To evaluate the impact of mild hypoglycemia on CNS function in healthy adults, we measured brain stem auditory evoked potentials and P300 potentials (elicited by cognitive processing of auditory stimuli) during hypoglycemic or euglycemic insulin clamps (80 mU · m−2 · min−1). In the hypoglycemic clamp study (n = 8), plasma glucose was allowed to fall from 4.6 to 3 mM in hourly ∼0.5-mM steps and subsequently returned to euglycemic baseline levels. In the euglycemic clamp study (n = 8), plasma glucose was maintained at baseline levels throughout. Neither brain stem nor P300 responses changed during the euglycemic control study; symptoms and counterregulatory hormones were also unaffected. During the hypoglycemia study, epinephrine and growth hormone rose once plasma glucose reached 3.4 ± 0.1 mM. Brain stem and P300 potentials remained unchanged until the 3-mM glucose step, when neurophysiological changes suddenly developed in conjunction with reported symptoms. At this glucose level, the wave V component of the brain stem potential was selectively altered in 7 of 8 subjects. Furthermore, P300 latency significantly increased, and amplitude diminished. Changes in both brain stem and cortical (P300) responses reversed when euglycemia was restored. We conclude that modest reductions in plasma glucose (to 3 mM) produce marked alterations in both brain stem and cortical responses to auditory stimuli. These changes in neural function appear at the same time as symptoms and follow rather than precede the rise in counterregulatory hormones during hypoglycemia. Our data suggest that the adverse effects of mild hypoglycemia on brain function are not limited to higher centers but also involve the brain stem.
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Original Articles|
December 01 1990
Mild Hypoglycemia and Impairment of Brain Stem and Cortical Evoked Potentials in Healthy Subjects
Timothy W Jones;
Timothy W Jones
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Gregory McCarthy;
Gregory McCarthy
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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William V Tamborlane;
William V Tamborlane
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Sonia Caprio;
Sonia Caprio
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Elizabeth Roessler;
Elizabeth Roessler
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Deborah Kraemer;
Deborah Kraemer
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Kathleen Starick-Zych;
Kathleen Starick-Zych
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Truett Allison;
Truett Allison
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Susan D Boulware;
Susan D Boulware
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Robert S Sherwin
Robert S Sherwin
Departments of Pediatrics, Internal Medicine, and Neurosurgery, Yale University School of Medicine, and the Department of Psychology, Yale University
New Haven, Connecticut
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Address correspondence and reprint requests to R.S. Sherwin, MD, Department of Medicine, Fitkin 1, 333 Cedar Street, Yale University School of Medicine, New Haven, CT 06510.
Diabetes 1990;39(12):1550–1555
Article history
Received:
February 20 1990
Revision Received:
July 27 1990
Accepted:
July 27 1990
PubMed:
2245879
Citation
Timothy W Jones, Gregory McCarthy, William V Tamborlane, Sonia Caprio, Elizabeth Roessler, Deborah Kraemer, Kathleen Starick-Zych, Truett Allison, Susan D Boulware, Robert S Sherwin; Mild Hypoglycemia and Impairment of Brain Stem and Cortical Evoked Potentials in Healthy Subjects. Diabetes 1 December 1990; 39 (12): 1550–1555. https://doi.org/10.2337/diab.39.12.1550
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