Unusual cause of 'piriformis muscle syndrome'
S. M. Papadopoulos, J. E. McGillicuddy and J. W. Albers
Section of Neurosurgery, University of Michigan, Ann Arbor.
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.
