P Pu ur rp po os se e: : Bilateral flexion-induced ankle clonus has been proposed as a test of spinal cord integrity during anesthesia for scoliosis surgery. The purpose of this study was to establish the reliability of this test in normal children emerging from volatile anesthesia. A secondary objective was to determine if there was a difference in the validity of this test with either sevoflurane or isoflurane anesthesia. M Me et th ho od ds s: :In a randomized, prospective blinded clinical trial, 32 healthy children aged three to 13 yr, were randomized to receive either isoflurane (Group I, n = 15) or sevoflurane (Group S, n = 17) for maintenance of anesthesia during dental restorative surgery. During emergence, an observer, blinded to group allocation, recorded ankle clonus scores (number of beats to a maximum of 5 on each side) at 60-sec intervals until tracheal extubation. End-tidal anesthetic concentration was measured contemporaneously.