Transcranial Alternating Current for Oscillopathies

Summary

The need for non-invasive, non-pharmacological and cost-effective therapeutic options has revived the use of transcranial current stimulation, either direct (tDCS) or alternating (tACS), in a wide range of pathologies and cognitive disturbances. Results, although often promising, are not unequivocal, possibly due to different stimulation parameters and sites, or non-homogenous patient selection. tDCS has been widely applied but few studies have focused on tACS which has the advantage of potentially entraining brain oscillations at the same frequency of stimulation. This overcomes the basic mechanism of tDCS which deploys anodal or cathodal currents to broadly excite or inhibit supposedly dysfunctional underlying cortex.

Whether a stimulation paradigm based on sound neurophysiological markers could provide a better and longer-lasting clinical outcome has not yet been ascertained.

The investigators aim to establish, with a trans-disease approach, categories characterized by defective EEG oscillatory activity and related dysfunctional networks. This classification, expected as the result of the first stage of this project, will guide the stimulation paradigm: categories with a pathologically low-band EEG prevalence will be treated with high-frequency tACS, and vice-versa, while the stimulation site will correspond to the defective sites of pathological EEG band maps. Parkinson's disease (PD), the EEG marker of which is a shift towards fast frequencies, and neuropathic pain (NP), with an EEG prevalence of slow bands, will be considered.

In order to categorize pathologies on the basis of their EEG frequencies, EEG power spectrums will be derived from resting EEG, and cortical oscillatory reactivity will be assessed by EEG-TMS (electroencephalographic-Transcranial Magnetic Stimulation) co-registration. This method appears to elicit state-dependent brain oscillatory response and is expected to support power spectrum data. The identified prevailing EEG band will be used subsequently to reconstruct scalp EEG band distribution. tACS paradigms will be tailored according to these findings: the anode will be placed over the scalp area corresponding to the dysfunctional rhythm and frequency will be set in order to correct the prevailing EEG band (slow stimulation if fast frequencies prevail, and vice-versa).

The translational element of this research proposal will consist of its clinical application in day-to-day practice for the benefit of people with the target conditions. The patient-groups, after undergoing the neurophysiology studies, will be tested with disease-specific scales and a neuropsychological battery. A 2-weeks tACS, either real or active sham, protocol will then be performed (30 minutes/day, 5 days/week), associated with an ad hoc rehabilitation protocol (60 minutes/day 5 days/week). During the last day of stimulation, patients will be tested again with the disease specific scales, neuropsychological battery and standard EEG to detect EEG frequencies modifications. At 4-weeks follow up, the same tests and EEG recording will be carried out, to assess the persistence of after-effects.

The expected result is a valid, non-invasive and cost-effective stimulation paradigm based on sound neurophysiologic markers which transcend traditional disease classifications.

Conditions

• Parkinson Disease
• Pain

Interventions

DEVICE

transcranial alternating current stimulation (tACS)

Sponsors & Collaborators

• University of Padova

  lead OTHER

Principal Investigators

• Alessandra Del Felice, PhD · University of Padua, Italy

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2016-05-01

Primary Completion

2018-09-01

Completion

2019-03-31

Countries

• Italy

Study Locations