Cognitive dysfunction remains a frequent complication of cardiac surgery. Despite many years of research, few preventive strategies and no definitive therapeutic options exist for the management of this troublesome clinical problem. This shortcoming may be secondary to an incomplete understanding of the pathophysiology and etiology of cognitive loss after cardiac surgery; a better understanding of the etiology is essential to finding new therapies. The etiology of cognitive dysfunction after cardiac surgery is multifactorial and includes cerebral microembolization, global cerebral hypoperfusion, systemic and cerebral inflammation, cerebral temperature perturbations, cerebral edema, and possible blood-brain barrier dysfunction, all superimposed on genetic differences in patients that may make them more susceptible to injury or unable to repair from injury once it has occurred. This review expands on these potential etiologies in detailing the evidence for their existence.
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