Piriformis syndrome often mimics sciatica as it is pain in sciatic distribution secondary to irritation or compression of the sciatic nerve from the overlying Piriformis muscle and not from an abnormal disc problem. Pain can occur along with numbness and tingling from the buttocks down to the lower leg. Diagnosis often results from ruling out true primary sciatica of a disc/spinal nerve root etiology.
The Piriformis muscle can shorten or spasm as it overlies the sciatic nerve. Other factors can include inactive/shortened gluteal muscles that occur with prolonged sitting, the piriformis muscle and other muscle groups can then become overdeveloped in compensatory use leading to pressure on the nerve. Bicyclists, rpwers and runners can have similar patterns of gluteal muscle use that can result in Piriformis syndrome. Sacroiliac dysfunction and over pronation of the foot have also been linked to Piriformis syndrome.
Diagnosis can be difficult and relies on positioning tests of the lower extremity that either do or do not elicit the painful condition. Sophisticated electrophysiology tests have shown to be of some help in diagnosis but are not commonly performed. Many times the syndrome is diagnosed by defining the symptoms and eliminating true sciatica.
Treatment involves non steroidal anti-inflammatories, muscle relaxants, stretching, strengthening and as a last resort corticosteroid injection or botox injections to then help stretching/strengthening succeed.