Correlating brain stem auditory evoked potentials measurement to clinical and neurophysiological findings in patients with diabetes mellitus

ABSTRACT

Diabetes mellitus is a multisystem metabolic disorder. One of its rarely probed complications is brainstem dysfunction. We investigated brainstem auditory evoked potential studies [BAEPs] in diabetic patients, as well as its to microangiopathy. The study was conducted on 40 [type 1 and type 2] diabetic patients, calssified into group [< 5 years duration of illness] and group 11 [> 5 years duration of illness]. The patients were examined clinically and neurologically. Neurophysiological tests in the form of BAEPs, nerve conduction studies and flash electroretinography were performed to all patients. Urine analysis, instantaneous random blood sugar and funduscopy were also performed for patients. The BAEPs patients' results were compared to those of 30 normal subjects. Wave V absolute latency, III-V IPL and I-V IPL were positively correlated with the patients' age. Latency of wave III and V/I amplitude ratio were significantly higher in male patients. Tinnitus was associated with statistically significant increase in wave V latency, III-V IPL and I-V IPL. The same finding was reported in the 21 patients who showed evidence of nerve conduction abnormalities during nerve conduction studies. Retinal changes detected by fundus examination and abnormal F-ERG was associated with statistically significant increase in wave III latency. Brainstem dysfunction occurs early in the course of diabetes [type I and III similarly] and it is further affected by its duration. BAEP studies will be of help in detecting early subclinical central nervous system involvement in diabetic patients