Clinical Trials Logo

Clinical Trial Summary

The effect of Levodopa medication on inhibitory control in Parkinson's patients is extremely debated despite the fact that this has potential clinical and therapeutic implications. A key confounding factor of many previous studies is that they did not take the disease duration in consideration. In fact, in moderate-to-advanced stages of Parkinson dopaminergic drugs could not produce a clear effect because too few dopaminergic cells for the drugs to operate on survived. Hence, in this study, we will compare the performance in the stop signal task in early-stage versus moderate-to-advanced stages Parkinson's patients both in ON and in OFF medication. In addition, to have a baseline measure of inhibitory control we will compare patient's performances with that of age-matched subjects.


Clinical Trial Description

The ability to stop a pending action is fundamental for survival in a natural environment where events cannot be fully predicted. Sudden events, such as the appearance of a physical obstacle, often require a quick change of the planned motor strategy and the first step toward this goal is to suppress the pre-programmed actions. Thus voluntary inhibition plays a crucial role in cognitive control and behavioral flexibility (1, 2). It has been shown that Parkinson's patients suffer from a specific deficit in this functions (3, 4, 5). However, it is extremely debated whether and how Levodopa medication (levodopa, dopamine agonists, anticholinergic drugs, or a combination of levodopa and an anticholinergic drug) affects response inhibition. A number of studies measuring inhibitory control via the stop signal task in Parkinson's patients seem to indicate that dopaminergic medications do not influence this executive function (5, 6, 7). However, a recent study (8) found that Levodopa medication does not affect specifically inhibitory control or movement readiness, but the balance between them. In fact, Parkinson's patients in the OFF medication state were able to maintain response latencies in the same range as healthy controls, but they showed a significant reduction in the ability to stop reactions abruptly. In contrast, patients' performance shifted significantly when taking dopaminergic medications. They move slower but stopping improved relative to the off dopamine state. This pattern suggests a role for dopamine in modulating the tradeoff between the two action control processes. In addition, studies of other specific populations and healthy adults suggest that dopaminergic medications deserve reconsideration in response inhibition. For instance, positron emission (PET) studies have found that higher levels of striatal D1 and D2/D3 receptor availability predict better performance on the stop signal task (9, 10) and that response inhibition performance evokes dopamine release in prefrontal, parietal, and temporal cortex in healthy adults (11). Even more importantly, a few recent studies provided evidence that early-stage Parkinson's patients with response inhibition impairment seem to benefit from dopaminergic treatment (12,13). Therefore, a plausible hypothesis is that the absence of a clear effect of dopaminergic medications could be ascribed to the fact that in most previous studies included Parkinson's patients in the moderate-to-advanced stages. In those patients, the diminished efficacy of dopaminergic drugs could be a consequence that too few dopaminergic cells for the drugs to operate on survived (14). Hence, the aim of the present work is to re-assess the impact of dopaminergic medications on inhibitory control on Parkinson's patients using a reaching version of the stop signal task (e.g. 4, 15, 16, 17, 18) taking the disease duration in consideration. To this aim, the investigators will compare the performance in the stop signal task in early-stage versus moderate-to-advanced stages Parkinson's patients both in ON and in OFF medication. Finally, to have a baseline measure of inhibitory control the investigators will compare patients' performances with those of age-matched subjects. ;


Study Design


Related Conditions & MeSH terms


NCT number NCT03665493
Study type Interventional
Source Neuromed IRCCS
Contact
Status Completed
Phase N/A
Start date September 30, 2020
Completion date November 10, 2023

See also
  Status Clinical Trial Phase
Completed NCT02227355 - Evaluating the Effectiveness of Neupro® (Rotigotine) and L-dopa Combination Therapy in Patients With Parkinson's Disease N/A
Completed NCT01026428 - A Study to Assess the Effect of Safinamide on Levodopa Pharmacokinetics Phase 1/Phase 2
Completed NCT00664157 - Facial Expression Recognition of Emotion and Categorization of Emotional Words in Parkinson's Disease. Impact of L-Dopa and Deep Brain Stimulation of Subthalamic Nucleus N/A
Completed NCT04524143 - The Acute Effect of Cervical Mobilization in Parkinson's Disease N/A
Completed NCT05107531 - Investigation of Gait, Foot Pressure Distribution and Balance in Parkinson's Patients With Motor Freezing
Completed NCT04524182 - The Acute Effect of Lumbosacral Mobilization in Parkinson's Disease N/A
Completed NCT00985517 - Safety and Efficacy of CERE-120 in Subjects With Parkinson's Disease Phase 1/Phase 2
Completed NCT01968031 - A 12-week Randomized Study to Evaluate Oral Istradefylline in Subjects With Moderate to Severe Parkinson's Disease Phase 3
Completed NCT01970813 - Efficacy of Acupuncture and Bee Venom Acupuncture on Patients With Idiopathic Parkinson's Disease N/A
Completed NCT01221948 - Vercise Implantable Stimulator for Treating Parkinson's Disease Phase 2
Terminated NCT01028586 - MOTION, Safinamide in Early Idiopathic Parkinson's Disease (IPD), as add-on to Dopamine Agonist (Extension of Trial 27918) Phase 3
Completed NCT00239564 - Pharmacokinetics and Pharmacodynamics of IPX054 in Subjects With Parkinson's Disease Phase 1/Phase 2
Completed NCT02240030 - Efficacy and Safety Study of CVT-301 In Parkinson's Disease Patients With OFF Episodes Phase 3
Completed NCT00605683 - MOTION, Safinamide in Early IPD, as add-on to Dopamine Agonist Phase 3
Completed NCT00400634 - Double-Blind, Multicenter, Sham Surgery Controlled Study of CERE-120 in Subjects With Idiopathic Parkinson's Disease Phase 2
Completed NCT01227265 - Placebo Controlled Study of Preladenant in Participants With Moderate to Severe Parkinson's Disease (P07037) Phase 3
Completed NCT02565628 - PF-06669571 In Subjects With Idiopathic Parkinson's Disease Phase 1
Completed NCT01617135 - Safety, Pharmacokinetics and Efficacy Study of CVT-301 Inpatients With Parkinson's Disease and "Off" Episodes Phase 2
Completed NCT01606670 - Observational Study With Neupro® to Evaluate the Patient´s Perception of Pain Associated With Parkinson´s Disease
Terminated NCT00261781 - Walking Capacity in Parkinson's Disease (PD-Walk) N/A