Assessment of Cognitive Dysfunction in Hemodialysis Patients By the Mini Mental Test and the Clock Drawing Test

OBJECTIVE: Our aim was to assess cognitive dysfunction, which is common in hemodialysis patients and difficult to diagnose, by an easily applicable test, the Mini Mental State Examination and Clock Drawing Test. MATERIAL and METHODS: Two hundred and sixty six (266, 88.37%) dialysis patients that were followed-up at the Nephrology Clinic of Bursa Specialty Training and Research Hospital and private dialysis centers, and 35 (11.63%) healthy control individuals were involved in our study. Mini Mental State Examination and Clock Drawing Test were applied by a neurologist to the subjects. MMSE and CDT scores of the patients were compared with the control group. RESULTS: Patient and control groups were similar in terms of age, gender, diabetes, and smoking. The rate of hypertension was significantly higher in the dialysis group. Mini Mental State Examination and Clock Drawing Test success rates were significantly higher in the control group. Orientation, attention and language modalities evaluated in the MMSE were observed to be significantly lower in the hemodialysis group. A statistically significant inverse correlation was found between registration memory and recall scores in MMSE, and urea. CONCLUSION: Cognitive performances of hemodialysis patients must be monitored closely. The relationship between record memory and recall scores and urea suggests that uremic toxins may affect memory functions negatively. In addition, cognitive performance can be monitored by Clock Drawing Test in these patients.