Frequently Asked Questions

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Frequently Asked Questions (FAQ)

This FAQ is intended for informational purposes only and in no way represents an attempt to provide medical advice. This information may or may not apply to your case and anyone with a question or concern about their health is strongly encouraged to consult with a medical professional. While every effort has been made to provide accurate information, C&S Patient Education Foundation is not responsible for any errors of content or omission.

Still have questions? Email: director@conquerchiari.org

What is a Chiari Malformation?
Is Arnold-Chiari different from Chiari?
What are the symptoms?
Does the size of the malformation matter?
How is a Chiari Malformation diagnosed?
What is a cine MRI?
What is a borderline Chiari?
How did my child get this condition?
My child doesn't have any symptoms, but an MRI shows a malformation. What does this mean?
Does Chiari run in families? What about my other children?
Is there a genetic test to see if someone has Chiari?
How is Chiari treated?
What is the surgery like?
Is the surgery always successful?
What are the risks of surgery?
What are the possible complications from surgery?
What will happen if my child doesn't have surgery?
How long does it take to recover from surgery?
How can I find a doctor with a lot of Chiari experience?
How many people have Chiari?
Will my child be able to participate in sports after surgery?
Will my child need regular MRIs after surgery?
A doctor told me my child's Chiari is nothing to worry about, but I'm not so sure. What should I do?
Can Chiari cause problems with thinking, learning, and memory?
Is Chiari fatal?
What is syringomyelia?
What is tethered cord?

1. What is a Chiari Malformation?
Chiari Malformation Type I (CM) is a neurological disorder where part of the brain, the cerebellum (or more specifically the cerebellar tonsils), descends out of the skull into the spinal area. This results in compression of parts of the brain and spinal cord, and disrupts the normal flow of cerebrospinal fluid (a clear fluid which bathes the brain and spinal cord). Return To Top.

2. Is Arnold-Chiari different from Chiari?
Not everyone uses the same terminology when describing Chiari. Some people use Arnold-Chiari (ACM) interchangeably with Chiari. Others only use Arnold-Chiari to refer to Chiari Type II which involves more of the brain descending out of the skull, is predominantly diagnosed in children, and is associated with Spina Bifida. Other terms for Chiari include tonsillar ectopia and hindbrain herniation, meaning the cerebellar tonsils are out of position. Return To Top.

3. What are the symptoms?
Because Chiari involves the nervous system, symptoms can be numerous and varied. In fact, one large study showed that the vast majority of Chiari patients reported 5 or more symptoms, and 49 distinct symptoms were reported by 2 or more patients. Despite this variety, the most common Chiari symptom, and the hallmark of the disease, is a headache. Usually, the Chiari headache is described as an intense pressure in the back of the head and is brought on, or aggravated, by exercise, straining, coughing, sneezing, laughing, bending over, or similar activities. Other common symptoms include balance problems and fullness in the ears. In very young children, trouble swallowing is one of the most frequent symptoms. In older children, scoliosis - an abnormal curvature of the spine - is a common symptom. Return To Top.

4. Does the size of the malformation matter?
Traditionally, Chiari Malformation has been defined as the cerebellar tonsils descending more than 3-5mm out of the skull. However, research has shown there is no real correlation between the amount of descent (or herniation) and clinical symptoms. Some people with herniations of less than 3mm are extremely symptomatic and some people with quite large herniations are symptom free. Because of this, surgeons will look not only at the amount of herniation, but how crowded the space is and whether there is room for the natural flow of spinal fluid. Return To Top.

5. How is a Chiari Malformation diagnosed?
An MRI (Magnetic Resonance Imaging - a non-invasive test which uses a large magnet to create a picture of internal organs) can clearly show if the cerebellar tonsils are out of position, but can not say whether a person's symptoms are due to the herniation. In fact, there is no single, objective test to say whether a person has symptomatic Chiari. Rather, diagnosis is based on a combination of reported symptoms, a neurological exam, MRI results, and the physician's experience and judgment. Return To Top.

