Intracarotid amobarbital memory protocol: Muteness, dysphasia, and variations in arterial distribution of the drug do not affect recognition results

Abstract

It has already been suggested that recognition memory testing in the intracarotid (ICA) sodium amobarbital procedure could be used to assess risk of global amnesia in candidates for temporal lobectomy. The purpose of this retrospective study was to evaluate assumptions about the putative limitations of the ICA memory test. We examined the results of bilateral amobarbital memory assessments for 83 patients with unilateral temporal lobe epilepsy for whom memory items had been presented during, and recognition tested after, the period of the unilateral drug effect. We found that perfusion of the PCA (inferred by prior ICA injection of contrast) had no effect on recognition memory scores after amobarbital injection. Second, although injection of the speech-dominant hemisphere produced a 12% reduction in recognition scores relative to nondominant injection, rates of passing or failing the memory test were not significantly affected by speech dominance. Thus, for most patients, the objections raised to the ICA procedure may not be as critical to clinical interpretation as initially proposed.