Chiari Malformation
Chiari malformation is a structural condition in which part of the cerebellum—the lower portion of the brain involved in balance and coordination—extends downward through the opening at the base of the skull into the upper spinal canal. This may disrupt the normal flow of cerebrospinal fluid (CSF) and place pressure on the brainstem or spinal cord. Some people have no symptoms, while others may experience headaches, neck pain, dizziness, or neurological changes that can progress over time.
What is it?
Chiari malformation occurs when the cerebellar tonsils extend below the base of the skull into the upper spinal canal. This can crowd nearby structures and interfere with the normal circulation of cerebrospinal fluid between the brain and spine. The condition is classified into several types based on anatomy and severity. Chiari I malformation is the most common form and is often diagnosed during adolescence or adulthood, while more severe forms are typically identified earlier in life.
MRI is the preferred imaging test for evaluating Chiari malformation because it provides detailed views of the cerebellum, brainstem, spinal cord, and surrounding CSF spaces. In some cases, a specialized CSF flow study performed during the MRI exam may help determine whether fluid movement is being obstructed, which can assist physicians in treatment planning.
Important to Know
Many people with Chiari malformation never require treatment, especially when symptoms are mild or absent. When symptoms significantly affect daily life or imaging reveals associated conditions such as syringomyelia—a fluid-filled cavity within the spinal cord—surgical decompression may help relieve pressure and improve CSF flow. Follow-up MRI imaging may be recommended to monitor for progression or complications over time.
Red flag symptoms include worsening headaches triggered by coughing or straining, progressive weakness, difficulty swallowing, problems with coordination, or new sensory changes. These symptoms warrant prompt medical evaluation.