Chiari Malformation

What This Page Is and Isn’t

This page offers a plain-language explanation of Chiari Malformation, along with what I learned from living with it before anyone could fully separate it from everything else that was happening in my body. In my case, Chiari Malformation was identified during the neurosurgeon consultation that followed my Atlantoaxial Instability (AAI) diagnosis. The Craniocervical Instability (CCI) diagnosis was confirmed during that same consultation. This started a chain of discoveries that eventually led to a diagnosis of Tethered Cord Syndrome (TCS) and Hypermobile Ehlers-Danlos Syndrome (hEDS), the connective tissue disorder underneath all of it.

It is also a condition that can be difficult to fully understand. For many people, Chiari rarely arrives alone.

What I share here comes from lived experience, a path I can point to because I walked it. This is not medical advice and does not replace consultation with a qualified healthcare professional.

What Is Chiari Malformation?

Chiari malformation is a structural condition in which the lower portion of the cerebellum extends downward into the opening at the base of the skull, where the brain meets the spinal canal. That space is not meant to be crowded. When it is, nearby structures can be compressed, including the brainstem, and the normal flow of cerebrospinal fluid can be affected.

There are several types. Type I is the most commonly diagnosed in adults. Sometimes it is discovered incidentally. Mine wasn't. It took years and an upright MRI to find it.

Why It Gets Missed

Chiari does not always appear clearly on standard imaging.

The symptoms also work against early identification. Headaches get treated like migraines. Pressure at the back of the head gets called tension. Dizziness gets folded into stress, hormones, or anxiety. Brain fog becomes burnout. Balance issues get attributed to inner ear problems or aging. Each symptom gets treated in isolation, and the structural cause stays hidden.

The pattern is harder to see when symptoms come and go, overlap with other diagnoses, or worsen only with certain positions or strain. Some people with Chiari have no obvious symptoms at all. Others have symptoms that accumulate slowly enough that no single appointment captures the full picture.

In my case, the Chiari was not identified until after my AAI had been diagnosed. The upright MRI ordered for the neurosurgeon consultation revealed the Chiari alongside CCI. That imaging changed the direction of the conversation.

Questions I Found Myself Asking

What does Chiari Malformation feel like?

Can Chiari cause headaches at the back of the head?

Why do I feel pressure at the base of my skull?

Can Chiari cause brain fog or trouble thinking clearly?

Can Chiari cause dizziness or balance problems?

Why do I feel worse when I cough, strain, or bear down?

Can Chiari be mistaken for migraines, stress, or anxiety?

Does Chiari always require surgery?

What is Chiari decompression?

Can Chiari and craniocervical instability happen together?

Can Chiari symptoms overlap with hEDS or Tethered Cord Syndrome?

Can a neck brace help tell the difference between Chiari and CCI?

Symptoms People Commonly Describe

Headaches at the back of the head, often worsened by coughing, straining, or changes in position. Pressure near the base of the skull. Brain fog or slowed thinking. Difficulty with short-term memory or multitasking. Dizziness. Balance problems. Neck pain. Blurred vision. Difficulty swallowing. Numbness or tingling in the hands or feet. A sense that thinking takes more effort than it used to. Fatigue that is out of proportion to what the day required.

Not everyone experiences all of these, and this list is not exhaustive. The combination and severity vary. What makes Chiari difficult to pin down is that nearly every one of these symptoms can be explained by something else.

They often are. Many people search for these symptoms long before they ever hear the term Chiari malformation.

In my case, Chiari was not a stand-alone story. It existed alongside CCI. My surgical team explained that the two conditions overlap in ways that make it difficult to separate the symptoms. Before surgery, I wore a rigid neck brace for three months as a diagnostic trial. The brace helped stabilize my neck and reduced some symptoms. My brain fog, short-term memory issues, and difficulty multitasking did not improve with the brace. My surgical team said those symptoms could be related to the Chiari rather than the instability.

What I Wish I’d Known

If some of this sounds familiar from the blog posts, it should. The conditions overlap. So does the story.

I wish I’d known that standard imaging doesn't always tell the full story. For years the symptoms were there. The scans simply weren’t capturing what was happening when my body was upright and under the weight of gravity.

I told my doctors that my head felt too heavy, like it was hard to hold it up. I said it in appointment after appointment. It wasn't pursued as a possible structural problem.

I was told it was stress. Maybe perimenopause. Tech neck. Anxiety.

Every specialist handled their piece. The orofacial specialist focused on the jaw. The neurologist treated the headaches. The orthopedic specialist offered a diet list and a trigger point hook. At one point, a doctor referred me to both a pain psychologist and a pain psychiatrist.

No one looked at the whole picture.

It took 111 medical appointments across 26 providers before someone ordered the right imaging. The DMX revealed extreme instability between C1 and C2. The upright MRI revealed the Chiari and CCI.

What I didn't expect was how often Chiari appears alongside other conditions. In my case, it was identified through the same neurosurgeon consultation, and it was part of a chain of diagnoses that eventually led to hEDS. When symptoms stretch across multiple specialties, they can still belong to the same underlying problem. No one told me that.

And even after the diagnosis, I didn’t know what came next. Understanding what Chiari decompression meant alongside an occipital fusion took its own time. I asked my neurosurgeons specific questions:

• Do I have Chiari?

• Is a Chiari decompression needed now?

• Is it better to perform the decompression at the same time as the fusion?

• What are the risks of waiting on the decompression surgery?

Those conversations were the ones that shaped the path forward. That’s part of why this page exists.

What I Did Next

After Chiari was diagnosed, I sought a second opinion to confirm the diagnosis and understand the treatment options. I wanted to know whether decompression was necessary, and whether it should be performed alongside the fusion or addressed separately.

The second opinion confirmed both the diagnosis and the recommendation to combine the procedures. And that confirmation gave me more clarity about the path forward.

Once I made the decision to have an occipital to C3 fusion and found my surgical team, I asked them for a patient I could speak to who had been through this surgery. They connected me, and that conversation was one of the most valuable things I did to prepare.

For the full account of what the surgery and recovery looked like, see Chiari Decompression: A Patient's Perspective, followed by Occipital to C3 Fusion with Chiari Decompression: A Patient's Perspective.

Often Discussed Alongside

Chiari Malformation is frequently seen alongside other conditions, and many patients receive multiple related diagnoses:

Craniocervical Instability (CCI)

Atlantoaxial Instability (AAI)

Hypermobile Ehlers-Danlos Syndrome (hEDS)

Tethered Cord Syndrome (TCS)

Eagle Syndrome

Postural Orthostatic Tachycardia Syndrome (POTS)

Mast Cell Activation Syndrome (MCAS)