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

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified November 2013 by Bernhard A. Sabel, University of Magdeburg.
Recruitment status was:  Active, not recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT01418820
First Posted: August 17, 2011
Last Update Posted: December 2, 2013
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
EBS Technologies GmbH
Information provided by (Responsible Party):
Bernhard A. Sabel, University of Magdeburg
  Purpose

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.


Condition Intervention Phase
Complete Hemianopia Incomplete Hemianopia Scotoma Quadrantanopia Stroke Hemorrhage Brain Trauma Device: Verum stimulation Device: Placebo stimulation Phase 2 Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Paraorbital-Occipital Alternating Current Stimulation Therapy of Patients With Post-Chiasmatic Lesions

Further study details as provided by Bernhard A. Sabel, University of Magdeburg:

Primary Outcome Measures:
  • 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)


Secondary Outcome Measures:
  • 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)

  • visual acuity (LogRAD) [ Time Frame: 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

  • 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)

  • reaction time (ms) [ Time Frame: baseline to 8 weeks after stimulation ]
    average reaction time in ms, measured by computer-based high resolution perimetry (HRP)


Enrollment: 32
Study Start Date: March 2011
Estimated Study Completion Date: December 2013
Estimated Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Verum stimulation
repetitive transorbital alternating current stimulation (rtACS)
Device: Verum stimulation
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
Device: Placebo 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.

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

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
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01418820


Locations
Germany
Inst. f. Medical Psychology, Univ. of Magdeburg
Magdeburg, Germany, 39120
Sponsors and Collaborators
University of Magdeburg
EBS Technologies GmbH
Investigators
Principal Investigator: Bernhard A Sabel, Ph.D. Univ. of Magdeburg
  More Information

Responsible Party: Bernhard A. Sabel, Prof. Dr., University of Magdeburg
ClinicalTrials.gov Identifier: NCT01418820     History of Changes
Other Study ID Numbers: EBS-PP-2011-02-16-001
First Submitted: August 16, 2011
First Posted: August 17, 2011
Last Update Posted: December 2, 2013
Last Verified: November 2013

Keywords provided by Bernhard A. Sabel, University of Magdeburg:
hemianopia
visual field defect
stroke
non-invasive brain stimulation
alternating current stimulation

Additional relevant MeSH terms:
Hemorrhage
Brain Injuries, Traumatic
Scotoma
Hemianopsia
Pathologic Processes
Brain Injuries
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Craniocerebral Trauma
Trauma, Nervous System
Wounds and Injuries
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Eye Diseases
Signs and Symptoms
Blindness