Local anesthesia is widely used, in isolation or in conjunction with general anesthesia. The authors describe 2 adolescent patients presenting with absent brainstem reflexes and delayed awakening following elective foramen magnum decompression for Chiari Type I malformation. In both cases, neurological deficits were closely associated with the administration of a levobupivacaine field block following wound closure. In the absence of any structural or biochemical abnormalities, and with spontaneous recovery approximating the anesthetic half-life, the authors' observations are consistent with transient brainstem paralysis caused by perioperative local anesthetic infiltration.