Mathematical analysis of EEG signals of patients with prion disease

摘要

Mathematical analysis of EEG recordings of a 79-year-old man and a 73-year-old woman, with a sCJD disease indicated that the mean and variance of the signals were the highest at the Centre of the scalp followed by front right region, when compared to other locations. The standard deviation of the signals from the front-right location increased by a factor of ten from -30 to -16 days (prior to death) for the male, while it increased by only 20% from -53 to -3 days for the female. Initially the signals were of low amplitude and as the days prior to death decreased sharp bursts were observed. The largest Lyapunov exponent increased with decrease in days from death, and a positive value indicated chaos. Poincare' map for the male patient showed that the -16 days signals had larger excursion covering a wider state space when compared to the -30 days data.