RESUMEN
BACKGROUND: Uremia has long been associated with cognitive deficits. This study explored the importance of the time of measurement of neurocognitive functioning, by directly comparing changes in neurocognitive functioning from immediately after hemodialysis treatment to immediately before treatment. METHODS: Twenty-five hemodynamically stable hemodialysis patients and 6 peritoneal dialysis controls completed 2 computer-based assessment batteries (ANAM), one immediately before dialysis and the second upon completion of that dialysis session. Paired sample t-tests were used to compare postdialysis with predialysis neurocognitive functioning scores for both a composite measure of global functioning and the neurocognitive subtests. RESULTS: There was significant improvement in global neuropsychological functioning from predialysis to postdialysis (t (24) = -7.5, p<0.001), showing an average of 18% improvement in the hemodialysis group, with no significant change in the peritoneal dialysis group. CONCLUSION: This study suggests that computer-based testing can offer information on the cognitive fluctuations of medically complex populations and suggests that the end of the session may be a better time to discuss important and complex health messages with hemodialysis patients. It further implies that some of the neurocognitive impairment that is associated with end-stage renal disease is a consequence of uremia and is improved by hemodialysis.