Significance of Lyapunov Exponent in Parkinson's Disease Using Electroencephalography

A neurodegenerative disorder which is caused due to loss of a neurotransmitter called dopamine in the substania nigra of the mid brain is known as Parkinson's disease (PD). It is mostly affected to the people after the age of 50 years. The disease results in the loss of coordination between brain and muscle; hence the person is disturbed. Electroencephalography (EEG) is one of the primitive methods for studying the human brain function. It is used for the detection of cognitive decline in neurodegenerative disorders including PD. In this paper, we reported a study of the frontal and temporal EEG of Parkinson's disease patients using MATLAB platform. Lyapunov exponent and inverse Lyapunov exponent for both PD and healthy subjects were calculated within a given time frame. It was found that for PD subjects, the Lyapunov exponent for the temporal part of the brain is less than that of the frontal while the inverse Lyapunov exponent is reverse order of the brain. This result signifies that the correlations between neurons are stronger in frontal region for healthy subjects than PD.