BRAIN MRI FINDINGS AND COGNITIVE IMPAIRMENT IN PATIENTS UNDERGOING CHRONIC-HEMODIALYSIS TREATMENT

Although both morphologic cerebral damage and cognitive dysfunction ar e known to occur in patients on chronic hemodialysis (CHD) their exten t and possible relation have been rarely studied. We therefore perform ed magnetic resonance imaging of the brain and neuropsychological test ing in 30 consecutive CHD patients (mean age 58 years; range 37-69) an d in an equal number of asymptomatic volunteers matched for age, sex a nd major cerebrovascular risk factors. Twenty-four (80%) of the CHD pa tients were demented according to the criteria of the Diagnostic and S tatistical Manual of Mental Disorders IIIR and their mean scores on th e Mini Mental State Examination (22.9 +/- 4 vs. 27.9 +/- 1.4; p < 0.00 1) and Mattis Dementia Rating Scale (112.3 +/- 21.5 vs. 141.9 +/- 2.3) ; p < 0.001) were significantly lower than those of controls. The brai ns of CHD patients showed significantly more atrophy on visual rating and semiquantitative morphometric measures. Multiple lacunes or conflu ent white matter hyperintensities predominated in 10 (33%) patients, t hree showed territorial infarcts and two a combination of both. Clinic ally these findings were unexpected in almost half of individuals. Mar ked cognitive impairment was associated with more extensive enlargemen t of the third ventricle (5.8 +/- 1.8 vs. 7.3 +/- 2 mm; p < 0.04) and the temporal hems (3.5 +/- 1.6 vs. 5.1 +/- 1.8 mm; p < 0.02) but not w ith the presence of cerebral ischemic lesions or any difference in lab oratory data. These results call attention to a very high rate of cere bral damage in individuals undergoing CHD and suggest brain degenerati on of probably toxic-metabolic etiology to be associated with severe c ognitive impairment of these patients.