History
Patients with piriformis syndrome have the following symptomatic history:
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Chronic pain in the buttocks
This pain may radiate to the lower leg and worsens with walking or squatting.
This pain may imitate LBP.
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Pain with bowel movements
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Pain in the labia majora in women; pain in the scrotum in men
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Dyspareunia in women
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Pain when getting up from bed
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Pain exacerbated by hip adduction and internal rotation
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Intolerance to sitting
Physical Examination
Piriformis syndrome is a diagnosis of exclusion.
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At physical examination, the most important factor that differentiates sciatic pain from piriformis syndrome is the absence of neurologic deficit in piriformis syndrome.
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Herniation or disc compression results in intraneural derangement of the nerve root structure, whereas piriformis syndrome causes a qualitative epineural irritation.
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In piriformis syndrome, the only true-positive sign is tenderness over the gluteal region. [5]
The pain can be reproduced with maximum elongation of the piriformis muscle in flexion, adduction, and internal rotation of the hip.
Weakness can be observed with resisted external rotation and abduction of the hip.
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Several authors describe the use of the following signs in diagnosing piriformis syndrome:
Lasegue sign: Pain is present in the vicinity of the greater sciatic notch during extension of the knee with the hip flexed to 90 º, tenderness to palpation of the greater sciatic notch is noted.
Pace sign: Pain and weakness are present on resisted abduction-external rotation of the thigh.
Freiberg sign: Pain occurs with passive internal rotation of the extended thigh when the patient is supine.
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Robinson, who first described the syndrome, stated that piriformis syndrome had 6 cardinal features:
Positive Lasegue sign
Sausage-shaped mass over the piriformis muscle
Gluteal atrophy in chronic cases
Trauma to the region
Pain in the sacroiliac joint region, gluteal muscles, or greater sciatic notch
Pain exacerbated by lifting and relieved by traction on the affected extremity
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Beatty reproduced the pain of piriformis syndrome in the following way [6] :
The patient lies with the painful side up and the involved leg flexed.
The knee of the affected side rests on the table. Pain in the buttocks is reproduced when the patient lifts the leg and knee slightly above the table.
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Other authors conclude that pain can be reproduced in the lateral pelvic wall by means of rectal or pelvic examination.
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Nerve irritation in the herniated disk occurs at the root (sciatic radiculitis). In piriformis syndrome, the irritation extends to the full thickness of the nerve (sciatic neuritis).