NCT04759898

Direct Measurement of Motor Cortical Responses to tDCS

Direct Measurement of Motor Cortical Responses to Transcranial Direct Current Stimulation

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 80 (actual)
• Sponsor: Medical University of South Carolina · Academic / Other
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Accepted

Summary

Transcranial direct current stimulation (tDCS) has shown the potential to improve symptoms in patients with movement deficits, such as Parkinson's disease and chronic stroke. However, the effects of tDCS have so far not been proven on a wider scale due to lack of knowledge regarding exactly how tDCS works. This has limited the adoption of this potentially useful therapy for patients with Parkinson's disease, chronic stroke and other conditions affecting movement. The investigators hypothesize that by studying the effects of tDCS in subjects performing a motor task, the brain signals mediating improvements in motor control will be identified. The investigators will use both noninvasive and invasive methods to explore this hypothesis. The investigators expect this combined approach to broaden understanding of tDCS application in conditions affecting movement and possibly lead to therapeutic advances in these populations.

Conditions

• Parkinson Disease
• Chronic Stroke

Interventions

Type	Name	Description
DEVICE	transcranial direct current stimulation (noninvasive recording)	Subjects will enter the EEG lab and be seated in a chair. The 26-electrode EEG array will be placed using a conductive paste. The electrodes will be connected to a clinical grade EEG machine used in standard of care routine EEG monitoring. Next, a soft cloth cap will be placed over the subject's head with the tDCS electrodes pre-positioned in place. The cap will be positioned so that the tDCS electrodes cover the scalp without disturbing the underlying EEG electrodes. Conducting gel will be applied in direct contact with the scalp to facilitate stimulation. In addition, lidocaine jelly will be added topically to provide local anesthesia. The tDCS electrodes will be connected to a low-current generator. Participants receive 2.0 milliamps in electrical stimulation from the tDCS machine for 20 minutes. The device will be manually controlled by study personnel assisting with the experiment. A virtual reality environment will be utilized to collect kinematic data during the study.
DEVICE	sham transcranial direct current stimulation (noninvasive recording)	Subjects receiving sham undergo the same setup as the stimulation group with the exception that sham subjects experience stimulation for one minute only (30 second ramp-up to 2 milliamps immediately followed by 30 second ramp-down to 0 milliamps for the remaining 19 minutes). This provides similar sensory feedback to sham subjects that treatment subjects experience. The same electrode array, soft cloth cap, conducting gel application, and lidocaine are applied as in a stimulation subject. The tDCS electrodes will be connected to a low-current generator. A virtual reality environment will be utilized to collect kinematic data during the study.
DEVICE	transcranial direct current stimulation (invasive recording)	Subjects are brought into the operating room. The scalp is prepped with a sterilizing solution. Following infiltration with local anesthetic and incision, a 6-contact electrocorticography strip is inserted into the burr hole covering primary motor cortex. Electrocorticography strip terminals are connected to an amplifier for signal recording. Gas-sterilized transcranial direct current stimulation electrodes are placed on the scalp directly overlying primary motor cortex. tDCS electrodes are connected to a low-current generator. During electrocorticographic recording, stimulation is turned on while subjects are asked to flex each arm. At the conclusion of the experiment, the electrocorticography strip and tDCS electrodes are removed and the surgery proceeds as planned.

Timeline

• Start date: 2021-01-01
• Primary completion: 2025-01-01
• Completion: 2025-01-01
• First posted: 2021-02-18
• Last updated: 2025-06-22

Locations

1 site across 1 country: United States