[Preexisting seizure was enhanced under general anesthesia in a AVM patient]

A 21-year-old patient with right basal ganglial AVM was scheduled twice for cranioplasty under general anesthesia (nitrous oxide oxygen isoflurane anesthesia and modified neurolept anesthesia), after a surgery for removal of hematoma from the AVM three months previously. After this operation and before anesthesia for cranioplasties, he showed tremor-like seizure around the left arm and leg about once a day. During anesthesia for cranioplasties, he developed the similar and enhanced seizure frequently in response to intravenous injections of thiopental and midazolam, needle injections into the skin, intratracheal as well as oral suctions and other stimuli. The reason of decreased cerebral perfusion is probably due to the previous operation and administrations of thiopental and midazolam. Because of decreased perfusion around this cerebral lesion, concentrations of the anesthetics might have remained low around the lesion under general anesthesia. Therefore, the resulting hypoxia and prolonged light anesthesia in the basal ganglia, might have enhanced the seizure.