Abstract: The objective was to explore the change of blink reflex (BR) in patients with type 2 diabetes mellitus and its relationship with other correlated factors. The latencies and amplitudes of waves of bilateral R1, R2 and R2'in BR were detected in 85 patients, whose average were contrasted with normal value. The patients were divided into two groups, the BR-positive group and the BR-negative group. The latencies and amplitudes of waves of bilateral R1, R2 and R2'in patients with type 2 diabetes mellitus were somewhat longer than the normal. The difference was significant in statistics(P<0.05). Also significant differences of ages and disease courses were found between the BR-positive group and the BR-negative group. The longer diabetes course lasted, the more notably each value of BRchanged. They had some correlation. Type 2 diabetes mellitus could cause some impairments of the central nervous system and affect the function of brainstem. Patients'ages and disease course had certain correlation with the latencies and amplitudes of waves of BR. Different patients had different proportion of abnormality in BR. With the extension of course of diabetes, abnormal ratio increased. So BR might provide an objective and sensitive index for the asymptomatic impairment of the central nervous system caused by diabetes.

Key words: diabetes mellitus, blink reflex, impairments of the central nervous system