Post-operative cognitive dysfunction and short-term neuroprotection from blueberries: a pilot study.

BACKGROUND: General anesthesia may be a risk factor for postoperative cognitive impairment, which could be counteracted by neuroprotective compounds. The aims of this study were to determine cognitive functions impaired by general anesthesia and to test blueberry juice as a neuroprotective agent against neuropsychological dysfunctions induced by general anesthesia. METHODS: Twenty-six patients undergoing elective major surgery were randomized into two groups, receiving either 500 milliliters/day of blueberry juice within 14 preoperative days (G1) or to a control group (G0). Neuropsychological tests were performed around 20 days before surgery (T0), as well as both 3 hours (T1) and 24 hours (T2) postsurgery. All the scores were statistically analyzed to find significant differences between groups and within the three times. RESULTS: The control (G0) group showed a significant decrease in the performance of Prose Memory (p < 0.001), Attentional Matrices (p < 0.01) and Trail Making Test Part B (p < 0.01) after general anesthesia. Significant differences were reported in the Prose Memory test, T0 versus T1 (p < 0.01), T0 versus T2 (p < 0.001); in the Trail Making Test Part B, T0 versus T2 (p < 0.01); and the Attentional Matrices test, and T0 versus T2 (p < 0.001). The G1 group did not show any decrease in the performance of the three tests. CONCLUSIONS: General anesthesia induces a shortterm impairment of verbal memory and selective and divided attention. Blueberry compounds may prevent these neuropsychological deficits through a neuroprotective action in patients undergoing general anesthesia.