Abstract
Background and Objectives: Peripheral neuropathy (PN) is one of the common late complications of diabetes mellitus, including distal symmetric sensory polyneuropathy and cranial neuropathy. Cranial nerves III , V and VII are among the most commonly affected in diabetic patients. Electrodiagnostic (Edx) studies are useful methods for diagnosis of PN and symptomatic cranial neuropathy, but not for subclinical involvement of cranial nerves. The goal of this study was to evaluate the role of blink reflex (BR) for early diagnosis of cranial neuropathy in diabetic patients compromised with PN.
Materials and Methods: A prospective study was performed on diabetic patients (type II) with a PN. Patients were excluded if they had previous clinical nerve lesions, stroke, other diseases with PN, or were treated with drugs known as potentially causing PN. Routine nerve conduction studies were performed and only patients with PN were included in the study.
Results: forty six diabetic patients were included in our study. The control group consisted of 142 subjects. We found abnormal BR in 54.4% of patients. R1, IR2 and CR2 were more prolonged than the control group (p<0.001). R/D ratio did not differ statistically compared to the control group (p = 0.201) . Also there was a positive correlation between R1, IR2 and CR2 latencies with duration of diabetes and severity of PN, but not for R/D. The greatest correlation was shown in R1 latency (69.9% abnormality).
Conclusion: BR is a noninvasive and very useful method for evaluation and diagnosis of subclinical cranial nerve involvement in diabetic patients.