Chiari Malformation

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.