Skip to main content
OpenTrials
Completed

NCT Number: NCT01418820

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

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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Complete Hemianopia Blindness Brain Diseases Brain Injuries Brain Injuries, Traumatic Brain Trauma Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Craniocerebral Trauma Eye Diseases Hemianopsia Hemorrhage Incomplete Hemianopia Nervous System Diseases Neurologic Manifestations Pathologic Processes Pathological Conditions, Signs and Symptoms Quadrantanopia Scotoma Sensation Disorders Signs and Symptoms Stroke Trauma, Nervous System Vascular Diseases Vision Disorders Wounds and Injuries

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Inst. f. Medical Psychology, Univ. of Magdeburg

Magdeburg, 39120, Germany

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Verum stimulation

Device

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.

Placebo stimulation

Device

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.

Primary outcomes

  1. 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 outcomes

  1. 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)

  2. visual acuity (LogRAD)

    Time frame: baseline to 8 weeks after stimulation

  3. EEG parameters

    Time frame: baseline to 8 weeks after stimulation

    entrainment of stimulation frequencies (EEG power spectra) and measures of functional connectivity

  4. 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)

  5. reaction time (ms)

    Time frame: baseline to 8 weeks after stimulation

    average reaction time in ms, measured by computer-based high resolution perimetry (HRP)

Sponsors and collaborators

Lead sponsor

University of Magdeburg

Other

Collaborators

  • EBS Technologies GmbH

Registry information

Important dates

Study start
2011
Primary completion
2013
Study completion
2013
First posted
Aug 17, 2011
Registry last updated
Jul 5, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.