A Chiari malformation (CM) is a defect in the structure of the brain, specifically the cerebellum, and sometimes involves the spinal cord. Because of the abnormal structure of the skull or spinal cord, the cerebellum and brain stem can be compressed. That can affect the flow of cerebrospinal fluid (CSF)—a watery fluid that protects your spine and brain.
While CM is a relatively rare condition, it can be debilitating. If Chiari malformations prevent you from working enough to support yourself, you might qualify for Social Security disability benefits.
Chiari malformations are divided into four types. Most types of CM develop before birth. All involve the cerebellum, the part of the brain responsible for:
Type I CM is the only type of Chiari malformation that can develop after birth. It can occur if a large amount of CSF is drained away because of:
In Type I CM, the lower part of the cerebellum extends through the opening at the base of the skull that the spinal cord passes through. This type of Chiari malformation is the most common and often has no symptoms.
Type II CM is also known as Arnold-Chiari malformations or "classic" Chiari malformations. In Type II CM, both the cerebellum and the brain stem extend through the opening at the base of the skull.
Arnold-Chiari malformations are generally only seen in children born with spina bifida (a congenital spinal cord defect). And most children born with this type of CM also have hydrocephalus (a buildup of cerebrospinal fluid in the skull that causes the brain to swell).
Type III CM is a rare form of Chiari malformation. It's the most serious form of CM, usually causing severe neurological defects. With Type III CM, both the cerebellum and brain stem extend through the opening at the base of the skull and into the spinal cord.
Type IV CM is a rare form of Chiari malformation. In Type IV CM, the cerebellum is where it's supposed to be, but it's incomplete (underdeveloped), and parts of the skull and spinal cord are sometimes visible. This condition is also called cerebellar hypoplasia.
The symptoms of CM vary, depending on which type of Chiari malformations you have and how severe the malformations are. You might have no symptoms (especially with Type I CM). Or you could have a range of symptoms like:
Medication might lessen your CM symptoms, but surgery is the only way to correct the physical malformation. Chiari malformations can also be associated with syringomyelia (fluid-filled cysts that form inside the spinal cord).
Although a diagnosis of CM alone won't automatically qualify you for disability, you could win your claim if your symptoms are severely limiting.
At the initial stage of the disability determination, the Social Security Administration (SSA) must determine whether your Chiari malformations match the requirements of a disability listing. One listing that addresses some cases of CM is listing 11.08 for spinal cord disorders. Your CM could meet the requirements of this listing if you have the following limitations and they've lasted for at least three consecutive months:
If your limitations are more moderate than the requirements of the listing, Social Security will look at how your limitations affect your ability to work. The SSA will first determine if you can still do your most recent jobs and then whether you can do (or learn to do) any other kind of work.
To make these determinations, Social Security will prepare a residual functional capacity (RFC) assessment that details how your symptoms affect your ability to do job-related tasks. An RFC is created based on the medical records you've provided to Social Security and any examinations performed by an SSA doctor (called consultative examinations.)
For example, more severe forms of CM can significantly impair your balance and coordination. An RFC that includes balance and coordination deficits would rule out any jobs that require you to use heavy machinery or dangerous equipment, such as construction work.
CM can also affect the use of your hands and fingers, impairing your fine motor skills. Fine motor skills are necessary for activities like:
So, the inability to perform these tasks would eliminate most secretarial and factory positions.
CM can also cause significant numbness and tingling in your hands, limiting your ability to lift and carry or push and pull even light objects. This limitation alone could prevent most work.
Some CM sufferers also experience difficulty with vision and speech. You might have great difficulty performing jobs that require good vision or hearing, depending on the severity of your vision or hearing loss.
You should ask your treating physician to fill out an RFC form for you. Although Social Security will accept RFCs from any doctor, reports prepared by a doctor specializing in diagnosing and treating Chiari malformations will carry more weight.
Social Security will also want to see objective medical evidence that supports your doctor's opinion, like:
Be sure to include information and records for all your medical conditions—even those not severe enough to qualify for disability on their own. Social Security is required to consider the combined effect of all your impairments on your ability to work. For instance, if you have moderate CM symptoms and another health condition like depression, the combined effect might be enough to qualify you for disability benefits. (Learn more about how Social Security evaluates multiple impairments.)
In addition, to qualify for SSDI, you must have a significant and recent work history where you paid Social Security taxes (FICA or self-employment tax). Learn more about how your work history affects your SSDI eligibility.
SSI is available to people who don't have a qualifying work history and who meet the Social Security's limit on income and assets. Learn more about qualifying for SSI disability even if you've never worked.
Applying for SSDI or SSI disability benefits isn't difficult, but it does require a lot of information. And because the disability claims process can take a year or more, it's not something you should put off.
You can file your application for disability benefits in one of three ways:
If you're applying for SSI disability (and not SSDI), you can only start your application online. You'll need to speak with a Social Security representative to complete the SSI application process. Once you complete the online portion, the SSA will contact you by mail (and email) with an appointment to finish your SSI application.
Whether you're applying for SSDI or SSI disability benefits, you should gather as much of the following information as you can before you start:
But don't delay filing because you're missing some of the information or documents. Social Security will help you gather any medical records you don't already have.
Learn more about the steps involved in applying for Social Security disability benefits.
Updated October 17, 2023