Assessment of cognitive dysfunction in kidney disease

Cognitive dysfunction includes reduced mental alertness, intellectual impairment, decreased attention and concentration, memory deficits and diminished perceptual-motor coordination. Chronic kidney disease (CKD) patients may suffer from cognitive impairment, which may decrease an individual's quality of life, increase resource utilization and result in suboptimal medical care. This study was carried out on 120 patients with different stages of CKD from our nephrology outpatient clinic divided into three groups: Group I: 50 CKD patients, stage 3 and stage 4; Group II: 50 end-stage renal disease patients on regular hemodialysis with K t/v >1.1; and Group III: 20 acute kidney injury patients, followed-up till their renal functions stabilized besides Group IV: 20 healthy subjects served as controls. All patients underwent laboratory investigations and psychometric tests, which include trial making test part B, digit span test, digit symbol test and mini-mental state examination. There was a significant difference of mean values of cognitive function tests in Groups I, II and III on comparing them with Group IV. Stage 3 CKD scored better than stage 4 CKD, which was worse than hemodialysis patients, and lastly acute kidney injury patients had mild cognitive impairment, which was restored after recovery. We found an association between hemoglobin and cognitive function tests score in the studied groups. The degree of cognitive impairment was associated with the severity of CKD, and dialysis improved cognitive performance.