The heartbeat-evoked brain potential in patients suffering from diabetic neuropathy and in healthy control persons

Objectives: Neurotransmission from the heart to the brain results in a heartbeat evoked potential (HEP). This potential appears as a positive waveform ranging from 250 to 600 ms after the onset of ventricular contraction. Only limited information exists as to what extent the HEP is sensitive to a dysfunction in cardio-afferent pathways. Thus. the HEP was studied in patients with autonomic diabetic neuropathy. Methods: Twenty-five patients and a healthy control group of equal size participated The HEP was obtained as the average over 1200 EEG sweeps (18 channels) sampled contingent upon the onset of ventricular contraction. A heartbeat attention task and a distraction task were employed. Patients answered a questionnaire pertaining to the frequency of subjective symptoms related to diabetic neuropathy. Results: The HEP amplitude at frontal, central and temporal locations was significantly diminished in patients in the latency range of 280-330 ms. A significant correlation was found between the questionnaire score of subjective autonomic symptoms and the reduction in the HEP. Conclusions: We conclude that the HEP is sensitive to a comparably moderate abnormality in nerve function. Furthermore, we assume that the processing of subjective symptoms of the disease and the generation of the HEP share some common neuronal pathways. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.