6. What is a cine MRI?
Cine MRI is a type of MRI where the machine is programmed to measure the flow of cerebrospinal fluid (CSF). Doctors use this to see if the cerebellar tonsils are blocking the normal flow of CSF from the brain to the spinal area and back. While many doctors now consider cine MRI to be a routine test in diagnosing Chiari, some experts question it's usefulness and are reserving judgment. Return To Top.

7. What is a borderline Chiari?
Since Chiari was traditionally defined based on the size of tonsillar herniation, a borderline Chiari can refer to when the cerebellar tonsils are descended only a couple of millimeters out of the skull. Alternatively, borderline Chiari can refer to someone with mild symptoms which may not be directly attributable to Chiari. It is important to keep in mind that borderline Chiari does not have a common definition and the term can be used differently by different people. Return To Top.

8. How did my child get this condition?
The latest thinking is that there are several underlying causes which can lead to Chiari. The most common is thought to be a congenital issue where the back of the skull is smaller than normal which then does not have enough room for a normal sized brain. Other Chiari cases are thought to be related to problems with cerebrospinal fluid, such as hydrocephalus and pseudotumor cerebri (abnormally high pressure in the brain). Chiari can also be acquired (meaning people are not born with it) as a result of a mass in the brain, such as a tumor or cyst. Other causes of Chiari are still being investigated. Return To Top.

9. My child doesn't have any symptoms, but an MRI shows a malformation. What does this mean?
This is sometimes referred to as an incidental finding. A child has an MRI for an unrelated reason, but it shows a Chiari malformation - meaning the cerebellar tonsils are descended - yet the person has no Chiari type symptoms. As MRI's become more common, this is happening more frequently and is one reason that diagnosing Chiari can be difficult and can not be based on an MRI alone. Although more research, over longer time periods is required, some preliminary studies have shown that a majority of incidental cases did not develop symptoms over the course of the next six years. Return To Top.

10. Does Chiari run in families? What about my other children?
An ongoing study at Duke University has identified more than 100 families where two or more members are affected by Chiari. This implies that for some cases there is a genetic basis for Chiari. It is not known, however, what percent of cases may have a genetic component. In other words, this does not mean that the family of everyone with Chiari is carrying a Chiari gene. There are different schools of thought on whether the siblings of Chiari children should have an MRI. The conservative approach is to only get an MRI if there are symptoms. However, some surgeons think it is better to get an MRI for sibling in order to know what the situation is. Return To Top.

11. Is there a genetic test to see if someone has Chiari?
A Chiari gene has not yet been identified, so there is currently no genetic test. Return To Top.

12. How is Chiari treated?
If the symptoms aren't severe, doctors may recommend just monitoring the situation with regular MRIs and treating the symptoms individually. However, if symptoms are interfering with quality of life, are getting worse, or if the nervous system is being impaired, doctors may recommend surgery. The most common surgical treatment, performed by a neurosurgeon, is known as decompression surgery. An alternative surgery (if there are spinal fluid issues) involves placing a shunt (a tube like device) to channel the flow of spinal fluid and relieve pressure. Return To Top.

13. How do I know whether my child should have surgery?
The decision whether to have surgery is up to each family and their doctor. Some of the factors that are considered are the severity of symptoms, whether the symptoms are getting worse, whether the nervous system is being compromised, whether there are any complicating issues, and the surgeon's own experience and judgment. Unfortunately, there is no single, objective measure to say whether someone should have surgery and many patients will find that different doctors may have different opinions. Some doctors are more aggressive in their treatment approach and some are more conservative. A recent survey about when to recommend surgery showed that there was general agreement among surgeons in the extreme cases - no or mild symptoms, don't operate; severe, progressive symptoms or syringomyelia, operate - but there was little agreement in the middle. In one of the survey's hypothetical cases, the surgeons were split almost evenly down the middle on whether to operate or not. Return To Top.

