Is there a relationship?I t became clear in the last decades that neuropathy is not a separate clinical entity, but a component of several related complications (1). Although the functional consequences of neuropathy are well defined in various organ systems, the relationship of the alterations in the networks of the neuronal system is still poorly documented. Assessment of the potential common alterations of the different neuronal functions in patients with diabetic neuropathy may provide new pathogenetic and diagnostic considerations. Previously, we observed correlations between the delay of certain auditory-evoked potentials and the severity of autonomic and peripheral sensory neuropathy in patients with type 1 diabetes (2). In addition, we found a relationship between the latency of visual-evoked potentials and the peripheral neuronal function (3). The aims of this study were to analyze the possible correlations between the central auditory and visual afferentations and the severity of autonomic and sensory neuropathy in patients with long-standing type 1 diabetes.A total of 10 middle-aged type 1 diabetic patients with long-standing diabetes were included in the study (4 male and 6 female subjects aged 43.8 Ϯ 15.2 years [mean Ϯ SD], duration of diabetes 23.1 Ϯ 9.3 years, BMI 27.9 Ϯ 3.9 kg/m 2 ). Patients with abnormal hearing, proliferative retinopathy, impaired visual acuity, or neuropathy of origin other than diabetes were excluded. The quantitative characteristics of the brainstem function were evaluated by the detection of auditoryevoked potentials after the delivery of an audible click of short duration via an earphone (4). The latencies of the first five waves (I-V) were analyzed in this study.The central afferent visual function was evaluated via the delay of the major positive component (P100) of the visualevoked potentials that was generated following a pattern-reversal checkboard stimulation (5). Cardiovascular autonomic function was assessed by means of the five standard cardiovascular reflex tests (2,3,6). The heart rate tests (the heart rate response to deep breathing, the 30:15 ratio, and the Valsalva ratio) mainly reflect the parasympathethic function, whereas the systolic blood pressure response to standing up and the diastolic pressure change to a sustained handgrip predominantly characterize the sympathetic integrity. Detection of current perception thresholds (CPTs) with a neuroselective transcutaneous stimulator, the Neurometer (Neurotron, Baltimore, MD), allowed for the assessment of the sensory function at three different frequencies on the median and peroneal nerves (6). The analysis of the auditoryevoked potentials revealed negative relationships between the heart rate tests and the prolongation of the latencies of waves III and V (heart rate response to breathing-wave III, r ϭ Ϫ0.586, P Ͻ 0.01; 30:15 ratio-wave III, r ϭ Ϫ0.588, P Ͻ 0.01; heart rate response to breathingwave V, r ϭ Ϫ0.498, P Ͻ 0.05; Valsalva ratio-wave V, r ϭ Ϫ0.463, P Ͻ 0.05; and 30:15 ratio-wave V, r ϭ Ϫ0.599, P Ͻ 0...