Paraorbital-Occipital Alternating Current Stimulation Therapy of Patients With Post-Chiasmatic Lesions
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|ClinicalTrials.gov Identifier: NCT01418820|
Recruitment Status : Completed
First Posted : August 17, 2011
Last Update Posted : July 5, 2019
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 or disease||Intervention/treatment||Phase|
|Complete Hemianopia Incomplete Hemianopia Scotoma Quadrantanopia Stroke Hemorrhage Brain Trauma||Device: Verum stimulation Device: Placebo stimulation||Phase 2|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||32 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Triple (Participant, Investigator, Outcomes Assessor)|
|Official Title:||Paraorbital-Occipital Alternating Current Stimulation Therapy of Patients With Post-Chiasmatic Lesions|
|Actual Study Start Date :||March 2011|
|Actual Primary Completion Date :||December 2013|
|Actual Study Completion Date :||December 2013|
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.
- 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)
- 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)
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
|Inst. f. Medical Psychology, Univ. of Magdeburg|
|Magdeburg, Germany, 39120|
|Principal Investigator:||Bernhard A Sabel, Ph.D.||Univ. of Magdeburg|