Head scan appearances and cognitive function in renal failure

Cognitive function was assessed, and unenhanced CT head scans were carried out in 44 patients with renal failure. Thirteen had been on regular hemodialysis for 5 years or more (long-term hemodialysis group, LTHD), 12 had received hemodialysis for less than 5 years (short-term hemodialysis, STHD), 9 were on continuous ambulatory peritoneal dialysis (CAPD group) and 10 had severe chronic renal failure and were near to-but had not reached-dialysis dependence (chronic renal failure group, CRF). Employing an index of deterioration (the "discrepancy score") based on the discrepancy between current reading skills and current performance on the Wechsler Adult Intelligence Scale, 6 LTHD patients, 2 STHD patients, 2 CAPD patients and 5 CRF patients were identified as functioning below their predicted premorbid optimum level. Cerebral sulci were abnormally wide in 22 patients (8 LTHD, 2 STHD, 6 CAPD and 6 CRF) and one of the STHD group also had cerebral ventricular dilatation. Nine patients had both an abnormal scan and evidence of cognitive deterioration, 13 had an abnormal scan in the absence of such evidence and 6 had evidence of cognitive deterioration and a normal scan. Both cognitive deterioration and the CT scan finding of widening of cerebral sulci were commoner in these patients than would be expected in an age-matched sample of the general population, but no simple relationship was found between anatomical abnormality and cognitive functioning. Statistically significant correlations were found between discrepancy score and the cumulative amount of aluminum prescribed to be taken orally in both LTHD and CAPD groups.