Higuchi fractal dimension as a method for assessing response to sound stimuli in patients with diffuse axonal brain injury

Abstract

The aim of the research was to study the fractal dimension of the EEG signal by the Higuchi’s method in patients with diffuse axonal injury (DAI) of the brain. Materials and Methods. The study was performed in 28 patients with DAI of different severity and 13 sex-and age-matched controls. The Higuchi’s method of fractal dimension was used to investigate brain response to sound stimuli of different emotional coloring as well as the features of the EEG signal in the resting state. Results. The EEG data demonstrated the highest values of fractal dimension in patients with DAI in the resting state. The values of fractal dimension in different emotional states considerably differ both in healthy subjects and in those with DAI. An increase in fractal dimension in response to stimuli occurs predominantly at the frequency of the theta rhythm in the control group and the frequency of the alpha rhythm in the patients with severe DAI. Conclusion. Higuchi fractal dimension can be used as a complementary diagnostic tool that allows differentiating perception of emotionally significant audio information in patients with brain injury.