title: Slowing of M1 oscillations in brain tumor patients in resting state and during movement.
abstract: OBJECTIVE
  Brain tumors may severely disrupt the structure and function of the brain. While abnormal low-frequency activity can be found around tumor borders, disrupted structural connectivity may also impinge on neural activity in distant brain regions and other frequency bands. We investigated how glioma in patients with normal motor functioning affects activity in primary motor areas (M1).
  
  
  METHODS
  Using magnetoencephalography in 12 patients with unilateral glioma located around the central sulcus, we studied activity in bilateral M1s in resting state and during movement with focus on motor-related mu (8-12Hz) and beta rhythms (15-30Hz). Principal component analysis served to test for differences in spectral content.
  
  
  RESULTS
  A shift was found towards lower frequencies for M1 in the tumor hemisphere compared to M1 in the healthy hemisphere, caused by an increase in mu and decrease in beta power. This pattern was observed both in resting state and during movement.
  
  
  CONCLUSIONS
  This 'slowing' of brain oscillations in M1 resembles findings in patients with monohemispheric stroke and Parkinson's disease. A loss of intra-cortical connectivity may account for these findings, possibly supplemented by tumor-induced changes in neurotransmitter systems.
  
  
  CONCLUSIONS
  Motor functioning may be unaffected by a spectral shift of mu and beta oscillations.
authors.affiliation: Research Institute MOVE, VU University Amsterdam, Amsterdam, The Netherlands. b.c.m.van.wijk@vu.nl
authors.forename: Bernadette C M
authors.initials: BC
authors.lastname: van Wijk
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Willemse
authors.forename: W
authors.initials: W
authors.lastname: Peter Vandertop
authors.forename: Andreas
authors.initials: A
authors.lastname: Daffertshofer
mesh_terms: D000328:Adult; D001611:Beta Rhythm / Q000502:physiology; D001932:Brain Neoplasms / Q000503:physiopathology*; D058256:Brain Waves / Q000502:physiology*; D005260:Female; D005910:Glioma / Q000503:physiopathology*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology; D009991:Oscillometry; D012146:Rest / Q000502:physiology*; D013057:Spectrum Analysis
chemical_list: D018377:Neurotransmitter Agents