Basilar invagination is a health problem that affects your spine, neck, and — in some cases — your brain. It may be due to spine-related accidents, issues due to bone diseases and arthritis, or defects with which you are born. A person with severe basilar invagination often has neck or head pain, hand weakness, trouble walking, and other symptoms.
It's crucial to see a doctor right away if you think you have basilar invagination, though symptoms usually come on slowly.
Basilar invagination can be mild or severe. Severe cases may need surgery. Other treatments include medication and physical therapy.
Learn about the treatment options for Basilar Invagination at the UPMC Center for Skull Base Surgery.
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Doctors define basilar invagination as a defect or injury to the vertebrae (neck bones) that connect the head to the neck and puts pressure on the spinal cord and/or brainstem. It occurs when the peg in the front of the second neckbone (the C2 vertebra) moves slowly upward through the opening at the bottom of the skull. It can lead to issues with the brain, spine, or nerves.
Basilar invagination is not common. It may:
You may also hear the term basilar impression. The terms are often used interchangeably. Basilar impression is a milder form of basilar invagination.
Back to topSome people are born with abnormally formed vertebrae at the top of the spine, which can lead to basilar invagination. Doctors often don't know why, but it may sometimes be related to other diseases like Chiari syndrome, Klippel-Feil syndrome, and even Down syndrome.
Basilar invagination also happens in people with health problems that cause their bones to soften or joints erode. This can include:
Others may get basilar invagination as a result of a fall, car, bike, or diving accident. For instance, someone diving into a too-shallow pool may hit their head on the bottom, causing a fracture which, if undiagnosed or poorly healed, can lead to basilar invagination.
Back to topThose with basilar invagination may have symptoms including:
Symptoms of basilar invagination can worsen when the person bends their head toward the chest. This action drapes the brainstem or spinal cord over the top of the backbone. The body may react with pain or muscle spasm to prevent damage from this motion.
Back to topUPMC doctors diagnose basilar invagination through doing an exam and imaging tests. They will ask about symptoms and take a health history. If they suspect basilar invagination, they'll confirm it by ordering imaging tests.
Doctors use imaging studies — such as spine and skull X-rays, CT scans, and MRI scans — to confirm basilar invagination.
Back to topPeople with minor symptoms due to basilar invagination often don't need surgery. When basilar invagination does not put pressure on the spinal cord, treatments include:
People with symptoms that don't get better with these treatments may need spinal surgery. The surgeon will remove the bone that is putting pressure on the spine and/or fuse the vertebrae to prevent further pressure.
If you need surgery, UPMC surgeons often use the endoscopic endonasal approach. Surgeons use this less-invasive option to treat basilar invagination, which was first performed and described at UPMC.
Endoscopic endonasal surgery uses the nose and nasal cavities as an entryway. It gives the surgeon access to hard-to-reach areas they couldn't operate on before. Previously, surgery for this area required an incision in the back of the mouth, with increased risk of infection, prolonged healing, and worsening of swallowing.
The less-invasive surgical option means:
As part of endoscopic endonasal surgery for basilar invagination, people will usually need a second surgery, performed at the same time, to fuse the involved spinal bones. This helps stop the invagination from coming back and stabilizes the neck joints, which are often already unstable.
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