Symptoms of Ankylosing Spondylitis
Ankylosing spondylitis (AS) is a chronic disease that develops slowly. In the early stages of the disease, the sacroiliac joints (located at the back of the pelvis) become inflamed and painful. In fact, one of the earliest signs of AS is tenderness around the sacroiliac joints. Another early symptom is low back pain that may spread down into the buttocks and thighs. Pain varies in intensity and duration, and it is episodic (comes and goes). Stiffness is usually worse in the morning and improves with exercise.
As the disease progresses, ossification is triggered by the body's defense mechanism. Your body knows that joint movement is causing pain, so it attempts to limit movement by forming new bone that will stop movement.
This ossification causes new bone to grow between vertebrae, eventually fusing them together and increasing the risk for fracture.
Further, ossification may affect spinal ligaments, causing spinal stenosis (narrowing), which can result in neurologic deficit (problems related to the nerves, such as weakness or loss of function).
Other symptoms of ankylosing spondylitis:
- Limited motion in the lumbar spine
- As the disease progresses, the patient may notice the discomfort moves up the spine. AS generally starts in the low back (lumbar spine) and gradually moves up to the neck (cervical spine).
- The mid-back (thoracic spine) may be affected by pain, stiffness, and limited chest expansion when breathing.
- Pain, tenderness, and stiffness in the shoulders, hips, knees, and heels
- Cauda equina syndrome (specific nerve compression) may develop, causing lower extremity numbness, weakness, and incontinence.
- Inflammation of the intervertebral disc or disc space (spondylodiscitis) is a common complication caused by the hardening/thickening of fibrous tissue (sclerosis) affecting vertebral end plates. The resultant abnormal vertebral motion almost always causes pain.
- Spinal deformity: kyphosis (humpback), lordosis (swayback)