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Chiari and Syringomyelia Research Foundation - Working toward a life without pain.
The University of Missouri-Columbia Chiari Clinic website explains that Chiari I malformation was discovered by Dr. Chiari in 1891. Normally the brain is in a cavity inside the skull. The brainstem normally sits in a cone-shaped shaft, called the foramen magnum, right above the spinal cord. However in the case of Chiari I malformation, the back of the skull, called the posterior fossa, is not formed properly. When this happens there is not enough room in the cavity for the brain to exist in the skull properly. This forces tonsils on the cerebellum to elongate into the foramen magnum. This elongation blocks the flow of cerebral spinal fluid around the brain and spinal cord. Chiari I malformation is generally diagnosed through an MRI (magnetic resonance imaging).
As described by the Chiari InstituteпїЅs website, Chiari I malformation is generally a congenital disorder, however acquired cases do exist. According to the University of Missouri-Columbia Chiari Clinic website, while the actual cause of the disorder is unknown it is believed that the abnormality forms when the spinal cord and brain stem are forming in the embryo.
Many times patients with the disorder do not experience symptoms. However when symptoms are present, they usually occur during adolescence or early adulthood and less often, during childhood. The University of Missouri-Columbia Chiari Clinic website lists the following as symptoms of Chiari I Malformation: headaches, dysphagia (difficulty swallowing), pain, hoarseness, numbness, visual disturbance, ataxia (gait disturbance), syncope (episodes of passing out or loss of consciousness), nausea, vomiting, dizziness, disequilibrium (problems with balance), nosebleeds, fast or slow heart beat, high or low blood pressure, ringing in the ears, hearing loss, depression, shortness of breath and fatigue. Although this is a comprehensive list, more symptoms can occur.
Chiari I malformation is generally treated through surgery. The goal of the surgery is to decompress the posterior fossa and the foramen magnum areas. This is done by removing a small section of the skull in the area of the posterior fossa. Other procedures may be performed during surgery but the method depends on the surgeon and the patient.