EEG topography during insulin-induced hypoglycemia in patients with insulin-dependent diabetes mellitus.
A group of young patients with insulin-dependent diabetes mellitus (n = 14; 8 men, 6 women; 33.1 +/- 8.9 years) were examined by topographic EEG mapping under normoglycemic and hypoglycemic conditions (glucose levels after intravenous insulin injection down to 32.6 +/- 7.6 mg/dl). From the clinical aspect, 7 of them had a good and 7 had a poor awareness of hypoglycemia. During hypoglycemia, a decrease in alpha activity (p < 0.05), an increase in delta (p < 0.05), and especially in theta activity (p < 0.05) were found. The most sensitive parameter was the alpha/theta ratio. In the range of slight hypoglycemia (50-60 mg/dl) the increase in delta and theta activity showed a topographic maximum in lateral frontal regions. During deep hypoglycemia there was a topographic maximum of slow frequencies in posterior parts of the brain (centrotemporal to parieto-occipital regions). The differences between the group with good and with poor awareness of hypoglycemia were most pronounced during slight hypoglycemia in C3, C4, and Pz (p < 0.05). At lower glucose levels group distinction was no longer possible. These EEG changes correspond to a temporary organic brain syndrome.
Tribl
G
G
Clinic of Neurology, University of Vienna, Austria.
Howorka
K
K
Heger
G
G
Anderer
P
P
Thoma
H
H
Zeitlhofer
J
J
D000328:Adult; D001364:Awareness; D001931:Brain Mapping; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced* / Q000503:physiopathology* / Q000523:psychology; D007328:Insulin; D008297:Male; D012649:Self Concept
D007328:Insulin