Bypass and the brain: Neurobehavioral outcomes: Relevant and practical

The ultimate decision regarding the suitability of computer-based testing and the choice of which computerized test battery is chosen will relate to the underlying aim of the study being performed. On the one hand, to examine in detail the effects of CPB on the brain, perhaps a far more detailed traditional or computer-based examination needs to be performed than is routinely used in the cardiac surgery setting. In fact, it may be necessary to use a test battery more like that which a clinical neuropsychologist would perform on an individual patient in other clinical settings. Such an approach may allow us to adequately determine a pattern or patterns of injury unique to the cardiac surgical setting. Kneebone at al. (7), in their recent publication, highlight the difficulties of aligning data from a limited neuropsychologic test battery to traditional patterns of deficit. On the other hand, if we were to undertake a large screening program that included all patients undergoing cardiac surgical procedures, a simple and quick assessment, such as that which can be offered by the Cogstate battery (37), may be beneficial. In between these two poles lies the remainder of the computer systems available. To some extent we have not progressed far in our understanding of neurobehavioral changes associated with cardiac surgery. To quote Newman and Reves, "The first step in solving a clinical problem is defining it and identifying those patients likely to suffer from it. The second step is identifying the mechanisms that cause the problem, and the final step is perfecting methods to prevent the problem, in this case, brain injury." We seem to have stalled a little at the first step! However, maybe the adoption of computer-based assessment systems will allow more studies to be performed on a greater number of patients and further our understanding of this area.