What is a Chiari Malformation?
A Chiari malformation is a condition in which the cerebellum, which is at the base of the brain, drops from the skull into the spinal canal. These malformations are caused by defects in the skull base opening to the spinal canal (foramen magnum) and the cerebellum. The cerebellum controls balance which may be affected by a Chiari malformation. The flow of cerebrospinal fluid (CSF), which cushions the brain and spinal cord, can also be blocked which increased pressure on the brain.
A severe headache is the most common sign of Chiari malformation. The headache may worsen with sneezing, coughing or straining. Some patients may have no symptoms. Additional potential symptoms may include: neck pain, loss of balance, difficulty with speech or swallowing, hearing loss or ringing in the ears, coordination problems or depression.
Infants with a Chiari malformation may have difficulty swallowing, excessive drooling, a weak cry, gagging or vomiting, arm weakness, breathing problems, developmental delays, and failure to thrive.
Chiari malformations are either congenital (at birth) or acquired. Structural defects of the skull, cerebellum and spinal cord that occur during fetal development are the most common cause. These congenital (primary) Chiari malformations result of from genetic mutations or a nutrient deficient maternal diet. Secondary Chiari malformations can occur later in life if spinal fluid drains too rapidly from the spine from trauma, disease, or infection. Congenital Chiari malformations are much more common than secondary Chiari malformations.
There are no tests to determine if a child will be born with a Chiari malformation. There may be no symptoms and the Chiari malformation may be discovered during testing for an unrelated disorder. A physical and neurological exam will check memory, cognition, balance, reflexes, sensation, and motor skills. The best imaging study to diagnose a Chiari Malformation is magnetic resonance imaging (MRI) which uses powerful magnets and radio waves to create a detailed picture of soft tissue of the spine and brain. A computed axial tomography (CAT) scan uses the electromagnetic energy of X-rays to provide a detailed look at the bony anatomy in the area of the lower brain and upper spinal cord.
Chiari malformations that have no symptoms and do not interfere daily living only may need regular monitoring with an MRI. Other patients with pain or headaches may respond to medications to control symptoms. Surgery may be required to improve or stabilize symptoms or to stop progressive damage to the spinal cord and brain.
A posterior fossa decompression is the most common surgery to treat a Chiari malformation. The bony opening at the base of the skull is enlarged to allow more room for the cerebellum and upper spinal cord. Normal flow of CSF should be restored and symptoms may be improved. An incision in the dura (outer fibrous brain covering) may be needed to give the brain more room. A portion of the brain that has no known function, the cerebellar tonsils, may be removed to allow more room for the brain and spinal cord if needed. The dural incision is then patched to complete the operation. Increased pressure on the brain (hydrocephalus) may be treated with a drainage tube that removes excess CSF to decrease pressure inside the head.
The Norelle Health neurosurgeons are highly trained and skilled in the diagnosis, management, and treatment of Chiari Malformations. Our neurosurgeons can provide the optimal treatment. Neurosurgery is considered essential by insurances and should be covered with your plan. As out-of-network providers, we will check your benefits for you and let you know what they are so there are no surprises. We use an individualized treatment plan for your concerns to provide a personalized holistic plan of care. If you would like assistance, please feel free to contact us (link to contact page) or call our office (link to phone number).