Abducens Nerve (VI) Injury Caused by Halo-Femoral Traction: A Case Report

Abstract

Stretch and traction on cranial nerves during surgery may cause localized ischemia or change of position of the cranial nerve leading to subsequent dysfunction. Cranial nerve palsies (VI, IX, X and XII) are the commonly affected nerves. Here we report a cranial nerve VI palsy from a halo-femoral suspension following a posterior spinal fusion. We present an 11-year-old girl with idiopathic scoliosis who was admitted for surgical correction. She had no neurological problems preoperatively. The initial video-assisted thoracoscopic anterior release and cranial bifemoral traction were uneventful. Postoperatively, ten-pound weights were added at the head and another ten were added for counter-traction. Weights were added daily in 5-pound increments. Postoperative day 2, the patient complained of “double vision” which resolved upon decreasing the traction weight only by 5 pounds. She underwent an uneventful posterior spinal fusion one week later with a total intravenous anesthesia technique; motor evoked potentials were adequate throughout the procedure. One day later, she again developed left sixth cranial nerve palsy with inability to gaze laterally. There were no other neurological deficits, headaches or even double vision. Neurology and ophthalmology consultations excluded hypoxia/hypoperfusion as possible etiologies. The femoral pins and occipital frame were removed on day 3 in order to obtain imaging and also to remove a potential source of infection. The left lateral rectus palsy was noted to improve that same day. Radiological imaging results were ultimately normal. There is a need for frequent neurological examinations in patients in halo-tractions and prompt removal of the instrument at the first sign of eye problems. doi:10.4021/jnr39e