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What is a Chiari malformation?

A Chiari malformation (or hindbrain herniation) is when the back of the brain (cerebellum) pushes down through the bottom opening of the skull (the foramen magnum), which is only meant for the spinal cord to pass through. This can sometimes obstruct the flow of cerebrospinal fluid through that opening, which leads to headaches and, sometimes, spinal cord injury. The pain can radiate into the neck, shoulders and hands and can be extremely debilitating.

Our approach

Northwell Health has many resources dedicated to treating both children and adults with Chiari malformation. Many children with Chiari malformations do not have any symptoms and do not need treatment. However, when treatment is needed, Cohen Children’s pediatric neurosurgeons are experts, handling the largest volume of these cases in the region. We offer a variety of Chiari malformation treatment options, all of which are highly successful.

The staff at The Chiari Institute (TCI) is committed to the care of patients with complex neurosurgical disorders that have (or could have) resulted from birth defects or inherited diseases that persist into adulthood. These are the so-called “transition” patients whose conditions are poorly understood and for whom treatment may be difficult to find. Our goal is to individualize the care of individuals with complex, controversial and poorly understood conditions related to the Chiari 1 (the Arnold Chiari) malformation, Chiari 2 (spina bifida) malformation, and syringomyelia, including:

  • Tethered spinal cord syndrome
  • Craniovertebral instability
  • Complex anomalies of the skull base
  • Disorders related to abnormalities of intracranial pressure

We treat each patient according to their unique needs and educate them on their conditions. An important part of patient care is to help each patient understand what is actually wrong, how it should be treated, how to assess new or recurrent symptoms, and what to expect if further treatment is needed. This is the essential challenge of being a “transition” patient, and our goal is to empower all our patients to become experts on their disorders. Chiari-related surgeries are performed daily at TCI.

Research at Northwell

Our clinical research at TCI was the first to establish a link between the Chiari malformation and inherited disorders of connective tissue such as Ehlers Danlos and Marfan’s syndromes, and we continue this clinical research and outcomes assessment today. It is the commitment of the TCI to identify the underlying causes of the conditions we treat in order to individualize diagnostic testing and treatment. We maintain a database of patients treated with misunderstood conditions to monitor long-term treatment effects


Chiari malformation can occur when the section of the skull containing the cerebellum is too small for that portion of the brain, thus putting pressure on and crowding the brain

Related conditions

"Chiari malformation" as a set of diagnoses can also be associated with a form of spina bifida called myelomeningocele. This is called Chiari II malformation and the symptoms and signs may be quite different from Chiari I malformations.


Depending on the type and severity, Chiari malformations can cause a number of symptoms. Some of the most common symptoms are:

  • Severe headaches, usually after sudden coughing, sneezing or straining
  • Neck pain
  • Lack of balance
  • Poor hand coordination and fine motor skills
  • Numbness and tingling of the hands and feet
  • Dizziness
  • Difficulty swallowing
  • Blurred or double vision
  • Hoarseness or other speech problems

Many symptoms of Chiari malformation can also be associated with other disorders, so if you experience any of them, it’s important to see your doctor for a thorough medical evaluation.

How is it diagnosed?

A detailed diagnostic workup may include an MRI, Cine flow MRI, dynamic X-rays, 3D CTs, high-definition imaging and morphometrics. Once the patient is diagnosed, a determination will be made whether or not surgery is needed, and which type of surgery is best, depending on each specific case.

Types of treatments

We offer a variety of Chiari malformation treatment options, all of which are highly successful. Some are minimally invasive, where a neurosurgeon can simply make a small incision and open up the blocked passage in the skull opening to be a little bigger. Other treatments are more invasive, where a surgeon opens up the lining of the brain and expands that area with a patch.

Since these surgeries can cause discomfort, we have an ongoing study of using a long acting local analgesic to dramatically help with postoperative pain control.

It’s important to note that some Chiari malformations do not need treatment, especially if they are not causing significant symptoms. A conservative, non-surgical approach is always primarily considered when our surgeons provide a recommendation.

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