Non linear analysis of magnetoencephalographic signals as a tool for assessing malignant lesions of the brain: first results

• Published in: Brain topography 2004-12, Vol.17 (2), p.117-123
• Main Authors: Antoniou, Panagiotis E, Anninos, Photios A, Piperidou, Haritomeni, Adamopoulos, Adam, Kotini, Athanasia, Koukourakis, Michael I, Sivridis, Efthimios
• Format: Article
• Language: English
• Subjects: Aged; Brain Mapping; Brain Neoplasms - physiopathology; Electroencephalography - methods; Female; Humans; Magnetoencephalography - methods; Male; Middle Aged; Nonlinear Dynamics
• ISSN: 0896-0267; 1573-6792
• DOI: 10.1007/s10548-004-1009-0

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. 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. Evidence linking MEG signal characteristics (existence of low dimensionality chaotic dynamics) with the existence of the tumour was found from this analysis. 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.