, to eliminate pressure on the spinal cord and allow cerebrospinal fluid to flow more freely.
- Duraplasty: To relieve pressure on your brain, your surgeon will enlarge the dura, one of the membranes covering it.
- Electrocautery: Your surgeon will use an electric current to remove two small parts of the cerebellum called the cerebellar tonsils. Removing this material makes room for the cerebellum.
- Shunt placement: If you have hydrocephalus, your surgeon may place a shunt, or tube, in your skull to drain excess cerebrospinal fluid away from your brain.
Find specialized care
We offer several locations for specialized care and treatment of Chiari malformations, including neurology centers across North and Central Texas. Our experienced team is ready to provide personalized care to help manage your condition and improve your quality of life. Whether you're seeking diagnosis, treatment or ongoing support, we're here to guide you every step of the way.
Baylor Scott & White Dallas Diagnostic Association - Garland (Satellite)
5220 W University Dr POB II, Ste 250, McKinney, TX, 75071
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Neurology - McKinney
5236 W University Dr Ste 3700, McKinney, TX, 75071
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Medical Center - McKinney
5252 W University Dr Highway 380 at Lake Forest Drive, McKinney, TX, 75071
Baylor Scott & White Medical Center - Lake Pointe
6800 Scenic Dr , Rowlett, TX, 75088
Baylor Scott & White Neurology - Lake Pointe
7600 Lakeview Pkwy Ste 150, Rowlett, TX, 75088
- Monday: 8:00 am - 4:00 pm
- Tuesday: 8:00 am - 4:00 pm
- Wednesday: 8:00 am - 4:00 pm
- Thursday: 8:00 am - 4:00 pm
- Friday: 8:00 am - 4:00 pm
Baylor Scott & White Medical Center - Frisco at PGA Parkway
7600 Better Way , Frisco, TX, 75033
Baylor Scott & White Medical Center - Centennial
12505 Lebanon Rd , Frisco, TX, 75035
Baylor Scott & White Dallas Diagnostic Association - Garland
7217 Telecom Pkwy Ste 300, Garland, TX, 75044
- Monday: 8:00 am - 4:30 pm
- Tuesday: 8:00 am - 4:30 pm
- Wednesday: 8:00 am - 4:30 pm
- Thursday: 8:00 am - 4:30 pm
- Friday: 8:00 am - 4:30 pm
- Monday: 8:00 am - 4:15 pm
- Tuesday: 8:00 am - 4:15 pm
- Wednesday: 8:00 am - 4:15 pm
- Thursday: 8:00 am - 4:15 pm
- Friday: 8:00 am - 4:15 pm
Baylor Scott & White Medical Center - Sunnyvale
231 S Collins Rd , Sunnyvale, TX, 75182
Baylor Scott & White Neurology - Plano
4708 Alliance Blvd Pavilion I, Ste 550, Plano, TX, 75093
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 4:30 pm
Baylor Scott & White - Plano Brain and Spine Center
4708 Alliance Blvd Pavilion I, Ste 810, Plano, TX, 75093
Baylor Scott & White Dallas Diagnostic Association - Plano
4716 Alliance Blvd Pavilion II, Plano, TX, 75093
- Monday: 7:00 am - 5:00 pm
- Tuesday: 7:00 am - 5:00 pm
- Wednesday: 7:00 am - 5:00 pm
- Thursday: 7:00 am - 5:00 pm
- Friday: 7:00 am - 5:00 pm
- Saturday: 8:00 am - 12:00 pm
Baylor Scott & White Medical Center - Plano
4700 Alliance Blvd , Plano, TX, 75093
Baylor Scott & White Neurology Hospitalist Group - Plano
4700 Alliance Blvd , Plano, TX, 75093
The Headache Center at Baylor University Medical Center
9101 N Central Expy Ste 400, Dallas, TX, 75231
Baylor Scott & White Neuroscience Center
9101 N Central Expy Ste 400, Dallas, TX, 75231
Baylor Scott & White Headache Medicine Specialists of North Texas - Dallas
9101 N Central Expy Ste 400, Dallas, TX, 75231
- Monday: 8:00 am - 4:30 pm
- Tuesday: 8:00 am - 4:30 pm
- Wednesday: 8:00 am - 4:30 pm
- Thursday: 8:00 am - 4:30 pm
