Author(s): Sachin Pawar, Dipali Chatur, Vikas Udan, Ramji Singh
Cranial nerves are frequently affected in diabetic process. On routine nerve conduction studies, symptomatic peripheral and cranial neuropathy can be detected, however, subclinical involvement of cranial nerves may go unnoticed. . Blink Reflex, which is a polysynaptic reflex, has been shown to be an effective method for revealing subclinical involvement of cranial nerves in generalized neuropathies. The present study was undertaken to evaluate the efficacy of blink reflex as a method for early diagnosis of subclinical involvement of cranial nerves in diabetic patients with or without polyneuropathy. A case control study was conducted on 150 subjects between ages of 40 and 60 years (50 age and sex matched controls, 100 cases diagnosed with Diabetes mellitus).A routine nerve conduction study and blink reflex evaluation was done in all the subjects. We found abnormal blink reflex response in 67% of diabetic patients studied. Both R1, R2 (ipsilateral and contralateral) latencies were found to be significantly prolonged in diabetic patients with or without polyneuropathy (P < 0.05 Vs control).All the latencies in diabetic patients with polyneuropathy were significantly prolonged relative to diabetic patients without polyneuropathy. In conclusion, study suggests that blink reflex is a useful noninvasive method for the detection of clinically silent cranial nerve compromise in diabetic patients.