Interrelations between EEG Parameters and Personality Characteristics in Parkinsonian Patients

We studied a number of EEG parameters and indices of personality characteristics (evaluated with the use of the MMPI questionnaire) in sixty 44- to 73-year-old patients with Parkinson's disease (PD). According to the intensity of the symptoms, they were classified into groups 1 and 2, with an initial or moderate level of disease manifestation. In group-2 patients, the powers of the - and -range rhythms were greater, as compared with those in group 1. This was combined with higher indices in scales 2 (depression, D), 8 (individualism, Sc), and 0 (introversion/extraversion, Si). A clear correlations between the EEG parameters and indices of personality structure were found. There were positive correlations between the normalized power of ₂-rhythm and values of a few MMPI scales: 1 (supercontrol, Hs), 2 (depression, D), 4 (impulsivity, Pd), 7 (anxiety, Pt), 8 (individualism, Sc), and 0 (introversion/extraversion, Si). We also found negative correlations between the frequency of -rhythm and indices of supercontrol and anxiety scales. Correlations between different EEG parameters and MMPI scale indices depended on the level of disease manifestation. Our results allow us to assume a certain generality of the neurophysiological mechanisms determining modifications of the integral electrical activity of the brain and formation of individual psychological characteristics in parkinsonian patients.