Impaired cognition in hemodialysis patients: The Montreal Cognitive Assessment (MoCA) and important clues for testing

Clin Nephrol. 2019 May;91(5):275-283. doi: 10.5414/CN109506.

Abstract

Background: Cognitive impairment is common among hemodialysis (HD) patients and is associated with poor treatment compliance and mortality. The aim of this study is to evaluate relatively young HD patients with less comorbidities using the Montreal Cognitive Assessment (MoCA) and identify clues for earlier detection of cognitive impairment with the help of cognitive subscale scores.

Materials and methods: A total of 103 chronic HD patients (mean age 48.3 years) and 37 stage-3 to 5 chronic kidney disease (CKD) patients with similar demographics were included. Patients with cerebrovascular disease, dementia, depression, malignancy, and infections were excluded. All participants were tested with MoCA. Patients with an MoCA global score < 24/30 were considered cognitively impaired. Groups were compared for MoCA subscales and clinical features.

Results: 75 patients (72.8%) in the HD group and 19 in the CKD group (51.3%) had impaired cognition. The number of patients with cognitive impairment was significantly higher in the HD group compared with the CKD group (p = 0.024). The mean total MoCA score was lower in the HD group (p = 0.043). MoCA subscale analysis revealed that the mean score for visuospatial/executive domain was significantly lower in the HD group (p = 0.001).

Conclusion: In this study, we showed that cognitive impairment was more common in HD patients compared with predialytic CKD patients. This difference was predominantly related to the difference in executive scores. We may think that young HD patients with less comorbidities are also at risk for cognitive impairment. Noticing progressive declines in MoCA cognitive domains, before the development of global cognitive impairment, could be beneficial for HD patients. .

MeSH terms

  • Cognitive Dysfunction* / complications
  • Cognitive Dysfunction* / epidemiology
  • Cohort Studies
  • Humans
  • Mental Status and Dementia Tests
  • Middle Aged
  • Renal Dialysis* / adverse effects
  • Renal Dialysis* / statistics & numerical data
  • Renal Insufficiency, Chronic* / complications
  • Renal Insufficiency, Chronic* / epidemiology
  • Renal Insufficiency, Chronic* / therapy