Paraorbital-Occipital Alternating Current Stimulation Therapy for Optic Neuropathy (MCT_optnerve)

Sponsor

University of Magdeburg (Other)

Overall Status

Completed

CT.gov ID

NCT01280877

Collaborator

EBS Technologies GmbH (Industry)

Enrollment

Locations

Arms

Duration (Months)

22.5

Patients Per Site

1.6

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Aim is to validate that non-invasive brain stimulation can increase cortical excitability in the visual system. The investigators assess if transcranial alternating current stimulation (tACS) can improve visual field size in patients with optic nerve damage. Hypothesis: tACS would improve visual functions within the defective visual field (primary outcome measure).

Condition or Disease	Intervention/Treatment	Phase
Optic Nerve Diseases Optic Nerve Injuries Optic Neuropathies	Device: tACS Device: Sham stimulation	N/A

Detailed Description

In addition, the correlation between the brain-derived neurotrophic factor (BDNF) or other plasticity markers are correlated to the improvement of the visual field after stimulation.

Study Design

Study Type:

Interventional

Actual Enrollment :

90 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Participant, Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

Multicenter Study of Paraorbital-Occipital Alternating Current Stimulation Therapy in Patients With Optic Neuropathy

Study Start Date :

Dec 1, 2010

Actual Primary Completion Date :

Feb 1, 2012

Actual Study Completion Date :

Feb 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Verum stimulation Complete treatment with transorbital alternating current stimulation (tACS)	Device: tACS Transorbital alternating current stimulation (tACS) is applied with a multi-channel device with paraorbital montage of 4 stimulation electrodes generating weak current pulses in predetermined firing bursts of 8 to 14 pulses. The amplitude of each current pulse was below 1000 microA. Current intensity was individually adjusted according to how well patients perceived phosphenes, i.e. any sensation of flickering light in response to the rtACS stimulation.
Sham Comparator: Sham stimulation Same electrode montage set-up is used during tACS- and placebo-stimulation. Sham stimulation condition consists of minimal treatment with low intensity/few impulses tACS.	Device: Sham stimulation tACS is applied with the same device with equal electrodes set-up procedures but only one of four channels actually delivers current. The current intensity of this channel is individually adjusted (preselected on the side of lesioned eye) according with patient able to clearly perceive single phosphenes or any skin irritation phenomena (like weak sense of needles or vibration) whenever a single pulse is applied. The amplitude of pulses is always below 1000 microA. Current pulses are given as 1 pulse per minute during 25-35 min of session time. Session duration is equal for verum and sham patients. The perception of the single pulses leaves sham patients at the impression that they might receive the verum intervention, but total number of pulses is less than 0,5% of verum tACS.

Arm

Intervention/Treatment

Experimental: Verum stimulation

Complete treatment with transorbital alternating current stimulation (tACS)

Device: tACS

Transorbital alternating current stimulation (tACS) is applied with a multi-channel device with paraorbital montage of 4 stimulation electrodes generating weak current pulses in predetermined firing bursts of 8 to 14 pulses. The amplitude of each current pulse was below 1000 microA. Current intensity was individually adjusted according to how well patients perceived phosphenes, i.e. any sensation of flickering light in response to the rtACS stimulation.

Sham Comparator: Sham stimulation

Same electrode montage set-up is used during tACS- and placebo-stimulation. Sham stimulation condition consists of minimal treatment with low intensity/few impulses tACS.

Device: Sham stimulation

tACS is applied with the same device with equal electrodes set-up procedures but only one of four channels actually delivers current. The current intensity of this channel is individually adjusted (preselected on the side of lesioned eye) according with patient able to clearly perceive single phosphenes or any skin irritation phenomena (like weak sense of needles or vibration) whenever a single pulse is applied. The amplitude of pulses is always below 1000 microA. Current pulses are given as 1 pulse per minute during 25-35 min of session time. Session duration is equal for verum and sham patients. The perception of the single pulses leaves sham patients at the impression that they might receive the verum intervention, but total number of pulses is less than 0,5% of verum tACS.

Outcome Measures

Primary Outcome Measures

Detection accuracy (DA) change in percent over baseline within defective visual field [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]
Central visual fields assessed with computer-based high-resolution perimetry (HRP). Based on such plots, areas of the visual field are characterized as intact, partially damaged or absolutely impaired (blind). Detection accuracy (DA) change in percent above baseline within defective visual field sectors is defined as the primary outcome criterion.

Secondary Outcome Measures

DA change in percent over baseline regarding the damage region of the tested visual field (computer-based high-resolution perimetry) [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]
This parameter includes also intact sectors that are tested with HRP. It is hypothesized that improvements of the primary outcome criterion will outweigh the relative change in intact sectors as measured with HRP.
EEG parameters [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]
EEG power spectra
Reaction time change in ms [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]
Reaction time (RT) in HRP
Visual acuity (VA) [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]
DA in static and kinetic conventional perimetry [Baseline - 8 weeks after stimulation; First follow-up 2 days after treatment course; Second follow-up 8 weeks after treatment course]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

patients with optic nerve lesion
stable visual field defect with residual vision
lesion age at least 6 months
age at least 18 years
no completely blindness, residual vision still existent

Exclusion Criteria:

electric or electronic implants, e.g. heart pacemaker
any metal artefacts in head and truncus
epilepsy
auto-immune diseases in acute stage
mental diseases, e.g. schizophrenia etc.
unstable diabetes, diabetes causing diabetic retinopathy
addiction
high blood pressure (max. 160/100 mmHg)
instable or high level of intraocular pressure (i.e. > 27 mmHg)
retinitis pigmentosa
pathological nystagmus
presence of an un-operated tumor anywhere in the body
pregnant or breast-feeding women
photo sensibility
Fundus hypertonicus
acute conjunctivitis

Contacts and Locations

Locations

	Site	City	Country	Postal Code
1	Klinik für Neurologie, Charité Campus Mitte, Universitätsmedizin Berlin	Berlin	Germany	10117
2	Klinische Neurophysiologie & Abteilung Augenheilkunde, Universitätsmedizin Göttingen	Göttingen	Germany	37075
3	Augenklinik Kassel am Klinikum Kassel GmbH	Kassel	Germany	34125
4	Inst. f. Medizinische Psychologie, Universitätsklinikum Magdeburg	Magdeburg	Germany	39120