Chiari malformations are structural problems in the base of the skull, especially with the cerebellum, the brain area that controls balance, and the brain stem. Normally the cerebellum sits above an opening in the skull called the foramen magnum, which permits the spinal cord to pass through it.
When part of the cerebellum extends below the opening and into the upper spinal canal, it’s called a Chiari malformation (CM). Such a condition can lead to severe complications, including hydrocephalus — literally “water on the brain,” but actually a buildup of cerebrospinal fluid within the cranial cavity — and spina bifida, a cleft in the spinal column. It’s estimated to affect less than one in 1,000 people.
At Center for Neurosurgery Las Vegas, board-certified neurosurgeon Dr. Scott Glickman and his team offer surgical options for their patients with Chiari malformations. Here’s what you need to know about the risks for this condition and what can be done to treat it.
CM is caused by developmental problems in the brain and spinal cord that occur during pregnancy. This form is known as primary or congenital Chiari malformation. The condition can also be caused later in life if an excessive amount of cerebrospinal fluid is drained as a result of traumatic injury, disease, or infection. This form is known as acquired or secondary Chiari malformation, and is less common than the primary form.
Doctors divide CM into three types, depending on which parts of the brain tissue are displaced into the spinal canal and whether or not developmental problems of either the brain or spine are evident.
Chiari malformations may run in some families, suggesting a genetic link. However, research is still in an early phase. Exposure to toxins during pregnancy is another possible risk factor.
Many people with CM don’t display any symptoms, especially those with type I, and the condition may not be discovered until later in life during routine testing for another condition.
People with a type I Chiari malformation experience severe headaches at the base of the skull that often occur after a sudden fit of coughing or sneezing. Other symptoms include:
People with type II Chiari malformation have a greater amount of tissue extending into the spinal canal, which almost always leads to symptoms of a myelomeningocele, where the backbone and spinal canal don't close properly before birth. Patients experience:
Type III is the most severe type of CM. It often comes with severe neurological problems and has a higher mortality rate than the other types.
CMs that don’t produce symptoms might not need treatment, and Dr. Glickman often recommends routine monitoring with periodic MRIs in these cases.
Often, surgery is the only treatment available to relieve symptoms or stop the ongoing damage to the central nervous system, and you might need more than one surgery to address all issues.
The most common surgery is posterior fossa decompression, a procedure that creates more space for the cerebellum, relieving pressure on the spinal cord and helping restore the normal flow of cerebrospinal fluid. Dr. Glickman makes an incision at the back of the head and removes a small portion of the bone at the bottom of the skull (craniectomy). In some cases, he may also remove the arched, bony roof of the spinal canal, called the lamina (spinal laminectomy).
For hydrocephalus, Dr. Glickman may insert a shunt (tube) into the head to drain the excess fluid into either the chest cavity or the abdomen, where it’s absorbed by the body.
If you’d like to learn more about Chiari malformation and what you can do to treat it, contact the Center for Neurosurgery Las Vegas to schedule a consultation with Dr. Glickman. Call the office at 702-929-8242, text us at 725-210-0057, or book online with us today.