In a recent article in Perfusion about the role of asymmetry and the nature of microembolization in cognitive decline after heart valve surgery, 1 similar to an earlier article by the same investigators, 2 the authors explored the lateralization of function as seen in the vast majority of the cohorts they studied. However, there were no discussions as to the reason behind the two exceptions to the rule reported in their raw data (involving two right-handed participants, one person in each study). Thus, as shown in Figure 1 of Zanatta et al., 1 at least one of the 11 right-handed patients undergoing the trail making test (TMT B) showed a steep decline in his/her performance (~ 70%) compared to the remainder of participants whilst in Messerotti Benvenuti et al. s study, 2 only 45% of the right-handed subjects with hypoperfusion of the left hemisphere were afflicted with postoperative cognitive decline (POCD, ie one right-handed participant in that study failed to display a decline). The point is, of course, that the inventory-driven behavioral handedness of an individual corresponds to his/her neural handedness (ie lateralization of the command hemisphere), statistically not biologically. 3-5 In both of these exceptions, therefore, the decline/preservation of mentation following embolization of the right/left middle cerebral artery following cardiac surgery revealed that the patients involved were wired as right hemispheric persons (ie they both were neurally left handed, regardless of the fact that their inventory-driven behavioral handedness was the opposite direction).

The distinction between neural and behavioral handedness has a long history in neurology, beginning with Liepmanns Imperial Counselor who displayed apraxia of his ostensibly dominant right hand, instead of the left hand, following a callosal infarction. 6, 7 In our times, the most famous personality displaying the same trait (neurobehavioral mismatch) is the former US Congresswoman Gabrielle Giffords, a right-handed person who continues to speak, write and comprehend language despite a tragic gunshot wound to the head, involving her left hemisphere. In Giffords case, presence of partial deviation of the eyes to the side of the damaged hemisphere in the initial stage of her injury, together with preservation of