Internal iliac artery pseudoaneurysm: an unusual cause of sciatica and lumbosacral plexopathy.

This report describes an unusual case of lumbosacral plexopathy resulting from internal iliac artery pseudoaneurysm. A 50-yr-old woman presented with multiple penetrating trauma to the thorax, abdomen, and left buttock. Several weeks after the injury, severe sciatica and motor dysfunction developed in her left leg. Progressively worsening pain was followed by left foot drop. An electrodiagnostic evaluation suggested a lower lumbosacral plexopathy. Magnetic resonance imaging showed a hematoma extending adjacent to the left lumbosacral plexus. Computerized tomographic angiography revealed a left internal iliac artery pseudoaneurysm. The pseudoaneurysm was excised surgically. In the early postoperative period, the patient reported total relief of pain. Her motor function recovered gradually over several weeks; however, some residual weakness of foot dorsiflexion persisted. With this case presentation, we underscore that an arterial pseudoaneurysm should be remembered as an etiologic possibility of lumbosacral plexopathy and sciatica, especially in patients with history of iatrogenic or accidental trauma. An increased awareness of this rare cause of sciatica and lumbosacral plexopathy may enable early intervention alternatives.