title: Hypoglycemia-associated changes in the electroencephalogram in patients with type 1 diabetes and normal hypoglycemia awareness or unawareness.
abstract: Hypoglycemia is associated with increased activity in the low-frequency bands in the electroencephalogram (EEG). We investigated whether hypoglycemia awareness and unawareness are associated with different hypoglycemia-associated EEG changes in patients with type 1 diabetes. Twenty-four patients participated in the study: 10 with normal hypoglycemia awareness and 14 with hypoglycemia unawareness. The patients were studied at normoglycemia (5-6 mmol/L) and hypoglycemia (2.0-2.5 mmol/L), and during recovery (5-6 mmol/L) by hyperinsulinemic glucose clamp. During each 1-h period, EEG, cognitive function, and hypoglycemia symptom scores were recorded, and the counterregulatory hormonal response was measured. Quantitative EEG analysis showed that the absolute amplitude of the θ band and α-θ band up to doubled during hypoglycemia with no difference between the two groups. In the recovery period, the θ amplitude remained increased. Cognitive function declined equally during hypoglycemia in both groups and during recovery reaction time was still prolonged in a subset of tests. The aware group reported higher hypoglycemia symptom scores and had higher epinephrine and cortisol responses compared with the unaware group. In patients with type 1 diabetes, EEG changes and cognitive performance during hypoglycemia are not affected by awareness status during a single insulin-induced episode with hypoglycemia.
authors.affiliation: Faculty of Health, University of Southern Denmark, Odense, Denmark Nordsjællands Hospital Hillerød, Hillerød, Denmark sejl@regionh.dk.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Sejling
authors.affiliation: Roskilde Hospital, Roskilde, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Rigshospitalet, Copenhagen, Denmark.
authors.forename: Troels W
authors.initials: TW
authors.lastname: Kjær
authors.affiliation: Nordsjællands Hospital Hillerød, Hillerød, Denmark.
authors.forename: Ulrik
authors.initials: U
authors.lastname: Pedersen-Bjergaard
authors.affiliation: Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Diemar
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Hvidovre Hospital, Hvidovre, Denmark.
authors.forename: Christian S S
authors.initials: CS
authors.lastname: Frandsen
authors.affiliation: Rigshospitalet, Copenhagen, Denmark.
authors.forename: Linda
authors.initials: L
authors.lastname: Hilsted
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Herlev Hospital, Herlev, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Faber
authors.affiliation: Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Holst
authors.affiliation: Nordsjællands Hospital Hillerød, Hillerød, Denmark Health, Aarhus University, Aarhus, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Tarnow
authors.affiliation: Hvidovre Hospital, Hvidovre, Denmark.
authors.forename: Martin N
authors.initials: MN
authors.lastname: Nielsen
authors.affiliation: HypoSafe A/S, Lyngby, Denmark.
authors.forename: Line S
authors.initials: LS
authors.lastname: Remvig
authors.affiliation: Nordsjællands Hospital Hillerød, Hillerød, Denmark Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Birger
authors.initials: B
authors.lastname: Thorsteinsson
authors.affiliation: Faculty of Health, University of Southern Denmark, Odense, Denmark HypoSafe A/S, Lyngby, Denmark Sydvestjysk Sygehus, Esbjerg, Denmark.
authors.forename: Claus B
authors.initials: CB
authors.lastname: Juhl
mesh_terms: D000328:Adult; D000368:Aged; D001364:Awareness; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000378:metabolism* / Q000523:psychology; D008297:Male; D008875:Middle Aged