A Quantitative Study of the Electroencephalographic Response to Levodopa Treatment in Parkinsonian Patients

Abstract

A quantitative EEG study was done in order to confirm previous impressions that there is a significant EEG response to levodopa in parkinsonian patients, and in order to trace the existence of dopaminergic mechanisms in the generation of the human EEG. EEGs of twenty-five parkinsonian patients were recorded both before and during levodopa treatment, two to four weeks apart, when levodopa doses reached maintenance levels of 3-5g/d. Derivations from F7-T3, F8-T4, T5-O1, and T6-O2 were recorded and digitally processed into power density spectra. These spectra were analyzed for levodopa effects in a full factorial repeated measures multiple analysis of variance (MANOVA). A significant effect of levodopa treatment on the EEG was found, and localized to the left occipital lobe. This effect manifested as an increase in power in all the EEG frequency bands. These findings are compatible with multiband synchronization of the EEG generating processes, attributable to dopaminergic mechanisms.

Electroencephalographic lateralization, clinical correlates and pharmacological response in untreated Parkinson's disease

“…This suggests that PD subjects whose symptoms respond better to dopamine replacement by L-dopa, have a IL of alpha occipital activity more similar to controls and, from this point of view, a functional index of qEEG in PD could be considered a predictive factor of dopaminergic responsiveness. On the other hand, previous studies [5,6] and a recent report [7] demonstrated a relationship between EEG alpha activity and dopaminergic activation.…”

“…Indeed, some earlier studies reported on acute Ldopa effects on neural oscillatory activity detected using quantitative EEG (qEEG), indicating an effect on alpha rhythm asymmetrically localized in the occipital cortex regions [5,6]. Recently, L-dopa has been shown to acutely influence eye-closed resting state EEG alpha and beta rhythms [7].…”

Gender‐related differences in the human subthalamic area: a local field potential study

“…EEG studies in normal subjects reported higher beta power in women than in men (Wada et al ., 1994; Brenner et al ., 1995; Briere et al ., 2003; Nikulin & Brismar, 2006). The results of Yaar & Shapiro (1983) in patients with Parkinson's disease also imply that the beta band power in the scalp EEG was larger in females. Hence, our findings demonstrating higher beta power in female STN LFPs before levodopa agree with previous scalp EEG studies in healthy subjects and in patients with Parkinson's disease.…”

Dynamics of visual contextual interactions is altered in Parkinson’s disease

“…Background (no-stimulus) Frequency spectrum profiles. Since differences in background spectral EEG amplitude have previously been reported in PD [31][32][33][34] and would impact the estimation of ssVEP amplitudes driven by the external flicker-stimulation, it was important first to characterize such background spectral differences. EEG spectra computed from trials with zero foreground contrast and zero surround contrast (blank screen), averaged across a cluster of six parieto-occipital electrodes where ssVEPs were measured, revealed a broadly elevated spectrum in PD relative to controls ( Figure 1).…”