Investigation of the Benefits of Electrical Non-invasive Stimulation on Cognitive Symptoms in Parkinson's Disease

Summary

Parkinson's disease is the second most common neurodegenerative disease after Alzheimer's disease.

It is mostly characterized by the presence of motor difficulties. However, it can also be accompanied by cognitive disorders which have an equally significant impact on the quality of life of patients and which are not relieved by any treatment.

Among the functions affected by Parkinson's disease, inhibition is an essential process for adapting our behaviors in daily life. Inhibition allows us to stop an action that is no longer required or appropriate to the situation in which we find ourselves in. For example, it comes into play when we have to stop at a "stop" sign while driving.

Recent studies suggest that it could be possible to improve the functioning of these processes by using non-invasive brain stimulation tools. Transcranial alternating current electrical stimulation has thus showed promising results in improving functions such as working memory. This technique is completely painless and non-invasive and consists in applying an electric current of very low intensity (barely perceptible) at the level of the scalp, using electrodes.

The investigators are conducting a study to test whether transcranial alternating current electrical stimulation could improve the functioning of the inhibition process which is altered in patients. For this, the investigators will measure this process using a task performed on a computer (the Stop Signal Reaction Time Task), as well as brain activity using a method called "electroencephalography", before and after stimulation. For this study, the investigators will include 50 patients and 40 healthy participants to investigate the effect of the stimulation on inhibition.

Conditions

• Parkinson Disease

Interventions

OTHER

Neuropsychological assessment

interview with a neuropsychologist and carrying out tests measuring overall cognitive abilities, depression, apathy and anxiety (respectively using the MOCA, MADRS, LARS, STAI scales)

OTHER

Neurological assessment

Only for patients with Parkinson disease. Evaluation consisting in a disease severity assessment using the Hoehn and Yahr and Schwab and England scales, as a well as a measure of levodopa equivalent daily dose.

OTHER

Cognitive task

The task consists in pressing a left or right button as fast and as accurately as possible according to the direction of an arrow displayed at the center of a screen. On 25 % of the trials, a "stop" signal will occur right after the stimulus, indicating the participant to stop his impending button press. The delay between the presentation of the arrow stimulus and the stop signal will be adjusted to ensure a final 50% accuracy (decreased following an accurate response and increased after an error), which is necessary to comply with the assumptions for a robust calculation of the stop signal reaction time (SSRT).

PROCEDURE

EEG

A high-resolution (256 channels) electroencephalographic recording will be done at rest and during the Stop task, before and after each real or sham stimulation.

PROCEDURE

tACS (real or sham)

Real or sham tACS will be applied with the same equipment (StarStim, Neuroelectrics). The stimulation will consist in applying a current (max 2 mA) at frontal sites (F8 and Cz according to standard EEG position, and defined based on dosimetry analyses on averaged head models) for 12-15 minutes during the task. A 10 s ramp (fade-in/fade-out) will be used to avoid current perception of the stimulation and optimize blinding. Sham stimulation will be done using the same protocol, but with no stimulation in between onset and offset.

Sponsors & Collaborators

• Institut National de la Santé Et de la Recherche Médicale, France

  lead OTHER_GOV

Principal Investigators

• Paul Sauleau, MD · Rennes University Hospital

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

DOUBLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-05-03

Primary Completion

2026-01-15

Completion

2026-01-15

Countries

• France

Study Locations