title: Non linear analysis of magnetoencephalographic signals as a tool for assessing malignant lesions of the brain: first results.
abstract: OBJECTIVE
  Non linear signal analysis is a powerful technique that reveals qualitative and quantitative differentiations between different dynamical systems (biological or otherwise). Presented here are the first results of a work in progress to investigate the Magnetoencephalograms (MEG) from patients with malignant CNS lesions and from healthy volunteers.
  
  
  METHODS
  We present MEG recordings of 10 patients diagnosed with malignant CNS lesions and the corresponding ones from 10 healthy volunteers. A 122-channel SQUID biomagnetometer in an electromagnetically shielded room was used to record the MEG signals and the Grassberger-Procaccia method for the estimation of the correlation dimension was applied on the phase space reconstruction of the recorded signal from each patient.
  
  
  RESULTS
  Evidence linking MEG signal characteristics (existence of low dimensionality chaotic dynamics) with the existence of the tumour was found from this analysis.
  
  
  CONCLUSIONS
  The obtained results substantiate our hypothesis of a relation between tumours of the brain and the mathematically chaotic nature of the neural dynamics derived from their MEG recordings.
authors.affiliation: Lab of Medical Physics, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Panagiotis E
authors.initials: PE
authors.lastname: Antoniou
authors.forename: Photios A
authors.initials: PA
authors.lastname: Anninos
authors.forename: Haritomeni
authors.initials: H
authors.lastname: Piperidou
authors.forename: Adam
authors.initials: A
authors.lastname: Adamopoulos
authors.forename: Athanasia
authors.initials: A
authors.lastname: Kotini
authors.forename: Michael I
authors.initials: MI
authors.lastname: Koukourakis
authors.forename: Efthimios
authors.initials: E
authors.lastname: Sivridis
mesh_terms: D000368:Aged; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics