Modulating Pain Using Transcranial Alternating Stimulation (tACS) in Healthy Human Subjects

Summary

Pain is a highly complex and subjective phenomenon which results from the dynamic integration of sensory and contextual (i.e. cognitive, emotional, and motivational) processes. Recent evidence suggests that neural oscillations and their synchronization between different brain areas might form the basis of these integrative functions. When investigating tonic experimental pain lasting for several minutes, for example, objective stimulus intensity is inversely related to alpha (8-13 Hz) and beta (13-30 Hz) oscillations in early somatosensory areas, while subjective pain intensity is positively associated with gamma (30-100 Hz) oscillations in prefrontal cortex. Yet, with a few exemptions, reported links between oscillatory brain activity and pain have mostly been established by correlative approaches which do not allow to infer causality. The current project aims at comprehensively investigating the causal role of neural oscillations for tonic experimental pain in healthy human subjects. To this end, transcranial alternating current stimulation (tACS) will be employed to modulate oscillatory brain activity in alpha and gamma frequency bands and investigate effects of this manipulation on pain perception and pain-related autonomic responses. Using an established tonic pain stimulation protocol and a double-blind, sham-controlled design, effects of tACS of somatosensory as well as prefrontal brain areas will be investigated. Results promise to elucidate the neural mechanisms underlying tonic experimental pain by testing the mechanistic role of neural oscillations in different aspects of pain processing. Furthermore, they might contribute to the development of urgently needed new treatment approaches for chronic pain using neuromodulatory methods.

Conditions

• Experimental Pain in Healthy Human Subjects

Interventions

DEVICE

10 Hz tACS of the bilateral somatosensory cortex

10 Hz tACS at 1 mA will be applied over the bilateral somatosensory cortex for 10 minutes using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber electrodes placed at electrode positions CP3 and CP4 according to the international 10-20 system.

DEVICE

10 Hz tACS of the prefrontal cortex

10 Hz tACS at 1 mA will be applied over the prefrontal cortex for 10 minutes using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber electrodes placed at electrode positions F3 and F4 according to the international 10-20 system.

DEVICE

80 Hz tACS of the bilateral somatosensory cortex

80 Hz tACS at 1 mA will be applied over the bilateral somatosensory cortex for 10 minutes using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber electrodes placed at electrode positions CP3 and CP4 according to the international 10-20 system.

DEVICE

80 Hz tACS of the prefrontal cortex

80 Hz tACS at 1 mA will be applied over the prefrontal cortex for 10 minutes using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber electrodes placed at electrode positions F3 and F4 according to the international 10-20 system.

DEVICE

Sham stimulation of the bilateral somatosensory cortex

10 Hz tACS at 1 mA will be applied over the bilateral somatosensory cortex for 10 seconds at the beginning of the experimental session using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber electrodes placed at electrode positions CP3 and CP4 according to the international 10-20 system.

DEVICE

Sham stimulation of the prefrontal cortex

10 Hz tACS at 1 mA will be applied over the prefrontal cortex for 10 seconds at the beginning of the experimental session using a Neuroconn stimulator (DC-Stimulator MR; Neuroconn, Ilmenau, Germany) and 2 5\*5 cm rubber placed at electrode positions F3 and F4 according to the international 10-20 system.

Sponsors & Collaborators

• German Research Foundation

  collaborator OTHER

• Technical University of Munich

  lead OTHER

Principal Investigators

• Markus Ploner, Prof. Dr. med. · Department of Neurology, Klinikum rechts der Isar, Technische Universität München

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2019-04-15

Primary Completion

2019-10-23

Completion

2019-10-23

Countries

• Germany

Study Locations