Evaluation of asymptomatic central neuropathy in type I diabetes mellitus

OBJECTIVES: Diabetic neuropathy is recognized as the most common clinical picture of nervous system disorders caused by diabetes mellitus (DM). Although peripheral and autonomic nervous system involvements are frequently encountered, there exists a few data about the incidence of central diabetic neuropathies. Central nervous system degeneration is a well known pathology in diabetic patients in the long term. It is possible to reveal central nervous system involvement at the early stages by using evoked potentials (EP). The aim of this study is to evaluate the auditory, visual and sensorial abnormalities in type I diabetic patients, who also have normal nerve conduction studies, with somatosensory, brainstem auditory and visual EP studies (SEP, VEP BAEP); to determine the frequency of these abnormalities and to investigate the relationship between other variables such as age, gender, duration of the diabetes and degree of the metabolic control. PATIENTS AND METHODS: A total of 36 asymptomatic type I DM children, ages ranging between 6-17 (mean age 11 +/- 3.24) taking insulin treatments were included in this study. Control group was made up of healthy children. EPs were evaluated and comparisons were made between the two groups. RESULTS: In a large group of diabetic children (47.2%), independent from parameters such as age, gender, glycemic control degree, auditory and visual deficits, retinopathy, joint movement limitation; but dependent on the peripheral SEP pathologies and disease duration there were central electrophysiological disturbances. In 13 (36.1%) of the patients SEP pathologies; in 9 (25%) of the patients VEP pathologies and in 14 (38.9%) of the patients BAEP pathologies were detected. Conclusion: Besides independent from peripheral pathologies, central nervous system involvement could also be observed in diabetic children. EP changes can be detected in asymptomatic patients that would be a predictor of future symptoms.