Understanding Chiari Malformation: A Guide to Symptoms and Diagnosis

The brain stem and the spinal cord connect at an opening in the skull called the foramen magnum. The cerebellum, the part of the brain that helps to control balance, coordination, muscle movement, posture, and speech, normally sits above the foramen magnum. 

Chiari malformation (CM) is an abnormality in which the cerebellum extends down into the foramen magnum space. Symptoms range from nonexistent to severe. 

If you’re living with CM, you need the expertise of the doctors at Coast Neurosurgical Associates in Long Beach, California. We’ve prepared this guide to help you understand the potential symptoms of CM, as well as the ways the condition is diagnosed. 

The five types of Chiari malformation

There are types of CM, some more common than others. 

CM type 0

This is a rare type. There’s little or no cerebellum tissue in the foramen magnum. CM symptoms arise from problems due to cerebrospinal fluid crowding the space at the base of the skull. 

CM type I

This is the most common form of the condition. The cerebellum extends into the foramen magnum. Symptoms may not be present, or they may not emerge until adolescence or later. 

CM type II

The malformation occurs prior to birth and involves the cerebellum and brain stem growing abnormally, causing pressure in the skull. It’s common with forms of spinal bifida and myelomeningocele. 

CM type III

This is the most severe form of CM. It is also the rarest form. Brain tissues extend through another opening in the skull, not the foramen magnum. It’s severe and life-threatening and appears during childhood. 

CM type IV

Also rare, CM type IV results from problems with the cerebellum’s development, causing severe and life-threatening symptoms in infants. 

Symptoms of CM

The symptoms and their severity depend on which tissues are compressed and the degree of compression. Symptoms can include: 

• Headaches, particularly following coughing, sneezing, or physical strain
• Dizziness
• Problems with breathing, speaking, or swallowing
• Balance or hearing problems
• Tinnitus (ringing in the ear) 
• Scoliosis (spinal curvature)
• Muscle numbness or weakness
• Mood disorders, like depression
• Coordination difficulties, particularly with the hands and fine motor skills

It’s possible to have CM and be completely symptom-free or for symptoms to appear later in life. 

Diagnosing CM

Diagnosis of Chiari malformation starts with a review of your medical history and symptoms you’re currently experiencing, as well as an overall physical examination. Confirming the condition and its causes requires diagnostic imaging. 

Magnetic resonance imaging (MRI) creates detailed three-dimensional images of structures within the body using magnets and radio waves. MRIs can track the progression of CM over time. 

Computerized tomography (CT) scans use X-rays to generate cross-sectional images of the body that can also reveal details of your CM condition. 

Our team at Coast Neurosurgical Associates are Chiari malformation specialists. Contact our office online or by phone to book a consultation today.