Craniocervical junction disorders are abnormalities of the bones that join the head and neck. These disorders may be present at birth or result from injuries or disorders that occur later. Most often, people have neck pain and headache, but if the spinal cord or lowest part of the brain (brain stem) is affected, people may have difficulty sensing vibration, pain and temperature and may have weak muscles, dizziness and impaired vision. Doctors make their diagnosis based on symptoms, and magnetic resonance imaging (MRI) or computed tomography (CT). To relieve pressure on the brain, spinal cord, or nerves, doctors use traction or manipulate the head, then immobilize the neck. Surgery is sometimes needed.
The craniocervical junction consists of the bone that forms the base of the skull (occipital bone) and the first two bones in the spine (which are in the neck): the atlas and axis. Disorders that affect the large opening at the bottom of the occipital bone (called the foramen magnum) are a particular concern because important structures pass through this opening. These structures include the lowest part of the brain (brain stem), which connects to the spine, as well as some nerves and blood vessels.
Tumors can also affect craniocervical structures. If tumors spread to the bones of the neck, the first two spinal bones may become misaligned. A rare, slow-growing bone tumor (called a chordoma) can develop at the craniocervical junction and press on the brain or spinal cord.
What are the symptoms?
Among the symptoms are neck pains, often with a headache that starts at the back of the head. Moving the head usually makes neck pain and headache worse. Coughing or bending forward can trigger the pain. If there is pressure on the spinal cord, the arms and/or legs may feel weak, and people may have difficulty moving them. People may be unable to sense where their limbs are or feel vibration. When they bend their neck forward, they may feel an electrical shock or a tingling sensation shooting down their back, often into the legs (called Lhermitte sign). Occasionally, people become less sensitive to pain and temperature in their hands and feet. Pressure on parts of the brain or cranial nerves (which connect the brain directly to various parts of the head, neck and trunk) can affect eye movements. People may have double vision or be unable to move their eyes in certain directions, or the eyes may move involuntarily.
How is it diagnosed?
If symptoms appear suddenly or become worse quickly, patients should see a doctor immediately. Immediate diagnosis and treatment are necessary and can sometimes reverse symptoms or prevent permanent disability.
Doctors suspect a craniocervical junction disorder if people have neck pain or a headache at the back of the head, in addition to problems that are usually caused by pressure on lower parts of the brain or the top of the spinal cord or if people experience involuntary movement of the eyes.
The diagnosis can be confirmed by imaging tests, MRI or CT. If problems appeared suddenly or suddenly worsen, an imaging test is done immediately. CT shows bone better than an MRI and may be done more easily in an emergency. If MRI and CT are unavailable, plain X-rays are taken.
Angiography, which provides detailed images of bloods vessels, is done if MRI or CT scans suggest abnormalities that affect blood vessels.
What are the treatment options?
If the craniocervical junction structures are putting pressure on the brain, spinal cord or nerves, doctors try to realign (reduce) the structures by using traction or by manipulating the head into different positions. These techniques may relieve the pressure. After the structures are realigned, the head and neck are immobilized. If problems are due to a bone tumor, radiation therapy and a rigid neck brace to keep the neck from moving often help. If the cause is Paget’s disease of bone, drugs such as bisphosphonates (which increase bone density) or calcitonin may be prescribed.