Variation in the Dopaminergic Response During the Day in Parkinson Disease

Abstract

This study suggest that there is a change in responsiveness to dopaminergic stimulation during the day. The less effective dopaminergic response in afternoon depends on pharmacodynamic factors and not only on peripheral and central levodopa pharmacokinetic.

Outcomes from stimulation of the caudal zona incerta and pedunculopontine nucleus in patients with Parkinson's disease

“…Both problems have been previously reported by other groups. 9,20 At the 1-year follow-up, time between assessments for each of the patients varied to allow full recovery following changes in stimulation, prolonged periods of being off medication and repeated UPDRS assessments.…”

The effect of continuous levodopa treatment during the afternoon hours

“…More specifically, Mukai et al recently speculated that it is suspected that LCIG changes the blood concentration threshold for levodopa responses during the day. Monge et al noted that there is a change to dopaminergic stimulation during the day (including apomorphine and levodopa), and higher plasma concentrations are required to reach “on” states during the afternoon hours. In a study published by Bonuccelli et al in 2000, it was reported that the patients’ response declines as the day progresses, but this is not related to the pharmacokinetics of levodopa.…”

Expression of clock genes Per1 and Bmal1 in total leukocytes in health and Parkinson’s disease

“…The orthostatic hypotension in PD is associated with specific modifications of ambulatory blood pressure including loss of circadian rhythm of blood pressure, increased diurnal blood pressure variability and post‐prandial hypotension. Higher cortisol synthesis has also been reported in patients with PD, with a flattened diurnal cortisol secretory curve [2–4]. Changes in depression and sleep in PD patients, both of which symptoms are modulated by circadian control, were reported as early as the research of James Parkinson [5].…”