Attention and information processing in end stage renal disease and effect of hemodialysis: a bedside study

Abstract

The neurobehavioral syndrome of uremia in chronic kidney disease affects the functioning of the central nervous system. Cognitive impairment is one of the most important manifestations of this dysfunction. The process of hemodialysis is known to bring about conflicting changes in the cognitive status of patients. In the present study an assessment of cognitive status of patients with end stage renal disease was done in comparison to controls before and after a session of hemodialysis using simple bedside paper-pencil tests. Thirty patients of end stage renal disease on maintenance dialysis for at least one month with MMSE score >24 were assessed one hour before and one hour after hemodialysis using Digit Symbol Substitution Test, One Letter and Three Letter Cancellations tasks. Their results were compared to age and sex matched healthy controls. The patients with end stage renal disease had significantly lower performance in cognitive tests in comparison to controls. The performance improved 1 hour after hemodialysis in comparison to pre-dialysis values. However, the values after dialysis were significantly lower than in controls, thereby indicating that though the cognitive functions improved after hemodialysis, they did not reach the control levels. There was also a significant change in the biochemical parameters after dialysis. We conclude that patients with end stage renal disease suffered from cognitive impairment which improved on hemodialysis due to removal of metabolic waste products.

A Systematic Review of Cognitive Impairments Associated With Kidney Failure in Adults Before Natural Age-Related Changes

“…In terms of comorbid conditions, seven studies (Dixit et al, 2013;Egbi, Ogunrin, & Oviasu, 2015;Nasser, Shawki, El Shahawy, & Sany, 2012;Owolabi et al, 2016;Pi et al, 2016) excluded individuals with diabetes mellitus and/or cardiac risk or history. Five studies did not exclude these and reported rates of presentation (Hailpern, Melamed, Cohen, & Hostetter, 2007;Owolabi et al, 2016;Sanchez-Roman et al, 2011;Thornton, Shapiro, Deria, Gelb, & Hill, 2007;Tsai, Wang, & Fuh, 2010), with three conducting analyses comparing them between the groups and all finding no significant differences.…”

“…One other study reporting diabetes controlled for its presence in their analyses (Silverwood et al, 2014). Several other studies (Bae & Park, 2008;Dixit et al, 2013;Egbi et al, 2015;Nasser et al, 2012;Owolabi et al, 2016;Pi et al, 2016;Sanchez-Roman et al, 2011;Thornton et al, 2007) also excluded participants with other comorbidities such as history of Parkinson's disease and/or cerebrovascular diseases, hypertension, and head injuries. Two studies (Chen et al, 2015;Gad, Ramzy, Abdelhamid, ElMassry, & Masoud, 2012) did not report any related conditions to CKD.…”

“…Ten studies included in this review examined cognitive impairment in end stage CKD patients. Six of these studies examined an independent cohort of end stage CKD patients compared to a healthy control group (Bae & Park, 2008;Chen et al, 2015;Dixit et al, 2013;Nasser et al, 2012;Owolabi et al, 2016). A further three studies compared cognitive function across four separate groups, that is, healthy and stages 3, 4, and 5 (Egbi et al, 2015;Sanchez-Roman et al, 2011).…”

“…The third study (Owolabi et al, 2016) noted a significant reduction in performance for the end stage CKD group for overall auditory and visual processing speed, recognition memory, and attention (d = 0.88 to 2.46). The final study examined cognitive performance in end stage CKD patients before and after dialysis, compared to a control group (Dixit et al, 2013). For this review, only data in the pre-dialysis stage was considered, to account for the effects of hemodialysis on cognition, and to be consistent with the other reviewed studies.…”

Effect of a Single Dialysis on Cognitive Function in Chronic Kidney Disease Stage 5 Hemodialysis Patients

“…22,23 Hemodynamic stress during HD lead to temporary deterioration of cognitive function which subsequently improves several hours after HD as an effect of uremic toxin elimination. 20,22,24 Hemodynamic stress during HD will be transmitted to and causes dysregulation of cerebral circulation. 20,25 Fluid and electrolyte shift, intravascular volume loss during HD can also cause brain edema, decreased intracerebral pressure and perfusion to brain.…”