Diagnosing Piriformis Syndrome

What is piriformis syndrome?

Piriformis syndrome is a condition in which the piriformis muscle causes pain in the buttocks. The piriformis is a muscle located deep inside the buttock area and near the top of the hip joint. It is used to lift and rotate the thighs and in any motion by the hips and legs, such as walking, maintaining balance, running, lifting, engaging in sports, shifting weight from one leg to the other, etc.

The sciatic nerve is also located deep inside the buttock area. The sciatic nerve runs alongside the piriformis muscle, and after branching off into smaller nerves, it ends at the feet. The piriformis muscle can become irritated or spasm which causes pressure on the sciatic nerve. This results in pain that initiates in the buttocks, sometimes extends down the back of one or both legs, and occasionally enters the feet.

A health care professional should be consulted if pain or numbness in the buttocks or legs lasts longer than a few weeks or if symptoms frequently come and go.

How is piriformis syndrome diagnosed?

A definitive test for piriformis syndrome does not yet exist. During the diagnostic process, a health care professional will ask about an individual’s medical history, symptoms, and any activities that aggravate the pain. Symptoms should be discussed in detail for a thorough review. A doctor will perform a physical exam, including a range-of-movement test, to determine if the pain is exacerbated while stretching the piriformis muscle.

Since the symptoms of piriformis syndrome are similar to other health conditions, eliminating the possibility of other medical conditions is essential for a proper diagnosis. Imaging tests, such as a CT scan or MRI, may be ordered to determine if arthritis, spinal cord compression, a ruptured disc or a herniated disc is the cause of pain. An ultrasound of the piriformis muscle may also be ordered. Magnetic resonance neurography (another type of imaging test) may be performed to identify sciatic nerve irritation. Finally, if other diagnostic tests fail to provide a definitive diagnosis, an electrophysiologic nerve study may be conducted.