Chiari Malformation

The cerebellum is a relatively small and low-lying portion of the brain that regulates muscle movement and coordination. Normally, it sits at the back of the skull above an opening (foramen magnum) through which the spinal cord passes. Due to a structural defect known as a Chiari malformation, the cerebellum may protrude through the foramen magnum and into the spinal canal, where it can pressure the spinal cord and block the flow of cerebrospinal fluid, which surrounds and cushions the brain and spinal cord.

The highly specialized expertise required for diagnosing and treating Chiari malformations is available through Tampa General Hospital’s Neuroscience Institute, where some of the world’s most renowned neurosurgeons collaboratively practice in our Skull Base Surgery Center. As an academic medical center affiliated with the University of South Florida, TGH is continually contributing to advances in minimally invasive skull base surgery, making these complex procedures increasingly safer and more effective for our patients.

Chiari Malformation Causes

Primary (congenital) Chiari malformations are present at birth and develop because the skull is misshapen or smaller than normal. Secondary (acquired) Chiari malformations are less common and can result from head or neck trauma that forces the cerebellum into the foramen magnum.

Chiari Malformation Symptoms

Some Chiari malformations are completely asymptomatic, while others do not cause noticeable symptoms until late childhood, early adulthood or after a traumatic injury. Some people experience:

• Headaches, especially when coughing and sneezing
• Neck pain
• Dizziness and impaired balance
• Poor hand coordination
• Numbness and tingling sensations in the hands and feet
• Vision problems
• Vocal hoarseness
• Difficulty swallowing

How Is a Chiari Malformation Diagnosed?

If a Chiari malformation is suspected based on the symptoms or the results of an imaging scan performed for an unrelated reason, a physician may order a series of tests to confirm the diagnosis, which may include:

• Imaging studies, such as computed tomography (CT), magnetic resonance imaging (MRI) and myelogram
• A brainstem auditory evoked potential (BAER) test
• A somatosensory evoked potential (SSEP) test
• A sleep study
• A swallowing study

Chiari Malformation Treatments

If a Chiari malformation does not cause symptoms that interfere with daily living, a physician may suggest a “wait and watch” approach, which involves monitoring the progression of the condition with periodic imaging scans. If necessary, the physician may also prescribe medication to ease any related headaches.

The primary treatment for symptomatic Chiari malformations is skull base surgery. To create more space for the cerebellum and relieve pressure on the brain stem and spinal cord, a neurosurgeon may perform a posterior fossa decompression, which involves removing a small piece of bone at the back of the skull.

Choose TGH for World-Class Care

TGH’s neurosurgeons are globally acclaimed for their skill and expertise in performing skull base surgery. We diagnose and treat all types of brain conditions, including relatively rare Chiari malformations. If you would like to discuss your symptoms with a specialist at TGH, contact us at (800) 822-3627 to set up an appointment.