The EEG signal reflects the functional state and metabolism of the brain. The brain is almost totally dependent on a continuous supply of glucose, and when the glucose level is lower than the metabolic requirements of the brain, its function deteriorates. Neuroglycopenic hypoglycaemia in insulin-treated diabetic patients is associated with characteristic changes in EEG with a decrease in alpha activity and an increase in delta and theta activity (14-17). These changes are clearly seen at blood glucose ~2.0mmol/l (14;15) preceding the development of severe cognitive dysfunction (18). We have recently demonstrated that hypoglycaemia-associated EEG-changes can be recorded from subcutaneously placed electrodes using an automated mathematical algorithm based on non-linear spectral analysis and that EEG-changes above a predefined threshold can be demonstrated more than 10 minutes before development of severe hypoglycaemia in the majority of the patients (19). We found a very low rate of false alarms and no adverse reactions related to implantation of the electrodes. We have subsequently performed a number of studies with real-time alarms type 1 diabetes patients exposed to insulin induced hypoglycaemia. In these studies the patients were instructed to ingest carbohydrates when he/she heard the alarm sound. In three out of four cases the patients were able to do so, while a fourth patient did not spontaneously ingest the meal although, he was fully conscious and not clinically affect by the hypoglycaemia. These findings hold promises that an alarm, given at the time of EEG-changes, can help the patients to avoid severe hypoglycaemia by ingestion of carbohydrate.