- Friday: 8:00 am - 4:30 pm
Baylor Scott & White Cognitive and Behavioral Neurology Associates
9101 N Central Expy Ste 230, Dallas, TX, 75231
- Monday: 8:00 am - 4:30 pm
- Tuesday: 8:00 am - 4:30 pm
- Wednesday: 8:00 am - 4:30 pm
- Thursday: 8:00 am - 4:30 pm
- Friday: 8:00 am - 4:30 pm
Baylor University Medical Center, part of Baylor Scott & White Health
3500 Gaston Ave , Dallas, TX, 75246
Baylor Scott & White Neurology - Dallas
3434 Swiss Ave Ste 400, Dallas, TX, 75204
- Monday: 8:00 am - 4:30 pm
- Tuesday: 8:00 am - 4:30 pm
- Wednesday: 8:00 am - 4:30 pm
- Thursday: 8:00 am - 4:30 pm
- Friday: 8:00 am - 2:00 pm
Baylor Scott & White Medical Center - Irving
1901 N MacArthur Blvd , Irving, TX, 75061
Baylor Scott & White Neurology - Irving
2021 N MacArthur Blvd Ste 210, Irving, TX, 75061
- Monday: 8:00 am - 4:30 pm
- Tuesday: 8:00 am - 4:30 pm
- Wednesday: 8:00 am - 4:30 pm
- Thursday: 8:00 am - 4:30 pm
- Friday: 8:00 am - 1:00 pm
Baylor Scott & White Medical Center - Grapevine
1650 W College St , Grapevine, TX, 76051
Baylor Scott & White Medical Center - Waxahachie
2400 N Interstate 35E , Waxahachie, TX, 75165
Baylor Scott & White All Saints Medical Center - Fort Worth
1400 8th Ave , Fort Worth, TX, 76104
Baylor Scott & White Neurosciences Clinic - Waco
50 Hillcrest Medical Blvd Ste 201-A, Waco, TX, 76712
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Medical Center - Hillcrest
100 Hillcrest Medical Blvd , Waco, TX, 76712
Baylor Scott & White McLane Children's Specialty Clinic - Waco Hillcrest
120 Hillcrest Medical Blvd Bldg II, Ste 101, Waco, TX, 76712
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White McLane Children's at Baylor Scott & White Clinic - College Station University Drive
1700 University Dr E East Entrance 15, First Floor, Desk P, College Station, TX, 77840
- Monday: 8:00 am - 7:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 7:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Clinic - College Station Rock Prairie
800 Scott and White Dr , College Station, TX, 77845
- Monday: 7:30 am - 5:00 pm
- Tuesday: 7:30 am - 5:00 pm
- Wednesday: 7:30 am - 5:00 pm
- Thursday: 7:30 am - 5:00 pm
- Friday: 7:30 am - 5:00 pm
Baylor Scott & White Medical Center - College Station
700 Scott and White Dr , College Station, TX, 77845
Baylor Scott & White Medical Center - Temple
2401 S 31st St , Temple, TX, 76508
Baylor Scott & White Clinic - Temple
2401 S 31st St , Temple, TX, 76508
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White McLane Children's Medical Center - Temple
1901 SW H K Dodgen Loop , Temple, TX, 76502
Baylor Scott & White McLane Children's Specialty Clinic - Temple
1901 SW H K Dodgen Loop , Temple, TX, 76502
Baylor Scott & White Medical Center - Brenham
700 Medical Pkwy , Brenham, TX, 77833
Baylor Scott & White Specialty Clinic - Killeen Hemingway
2405 S Clear Creek Rd , Killeen, TX, 76549
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Medical Center - Taylor
305 Mallard Ln , Taylor, TX, 76574
Baylor Scott & White Clinic - Round Rock 300 University
300A University Blvd , Round Rock, TX, 78665
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White McLane Children's Specialties at Baylor Scott & White Clinic - Round Rock 425 University
425 University Blvd , Round Rock, TX, 78665
Baylor Scott & White Medical Center - Round Rock
300 University Blvd , Round Rock, TX, 78665
Baylor Scott & White Clinic - Pflugerville Medical Center (Building 1)
2600 E Pflugerville Pkwy Bldg 1, Ste 200, Pflugerville, TX, 78660