14. What is the surgery like?
Decompression surgery is a general term used to refer to any of a number of variations on the same basic procedure. The goal of the surgery is to create more space around the cerebellar tonsils and restore the normal flow of CSF. The procedure involves removing a piece of the skull in the back of the head near the bottom (craniectomy). Often part of the top one or two vertebra are also removed (laminectomy). At this point, depending on the individual case and doctor, some doctors will also open the covering of the brain, the dura, and sew a patch in to make it larger (duraplasty). There are many variations in how the surgery is performed, including (but not limited to) how much bone to remove, whether to open the dura, what type of material to use for a dural patch, whether to shrink or remove the cerebellar tonsils, and whether to replace the missing piece of skull with anything. Unfortunately, there is no consensus, and no strong evidence, on which technique(s) is the best. Because of this, it is important for patients to understand specifically what their surgeon will be doing and why. The procedure itself lasts a couple of hours and most children will spend a night in the ICU and an additional couple of days in the hospital. Return To Top.

15. Is the surgery always successful?
As with any surgery, the chance of success depends on the individual case, so each person should ask their doctor what their chance of having a successful surgery is. It should be noted that success can mean different things to different people, so it is best to ask specific questions such as what are the odds I will be symptom free; what are the odds I will be mostly better; and what are the odds I will get worse.

Unfortunately, there is not a lot of strong surgical outcome research, but there are enough reports to get a general idea of the overall success rates. For patients with just Chiari (no syringomyelia), up to 50% may become essentially symptom free after surgery, with another 10%-30% improving significantly. On the flip side, for 10%-20%, the surgery will be a failure and they will likely require additional surgeries. It is an unfortunate fact that there is a subset of Chiari children who end up requiring many surgeries and must deal with severe symptoms on a chronic basis. Keep in mind these are not scientific numbers and each patient should discuss their own chance of success with their doctor.
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16. What are the possible complications of surgery?
This is another question that is important for every patient to ask their doctor so that they fully understand the risks and potential outcomes of surgery. Many of the complications of decompression surgery have to do with opening the dura and research has shown that opening the dura does increase the complication rate. There is a risk of infection and sometimes the patch that is sewn in leaks or becomes scarred. A more serious complication - not necessarily related to opening the dura - occurs when the brain slumps further into the spinal area after the surgery. Return To Top.

17. What will happen if my child doesn't have surgery?
The natural progression of Chiari - as doctors call it - varies from person to person and is not well understood. For example, why do some people develop symptoms in their 30's while others have symptoms their whole life? For many people with no or mild symptoms, the symptoms will not get worse and surgery will not be necessary. However, there are also anecdotal reports of symptoms becoming rapidly worse, sometimes after a sneeze or a fall. If a patient does not have surgery, many doctors will recommend monitoring the situation with routine MRI's and neurological exams. Return To Top.

18. How long does it take to recover from surgery?
As to be expected, recovery will vary from person to person and depends on factors such as if there were surgical complications, other health conditions, whether the dura was opened, and the outcome of the surgery (do the symptoms go away). In general, it appears that children recover from decompression surgery more quickly than adults, so some kids will be back to regular activities in a matter of a few weeks. It is important to ask the surgeon about recovery issues, such as pain management and activity restrictions. Return To Top.

19. How can I find a doctor with a lot of Chiari experience?
The American Association of Neurological Surgeons (AANS) does not recognize Chiari as a sub-specialty. This, combined with liability issues and the difficulty in establishing expert-level criteria (what does it take to qualify as an expert?) make it difficult to put together a list of Chiari experts. Each person must find a doctor they are comfortable with. Some people like to see university based researchers, some would prefer a regular neurosurgeon; some are willing to travel for surgery, others aren't; some want a surgeon they can relate to, others think surgical skill is more important. When trying to find a doctor, some things to consider are how many Chiari surgeries they do a year, how many total surgeries they do a year, are they up to speed on the latest thinking on Chiari, how they relate to patients, and what type of reputation they have among patients and the medical community (this is by no means comprehensive). There is no right answer to these questions; they are just intended as a way for a patient to feel comfortable with their doctor. Click here for Tips on Finding a Neurosurgeon. Return To Top.

