Perforation of the soft palate using the GlideScope videolaryngoscope.

CAN J ANESTH 54: 7 www.cja-jca.org July, 2007 in several muscles. The frequency is usually around 1·sec–1, but may vary from 1–2·min–1 to 600·min–1. The electroencephalogram remains normal.4 Animal studies have demonstrated that the spinal cord can both initiate and maintain myoclonus. The various mechanisms postulated are trauma to the spinal cord with transient subacute spinal neuronitis,2 spontaneous, repetitive discharges of the anterior horn cell groups, or the effect of local anesthetic on inhibitory neurons which causes heightened irritability of alpha motor neurons.3 The mechanism of opioid-related myoclonus is probably similar to the mechanism of opioid-related tonic rigidity, involving opioid receptors in the brainstem and basal ganglia, and is not due to seizure activity. Both limb spasms and generalized myoclonus have been described following neuraxial administration of opioid drugs.5 In view of absent history of seizure disorder, a normal neurological examination, and unremarkable follow-up imaging, intrathecal bupivacaine appears to be the most likely cause in this case. The local anesthetic may have induced spinal cord irritation resulting in spontaneous, repetitive discharges of the anterior horn cell groups. Electromyography would have been an ideal diagnostic tool but was impractical in this situation. We suggest that spinal cord imaging should be considered in the setting of newly-diagnosed spinal myoclonus to exclude potential pathological causes. Finally, the anesthesiologist should have an awareness of the potential for this very rare phenomenon to occur in the pediatric population during the conduct of spinal anesthesia.