Tailored cognitive testing with provocative amobarbital injection preceding AVM embolization.

BACKGROUND AND PURPOSE Transarterial embolization of cerebral arteriovenous malformations (AVMs) has been associated with postprocedural neurologic complications in 7-39% of patients. We sought to determine whether a method of targeted neurologic and cognitive testing during AVM embolization reduces the incidence of focal cognitive and other neurologic deficits associated with the procedure. METHODS A cognitive neurologist extensively examined 12 patients prior to AVM embolization. In each patient, a battery of tests tailored to their specific abilities was developed by using stimuli selected from standard and experimental cognitive tests to probe specific brain regions related to the location of the AVM. In each feeder vessel to be embolized, a 50-mg bolus of sodium amobarbital was superselectively administered through a microcatheter; this was followed immediately by neurologic and cognitive testing with the tailored battery. After testing, the position of the microcatheter tip was checked with fluoroscopy. If the provocative test results were negative, the evaluated feeder was embolized with N-butyl cyanoacrylate glue. RESULTS Although results with 27 of 29 provocative amobarbital injections were negative, results with two injections in two different individuals revealed cognitive deficits during tailored provocative testing. In both, the evoked deficits resolved with dissipation of the amobarbital effect; the feeder vessels were not embolized. Neurologic and cognitive evaluation after each of 27 embolizations revealed no major or minor deficits. CONCLUSION In our experience, provocative amobarbital testing prior to AVM embolization was helpful in identifying vascular territories where embolization may lead to neurologic and cognitive deficits.