Amobarbital evaluation of neurobehavioral function prior to therapeutic occlusion of brain arteriovenous malformations: A new neuropsychological procedure

Because untreated arteriovenous malformations (AVMs) frequently result in some form of permanent neurological complication, treatment of AVMs is aggressively pursued. A relatively new treatment consists of sending micropellets into blood vessels supplying the AVM core to block blood flow and "shrink" the AVM. When vessels supplying the AVM are thought to also irrigate vital portions of brain, evaluations of neurobehavioral function after injection of amobarbital into intracranial vessels (Wada testing) may be performed to prevent significant complications following embolization. This study details our preliminary experience with Wada testing and electroencephalography (EEG) prior to AVM embolization in seven patients. Neurobehavioral functions were continuously monitored after injection of 50-75 mg of amobarbital into target cerebral vessels. No change in sensorimotor, cognitive, or EEG functions were detected in any of the superselective Wada examinations. Embolization was performed following all negative Wada evaluations. The only irreversible complication after embolization was a superior quadrantanopia. No other permanent neurobehavioral sequelae resulted from embolization. These preliminary findings suggest that simultaneous Wada/EEG monitoring may be useful in predicting neurobehavioral complications prior to AVM embolization.