Chiari malformation (also known as Arnold-Chiari malformation,tonsillar herniation, tonsillar ectopia, or hindbrain herniation) Read More →


Most people with Chiari malformation do not experience symptoms until adulthood,usually (although not Read More →


Some symptoms of Chiari malformation, such as headaches and dizziness, may be treated with medication. Read More →

What you need to know about Chiari malformation

By K. Michael Webb, M.D Dr. Webb is a neurosurgeon with extensive experience in Chiari malformation diagnosis and treatment, including decompression surgery. Learn more about his practice at

What is Chiari malformation?

A Chiari Type I malformation occurs when the cerebellum protrudes through the opening in the skull where the spinal cord exits, which can cause increased pressure on the brain stem, spinal cord, or cerebellum. It occurs in roughly one out of 1,000 births, more commonly in females. Even though Chiari malformation is present at birth, symptoms generally do not develop until adolescence or adulthood, and patients can go undiagnosed for years.

What are the symptoms?

The symptoms of Chiari malformation vary from person to person, and can range from mild to severe or debilitating. Some people have no symptoms at all. The most common symptom is a severe headache, which is usually in the back of the head and can be brought on by straining, coughing, sneezing, and laughing.
Another common symptom is neck pain which radiates across the shoulders and down the spine. Other symptoms include difficulty swallowing, trouble speaking or hoarseness, respiratory problems and sleep apnea, frequent urination and/or loss of bladder control, irritable bowel syndrome and/or lack of bowel control, weakness and stiffness in the arms and/or legs, numbness in the hands and/or feet, and vertigo and/or trouble balancing. Chiari malformation can also occasionally lead to syringomyelia, a disorder in which a cyst forms within the spinal cord, which can compress and damage the spinal cord, resulting in weakness or stiffness in the arms, legs, and cause chronic, severe pain.

How is the condition diagnosed?

Anyone who consistently experiences any of the symptoms described here should receive a neurological examination, including a complete medical history and physical exam. The best diagnostic tool to date for detecting Chiari malformation is magnetic resonance imaging (MRI). Recent advances in MRI techniques, most notably the ability to measure the flow of cerebrospinal fluid (CSF), allow doctors to identify many cases that would otherwise go undiagnosed.

What is the Treatment

Treatment options vary according to the severity of the disease. Many people who have Chiari malformation experience no symptoms at all and therefore require no treatment. Patients who complain of mild symptoms can sometimes be effectively treated with medication. However, medication can only relieve the symptoms and does not correct the problem. If the symptoms are severe and debilitating, affecting the patient’s overall quality of life or neurologic function, surgery may be considered. Surgery generally involves removal of the bone over the Chiari malformation to create more room for the cerebellum and brain stem. Additionally, the lining of the spinal cord is usually expanded to further improve the flow of spinal fluid.

What are the patient’s long-term prospects?

Though not everyone experiences the same severity of symptoms, living with Chiari malformation is a life-long struggle that can place a tremendous strain on patients and their families. With proper knowledge of the symptoms, diagnosis, and multidisciplinary treatment, Chiari malformation can be managed, allowing patients to achieve their best quality of life.