If you’ve had AS for a while, you’re probably well acquainted with terms to describe the basic disease process, as well as spinal anatomy in general. Here we’ll focus on different manifestations of the disease, as well as symptoms and complications that can develop outside the spinal region. Here are 11 key vocabulary terms that everyone with AS should know. Syndesmophytes These are bony growths that can develop inside the ligaments connecting your vertebrae. They’re one of the main ways AS can cause structural damage to your spine and loss of joint mobility. New syndesmophytes develop in about one-third of people with AS in a given two-year period, according to an article published in July 2015 in the journal Current Opinion in Rheumatology. Kyphosis This refers to excessive outward or forward curving of the spine, usually in the upper part of the back. It’s common in untreated AS and may develop because of osteoporosis (weak, porous bones) or postural changes triggered by pain. Referred to colloquially as a “roundback” or “hunchback” posture, kyphosis was once a hallmark feature of AS, but can now usually be prevented or delayed with routine treatment of the condition. Lordosis This refers to inner curvature of the lower back. Some lordosis is normal, and is considered an element of good, healthy posture. It can also be excessive, but this usually isn’t an issue in AS. Normal lordosis may be lost in untreated or advanced AS, with the lower part of the back (lumbar spine) becoming flat and immobile. Nociceptive pain This is pain that’s caused by a local, physical problem, such as an injury or ongoing damage. It stands in contrast to neuropathic pain, which is pain that occurs without a local, physical trigger. Nociceptive pain can occur in many different situations in AS, including ongoing joint damage, strained muscles, and systemic inflammation (inflammation that doesn’t just affect the spine). Referred pain This is pain that’s triggered in one area of the body but felt in another. It’s a form of neuropathic pain that is activated by nociceptive pain. If hip involvement occurs in AS, it can cause referred pain in your knees and thighs, according to the Spondylitis Association of America. Anterior uveitis Also known as iritis, this type of eye inflammation — affecting the front of the eye — is one of the most common complications of AS. It can occur independently of spinal inflammation and is usually resolved with local drug treatments (eye drops). About one-third of people with AS will experience anterior uveitis at least once, according to the Spondylitis Association of America. Enthesitis This is inflammation of the area where ligaments or tendons attach to bones and is very common in AS. It can cause areas of swelling or tenderness, which are sometimes called “hot spots,” in your back, pelvis, chest, or heel, and often significantly impairs mobility. Two areas of the foot are commonly affected by enthesitis in people with AS: the Achilles tendon (at the back of your heel and ankle) and the plantar fascia (at the bottom of your heel). Aortitis This is inflammation of the aorta, the largest artery in the human body, which carries blood from the left ventricle (pumping chamber) of your heart to other areas of the body. It can also affect the aortic valve, which separates your left ventricle and aorta. Aortitis can cause a range of symptoms, including headaches, jaw pain, dizziness, balance problems, and fatigue. Dactylitis Also known as “sausage digit,” this is a type of inflammation that affects an entire finger or toe. It can be painful and interfere with use of your hands or feet. Dactylitis is considered a feature of systemic inflammation in AS, and it usually requires no special treatment other than optimizing AS treatment. Compression radiculitis When an area where nerve roots exit your spine becomes compressed, it can pinch the nerve — causing symptoms that may include pain, tingling, or weakness in your back, arms, hands, or chest, depending on the area of your spine that’s affected. If optimizing AS treatment doesn’t do enough to address radiculitis, minimally invasive surgery may be an option. Cauda equina syndrome This condition, characterized by severe back pain, occurs when nerve roots in a bundle of nerves at the end of the spinal cord (called the cauda equina) are compressed. It can disrupt sensation and function in your legs and bladder. Cauda equina syndrome should be treated as a medical emergency. It can cause urinary incontinence and, in rare cases, permanent paralysis.