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
- Monday: 7:30 am - 4:00 pm
- Tuesday: 7:30 am - 4:00 pm
- Wednesday: 7:30 am - 4:00 pm
- Thursday: 7:30 am - 4:00 pm
- Friday: 7:30 am - 4:00 pm
Baylor Scott & White Clinic - Pflugerville Medical Center Building 2
2600 E Pflugerville Pkwy Building 2, Pflugerville, TX, 78660
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
- Monday: 8:00 am - 4:00 pm
- Tuesday: 8:00 am - 4:00 pm
- Wednesday: 8:00 am - 4:00 pm
- Thursday: 8:00 am - 4:00 pm
- Friday: 8:00 am - 4:00 pm
Baylor Scott & White Clinic - Austin River Place
10815 Ranch Rd 2222 , Austin, TX, 78730
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Medical Center - Lakeway
100 Medical Pkwy , Lakeway, TX, 78738
Baylor Scott & White Specialty Clinic - Lakeway
200 Medical Pkwy , Lakeway, TX, 78738
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Clinic - Buda Medical Center
5330 Overpass Rd Ste 100, Buda, TX, 78610
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Baylor Scott & White Specialty Clinic - Marble Falls
800 W State Hwy 71 , Marble Falls, TX, 78654
- Monday: 8:00 am - 5:30 pm
- Tuesday: 8:00 am - 5:30 pm
- Wednesday: 8:00 am - 5:30 pm
- Thursday: 8:00 am - 5:30 pm
- Friday: 8:00 am - 5:30 pm
Baylor Scott & White Medical Center - Marble Falls
810 W State Hwy 71 , Marble Falls, TX, 78654
Baylor Scott & White Specialty Clinic - Horseshoe Bay
201 Bay West Blvd , Horseshoe Bay, TX, 78657
- Monday: 8:00 am - 5:00 pm
- Tuesday: 8:00 am - 5:00 pm
- Wednesday: 8:00 am - 5:00 pm
- Thursday: 8:00 am - 5:00 pm
- Friday: 8:00 am - 5:00 pm
Frequently asked questions
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Is Chiari malformation hereditary?
Yes, Chiari malformation can be hereditary. Families with a history of the condition may have a higher risk, suggesting genetic factors are involved. However, the exact genes are not fully understood. Chiari malformation can also develop later in life due to factors like trauma, though this is less common.
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Can Chiari malformation cause seizures?
Yes, Chiari malformation can cause seizures in some cases, especially if it's severe or if there are other issues like fluid buildup in the brain. Seizures may affect part of the brain or the whole brain. If you experience seizures, contact your doctor right away for treatment options.
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How common is Chiari malformation?
Chiari malformation is found in about 0.5-3.5% of the general population, with Type I being the most common. Type II happens in about 1 in 1,000 births. Other types are rare. Many cases may go unnoticed because symptoms can be mild or not present, though more are being detected with MRI scans.
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Can Chiari malformation get worse?
Yes, Chiari malformation can get worse over time, causing symptoms like headaches, neck pain, numbness, weakness or fluid buildup in the brain. Things like age, the type of malformation and other health conditions can increase the risk. Regular check-ups and early treatment can help manage symptoms and improve quality of life.
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Can Chiari malformation go away?
Chiari malformation typically doesn't go away on its own. In very rare cases, especially in children, it may improve as the skull grows. This happens in less than 1% of cases. If symptoms continue, surgery might be needed to help relieve pressure and improve your condition.