title: Unusual cause of 'piriformis muscle syndrome'.
abstract: The piriformis muscle syndrome is a controversial "clinical" syndrome primarily characterized by signs and symptoms of sciatic nerve compression at the region of the piriformis muscle as it passes through the greater sciatic notch. The syndrome is often referred to; however, cases are rarely reported, and it is generally an uncommon diagnosis. Of those cases reported, the incidence is six times more frequent in females than in males, and is typically temporally related to minor pelvic or buttock trauma. We describe a case of a 40-year-old woman presenting with signs and symptoms suggestive of piriformis muscle syndrome following a gynecologic procedure performed in the dorsal lithotomy position. Electromyographic findings were consistent with this clinical entity. Operative exploration, however, revealed the source of neural compression to be a pseudoaneurysm of the inferior gluteal artery adjacent to the piriformis muscle. The diagnostic features of this clinical syndrome are discussed.
authors.affiliation: Section of Neurosurgery, University of Michigan, Ann Arbor.
authors.forename: S M
authors.initials: SM
authors.lastname: Papadopoulos
authors.forename: J E
authors.initials: JE
authors.lastname: McGillicuddy
authors.forename: J W
authors.initials: JW
authors.lastname: Albers
mesh_terms: D000328:Adult; D001707:Biopsy, Needle / Q000009:adverse effects; D004576:Electromyography; D005260:Female; D006406:Hematoma / Q000209:etiology; D006801:Humans; D008160:Lumbosacral Plexus; D009135:Muscular Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D009408:Nerve Compression Syndromes / Q000150:complications* / Q000175:diagnosis / Q000209:etiology; D012445:Sacrococcygeal Region; D012584:Sciatic Nerve; D013577:Syndrome; D014057:Tomography, X-Ray Computed; D014621:Vagina