title: Brain glucose metabolism during hypoglycemia in type 1 diabetes: insights from functional and metabolic neuroimaging studies.
abstract: Hypoglycemia is the most frequent complication of insulin therapy in patients with type 1 diabetes. Since the brain is reliant on circulating glucose as its main source of energy, hypoglycemia poses a threat for normal brain function. Paradoxically, although hypoglycemia commonly induces immediate decline in cognitive function, long-lasting changes in brain structure and cognitive function are uncommon in patients with type 1 diabetes. In fact, recurrent hypoglycemia initiates a process of habituation that suppresses hormonal responses to and impairs awareness of subsequent hypoglycemia, which has been attributed to adaptations in the brain. These observations sparked great scientific interest into the brain's handling of glucose during (recurrent) hypoglycemia. Various neuroimaging techniques have been employed to study brain (glucose) metabolism, including PET, fMRI, MRS and ASL. This review discusses what is currently known about cerebral metabolism during hypoglycemia, and how findings obtained by functional and metabolic neuroimaging techniques contributed to this knowledge.
authors.affiliation: Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. Hanne.Rooijackers@radboudumc.nl.
authors.forename: Hanne M M
authors.initials: HM
authors.lastname: Rooijackers
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Evita C
authors.initials: EC
authors.lastname: Wiegers
authors.affiliation: Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Cees J
authors.initials: CJ
authors.lastname: Tack
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.|Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Marinette
authors.initials: M
authors.lastname: van der Graaf
authors.affiliation: Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Bastiaan E
authors.initials: BE
authors.lastname: de Galan
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007003:Hypoglycemia / Q000378:metabolism* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D059906:Neuroimaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods
chemical_list: D005947:Glucose
keywords: Brain metabolism; Cerebral blood flow; Hypoglycemia; Impaired awareness of hypoglycemia; Neuroimaging; Type 1 diabetes mellitus