What Is Chiari I Malformation? Chiari I malformation (key-AR-ee mal-fore-MAY-shun) is when the cerebellum — the part of the brain that controls coordination and muscle movement — pushes down through the hole in the bottom of the skull. This hole is called the foramen (fer-AY-men) magnum. Usually just the spinal cord passes through the foramen magnum. Many kids with Chiari I malformation have no symptoms. Treatment can help kids who do have them. What Are the Signs & Symptoms of Chiari I Malformation? Some people with Chiari I malformation never have any symptoms. If symptoms do happen, they usually don't show up until late childhood or the teen years. Signs and symptoms can include: headache (especially after sneezing, coughing, or straining) balance problems neck pain dizziness vision problems poor hand coordination numbness and tingling of the hands and feet change in bladder (pee) or bowel (poop) habits trouble swallowing hoarseness Sometimes, children with Chiari I malformation can also have: a syringomyelia (ser-in-go-my-ILL-ee-uh): a fluid-filled space within the spinal cord hydrocephalus (hi-droh-SEF-eh-less): a buildup of spinal fluid in the spaces deep within the brain sleep apnea: periods when breathing stops during sleep scoliosis: curvature of the spine What Causes Chiari I Malformation? There are four different types of Chiari malformation (I, II, III, and IV). Chiari I is the most common. Doctors don't know exactly what causes Chiari I malformation. A baby can be born with Chiari I malformation or it can develop in the first few years of life. Less often, the malformation can happen later in life from trauma, infection, or other medical problems. Chiari I malformation can run in families. So it may have a genetic cause. Chiari malformations happen when the space for the cerebellum is smaller than normal or has an unusual shape. This squeezes part of the cerebellum down through the foramen magnum. If this puts pressure on the cerebellum and spinal cord, it can lead to symptoms. How Is Chiari I Malformation Diagnosed? Chiari I malformations usually don't cause symptoms. So many aren't found until an imaging study of the brain or upper spine is done for a different reason. How Is a Chiari Malformation Treated? For kids without symptoms, doctors usually recommend getting follow-up MRIs to check for any changes. Surgery is not usually needed. For children with severe symptoms, doctors often recommend a surgery called posterior fossa decompression. This surgery makes more space for the cerebellum and lowers pressure on the spinal cord. Kids with related problems (such as syringomyelia, hydrocephalus, sleep apnea, or scoliosis) may need medical treatment for those conditions. Some doctors recommend that kids with Chiari I malformation avoid certain activities like gymnastics, wrestling, and contact sports. What Can Parents Do? Many kids with Chiari I malformation do not have symptoms and never need treatment. But call your doctor right away if your child does show any symptoms, such as headache, balance or coordination problems, changes in pee or poop habits, or voice changes. To help your child stay healthy, follow your doctor's instructions for: making and keeping all follow-up appointments going for all recommended studies, such as X-rays or MRIs avoiding any activities, if recommended Back to Articles Related Articles Brain and Nervous System The brain controls everything we do, and is often likened to the central computer within a vast, complicated communication network, working at lightning speed. Read More Hydrocephalus Often called "water on the brain," hydrocephalus can cause babies' and young children's heads to swell to make room for excess cerebrospinal fluid. Learn how this condition is managed. Read More Brain and Nervous System If the brain is a central computer that controls all the functions of the body, then the nervous system is like a network that relays messages back and forth to different parts of the body. Find out how they work in this Body Basics article. Read More Scoliosis Scoliosis makes a person’s spine curve from side to side. Large curves can cause health problems like pain or breathing trouble. Health care providers treat scoliosis with back braces or surgery when needed. Read More Magnetic Resonance Imaging (MRI): Brain A brain MRI, a safe and painless test that produces detailed images of the brain and the brain stem, can help detect cysts, tumors, bleeding, and other problems. Read More CAT Scan: Head A head CAT scan is a painless test that uses a special X-ray machine to take pictures of a patient's brain, skull, and sinuses, as well as blood vessels in the head. It might be done to check for any number of conditions. Read More Spina Bifida Factsheet (for Schools) What teachers should know about spina bifida, and how to help students with the birth defect do their best in school. Read More Spina Bifida Occulta In spina bifida occulta, a baby is born with a gap in the spine's bones, but the spinal cord and its covering do not push through it. Read More Myelomeningocele Myelomeningocele is a type of spina bifida in which a baby is born with a gap in the bones of the spine. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.