EEG abnormalities with and without relation to severe hypoglycaemia in adolescents with type 1 diabetes

Diabetologia. 2005 Mar;48(3):412-9. doi: 10.1007/s00125-004-1666-2. Epub 2005 Mar 1.


Aims/hypothesis: The aim of the present study was to identify whether adolescents with type 1 diabetes receiving modern multiple insulin injection therapy (MIT) have abnormal EEGs, and to elucidate possible correlations with a history of severe hypoglycaemia, poor metabolic control and nerve conduction defects.

Methods: We investigated 35 patients (age 14-19 years) with disease duration 7.6+/-4.6 years, and 45 healthy control subjects. EEG spectral components were obtained from 15-min recordings in resting, awake subjects. Nerve conduction was measured bilaterally in motor and sensory fibres in the median, peroneal and sural nerves.

Results: The EEGs of patients showed an increase in slow activity (delta and theta) and a reduction in alpha peak frequency, both of which were most pronounced in the frontal regions (p<0.001). They also showed a decrease in fast activity, which was most pronounced bilaterally in the posterior temporal regions (alpha p<0.001, beta p<0.01, gamma p<0.001). A history of severe hypoglycaemia was correlated with a global increase in theta activity (p<0.01-0.05). Poor metabolic control, measured as acute and long-term HbA1c levels, was correlated with an increase in delta activity and a decrease in alpha peak frequency. The decrease in fast activity in the temporal regions was a separate type of abnormality because it had a different distribution, and was not correlated with the increase in delta/theta power, poor metabolic control or with hypoglycaemia.

Conclusions/interpretation: Recurrent severe hypoglycaemia and poor metabolic control are risk factors for EEG abnormalities in adolescents with type 1 diabetes receiving MIT treatment. In addition, we found pronounced abnormalities in the temporal regions that were not related to these risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Age of Onset
  • Blood Glucose / metabolism
  • Brain / physiopathology*
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / physiopathology*
  • Electroencephalography*
  • Humans
  • Hypoglycemia / physiopathology*
  • Motor Neurons / physiology
  • Neural Conduction / physiology
  • Neurons, Afferent / physiology
  • Peroneal Nerve / physiopathology
  • Sural Nerve / physiopathology


  • Blood Glucose