Piriformis syndrome--a rare cause of extraspinal sciatica

Area of Science:

• Radiology
• Orthopedic Surgery
• Neuroscience

Background:

• Piriformis syndrome is a rare condition causing severe, unilateral buttock pain.
• The pain is typically shooting and non-discogenic in origin.
• Pelvic Magnetic Resonance (MR) imaging is essential for evaluating piriformis muscle anatomy and its relationship with the sciatic nerve.

Observation:

• A 35-year-old woman experienced a year of radiating leg pain with a normal lumbosacral spine MR.
• Pelvic MR imaging revealed an anomalous course of the left sciatic nerve through split piriformis muscle fibers.

Findings:

• The case highlights the diagnostic utility of pelvic MR imaging in identifying sciatic nerve entrapment by the piriformis muscle.
• Surgical decompression successfully relieved the patient's symptoms, confirming the diagnosis.

Implications:

• Pelvic MR imaging is vital for diagnosing piriformis syndrome in patients with isolated buttock pain and normal lumbosacral spine MR.
• This imaging modality aids in precise anatomical assessment, guiding surgical interventions for sciatic nerve decompression.