title: Impact of EEG-vigilance on brain glucose uptake measured with [(18)F]FDG and PET in patients with depressive episode or mild cognitive impairment.
abstract: BACKGROUND
  [(18)F]fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) is a well-established method for the examination of the cerebral glucose metabolism of patients with affective disorder or memory impairment. An understudied question is how far results are influenced by interindividual differences in central nervous arousal as assessed with electroencephalogram (EEG-vigilance) during the PET recording. Building upon previous neuroimaging studies, we supposed an association between EEG-vigilance and normalized brain [(18)F]FDG-uptake (nFDGu) as measured by [(18)F]FDG-PET. For the first time, the present study exploratively investigated this association in a routine diagnostic work-up.
  
  
  METHODS
  Simultaneous 31-channel EEG and [(18)F]FDG-PET under resting conditions were acquired from 14 patients with depressive episode or mild cognitive impairment (MCI). EEG-vigilance was automatically classified by using the VIGALL algorithm (Vigilance Algorithm Leipzig). A nonparametric voxelwise simple linear regression with vigilance measure as predictor and nFDGu as criterion was performed using the Statistical nonParametric Mapping toolbox.
  
  
  RESULTS
  The main finding was a significant negative correlation between vigilance measure and nFDGu in bilateral frontal and temporal regions, bilateral cingulate gyrus and right thalamus with vigilance-related changes of nFDGu between 17.1 and 44.4%.
  
  
  CONCLUSIONS
  Simultaneous EEG and [(18)F]FDG-PET under resting conditions revealed that brain regions associated with EEG-vigilance partly overlapped with regions of impaired nFDGu in depression and MCI, as reported by previous studies. Vigilance-related changes of nFDGu were about the same magnitude as disease-related metabolic changes in patients with affective disorder or memory impairment as reported in previous studies. Therefore, our data suggest that differences in EEG-vigilance might influence alterations of nFDGu in disorders such as depression or MCI. Whether this possible impact of vigilance on nFDGu should be taken into account during the routine diagnostic application of [(18)F]FDG-PET has to be explored in future studies with larger patient groups.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Leipzig, Semmelweisstr. 10, 04103 Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Guenther
authors.forename: Peter
authors.initials: P
authors.lastname: Schönknecht
authors.forename: Georg
authors.initials: G
authors.lastname: Becker
authors.forename: Sebastian
authors.initials: S
authors.lastname: Olbrich
authors.forename: Christian
authors.initials: C
authors.lastname: Sander
authors.forename: Swen
authors.initials: S
authors.lastname: Hesse
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Meyer
authors.forename: Julia
authors.initials: J
authors.lastname: Luthardt
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hegerl
authors.forename: Osama
authors.initials: O
authors.lastname: Sabri
mesh_terms: D000328:Adult; D000368:Aged; D001143:Arousal / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D001931:Brain Mapping; D003072:Cognition Disorders / Q000000981:diagnostic imaging*; D003866:Depressive Disorder / Q000000981:diagnostic imaging*; D004569:Electroencephalography; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012815:Signal Processing, Computer-Assisted
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose