Learn more about what Chiari is, what to do after getting a Chiari diagnosis and find more resources that may help.

basics of chiari-related diseases:

Other Related Disorders


Although it is still not well-known or understood, we have learned over the past few decades that Chiari malformation is shockingly common. Since there are so many people who have a Chiari, it is not all that uncommon that those individuals may also have another, “co-morbid” condition.

But what does that mean? Somewhat frequently, Chiari patients may present at the doctor’s office with other conditions, and not just syringomyelia– conditions like Ehlers-Danlos syndrome, dysautonomia, hydrocephalus, idiopathic intracranial hypertension, spina bifida (more common in Chiari II), tethered cord syndrome, and more.

So, while most Chiari patients present with just Chiari or just Chiari and syringomyelia, some patients may have one or more other co-morbidities. Whether or not the patient also has one of these other conditions may impact how they are appropriately treated, especially if surgery is being considered.


Very little is actually known about the connections between Chiari malformation and other conditions. What is most important to understand is that we are still learning about these co-morbidities and how strongly they are associated with Chiari… even as you read this sentence! In fact, if you are a patient or a caregiver of a patient with Chiari, syringomyelia and a related disorder, you can actually help us learn more about these possible connections by participating in the International Patient Registry. New studies are being added to address issues like craniocervical instability.

so what are these related disorders?

Some conditions that are suspected to be co-morbid to Chiari may include the following. And remember: this is NOT an exhaustive list!

Since we are still learning about co-morbidities every single day in our international registry and beyond, other disorders may need to be added as new discoveries are made!


This is by far the most common co-morbidity and is the most commonly studied. We have lots of information available in the syringomyelia section of our website. And don’t forget to check out the educational lecture series to find videos associated with syringomyelia (it is also sometimes called a “syrinx”).

More about syringomyelia:

Syringomyelia Update: Diagnosis, Treatment and Research
John D. Heiss, MD (2018)

Syringoymelia Pathophysiology: Basic & Clinical Science
Marcus Stoodley, MD (2017)

Mechanisms of Pain in Syringomyelia
Daniel Couture, MD (2016)

Charl Vorster, MD (2016)

View more videos about syringomyelia in our video library.


Ehlers-Danlos Syndrome (EDS)

Ehlers-Danlos syndrome is another commonly studied co-morbidity of Chiari malformation. There is a lot of information currently being learned about EDS and hypermobility as far as its relationship to Chiari malformation. It is particularly important to assess prior to undergoing surgery, because EDS and connective tissue disorders may cause a sort of instability in the spine that complicate the outcomes of surgery. More is being learned about this everyday. Sometimes, EDS can be seen as something called “complex Chiari”.

More about EDS:

International Guidelines: Diagnosis & Management of Ehlers-Danlos Syndrome
Clair Francomano, MD (2018)

Hypermobility, Genetic Etiologies and Relationship to Joints and the Spine
Andrew White, MD (2017)

EDS, Hypermobility & Evolving Perspectives
Derek Neilson, MD (2015)

Epidemiology of Hypermobility & Connective Tissue Disorders
Clair Francomano, MD (2015)

View more videos about Ehlers-Danlos syndrome in our video library.


Tethered Cord Syndrome

Tethered cord remains a very controversial topic because so little is understood about its possible connections to Chiari, syringomyelia and connective tissue disorders.

Tethered cord occurs due to one or more spinal cord anomalies being present– think spina bifida or another spinal cord defect people may be born with. The spinal anomaly/anomalies may cause the cord to tether (become attached) at the end of the spinal cord. Tethered cord syndrome can cause possible neurological and bladder/bowel function problems. Usually, it is formally diagnosed by an MRI of the spinal cord. But sometimes, a specialist can get a preliminary diagnosis from clinical symptoms and skin or limb abnormalities that are more frequently seen in pediatric patients.

More about tethered cord:

Tethered Cord & Ehlers-Danlos Syndrome
Sunil Patel, MD (2018)

The Occult Tethered Cord Syndrome
Sunil Patel, MD (2018)

Current Management of Tethered Cord Syndrome & Syringomyelia
Petra M. Klinge, MD, PhD (2016)

Tethered Spinal Cord Syndrome
Holly Gilmer, MD (2015)

View more videos about tethered cord in our video library.


Idiopathic Intracranial Hypertension (IIH)

Idiopathic intracranial hypertension is sometimes called pseudotumor cerebri. It occurs when the intracranial pressure, or “ICP”, in the skull becomes chronically increased. The “idiopathic” part of its name means that doctors are not quite sure why it is occurring. Usually, increased ICP is caused by something that is clear on imaging, like a lesion or even a tumor. But in the case of IIH, specifically, it is not clear what is causing the increase. It is more common in women and those living with obesity.

Symptoms most frequently include headaches and vision problems. Other symptoms can include other neurological problems. In severe cases, vision problems can become permanent or cause blindness. So, it is very important for those who have IIH to be seen by a skilled neurologist, neurosurgeon or ophthalmologist who can diagnose something called “papilledema,” which is an increased pressure in the eye. Treatment depends on multiple things and should always be discussed with your doctor.

More about IIH:

Headaches in the EDS and CHiari Population & Intracranial Pressure Abnormalities
Malini Narayanan, MD (2020)

Lumbar Puncture & ICP Monitoring in Evaluation of CSF Disorders
Mark G. Luciano, MD, PhD (2018)

Idiopathic Intracranial Hypertension & Pseudotumor Cerebri Treatments
Imram Chaudry, MD (2017)

Additional, Excellent Resource: Child Neurology Foundation – IIH Information Page

View more videos about tethered cord in our video library.



Reviewed on 6/2022