Cognitive disorders in patients with insulin-dependent type I diabetes mellitus

Diabetes mellitus is a common disorder and causes a variety of central nervous system complications such as cognitive deficits. P300 auditory event related potential application is a well established neurophysiological approach in the assessment of cognitive performance. In this study، we compared the results of this application in patients with insulin-dependent (type I) diabetics mellitus and normal individuals. In this non-interventional study، auditory P300 was measured in oddball paradigm by using two tone burst stimuli (1000 and 2000 Hz) on 25 patients with type I diabetics mellitus with the mean age of 28. 76 years and 25 age-، education- and sex-matched healthy controls with the mean age of 29. 68 years. The participants were enrolled by probable and category random sampling style. The mean P300 latency of the patients with type I diabetes mellitus was significantly prolonged compared with that of normal controls at all electrode sites and in both genders (p<0. 001). The mean P300 amplitude of these patients was significantly lower compared with that of normal controls at all electrode sites and in both genders (p<0. 001). Significant prolongation in P300 latency of the patients with type I diabetes mellitus shows that auditory information processing and information categorizing are slower in them. Significant reduction in P300 amplitude of the patients with type I diabetes mellitus demonstrates that working memory in these patients cannot recognize new events and update its context in accordance with them.