Effects of Parkinson's disease on brain-wave phase synchronisation and cross-modulation

¹  Institut für Physik, Martin-Luther-Universität Halle-Wittenberg - von-Seckendorff-Platz 1, 06099 Halle, Germany, EU
²  Laboratory for Gait & Neurodynamics, Movement Disorders Unit, Department of Neurology, Tel Aviv Sourasky Medical Center - 6 Weizmann Street, Tel Aviv 64239, Israel
³  Schlafmedizinisches Zentrum der Charité Berlin - Luisenstraße 13a, 10117 Berlin, Germany, EU
⁴  Department of Physical Therapy, Tel Aviv University - Ramat Aviv, Israel

Corresponding author: jan.kantelhardt@physik.uni-halle.de

Received: 27 October 2009
Accepted: 28 January 2010

Abstract

We study the effects of Parkinson's disease (PD) on phase synchronisation and cross-modulation of instantaneous amplitudes and frequencies for brain waves during sleep. Analysing data from 40 full-night EEGs (electro-encephalograms) of ten patients with PD and ten age-matched healthy controls we find that phase synchronisation between the left and right hemisphere of the brain is characteristically reduced in patients with PD. Since there is no such difference in phase synchronisation for EEGs from the same hemisphere, our results suggest the possibility of a relation with problems in coordinated motion of left and right limbs in some patients with PD. Using the novel technique of amplitude and frequency cross-modulation analysis, relating oscillations in different EEG bands and distinguishing both positive and negative modulation, we observe an even more significant decrease in patients for several band combinations.