A compound score for estimating the influence of inattention and somnolence during the intracarotid amobarbital test.

Alterations in the level of consciousness may render the interpretation of the memory test results from the intracarotid amobarbital procedure difficult. The present study was designed to investigate the impact of inattention and somnolence on memory performance during the Amytal test. Nineteen consecutive patients undergoing the test were investigated. The memory test was constructed to comprise two consecutive parts with identical design, so as to make possible comparisons over time in the same patients. Reaction level and somnolence were continuously assessed during the procedure and a stimulus-task response test to evaluate the degree of attention was used. On the basis of these parameters a compound 'inattention score' was constructed. The results indicate that inattention and somnolence negatively influence memory performance and should be taken into account when evaluating the Amytal memory test results. In cases with poor memory results high inattention scores may speak in favour of preoperative hemisphere memory testing or a repeat injection with reduced Amytal dosage before deciding upon the extent of a planned resection. On the other hand, low inattention scores together with amnesia for the testing procedure may indicate that the memory test results can be relied on.