Paraorbital-Occipital Alternating Current Stimulation Therapy of Patients With Post-Chiasmatic Lesions

July 3, 2019 updated by: Bernhard A. Sabel, University of Magdeburg

Visual field areas, which are not absolutely blind, are hypothesized to have some residual capacities that constitute their potential for vision restoration. Vision restoration can be achieved by varies methods including behavioral training and electrical brain stimulation such as transcranial direct current stimulation (tDCS) and repetitive transorbital alternating current stimulation (rtACS) which are able to influence the excitability and activity of cortical areas.

It is hypothesized that transorbital alternating current stimulation (tACS) can improve the residual field of vision in patients with post-chiasmatic lesions.

Study Overview

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Magdeburg, Germany, 39120
        • Inst. f. Medical Psychology, Univ. of Magdeburg

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • lesion of the tractus opticus or of the visual cortex
  • lesion age > 6 months
  • stable visual field defect with residual vision

Exclusion Criteria:

  • electric or electronic implants, e.g. heart pacer
  • any metal artefacts in the head
  • Epilepsy
  • Auto-immune diseases in acute stage
  • mental diseases, e.g. schizophrenia etc.
  • diabetic retinopathy
  • addictive diseases
  • blood pressure above 160/100 mmHg
  • instable or high level of intraocular pressure above 27 mmHg
  • retinitis pigmentosa
  • pathological nystagmus
  • presence of an un-operated tumor or tumor relapse (patients with non-progressive tumor are eligible if study participation is recommended by medical authorities)
  • focal findings in EEG or photosensitivity (patients with single seizure more than 10 yrs ago may participate)
  • recurrent transitional ischemic attacks after stroke
  • arteriosclerosis of large blood vessels with stenosis >75%
  • severe coronary heart disease (CHD)
  • unstable angina pectoris
  • diabetes with blood glucose level > 9 mmol/l
  • myocard infarct/ cardiomyopathy
  • ventricular fibrillation
  • risk of vascular thrombosis
  • pregnant or breast-feeding women

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Verum stimulation
repetitive transorbital alternating current stimulation (rtACS)
10 days (2x 5 working days), daily transorbital alternating current stimulation (rtACS) is applied with a device generating weak current pulses in predetermined firing bursts of 2 to 9 pulses. The amplitude of each current pulse is below 1000 µA. Current intensity is individually adjusted according to how well patients perceived phosphenes, e.g. any sensation of flickering light in response to the rtACS stimulation. Stimulation frequencies were between the individual alpha frequency peak and below flicker fusion.
Sham Comparator: Placebo stimulation
compared to verum stimulation the same electrode montage set-up is used during placebo stimulation, except that placebo patients receive a minimal stimulation
10 days (2x 5 working days), daily sham-stimulation with the same electrode montage set-up that is used for verum transorbital alternating current stimulation (rtACS). Minimal sham-stimulation was performed with single bursts (approx. one per min) of electrical currents at a given frequency of 5Hz and individually adjusted current amplitude.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
detection accuracy (%) in visual field measures over baseline
Time Frame: baseline to 8 weeks after stimulation
visual stimuli detection accuracy in residual and absolutely defect visual field will be assessed using computer-based high resolution perimetry (HRP)
baseline to 8 weeks after stimulation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
detection accuracy (%) in the intact visual field over baseline
Time Frame: baseline to 8 weeks after stimulation
visual stimuli detection accuracy in the intact visual field will be assessed using computer-based high resolution perimetry (HRP)
baseline to 8 weeks after stimulation
visual acuity (LogRAD)
Time Frame: baseline to 8 weeks after stimulation
baseline to 8 weeks after stimulation
EEG parameters
Time Frame: baseline to 8 weeks after stimulation
entrainment of stimulation frequencies (EEG power spectra) and measures of functional connectivity
baseline to 8 weeks after stimulation
conventional perimetry
Time Frame: baseline to 8 weeks after stimulation
visual fields obtained by static and kinetic perimetry (average threshold in db, average excentricity in degrees)
baseline to 8 weeks after stimulation
reaction time (ms)
Time Frame: baseline to 8 weeks after stimulation
average reaction time in ms, measured by computer-based high resolution perimetry (HRP)
baseline to 8 weeks after stimulation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Bernhard A Sabel, Ph.D., Univ. of Magdeburg

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2011

Primary Completion (Actual)

December 1, 2013

Study Completion (Actual)

December 1, 2013

Study Registration Dates

First Submitted

August 16, 2011

First Submitted That Met QC Criteria

August 16, 2011

First Posted (Estimate)

August 17, 2011

Study Record Updates

Last Update Posted (Actual)

July 5, 2019

Last Update Submitted That Met QC Criteria

July 3, 2019

Last Verified

July 1, 2019

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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