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.

Study Overview

• Status: Completed
• Conditions: Stroke; Hemorrhage; Scotoma; Quadrantanopia; Brain Trauma; Complete Hemianopia; Incomplete Hemianopia
• Intervention / Treatment: Device: Verum stimulation; Device: Placebo stimulation

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Phase 2

Contacts and Locations

Study Locations

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

Participation Criteria

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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
detection accuracy (%) in visual field measures over baseline	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	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)		baseline to 8 weeks after stimulation
EEG parameters	entrainment of stimulation frequencies (EEG power spectra) and measures of functional connectivity	baseline to 8 weeks after stimulation
conventional perimetry	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)	average reaction time in ms, measured by computer-based high resolution perimetry (HRP)	baseline to 8 weeks after stimulation

Collaborators and Investigators

• Sponsor: University of Magdeburg
• Collaborators: EBS Technologies GmbH
• Investigators: Principal Investigator: Bernhard A Sabel, Ph.D., Univ. of Magdeburg

Publications and helpful links

General Publications

• Räty S, Borrmann C, Granata G, Cárdenas-Morales L, Schoenfeld A, Sailer M, Silvennoinen K, Holopainen J, De Rossi F, Antal A, Rossini PM, Tatlisumak T, Sabel BA. Non-invasive electrical brain stimulation for vision restoration after stroke: An exploratory randomized trial (REVIS). Restor Neurol Neurosci. 2021;39(3):221-235. doi: 10.3233/RNN-211198.

Study record dates

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

Terms related to this study

• Keywords: stroke; non-invasive brain stimulation; alternating current stimulation; hemianopia; visual field defect
• Additional Relevant MeSH Terms: Pathologic Processes; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Wounds and Injuries; Craniocerebral Trauma; Trauma, Nervous System; Sensation Disorders; Vision Disorders; Blindness; Brain Injuries; Hemorrhage; Brain Injuries, Traumatic; Hemianopsia; Scotoma
• Other Study ID Numbers: EBS-PP-2011-02-16-001