Automated detection of hypoglycemia-induced EEG changes recorded by subcutaneous electrodes in subjects with type 1 diabetes—The brain as a biosensor

Juhl, Claus B.; Højlund, Kurt; Elsborg, Rasmus; Poulsen, Mikael Kjær; Selmar, Peter E.; Holst, Jens Juul; Christiansen, Claus; Beck-Nielsen, Henning

doi:10.1016/j.diabres.2010.01.007

« Previous Next »Diabetes Research and Clinical Practice
Volume 88, Issue 1 , Pages 22-28, April 2010

Automated detection of hypoglycemia-induced EEG changes recorded by subcutaneous electrodes in subjects with type 1 diabetes—The brain as a biosensor☆

Claus B. Juhl
- Medical Department, Clinic for Endocrinology and Diabetes, Sydvestjysk Sygehus Esbjerg, Denmark
- Department of Endocrinology, Odense University Hospital, Denmark
- Corresponding author at: Medical Department, Clinic for Endocrinology and Diabetes, Sydvestjysk Sygehus Esbjerg, Haraldsgade, Esbjerg 6700, Denmark. Tel.: +45 60867172; fax: +45 79182218.
Kurt Højlund
- Department of Endocrinology, Odense University Hospital, Denmark
Rasmus Elsborg
- Hyposafe A/S, Scion Research Park, Lyngby, Denmark
Mikael Kjær Poulsen
- Department of Endocrinology, Odense University Hospital, Denmark
Peter E. Selmar
- Department of Neurophysiology, Vejle Sygehus, Denmark
Jens Juul Holst
- Department of Physiology, University of Copenhagen, Denmark
Claus Christiansen
- Danish Research Foundation, Copenhagen and Nordic Bioscience A/S, Herlev, Denmark
Henning Beck-Nielsen
- Department of Endocrinology, Odense University Hospital, Denmark

Received 25 September 2009; received in revised form 18 December 2009; accepted 4 January 2010. published online 15 January 2010.

Abstract

Aims

Hypoglycemia unawareness is a common condition associated with increased risk of severe hypoglycemia. We test the hypothesis that specific changes in the electroencephalogram (EEG) during hypoglycemia can be recorded by subcutaneous electrodes and processed by a general mathematical algorithm, and that hypoglycemia associated EEG changes appear before the development of severe hypoglycemia.

Methods

Fifteen patients with type 1 diabetes were exposed to insulin-induced hypoglycemia and EEG was recorded. The cognitive function was evaluated by repeated cognitive testing. Insulin infusion was terminated when plasma glucose reached 1.8mmol/l or when the subjects showed obvious signs of cognitive dysfunction. EEG was analyzed by an automated mathematical algorithm with a predefined threshold of hypoglycemia.

Results

Hypoglycemia associated EEG changes were detected by the mathematical algorithm in all subjects. Plasma glucose at the time of EEG changes above the threshold value ranged from 2.0 to 3.4mmol/l and occurred 29±28min (range 3–113min) before termination of insulin infusion.

Conclusions

Hypoglycemia associated EEG changes could be detected by an automated mathematical algorithm in all subjects exposed to insulin-induced hypoglycemia. In 12 of 15 patients, EEG changes occurred before severe hypoglycemia as evaluated by the cognitive testing.

Keywords: Hypoglycemia, Diabetes, Electroencephalogram, Human