Your spine does more than just hold you upright. It
interacts with your immune, skeletal, muscular, and nervous systems. So when
something goes wrong with your spine, it may have far-reaching effects
throughout your body. Keeping your spine happy is an important part of your overall
Ankylosing spondylitis (AS) is a case in point. It’s a form
of arthritis associated with long-term inflammation of the joints in the spine.
The first symptoms of AS are usually pain in the low back and hips, and people
often pass it off as just a “bad back.” But AS tends to get worse with time,
especially if not treated. As the disease progresses, it may affect many parts
of the body, including other joints and the eyes, bowels, feet, and heart.
AS typically starts with pain in the low back and hips
caused by inflammation of spinal joints there. As the years pass,
inflammation—and the symptoms caused by it—may gradually move up the spine and
give rise to complications.
These are three important features of AS:
An early hallmark of AS is inflammation of the sacroiliac joints, located
where the spine meets the pelvis. This inflammation causes pain in the hips. Sometimes
the pain radiates down the thighs, but never below the knees.
Another characteristic of AS is inflammation of entheses—places where ligaments
and tendons attach to bones. This type of inflammation causes much of the pain and
loss of function that’s seen in the disease.
The body’s repeated attempts to heal inflamed entheses can lead to the scarring
of tissue, followed by the formation of extra bone. Ultimately, two or more
bones of the spine may become fused, limiting flexibility in the back. In
severe cases, the spine may develop a forward curvature, causing a permanently stooped
posture. Fortunately, it’s far less common to reach this stage today, thanks to
Beyond the Spine
As time goes by, the inflammation caused by AS may affect other
parts of the body as well:
Inflammation may cause pain and stiffness in joints of the neck, shoulders,
hips, knees, ankles, or, rarely, fingers and toes.
About 70 percent of people with AS develop inflammation at the junction of the
ribs and spine. The point where the ribs meet the breastbone in front may also
be affected, leading to chest pain. Eventually, stiffening of the ribcage may
limit how much the chest can expand, reducing how much air the lungs can hold.
Up to 40 percent of people with AS develop inflammation of the eye, called uveitis
or iritis. This inflammation may cause eye pain and redness, sensitivity to
light, and blurred vision. If not treated promptly, it can lead to vision loss.
Inflamed entheses may occur at the back or base of the heel. The pain and
tenderness can seriously hamper a person’s ability to walk.
Inflammation may cause symptoms of inflammatory bowel disease, including abdominal
cramps and diarrhea, sometimes with blood or mucus in the stool.
Inflammation of the jaw is uncommon, affecting no more than 15 percent of AS
patients. But it can be especially troublesome, making it difficult to eat.
In rare cases, the body’s largest artery, called the aorta, becomes inflamed.
It may enlarge so much that it distorts the shape of the valve connecting it to
People with very advanced AS may develop cauda equina
syndrome, a disorder affecting a bundle of nerve roots at the bottom of the
spinal cord. These nerve roots transmit messages between the brain and the lower
body. When damage caused by AS compresses the nerve roots, it can impair
functioning of the pelvic organs or sensation and movement in the lower limbs.
Be alert for warning signs of cauda equina syndrome:
with bladder or bowel function. You might either retain waste or be unable
to hold it.
progressively worsening problems in the lower limbs. You may experience
loss of or changes in sensation in key areas: between the legs, over the
buttocks, on the backs of the legs, or in the feet and heels.
numbness, or weakness spreading to one or both legs. The symptoms may make
you stumble when you walk.
you develop these symptoms, it’s crucial to seek prompt medical attention. Left
untreated, cauda equine syndrome can lead to impaired bladder and bowel
control, sexual dysfunction, or paralysis.
What’s the Good News?
long list of potential complications can be intimidating. However, treatment for
AS may be able to prevent or delay many problems. In particular, some doctors
believe that a newer group of medications called tumor necrosis factor (TNF)
inhibitors may be able to change the course of the disease.