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

Active, not recruiting

Phase 2/3 Results N/A

Trial Description

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.

Conditions

Interventions

  • Placebo stimulation Device
    Intervention Desc: 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.
    ARM 1: Kind: Experimental
    Label: Placebo stimulation
    Description: A clicking sound is presented and the same electrode montage set-up is used during rACS- and Placebo-stimulation, except that placebo patients receive no current (stimulator turned off)
  • Verum Stimulation Device
    Intervention Desc: 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.
    ARM 1: Kind: Experimental
    Label: Verum stimulation
    Description: Repetitive paraorbital alternating current stimulation (rtACS)

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Detection accuracy change in percent over baseline of the visual field between baseline and 60 days after stimulation No
Secondary change in visual stimulus detection rate in the intact field of vision baseline to 8 weeks after stimulation No
Secondary improvement of the acuteness of vision (LogRAD) baseline to 8 weeks after stimulation No
Secondary EEG parameters baseline to 8 weeks after stimulation No
Secondary improvement of visual field in conventional perimetry baseline to 8 weeks after stimulation No
Secondary improvement of reaction time baseline to 8 weeks after stimulation No
Primary detection accuracy (%) in visual field measures over baseline baseline to 8 weeks after stimulation No
Secondary detection accuracy (%) in the intact visual field over baseline baseline to 8 weeks after stimulation No
Secondary visual acuity (LogRAD) baseline to 8 weeks after stimulation No
Secondary conventional perimetry baseline to 8 weeks after stimulation No
Secondary reaction time (ms) baseline to 8 weeks after stimulation No

Sponsors