Neurological, psychological, and cognitive disorders in patients with chronic kidney disease on conservative and replacement therapy

Chronic kidney disease (CKD) is a highly prevalent condition in the world. Neurological, psychological, and cognitive disorders, related to CKD, could contribute to the morbidity, mortality, and poor quality of life of these patients. The aim of this study was to assess the neurological, psychological, and cognitive imbalance in patients with CKD on conservative and replacement therapy. Seventy-four clinically stable patients affected by CKD on conservative therapy, replacement therapy (hemodialysis (HD), peritoneal dialysis (PD)), or with kidney transplantation (KT) and 25 healthy controls (HC), matched for age and sex were enrolled. Clinical, laboratory, and instrumental examinations, as renal function, inflammation and mineral metabolism indexes, electroencephalogram (EEG), psychological (MMPI-2, Sat P), and cognitive tests (neuropsychological tests, NPZ5) were carried out. The results showed a significant differences in the absolute and relative power of delta band and relative power of theta band of EEG (P = 0.008, P < 0.001, P = 0.051), a positive correlation between relative power of delta band and C-reactive protein (CRP) (P < 0.001) and a negative correlation between estimated glomerular filtration rate (eGFR) (P < 0.001) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) (P < 0.001), in all the samples. Qualitative analysis of EEG showed alterations of Grade 2 (according to Parsons–Smith classification) in patients on conservative therapy, and Grade 2–3 in KT patients. The scales of MMPI-2 hysteria and paranoia, are significantly correlated with creatinine, eGFR, serum nitrogen, CRP, 1,25-(OH)2D3, intact parathyroid hormone (iPTH), phosphorus, and cynical and hysterical personality, are correlated with higher relative power of delta (P = 0.016) and theta band (P = 0.016). Moreover, all NPZ5 scores showed a significant difference between the means of nephropathic patients and the means of the HC, and a positive correlation with eGFR, serum nitrogen, CRP, iPTH, and vitamin D. In CKD patients, simple and noninvasive instruments, as EEG, and cognitive-psychological tests, should be performed and careful and constant monitoring of renal risk factors, probably involved in neuropsychological complications (inflammation, disorders of mineral metabolism, electrolyte disorders, etc.), should be carried out. Early identification and adequate therapy of neuropsychological, and cognitive disorders, might enable a better quality of life and a major compliance with a probable reduction in the healthcare costs.