In Vivo Imaging of Therapeutic Electric Current Flow

Stroke Clinical Trial

— tDCS  

Official title:

In Vivo Imaging of Therapeutic Electric Current Flow

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02453763
• Other study ID #: 506-2012-N
• Secondary ID: 1R21NS081646-01A
• Status: Completed
• First received: May 21, 2015
• Last updated: April 4, 2018
• Start date: June 2015
• Est. completion date: July 6, 2017

Study information

• Verified date: April 2018
• Source: University of Florida
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The purpose of this research study is to measure current flow inside the head using magnetic resonance imaging (MRI). The data from this study will be used to map the current flow caused from the electrical stimulation inside the head. The methods develop will be used to map and better control delivery of the current for electrical stimulation to modify a psychiatric condition such as depression; or other conditions such as epilepsy, Parkinson's disease or autism.

Description:

Transcranial direct current stimulation (tDCS) and deep brain stimulation (DBS) are examples of electrical stimulation therapies that are rapidly gaining attention as means of modulating motor function, semantic processing, and executive function. Both therapies have attracted many clinical and experimental studies. tDCS has been found to have both facilitatory and inhibitory effects on the brain depending on stimulation polarity and electrode position. DBS has been thoroughly evaluated clinically for treatment of movement disorders, principally Parkinson's disease, and is extending its reach to include treatment of disorders such as focal dystonia, depression and chronic pain. While still mostly in the experimental stage, tDCS applications and acceptance are growing extremely rapidly.

Although the functional alterations associated with tDCS can be categorized without knowledge of the underlying neurophysiology, an understanding of where externally applied current actually flows in any electrical stimulation technique is crucial as a basis for understanding which brain regions, circuits, or elements are affected by these therapies, and how these changes may occur. Such knowledge will lead to a better understanding of the mechanisms underlying these therapies, and thus to more focused and effective stimulation patterns and locations. Ultimately, this will lead to more efficient and novel clinical applications.

Many studies have simulated the effects of current application in both extra- and intracranial modalities using computer simulation. Simulations will always be limited by errors in interpreting MRI data during segmentation, differences between assumed and actual electrical conductivity values, and mismatches between actual and presumed electrode locations and sizes. Thus, better methods to understand and verify current flow distributions are badly needed.

In this study a recently developed MRI-based phase imaging technique to more directly measure current densities in vivo. Unlike earlier MRI-based methods of measuring electrical current flow, the technique works without requiring subject repositioning. This methods will be validated against high-resolution subject-specific models incorporating many tissue compartments, including anisotropic white matter. Thus, a new direct measurement method against state-of-the-art modeling approaches.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 17
• Est. completion date: July 6, 2017
• Est. primary completion date: July 6, 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 30 Years

Eligibility

Inclusion Criteria:

• right handed (as determined by the Edinburgh battery),

• English as native language.

Exclusion Criteria:

• appreciable deficits in hearing,

• appreciable problems with articulation,

• appreciable accent schizophrenia, bipolar disorder, or major depression,

• any neurological disorder associated with cognitive impairment or neuroanatomic abnormality,

• language-based learning disorder,

• any implanted metal device (precludes use of tDCS), any implanted cardiac pacemaker,

• dementia or mini-mental state exam,

• <24 estimated verbal intelligence,

• <70 active or prior history of seizure disorder, family history of seizure disorder, prescribed seizure inducing medication.

Related Conditions & MeSH terms

• Alzheimer Disease
• Alzheimer's Disease
• Autism
• Depression
• Epilepsy
• Parkinson Disease
• Schizophrenia
• Stroke

Intervention

Device:
• Transcranial direct current stimulation
All participants will receive transcranial direct current stimulation. During the MRI images of the head a battery-powered device pulses a small current between a pair of the electrodes which will be immediately followed by more MRI images. The current pulses will be very short and there should be no feeling from the pulses. The entire imaging period will be at most 90 minutes.

Procedure:
• MRI
All participants will receive an MRI. During the MRI images of the head a battery-powered device pulses a small current between a pair of the electrodes which will be immediately followed by more MRI images. The current pulses will be very short and there should be no feeling from the pulses. The entire imaging period will be at most 90 minutes.

Locations

Country	Name	City	State
United States	University of Florida	Gainesville	Florida

Sponsors (3)

Lead Sponsor	Collaborator
University of Florida	Arizona State University, National Institute of Neurological Disorders and Stroke (NINDS)

Country where clinical trial is conducted

United States, 

References & Publications (4)

DeMarse TB, Carney PR. Augmentation of cognitive function in epilepsy. Front Syst Neurosci. 2014 Aug 14;8:147. doi: 10.3389/fnsys.2014.00147. eCollection 2014. — View Citation

Meng ZJ, Sajib SZ, Chauhan M, Sadleir RJ, Kim HJ, Kwon OI, Woo EJ. Numerical simulations of MREIT conductivity imaging for brain tumor detection. Comput Math Methods Med. 2013;2013:704829. doi: 10.1155/2013/704829. Epub 2013 Apr 29. — View Citation

Sadleir RJ, Sajib SZ, Kim HJ, Kwon OI, Woo EJ. Simulations and phantom evaluations of magnetic resonance electrical impedance tomography (MREIT) for breast cancer detection. J Magn Reson. 2013 May;230:40-9. doi: 10.1016/j.jmr.2013.01.009. Epub 2013 Feb 4. — View Citation

Sadleir RJ, Vannorsdall TD, Schretlen DJ, Gordon B. Target optimization in transcranial direct current stimulation. Front Psychiatry. 2012 Oct 17;3:90. doi: 10.3389/fpsyt.2012.00090. eCollection 2012. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Magnetic Resonance Imaging (MRI) of therapeutic current flow	The MRI will be used to measure current flow in the brain as a result of therapeutic electrical stimulation techniques by using a recently developed MRI-based phase imaging technique to more directly measure current densities in vivo.	Day 1