Ann Rehabil Med.  2015 Dec;39(6):1042-1046. 10.5535/arm.2015.39.6.1042.

Leg Weakness Caused by Bilateral Piriformis Syndrome: A Case Report

• Moon HB
• Nam KY
• Kwon BS
• Park JW
• Ryu GH
• Lee HJ
• Kim CJ

• KMID: 2165634
• DOI: http://doi.org/10.5535/arm.2015.39.6.1042

Abstract

Piriformis syndrome (PS) is an uncommon neuromuscular disorder caused by the piriformis muscle (PM) compressing the sciatic nerve (SN). The main symptom of PS is sciatica, which worsens with certain triggering conditions. Because the pathophysiology is poorly understood, there are no definite diagnostic and therapeutic choices for PS. This case report presents a young woman who mainly complained of bilateral leg weakness. Electromyography revealed bilateral sciatic neuropathy and magnetic resonance imaging confirmed structural lesions causing entrapment of the bilateral SNs. After a laborious diagnosis of bilateral PS, she underwent PM releasing surgery. Few PS cases present with bilateral symptoms and leg weakness. Therefore, in such cases, a high level of suspicion is necessary for accurate and prompt diagnosis and treatment.

Keyword

Piriformis muscle syndrome; Bilateral; Muscle weakness

MeSH Terms

Diagnosis
Electromyography
Female
Humans
Leg*
Magnetic Resonance Imaging
Muscle Weakness
Piriformis Muscle Syndrome*
Sciatic Nerve
Sciatic Neuropathy
Sciatica

Figure

• 

  Fig. 1 Axial T2-weighted images of the spine MRI. (A) Central to right disc bulging and left S1 nerve root swelling observed in 2008. (B) Improved disc bulging and left S1 nerve root swelling is not observed anymore in 2014.

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  Fig. 2 Images of the first hip MRI whose reading was noted as normal. In fact, (A) axial T1-weighted image of hip MRI shows asymmetric enlargement of right piriformis muscle. (B) Axial T2-weighted image shows dark signal band-like structure at anterior to left piriformis muscle.

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  Fig. 3 Recent hip MRI images taken in 2014. (A) Axial T1-weighted image shows asymmetric enlargement of right piriformis muscle, which increased in size, compared with previous exam. (B) Axial T2-weighted image shows dark signal band-like structure at anterior to left piriformis muscle, reducing space around the left sciatic nerve tract.

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