Diabetes mellitus is a group of metabolic diseases characterized by hyperglycaemia resulting from defects in insulin secretion, insulin action or both. Diabetes affects many systems and produces complications in the human body, in those complications one is diabetic central neuropathy. The pathological mechanisms involved in the central neuropathy include chronic hyperglycaemia, hypoglycaemic episodes, angiopathy and blood–brain barrier dysfunction. Diabetic central neuropathy is detected by using of brainstem auditory evoked response (BAER), Visual evoked potential (VEP), somatosensory evoked potential (SEP). These abnormalities are present at different levels and may appear before appearance of overt complications. The central nervous system abnormalities are more frequent in patients with peripheral neuropathy but evoked potentials can be abnormal even in patients without neuropathy. The BAER is a physiological recording technique to study the auditory pathway and does not require subject’s attention and generates waves during the first 10 ms after the sound stimulus. Each BAER wave is generated by the activation of a sub-cortical component of the auditory pathway with 90% sensitivity and 70–90% of specificity.
Part of the book: Hearing Loss