What is Piriformis Syndrome?

Piriformis Syndrome is a condition in which irritation of the sciatic nerve causes pain in the buttock, radiating down the leg. The main difference between Sciatica and Piriformis Syndrome is the cause. Sciatica is due to pressure on the sciatic nerve from a bulging or herniated lumbar disc. With Piriformis Syndrome, the irritation of the sciatic nerve is due to spasms or tightening of the piriformis muscle, resulting in pain. The piriformis is a small muscle located deep within the hip and buttocks region. It connects the sacrum, which is the 'tailbone' or lower end of the spine, to the top of the femur, the hip bone. The piriformis muscle aids in external rotation, turning out, of the hip, leg, and foot. The sciatic nerve usually passes underneath the piriformis muscle but, in approximately 10% to 15% of people, it travels through the muscle. In both cases, spasms and tightening of the muscle irritate or pinch the sciatic nerve, causing painful symptoms. Symptoms of Piriformis Syndrome

- Pain deep within the buttocks
- Pain becomes worse with sitting, climbing stairs, performing squats.
- Sitting is often difficult and the patient can't sit flat on a seat.
- Sufferers tend to sit with their weight off the painful buttock, which is tilted up off the seat.
- Sciatica type pain radiating from buttock down thigh, calf, possibly to foot
- Numbness and muscle weakness may develop in affected limb.

Causes Of Piriformis Syndrome Contractions and spasms of the piriformis muscle cause the pain and pressure on the sciatic nerve. The most common reasons for this are:

- Improper stretching or warming up before exercising
- Overly-strenuous exercises
- Prolonged sitting - sometimes sitting with a wallet or pressure causing object in the hip pocket
- Exercising on a hard surface, like concrete
- Exercising on uneven ground
- Increasing exercise intensity or duration too quickly
- Exercising in worn or poorly fitting shoes
- Excessive running or bicycle riding, unless accompanied by lateral strengthening and stretching exercises
- A fall onto the buttocks

Diagnosing Piriformis Syndrome A differential diagnosis must be made to determine the cause of the sciatica pain. It includes:

- Complete History and Physical Exam
- Checking to see what movements cause pain
- Evaluating sufferer's posture and gait
- Past history of any injuries or arthritis
- Review patient's exercise habits
- Evaluating muscle strength and reflexes, any other spine conditions
- Lab work may be done to rule out arthritis or infection
- X-rays of the lower back and pelvis, lumbar spine and hips
- A MRI (Magnetic Resonance Imaging) to give a detailed picture of the spine and soft tissues
- Neurography is like a MRI but it examines nerves for irritation. This is often helpful in diagnosing Piriformis Syndrome.
- A Bone Scan will show injuries, inflammation, or infection.
- The most accurate method of diagnosing the syndrome is a diagnostic injection into the muscle with the help of a fluoroscope. An anesthetic is injected into the piriformis muscle and if the pain subsides, the diagnosis is confirmed.

This would have no effect if the cause of the sciatica was pressure on the sciatic nerve from a lumbar disc.