What are Basilar Invagination, Basilar Impression, And Cranial Settling?

Basilar invagination, basilar impression, and cranial settling are different but similar diseases. All three of these complex conditions are associated with the skull and the highest vertebral level, and each can cause spinal cord compression.

The basilar impression is when parts of the cervical (neck) vertebrae enter into the hole in the bottom of the skull (foramen magnum).
Basilar invagination is the same condition but due to softening at the base of the skull.
Cranial settling occurs when the bone at the top of the neck on which the skull pivots extends into the foramen magnum.
It can be congenital, present at birth, or acquired later in life due to conditions such as rheumatoid arthritis and Paget's disease.

What are the manifestations of these spinal conditions?

Symptoms of these spinal conditions come in varying degrees and range from the following:

Pain in the head or neck
Weakness
Lightheadedness or dizziness
Altered consciousness or confusion
Inability to swallow or numbing

How do I diagnose and evaluate these spinal conditions?

If we think a patient has basilar invagination, basilar impression, or cranial settling, we will administer some form of physical assessment plus additional testing. Various forms of tests, procedures, and imaging studies performed when diagnosing these medical conditions are as follows:

Magnetic resonance imaging (MRI)
Bone scans
Myelography
CT scan
X-rays
Studies performed on nerve conduction in order to analyze the electrical impulses produced by the muscles and nerves