20. How many people have Chiari?
Precise data is not available, but based on a survey of the number of decompression surgeries performed each year, Conquer Chiari believes that a reasonable estimate is that Chiari affects 1 in 1,000 people. This translates to 300,000 people in the US. Chiari appears to affect people of all races and there is some indication that women are more commonly affected than men. Return To Top.

21. Will my child be able to participate in sports after surgery?
This is a very controversial subject, especially as it pertains to contact sports. Some surgeons believe that if the decompression is successful there should not be any restrictions, and indeed there are case reports of athletes at high levels of competition returning to their sports. However, there are also doctors who believe that children with Chiari should not participate in contact sports. It is important to get your specific surgeon's opinion on this issue in regard to your child. Unfortunately, there is no real research to base this decision on. Return To Top.

22. Will my child need regular MRIs after surgery?
There will likely be several follow-up MRIs in the first year after surgery. After one year, if there are no symptoms, many doctors will say that routine follow-up is not necessary. However, if it is a complicated case, there are complications, or symptoms persist, then the doctor may recommend monitoring with regular MRIs. Return To Top.

23. A doctor told me my child's Chiari is nothing to worry about, but I'm not so sure. What should I do?
Conquer Chiari recommends that any one with an MRI report that shows a Chiari malformation be evaluated by a neurosurgeon rather than a neurologist or other type of doctor. Since the primary treatment for Chiari is surgical, neurosurgeons tend to be in the best position to evaluate treatment options. Note that some surgeons who treat a lot of Chiari patients will have them see a neurologist associated with their group before seeing the surgeon. Return To Top.

24. Can Chiari cause problems with thinking, learning, and memory?
There are anecdotal reports of cognitive issues associated with Chiari, but to date there has not been sufficient research in this area to draw any conclusions. Conquer Chiari has funded a research project at the University of Chicago to study the cognitive effects of Chiari in both children and adults. The results should be available by the end of 2010. Return To Top.

25. Is Chiari fatal?
In general Chiari I is not considered fatal. For example 5 year survival rates are not calculated or discussed. However, there are case reports of sudden death associated with Chiari I due to breathing problems, although this is likely very uncommon. Also, the impact that long-term symptoms may have on life expectancy has not been studied. Finally, severe cases of Chiari II and III in infants and children can be fatal. Return To Top.

26. What is syringomyelia?
Syringomyelia refers to a neurological condition where fluid collects inside the tissue of the spinal cord (this is known as a syrinx). The most common cause of syringomyelia is Chiari and up to 50% of Chiari patients (of all ages) also have a syrinx. Other causes of syringomyelia include trauma and tumors. Chiari related syringomyelia is thought to be caused by the disruption of the natural flow of spinal fluid between the brain and spine. It is treated by Chiari decompression surgery. More information on syringomyelia can be found on the main Conquer Chiari site: www.conquerchiari.org Return To Top.

27. What is tethered cord?
Tethered cord refers to when the spinal cord is abnormally attached, or tethered to the bony part of the spine. This can as a result of a number of conditions which are well defined and understood. However, the cord can also be put under tension if the filum terminale (thread like structure at the bottom of the spine) is abnormally thick or fatty. Certain aspects of tethered cord are controversial. First, some researchers are looking at whether some children can have tethered cord which does not show up on MRI. This is referred to as occult tethered cord. These children have symptoms associated with tethered cord, such as leg pain and weakness and urinary issues, but the filum and spine look normal on MRI. Even more controversial is whether there is a connection between tethered cord and Chiari. Some researchers have proposed that a tight filum terminale which puts the spinal cord in traction can result in small herniations of the cerebellar tonsils. However, much more research is required in this area to fully understand if and what the connection between tethered cord and Chiari may be.
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