[Specific features of cognitive impairments in patients with predialysis chronic kidney disease].

AIM

To study the specific features of cognitive impairments (CI) in patients with predialysis chronic kidney disease (CKD).

SUBJECTS AND METHODS

Examinations were made in 51 patients aged 52 +/- 10 years with CKD, including 20 patients with Stages I-II CKD (glomerular filtration rate (GFR) > or = 60 ml/min/1.73 m2; signs of kidney lesion), 20 with Stage III (GFR 60-30 ml/min/1.73 m2), and 11 with Stage IV (GFR 30-15 ml/min/1.73 m2). GFR was estimated using the Modification of Diet in Renal Disease (DMRD) formula. The authors made a questionnaire survey to identify day-to-day activity limitations and depressions and performed neuropsychological tests using the mini-mental state examination (MMSE), a frontal assessment battery (FAB) for frontal lobe dysfunction, a short-term and delayed memory test (Luria's 10 words test), and a regulatory function assessment test (RFAT). Magnetic resonance imaging (MRI) was carried out to clarify the etiology of CI.

RESULTS

CI was detected more frequently in the patients with chronic renal failure (CRF) (Stages III-IV CKD) than in those without CRF (Stages I-II CKD) (in 90.3 and 35%, respectively (p < 0.001)). CI was statistically significantly more frequently found using MMSE (p < 0.001), FAB (p = 0.001), and RFAT (p < 0.001). There was a statistically significant rise in the magnitude of CI with the higher stage of CKD, as shown by MMSE, FAB, and RFAT, other than the short-term and delayed memory test. Brain MRI in the patients with CI revealed focal changes in 9 (30%) patients, leukoaraiosis in 7 (23.3%), lateral cerebral ventricular dilatation in 15 (50%), and markedly dilated hemispheric sulci in 3 (10%).

CONCLUSION

The higher stage of CKD is associated with the increased incidence and magnitude of CI, as evidenced by MMSE, and with those of anterior brain dysfunctions. The comparisons of clinical and MRI findings suggest that cerebrovascular disorders underlie CI in CKD.