Changes in the EEG parameters related to parkinsonism and aging

The EEG parameters were analyzed in 73 patients with parkinsonism characterized by different levels of clinical disorders and duration of the disease (44- to 77-year-old persons, mean 58.1 years; group P) and in 60 practically healthy persons (control group, group C). Group C was divided into two subgroups: Cy and Co (persons younger and older than 40 years, respectively). In the P group, the powers of fluctuations in 1- and 2-ranges and of -waves in anterior recording sites, (F,C), was noticeably higher than those in the C group. These parameters were in positive correlation with the disease intensity; there was a trend toward a lower level of the above EEG components in older patients. Patients with a lower level of clinical symptoms showed lower power of -waves in posterior recording sites, (P,O), than that in the Co and, moreover, Cy subgroups. Yet, a higher level of clinical symptoms correlated with a higher level of this parameter. A decrease in the frequency of (F,C) and (P,O) components in the P group was found. These findings show that there are obvious shifts in spatial distribution, and relative levels and frequency parameters of brain electrical activity in parkinsonian patients, which reflects the multilevel pattern of brain disorders related to this disease.Neirofiziologiya/Neurophysiology, Vol. 27, No. 5/6, pp. 396–402, September–December, 1995.