title: The influence of low-grade glioma on resting state oscillatory brain activity: a magnetoencephalography study.
abstract: OBJECTIVE
  In the present MEG-study, power spectral analysis of oscillatory brain activity was used to compare resting state brain activity in both low-grade glioma (LGG) patients and healthy controls. We hypothesized that LGG patients show local as well as diffuse slowing of resting state brain activity compared to healthy controls and that particularly global slowing correlates with neurocognitive dysfunction.
  
  
  METHODS
  Resting state MEG recordings were obtained from 17 LGG patients and 17 age-, sex-, and education-matched healthy controls. Relative spectral power was calculated in the delta, theta, upper and lower alpha, beta, and gamma frequency band. A battery of standardized neurocognitive tests measuring 6 neurocognitive domains was administered.
  
  
  RESULTS
  LGG patients showed a slowing of the resting state brain activity when compared to healthy controls. Decrease in relative power was mainly found in the gamma frequency band in the bilateral frontocentral MEG regions, whereas an increase in relative power was found in the theta frequency band in the left parietal region. An increase of the relative power in the theta and lower alpha band correlated with impaired executive functioning, information processing, and working memory.
  
  
  CONCLUSIONS
  LGG patients are characterized by global slowing of their resting state brain activity and this slowing phenomenon correlates with the observed neurocognitive deficits.
authors.affiliation: Department of Neurology, VU University Medical Center, De Boelelaan 1117, Amsterdam, The Netherlands. i.bosma@vumc.nl
authors.forename: I
authors.initials: I
authors.lastname: Bosma
authors.forename: C J
authors.initials: CJ
authors.lastname: Stam
authors.forename: L
authors.initials: L
authors.lastname: Douw
authors.forename: F
authors.initials: F
authors.lastname: Bartolomei
authors.forename: J J
authors.initials: JJ
authors.lastname: Heimans
authors.forename: B W
authors.initials: BW
authors.lastname: van Dijk
authors.forename: T J
authors.initials: TJ
authors.lastname: Postma
authors.forename: M
authors.initials: M
authors.lastname: Klein
authors.forename: J C
authors.initials: JC
authors.lastname: Reijneveld
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001611:Beta Rhythm; D001921:Brain / Q000503:physiopathology*; D001932:Brain Neoplasms / Q000503:physiopathology* / Q000523:psychology; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology; D003700:Delta Rhythm; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D005910:Glioma / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D008606:Mental Processes / Q000502:physiology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology; D013826:Theta Rhythm