Sciatic Nerve Paralysis Following Arteriovenous Malformation Embolization

Abstract

In the workup of a right gluteal mass, a 32-yr-old male patient was diagnosed on angiography with an arteriovenous malformation, which was fed from the posterior branch of the right internal iliac artery (Fig. 1A). Arteries participating in the arteriovenous malformation were successfully embolized (Fig. 1B). However, he felt numbness and weakness in his right foot 3 hrs after the procedure and was subsequently referred to our clinic. His physical examination revealed motor weakness in ankle dorsiflexion and big toe extension (muscle strength grade 0/5 in both), as well as the right gastrosoleus muscle complex (muscle strength grade 4/5). He had hypoesthesia in the right L5 and anesthesia of the right S1 dermatomes. Achilles’ tendon reflex was absent. Laboratory tests were unremarkable.FIGURE 1: Posterior branch of the right internal iliac artery is feeding arteriovenous malformation (A); postembolization intact iliac arteries (B).The major cause of foot drop is weakness of the muscles of ankle dorsiflexion (particularly tibialis anterior) and the long extensors of the toes (extensor hallucis longus and extensor digitorum longus), all of which are innervated by the sciatic nerve.1 Most sciatic neuropathies occur in the hip but may also occur rarely in the thigh. The most common cause of sciatic neuropathy in recent years has been total hip arthroplasty. Intramuscular injections, vasculitis, arterial thrombosis, arterial bypass surgery, diabetes mellitus, postradiation therapy, benign tumors, malignant tumors, endometriosis, arterial aneurysms, persistent sciatic artery, myositis ossificans, and abscesses are other causes of sciatic nerve injury.2–4 To our knowledge, this is the first case of sciatic nerve paralysis after an arteriovenous malformation embolization procedure in the buttock region. We suggest that concurrent embolization of the arteries that nourish the sciatic nerve may have caused this paralysis. Clinicians should be aware of this interesting and unusual complication. Erkan Özgüçlü, MD Erkan Kıilıç, MD Department of Physical Medicine and Rehabilitation Hacettepe University Medical School Ankara, Turkey